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2019
González-Serrano L E, Chihade J W, Sissler M
When a common biological role does not imply common disease outcomes: Disparate pathology linked to human mitochondrial aminoacyl-tRNA synthetases Article de journal
Dans: J Biol Chem, vol. 294, non 14, p. 5309-5320, 2019, ISBN: 30647134.
Résumé | Liens | BibTeX | Étiquettes: aminoacyl tRNA synthetase central nervous system (CNS) genetic disease mitochondria mutant, SISSLER, Unité ARN
@article{,
title = {When a common biological role does not imply common disease outcomes: Disparate pathology linked to human mitochondrial aminoacyl-tRNA synthetases},
author = {L E González-Serrano and J W Chihade and M Sissler},
url = {https://www.ncbi.nlm.nih.gov/pubmed/30647134?dopt=Abstract},
doi = {10.1074/jbc.REV118.002953},
isbn = {30647134},
year = {2019},
date = {2019-01-01},
journal = {J Biol Chem},
volume = {294},
number = {14},
pages = {5309-5320},
abstract = {Mitochondrial aminoacyl-tRNA synthetases (mt-aaRSs) are essential components of the mitochondrial translation machinery. The correlation of mitochondrial disorders with mutations in these enzymes has raised the interest of the scientific community over the past several years. Most surprising has been the wide-ranging presentation of clinical manifestations in patients with mt-aaRS mutations, despite the enzymes' common biochemical role. Even among cases where a common physiological system is affected, phenotypes, severity, and age of onset varies depending on which mt-aaRS is mutated. Here we review work done thus far and propose a categorization of diseases based on tissue specificity that highlights emerging patterns. We further discuss multiple in vitro and in cellulo efforts to characterize the behavior of wildtype and mutant mt-aaRSs that have shaped hypotheses about the molecular causes of these pathologies. Much remains to do in order to complete our understanding of these proteins. We expect that futher work is likely to result in the discovery of new roles for the mt-aaRSs in addition to their fundamental function in mitochondrial translation, informing the development of treatment strategies and diagnoses.},
keywords = {aminoacyl tRNA synthetase central nervous system (CNS) genetic disease mitochondria mutant, SISSLER, Unité ARN},
pubstate = {published},
tppubtype = {article}
}
Mitochondrial aminoacyl-tRNA synthetases (mt-aaRSs) are essential components of the mitochondrial translation machinery. The correlation of mitochondrial disorders with mutations in these enzymes has raised the interest of the scientific community over the past several years. Most surprising has been the wide-ranging presentation of clinical manifestations in patients with mt-aaRS mutations, despite the enzymes' common biochemical role. Even among cases where a common physiological system is affected, phenotypes, severity, and age of onset varies depending on which mt-aaRS is mutated. Here we review work done thus far and propose a categorization of diseases based on tissue specificity that highlights emerging patterns. We further discuss multiple in vitro and in cellulo efforts to characterize the behavior of wildtype and mutant mt-aaRSs that have shaped hypotheses about the molecular causes of these pathologies. Much remains to do in order to complete our understanding of these proteins. We expect that futher work is likely to result in the discovery of new roles for the mt-aaRSs in addition to their fundamental function in mitochondrial translation, informing the development of treatment strategies and diagnoses.
2018
Hosseini M, Roy P, Sissler M, Zirbel C L, Westhof E, Leontis N
How to fold and protect mitochondrial ribosomal RNA with fewer guanines Article de journal
Dans: Nucleic Acids Res, vol. 46, non 20, p. 10946-10968, 2018, ISBN: 30215760.
Résumé | Liens | BibTeX | Étiquettes: SISSLER, Unité ARN, WESTHOF
@article{,
title = {How to fold and protect mitochondrial ribosomal RNA with fewer guanines},
author = {M Hosseini and P Roy and M Sissler and C L Zirbel and E Westhof and N Leontis},
url = {https://www.ncbi.nlm.nih.gov/pubmed/30215760?dopt=Abstract},
doi = {10.1093/nar/gky762},
isbn = {30215760},
year = {2018},
date = {2018-01-01},
journal = {Nucleic Acids Res},
volume = {46},
number = {20},
pages = {10946-10968},
abstract = {Mammalian mitochondrial ribosomes evolved from bacterial ribosomes by reduction of ribosomal RNAs, increase of ribosomal protein content, and loss of guanine nucleotides. Guanine is the base most sensitive to oxidative damage. By systematically comparing high-quality, small ribosomal subunit RNA sequence alignments and solved 3D ribosome structures from mammalian mitochondria and bacteria, we deduce rules for folding a complex RNA with the remaining guanines shielded from solvent. Almost all conserved guanines in both bacterial and mammalian mitochondrial ribosomal RNA form guanine-specific, local or long-range, RNA-RNA or RNA-protein interactions. Many solvent-exposed guanines conserved in bacteria are replaced in mammalian mitochondria by bases less sensitive to oxidation. New guanines, conserved only in the mitochondrial alignment, are strategically positioned at solvent inaccessible sites to stabilize the ribosomal RNA structure. New mitochondrial proteins substitute for truncated RNA helices, maintain mutual spatial orientations of helices, compensate for lost RNA-RNA interactions, reduce solvent accessibility of bases, and replace guanines conserved in bacteria by forming specific amino acid-RNA interactions.},
keywords = {SISSLER, Unité ARN, WESTHOF},
pubstate = {published},
tppubtype = {article}
}
Mammalian mitochondrial ribosomes evolved from bacterial ribosomes by reduction of ribosomal RNAs, increase of ribosomal protein content, and loss of guanine nucleotides. Guanine is the base most sensitive to oxidative damage. By systematically comparing high-quality, small ribosomal subunit RNA sequence alignments and solved 3D ribosome structures from mammalian mitochondria and bacteria, we deduce rules for folding a complex RNA with the remaining guanines shielded from solvent. Almost all conserved guanines in both bacterial and mammalian mitochondrial ribosomal RNA form guanine-specific, local or long-range, RNA-RNA or RNA-protein interactions. Many solvent-exposed guanines conserved in bacteria are replaced in mammalian mitochondria by bases less sensitive to oxidation. New guanines, conserved only in the mitochondrial alignment, are strategically positioned at solvent inaccessible sites to stabilize the ribosomal RNA structure. New mitochondrial proteins substitute for truncated RNA helices, maintain mutual spatial orientations of helices, compensate for lost RNA-RNA interactions, reduce solvent accessibility of bases, and replace guanines conserved in bacteria by forming specific amino acid-RNA interactions.
González-Serrano L E, Karim L, Pierre F, Schwenzer H, Rotig A, Munnich A, Sissler M
Three human aminoacyl-tRNA synthetases have distinct sub-mitochondrial localizations that are unaffected by disease-associated mutations Article de journal
Dans: J Biol Chem, vol. 293, non 35, p. 13604-13615, 2018, ISBN: 30006346.
Résumé | Liens | BibTeX | Étiquettes: aminoacyl tRNA synthetase dual-localization human leukodystrophy membrane-anchored mitochondria mitochondrial disorder neurodegenerative disease pontocerebellar hypoplasia translation, SISSLER, Unité ARN
@article{,
title = {Three human aminoacyl-tRNA synthetases have distinct sub-mitochondrial localizations that are unaffected by disease-associated mutations},
author = {L E González-Serrano and L Karim and F Pierre and H Schwenzer and A Rotig and A Munnich and M Sissler},
url = {https://www.ncbi.nlm.nih.gov/pubmed/30006346?dopt=Abstract},
doi = {10.1074/jbc.RA118.003400},
isbn = {30006346},
year = {2018},
date = {2018-01-01},
journal = {J Biol Chem},
volume = {293},
number = {35},
pages = {13604-13615},
abstract = {Human mitochondrial aminoacyl-tRNA synthetases (mt-aaRSs) are key enzymes in the mitochondrial protein translation system and catalyze the charging of amino acids on their cognate tRNAs. Mutations in their nuclear genes are associated with pathologies having a broad spectrum of clinical phenotypes, but with no clear molecular mechanism(s). For example, mutations in the nuclear genes encoding mt-AspRS and mt-ArgRS are correlated with the moderate neurodegenerative disorder leukoencephalopathy with brainstem and spinal cord involvement and lactate elevation (LBSL) and with the severe neurodevelopmental disorder pontocerebellar hypoplasia type 6 (PCH6), respectively. Previous studies have shown no or only minor impacts of these mutations on the canonical properties of these enzymes, indicating that the role of the mt-aaRSs in protein synthesis is mostly not affected by these mutations, but their effects on the mitochondrial localizations of aaRSs remain unclear. Here, we demonstrate that three human aaRSs, mt-AspRS, mt-ArgRS, and LysRS, each have a specific sub-mitochondrial distribution, with mt-ArgRS being exclusively localized in the membrane, LysRS exclusively in the soluble fraction, and mt-AspRS being present in both. Chemical treatments revealed that mt-AspRs is anchored in the mitochondrial membrane through electrostatic interactions, whereas mt-ArgRS uses hydrophobic interactions. We also report that novel mutations in mt-AspRS and mt-ArgRS genes from individuals with LBSL and PCH6, respectively, had no significant impact on the mitochondrial localizations of mt-AspRS and mt-ArgRS. The variable sub-mitochondrial locations for these three mt-aaRSs strongly suggest the existence of additional enzyme properties, requiring further investigation to unravel the mechanisms underlying the two neurodegenerative disorders.},
keywords = {aminoacyl tRNA synthetase dual-localization human leukodystrophy membrane-anchored mitochondria mitochondrial disorder neurodegenerative disease pontocerebellar hypoplasia translation, SISSLER, Unité ARN},
pubstate = {published},
tppubtype = {article}
}
Human mitochondrial aminoacyl-tRNA synthetases (mt-aaRSs) are key enzymes in the mitochondrial protein translation system and catalyze the charging of amino acids on their cognate tRNAs. Mutations in their nuclear genes are associated with pathologies having a broad spectrum of clinical phenotypes, but with no clear molecular mechanism(s). For example, mutations in the nuclear genes encoding mt-AspRS and mt-ArgRS are correlated with the moderate neurodegenerative disorder leukoencephalopathy with brainstem and spinal cord involvement and lactate elevation (LBSL) and with the severe neurodevelopmental disorder pontocerebellar hypoplasia type 6 (PCH6), respectively. Previous studies have shown no or only minor impacts of these mutations on the canonical properties of these enzymes, indicating that the role of the mt-aaRSs in protein synthesis is mostly not affected by these mutations, but their effects on the mitochondrial localizations of aaRSs remain unclear. Here, we demonstrate that three human aaRSs, mt-AspRS, mt-ArgRS, and LysRS, each have a specific sub-mitochondrial distribution, with mt-ArgRS being exclusively localized in the membrane, LysRS exclusively in the soluble fraction, and mt-AspRS being present in both. Chemical treatments revealed that mt-AspRs is anchored in the mitochondrial membrane through electrostatic interactions, whereas mt-ArgRS uses hydrophobic interactions. We also report that novel mutations in mt-AspRS and mt-ArgRS genes from individuals with LBSL and PCH6, respectively, had no significant impact on the mitochondrial localizations of mt-AspRS and mt-ArgRS. The variable sub-mitochondrial locations for these three mt-aaRSs strongly suggest the existence of additional enzyme properties, requiring further investigation to unravel the mechanisms underlying the two neurodegenerative disorders.
2017
Sissler M, González-Serrano L E, Westhof E
Recent Advances in Mitochondrial Aminoacyl-tRNA Synthetases and Disease Article de journal
Dans: Trends Mol Med, vol. 23, non 8, p. 693-708, 2017, ISBN: 28716624.
Résumé | Liens | BibTeX | Étiquettes: aminoacyl-tRNA synthetase central nervous system mitochondrial disease mitochondrial translation moonlighting proteins unfolded protein response, SISSLER, Unité ARN, WESTHOF
@article{,
title = {Recent Advances in Mitochondrial Aminoacyl-tRNA Synthetases and Disease},
author = {M Sissler and L E González-Serrano and E Westhof},
url = {https://www.ncbi.nlm.nih.gov/pubmed/28716624?dopt=Abstract},
doi = {10.1016/j.molmed.2017.06.002},
isbn = {28716624},
year = {2017},
date = {2017-01-01},
journal = {Trends Mol Med},
volume = {23},
number = {8},
pages = {693-708},
abstract = {Dysfunctions in mitochondria - the powerhouses of the cell - lead to several human pathologies. Because mitochondria integrate nuclear and mitochondrial genetic systems, they are richly intertwined with cellular activities. The nucleus-encoded mitochondrial aminoacyl-tRNA synthetases (mt-aaRSs) are key components of the mitochondrial translation apparatus. Mutations in these enzymes predominantly affect the central nervous system (CNS) but also target other organs. Comparable mutations in mt-aaRSs can lead to vastly diverse diseases, occurring at different stages in life, and within different tissues; this represents a confounding issue. With newer information available, we propose that the pleiotropy and tissue-specificity of mt-aaRS-associated diseases result from the molecular integration of mitochondrial translation events within the cell; namely, through specific crosstalk between the cellular program and the energy demands of the cell. We place particular focus on neuronal cells.},
keywords = {aminoacyl-tRNA synthetase central nervous system mitochondrial disease mitochondrial translation moonlighting proteins unfolded protein response, SISSLER, Unité ARN, WESTHOF},
pubstate = {published},
tppubtype = {article}
}
Dysfunctions in mitochondria - the powerhouses of the cell - lead to several human pathologies. Because mitochondria integrate nuclear and mitochondrial genetic systems, they are richly intertwined with cellular activities. The nucleus-encoded mitochondrial aminoacyl-tRNA synthetases (mt-aaRSs) are key components of the mitochondrial translation apparatus. Mutations in these enzymes predominantly affect the central nervous system (CNS) but also target other organs. Comparable mutations in mt-aaRSs can lead to vastly diverse diseases, occurring at different stages in life, and within different tissues; this represents a confounding issue. With newer information available, we propose that the pleiotropy and tissue-specificity of mt-aaRS-associated diseases result from the molecular integration of mitochondrial translation events within the cell; namely, through specific crosstalk between the cellular program and the energy demands of the cell. We place particular focus on neuronal cells.
Moulinier L, Ripp R, Castillo G, Poch O, Sissler M
MiSynPat: an integrated knowledge base linking clinical, genetic, and structural data for disease-causing mutations in human mitochondrial aminoacyl-tRNA synthetases. Article de journal
Dans: Hum Mutat, vol. 38, non 10, p. 1316-1324, 2017, ISBN: 28608363.
Résumé | Liens | BibTeX | Étiquettes: 3D structures aminoacyl-tRNA synthetases disease-causing mutations knowledge base mitochondrial disorders sequence alignments, SISSLER, Unité ARN
@article{,
title = {MiSynPat: an integrated knowledge base linking clinical, genetic, and structural data for disease-causing mutations in human mitochondrial aminoacyl-tRNA synthetases.},
author = {L Moulinier and R Ripp and G Castillo and O Poch and M Sissler},
url = {https://www.ncbi.nlm.nih.gov/pubmed/28608363},
doi = {10.1002/humu.23277},
isbn = {28608363},
year = {2017},
date = {2017-01-01},
journal = {Hum Mutat},
volume = {38},
number = {10},
pages = {1316-1324},
abstract = {Numerous mutations in each of the mitochondrial aminoacyl-tRNA synthetases have been implicated in human diseases. The mutations are autosomal and recessive and lead mainly to neurological disorders, although with pleiotropic effects. The processes and interactions that drive the etiology of the disorders associated with mitochondrial aminoacyl-tRNA synthetases are far from understood. The complexity of the clinical, genetic and structural data requires concerted, interdisciplinary efforts to understand the molecular biology of these disorders. Towards this goal, we designed MiSynPat, a comprehensive knowledge base together with an ergonomic web server designed to organize and access all pertinent information (sequences, multiple sequence alignments, structures, disease descriptions, mutation characteristics, original literature) on the disease-linked human mitochondrial aminoacyl-tRNA synthetases. With MiSynPat, a user can also evaluate the impact of a possible mutation on sequence-conservation-structure in order to foster the links between basic and clinical researchers and to facilitate future diagnosis. The proposed integrated view, coupled with research on disease-related mitochondrial aminoacyl-tRNA synthetases, will help to reveal new functions for these enzymes and to open new vistas in the molecular biology of the cell. The purpose of MiSynPat, freely available at http://misynpat.org, is to constitute a reference and a converging resource for scientists and clinicians. This article is protected by copyright. All rights reserved.},
keywords = {3D structures aminoacyl-tRNA synthetases disease-causing mutations knowledge base mitochondrial disorders sequence alignments, SISSLER, Unité ARN},
pubstate = {published},
tppubtype = {article}
}
Numerous mutations in each of the mitochondrial aminoacyl-tRNA synthetases have been implicated in human diseases. The mutations are autosomal and recessive and lead mainly to neurological disorders, although with pleiotropic effects. The processes and interactions that drive the etiology of the disorders associated with mitochondrial aminoacyl-tRNA synthetases are far from understood. The complexity of the clinical, genetic and structural data requires concerted, interdisciplinary efforts to understand the molecular biology of these disorders. Towards this goal, we designed MiSynPat, a comprehensive knowledge base together with an ergonomic web server designed to organize and access all pertinent information (sequences, multiple sequence alignments, structures, disease descriptions, mutation characteristics, original literature) on the disease-linked human mitochondrial aminoacyl-tRNA synthetases. With MiSynPat, a user can also evaluate the impact of a possible mutation on sequence-conservation-structure in order to foster the links between basic and clinical researchers and to facilitate future diagnosis. The proposed integrated view, coupled with research on disease-related mitochondrial aminoacyl-tRNA synthetases, will help to reveal new functions for these enzymes and to open new vistas in the molecular biology of the cell. The purpose of MiSynPat, freely available at http://misynpat.org, is to constitute a reference and a converging resource for scientists and clinicians. This article is protected by copyright. All rights reserved.
Carapito C, Kuhn L, Karim L, Rompais M, Rabilloud T, Schwenzer H, Sissler M
Two proteomic methodologies for defining N-termini of mature human mitochondrial aminoacyl-tRNA synthetases. Article de journal
Dans: Methods, vol. 113, p. 111-119, 2017, ISBN: 27793688.
Résumé | Liens | BibTeX | Étiquettes: PPSE, SISSLER, Unité ARN
@article{,
title = {Two proteomic methodologies for defining N-termini of mature human mitochondrial aminoacyl-tRNA synthetases.},
author = {C Carapito and L Kuhn and L Karim and M Rompais and T Rabilloud and H Schwenzer and M Sissler},
url = {https://www.ncbi.nlm.nih.gov/pubmed/27793688?dopt=Abstract},
doi = {10.1016/j.ymeth.2016.10.012},
isbn = {27793688},
year = {2017},
date = {2017-01-01},
journal = {Methods},
volume = {113},
pages = {111-119},
abstract = {Human mitochondrial aminoacyl-tRNA synthetases (mt-aaRSs) are encoded in the nucleus, synthesized in the cytosol and targeted for importation into mitochondria by a N-terminal mitochondrial targeting sequence. This targeting sequence is presumably cleaved upon entry into the mitochondria, following a process still not fully deciphered in human, despite essential roles for the mitochondrial biogenesis. Maturation processes are indeed essential both for the release of a functional enzyme and to route correctly the protein within mitochondria. The absence of consensus sequences for cleavage sites and the discovery of possible multiple proteolytic steps render predictions of N-termini difficult. Further, the knowledge of the cleavages is key for the design of protein constructions compatible with efficient production in bacterial strains. Finally, full comprehension becomes essential because a growing number of mutations are found in genes coding for mt-aaRS. In the present study, we take advantage of proteomic methodological developments and identified, in mitochondria, three N-termini for the human mitochondrial aspartyl-tRNA synthetase. This first description of the co-existence of different forms opens new perspectives in the biological understanding of this enzyme. Those methods are extended to the whole set of human mt-aaRSs and methodological advice are provided for further investigations.},
keywords = {PPSE, SISSLER, Unité ARN},
pubstate = {published},
tppubtype = {article}
}
Human mitochondrial aminoacyl-tRNA synthetases (mt-aaRSs) are encoded in the nucleus, synthesized in the cytosol and targeted for importation into mitochondria by a N-terminal mitochondrial targeting sequence. This targeting sequence is presumably cleaved upon entry into the mitochondria, following a process still not fully deciphered in human, despite essential roles for the mitochondrial biogenesis. Maturation processes are indeed essential both for the release of a functional enzyme and to route correctly the protein within mitochondria. The absence of consensus sequences for cleavage sites and the discovery of possible multiple proteolytic steps render predictions of N-termini difficult. Further, the knowledge of the cleavages is key for the design of protein constructions compatible with efficient production in bacterial strains. Finally, full comprehension becomes essential because a growing number of mutations are found in genes coding for mt-aaRS. In the present study, we take advantage of proteomic methodological developments and identified, in mitochondria, three N-termini for the human mitochondrial aspartyl-tRNA synthetase. This first description of the co-existence of different forms opens new perspectives in the biological understanding of this enzyme. Those methods are extended to the whole set of human mt-aaRSs and methodological advice are provided for further investigations.
2016
Sissler M
What is so special about neuronal translation? (comment on DOI 10.1002/bies.201600052). Article de journal
Dans: Bioessays, vol. 38, non 9, p. 816, 2016, ISBN: 27427507.
Liens | BibTeX | Étiquettes: SISSLER, Unité ARN
@article{,
title = {What is so special about neuronal translation? (comment on DOI 10.1002/bies.201600052).},
author = {M Sissler},
url = {http://www.ncbi.nlm.nih.gov/pubmed/27427507?dopt=Abstract},
doi = {10.1002/bies.201600131},
isbn = {27427507},
year = {2016},
date = {2016-01-01},
journal = {Bioessays},
volume = {38},
number = {9},
pages = {816},
keywords = {SISSLER, Unité ARN},
pubstate = {published},
tppubtype = {article}
}
2015
Simon M, Richard E M, Wang X, Shahzad M, Huang V H, Qaiser T A, Potluri P, Mahl S E, Davila A, Nazli S, Hancock S, Yu M, Gargus J, Chang R, Al-Sheqaih N, Newman W G, Abdenur J, Starr A, Hegde R, Dorn T, Busch A, Park E, Wu J F, Schwenzer H, Flierl A, Florentz C, Sissler M, Khan S N, Li R, Guan M X, Friedman T B, Wu D K, Procaccio V, Riazuddin S, Wallace D C, Ahmed Z M, Huang T, Riazuddin S
Mutations of Human NARS2, Encoding the Mitochondrial Asparaginyl-tRNA Synthetase, Cause Nonsyndromic Deafness and Leigh Syndrome. Article de journal
Dans: PLoS Genet, vol. 11, non 3, p. e1005097, 2015, ISBN: 25807530.
Résumé | Liens | BibTeX | Étiquettes: FLORENTZ, SISSLER, Unité ARN
@article{,
title = {Mutations of Human NARS2, Encoding the Mitochondrial Asparaginyl-tRNA Synthetase, Cause Nonsyndromic Deafness and Leigh Syndrome.},
author = {M Simon and E M Richard and X Wang and M Shahzad and V H Huang and T A Qaiser and P Potluri and S E Mahl and A Davila and S Nazli and S Hancock and M Yu and J Gargus and R Chang and N Al-Sheqaih and W G Newman and J Abdenur and A Starr and R Hegde and T Dorn and A Busch and E Park and J F Wu and H Schwenzer and A Flierl and C Florentz and M Sissler and S N Khan and R Li and M X Guan and T B Friedman and D K Wu and V Procaccio and S Riazuddin and D C Wallace and Z M Ahmed and T Huang and S Riazuddin},
url = {http://www.ncbi.nlm.nih.gov/pubmed/25807530?dopt=Abstract},
doi = {10.1371/journal.pgen.1005097. eCollection 2015},
isbn = {25807530},
year = {2015},
date = {2015-01-01},
journal = {PLoS Genet},
volume = {11},
number = {3},
pages = {e1005097},
abstract = {Here we demonstrate association of variants in the mitochondrial asparaginyl-tRNA synthetase NARS2 with human hearing loss and Leigh syndrome. A homozygous missense mutation ([c.637G>T; p.Val213Phe]) is the underlying cause of nonsyndromic hearing loss (DFNB94) and compound heterozygous mutations ([c.969T>A; p.Tyr323*] + [c.1142A>G; p.Asn381Ser]) result in mitochondrial respiratory chain deficiency and Leigh syndrome, which is a neurodegenerative disease characterized by symmetric, bilateral lesions in the basal ganglia, thalamus, and brain stem. The severity of the genetic lesions and their effects on NARS2 protein structure cosegregate with the phenotype. A hypothetical truncated NARS2 protein, secondary to the Leigh syndrome mutation p.Tyr323* is not detectable and p.Asn381Ser further decreases NARS2 protein levels in patient fibroblasts. p.Asn381Ser also disrupts dimerization of NARS2, while the hearing loss p.Val213Phe variant has no effect on NARS2 oligomerization. Additionally we demonstrate decreased steady-state levels of mt-tRNAAsn in fibroblasts from the Leigh syndrome patients. In these cells we show that a decrease in oxygen consumption rates (OCR) and electron transport chain (ETC) activity can be rescued by overexpression of wild type NARS2. However, overexpression of the hearing loss associated p.Val213Phe mutant protein in these fibroblasts cannot complement the OCR and ETC defects. Our findings establish lesions in NARS2 as a new cause for nonsyndromic hearing loss and Leigh syndrome.},
keywords = {FLORENTZ, SISSLER, Unité ARN},
pubstate = {published},
tppubtype = {article}
}
Here we demonstrate association of variants in the mitochondrial asparaginyl-tRNA synthetase NARS2 with human hearing loss and Leigh syndrome. A homozygous missense mutation ([c.637G>T; p.Val213Phe]) is the underlying cause of nonsyndromic hearing loss (DFNB94) and compound heterozygous mutations ([c.969T>A; p.Tyr323*] + [c.1142A>G; p.Asn381Ser]) result in mitochondrial respiratory chain deficiency and Leigh syndrome, which is a neurodegenerative disease characterized by symmetric, bilateral lesions in the basal ganglia, thalamus, and brain stem. The severity of the genetic lesions and their effects on NARS2 protein structure cosegregate with the phenotype. A hypothetical truncated NARS2 protein, secondary to the Leigh syndrome mutation p.Tyr323* is not detectable and p.Asn381Ser further decreases NARS2 protein levels in patient fibroblasts. p.Asn381Ser also disrupts dimerization of NARS2, while the hearing loss p.Val213Phe variant has no effect on NARS2 oligomerization. Additionally we demonstrate decreased steady-state levels of mt-tRNAAsn in fibroblasts from the Leigh syndrome patients. In these cells we show that a decrease in oxygen consumption rates (OCR) and electron transport chain (ETC) activity can be rescued by overexpression of wild type NARS2. However, overexpression of the hearing loss associated p.Val213Phe mutant protein in these fibroblasts cannot complement the OCR and ETC defects. Our findings establish lesions in NARS2 as a new cause for nonsyndromic hearing loss and Leigh syndrome.
2014
Schwenzer H, Zoll J, Florentz C, Sissler M
Pathogenic Implications of Human Mitochondrial Aminoacyl-tRNA Synthetases. Article de journal
Dans: Top Curr Chem, vol. 344, p. 247-292, 2014, ISBN: 23824528.
Résumé | Liens | BibTeX | Étiquettes: Aminoacyl-tRNA synthetase Human mitochondrial disorders Pathology-related mutations Respiratory chain defects, FLORENTZ, SISSLER, Unité ARN
@article{,
title = {Pathogenic Implications of Human Mitochondrial Aminoacyl-tRNA Synthetases.},
author = {H Schwenzer and J Zoll and C Florentz and M Sissler},
url = {http://www.ncbi.nlm.nih.gov/pubmed/23824528},
doi = {10.1007/128_2013_457},
isbn = {23824528},
year = {2014},
date = {2014-01-01},
journal = {Top Curr Chem},
volume = {344},
pages = {247-292},
abstract = {Mitochondria are considered as the powerhouse of eukaryotic cells. They host several central metabolic processes fueling the oxidative phosphorylation pathway (OXPHOS) that produces ATP from its precursors ADP and inorganic phosphate Pi (PPi). The respiratory chain complexes responsible for the OXPHOS pathway are formed from complementary sets of protein subunits encoded by the nuclear genome and the mitochondrial genome, respectively. The expression of the mitochondrial genome requires a specific and fully active translation machinery from which aminoacyl-tRNA synthetases (aaRSs) are key actors. Whilst the macromolecules involved in mammalian mitochondrial translation have been under investigation for many years, there has been an explosion of interest in human mitochondrial aaRSs (mt-aaRSs) since the discovery of a large (and growing) number of mutations in these genes that are linked to a variety of neurodegenerative disorders. Herein we will review the present knowledge on mt-aaRSs in terms of their biogenesis, their connection to mitochondrial respiration, i.e., the respiratory chain (RC) complexes, and to the mitochondrial translation machinery. The pathology-related mutations detected so far are described, with special attention given to their impact on mt-aaRSs biogenesis, functioning, and/or subsequent activities. The collected data to date shed light on the diverse routes that are linking primary molecular possible impact of a mutation to its phenotypic expression. It is envisioned that a variety of mechanisms, inside and outside the translation machinery, would play a role on the heterogeneous manifestations of mitochondrial disorders.},
keywords = {Aminoacyl-tRNA synthetase Human mitochondrial disorders Pathology-related mutations Respiratory chain defects, FLORENTZ, SISSLER, Unité ARN},
pubstate = {published},
tppubtype = {article}
}
Mitochondria are considered as the powerhouse of eukaryotic cells. They host several central metabolic processes fueling the oxidative phosphorylation pathway (OXPHOS) that produces ATP from its precursors ADP and inorganic phosphate Pi (PPi). The respiratory chain complexes responsible for the OXPHOS pathway are formed from complementary sets of protein subunits encoded by the nuclear genome and the mitochondrial genome, respectively. The expression of the mitochondrial genome requires a specific and fully active translation machinery from which aminoacyl-tRNA synthetases (aaRSs) are key actors. Whilst the macromolecules involved in mammalian mitochondrial translation have been under investigation for many years, there has been an explosion of interest in human mitochondrial aaRSs (mt-aaRSs) since the discovery of a large (and growing) number of mutations in these genes that are linked to a variety of neurodegenerative disorders. Herein we will review the present knowledge on mt-aaRSs in terms of their biogenesis, their connection to mitochondrial respiration, i.e., the respiratory chain (RC) complexes, and to the mitochondrial translation machinery. The pathology-related mutations detected so far are described, with special attention given to their impact on mt-aaRSs biogenesis, functioning, and/or subsequent activities. The collected data to date shed light on the diverse routes that are linking primary molecular possible impact of a mutation to its phenotypic expression. It is envisioned that a variety of mechanisms, inside and outside the translation machinery, would play a role on the heterogeneous manifestations of mitochondrial disorders.
Schwenzer H, Scheper G C, Zorn N, Moulinier L, Gaudry A, Leize E, Martin F, Florentz C, Poch O, Sissler M
Released selective pressure on a structural domain gives new insights on the functional relaxation of mitochondrial aspartyl-tRNA synthetase. Article de journal
Dans: Biochimie, vol. 100, p. 18-26, 2014, ISBN: 24120687.
Résumé | Liens | BibTeX | Étiquettes: Aminoacyl-tRNA synthetase Bioinformatics MTS Mitochondria Molecular biology Translation aaRS aminoacyl-tRNA synthetase (specificity is indicated by the name of the amino acid abbreviated in a three-letter code, e.g. AspRS stands for aspartyl-tRNA synthetase) mitochondrial mitochondrial targeting sequence mt, ERIANI, FLORENTZ, SISSLER, transferred to the cognate tRNA, Unité ARN
@article{,
title = {Released selective pressure on a structural domain gives new insights on the functional relaxation of mitochondrial aspartyl-tRNA synthetase.},
author = {H Schwenzer and G C Scheper and N Zorn and L Moulinier and A Gaudry and E Leize and F Martin and C Florentz and O Poch and M Sissler},
url = {http://www.ncbi.nlm.nih.gov/pubmed/24120687},
doi = {10.1016/j.biochi.2013.09.027},
isbn = {24120687},
year = {2014},
date = {2014-01-01},
journal = {Biochimie},
volume = {100},
pages = {18-26},
abstract = {Mammalian mitochondrial aminoacyl-tRNA synthetases are nuclear-encoded enzymes that are essential for mitochondrial protein synthesis. Due to an endosymbiotic origin of the mitochondria, many of them share structural domains with homologous bacterial enzymes of same specificity. This is also the case for human mitochondrial aspartyl-tRNA synthetase (AspRS) that shares the so-called bacterial insertion domain with bacterial homologs. The function of this domain in the mitochondrial proteins is unclear. Here, we show by bioinformatic analyses that the sequences coding for the bacterial insertion domain are less conserved in opisthokont and protist than in bacteria and viridiplantae. The divergence suggests a loss of evolutionary pressure on this domain for non-plant mitochondrial AspRSs. This discovery is further connected with the herein described occurrence of alternatively spliced transcripts of the mRNAs coding for some mammalian mitochondrial AspRSs. Interestingly, the spliced transcripts alternately lack one of the four exons that code for the bacterial insertion domain. Although we showed that the human alternative transcript is present in all tested tissues; co-exists with the full-length form, possesses 5'- and 3'-UTRs, a poly-A tail and is bound to polysomes, we were unable to detect the corresponding protein. The relaxed selective pressure combined with the occurrence of alternative splicing, involving a single structural sub-domain, favors the hypothesis of the loss of function of this domain for AspRSs of mitochondrial location. This evolutionary divergence is in line with other characteristics, established for the human mt-AspRS, that indicate a functional relaxation of non-viridiplantae mt-AspRSs when compared to bacterial and plant ones, despite their common ancestry.},
keywords = {Aminoacyl-tRNA synthetase Bioinformatics MTS Mitochondria Molecular biology Translation aaRS aminoacyl-tRNA synthetase (specificity is indicated by the name of the amino acid abbreviated in a three-letter code, e.g. AspRS stands for aspartyl-tRNA synthetase) mitochondrial mitochondrial targeting sequence mt, ERIANI, FLORENTZ, SISSLER, transferred to the cognate tRNA, Unité ARN},
pubstate = {published},
tppubtype = {article}
}
Mammalian mitochondrial aminoacyl-tRNA synthetases are nuclear-encoded enzymes that are essential for mitochondrial protein synthesis. Due to an endosymbiotic origin of the mitochondria, many of them share structural domains with homologous bacterial enzymes of same specificity. This is also the case for human mitochondrial aspartyl-tRNA synthetase (AspRS) that shares the so-called bacterial insertion domain with bacterial homologs. The function of this domain in the mitochondrial proteins is unclear. Here, we show by bioinformatic analyses that the sequences coding for the bacterial insertion domain are less conserved in opisthokont and protist than in bacteria and viridiplantae. The divergence suggests a loss of evolutionary pressure on this domain for non-plant mitochondrial AspRSs. This discovery is further connected with the herein described occurrence of alternatively spliced transcripts of the mRNAs coding for some mammalian mitochondrial AspRSs. Interestingly, the spliced transcripts alternately lack one of the four exons that code for the bacterial insertion domain. Although we showed that the human alternative transcript is present in all tested tissues; co-exists with the full-length form, possesses 5'- and 3'-UTRs, a poly-A tail and is bound to polysomes, we were unable to detect the corresponding protein. The relaxed selective pressure combined with the occurrence of alternative splicing, involving a single structural sub-domain, favors the hypothesis of the loss of function of this domain for AspRSs of mitochondrial location. This evolutionary divergence is in line with other characteristics, established for the human mt-AspRS, that indicate a functional relaxation of non-viridiplantae mt-AspRSs when compared to bacterial and plant ones, despite their common ancestry.
Maréchal-Drouard L, Sissler M, Tarassov I (Ed.)
Mitochondria: An organelle for life. Ouvrage
ELSEVIER, 2014.
BibTeX | Étiquettes: SISSLER, Unité ARN
@book{,
title = {Mitochondria: An organelle for life.},
editor = {L Maréchal-Drouard and M Sissler and I Tarassov},
year = {2014},
date = {2014-01-01},
volume = {100},
publisher = {ELSEVIER},
series = {Biochimie},
keywords = {SISSLER, Unité ARN},
pubstate = {published},
tppubtype = {book}
}
2012
Gaudry A, Lorber B, Neuenfeldt A, Sauter C, Florentz C, Sissler M
Re-designed N-terminus enhances expression, solubility and crystallizability of mitochondrial protein. Article de journal
Dans: Protein Eng Des Sel, vol. 25, non 9, p. 473-481, 2012, ISBN: 22871419.
Résumé | Liens | BibTeX | Étiquettes: FLORENTZ, FRUGIER, SISSLER, Unité ARN
@article{,
title = {Re-designed N-terminus enhances expression, solubility and crystallizability of mitochondrial protein.},
author = {A Gaudry and B Lorber and A Neuenfeldt and C Sauter and C Florentz and M Sissler},
url = {http://www.ncbi.nlm.nih.gov/pubmed/22871419?report=&dispmax=200&tool=PubCrawler_2.23},
isbn = {22871419},
year = {2012},
date = {2012-01-01},
journal = {Protein Eng Des Sel},
volume = {25},
number = {9},
pages = {473-481},
abstract = {Mitochondrial aminoacyl-tRNA synthetases are key enzymes in translation. They are encoded by the nuclear genome, synthesized as precursors in the cytosol and imported. Most are matured by cleavage of their N-terminal targeting sequence. The poor expression of mature proteins in prokaryotic systems, along with their low solubility and stability after purification are major obstacles for biophysical and crystallographic studies. The purpose of the present work was to analyze the influence of additives on a slightly soluble aspartyl-tRNA synthetase and of the N-terminal sequence of the protein on its expression and solubility. On the one hand, the solubility of the enzyme was augmented to some extent in the presence of a chemical analog of the intermediary product aspartyl-adenylate, 5'-O-[N-(L aspartyl) sulfamoyl] adenosine. On the other hand, expression was enhanced by extending the N-terminus by seven natural amino acids from the predicted targeting sequence. The re-designed enzyme was active, monodisperse, more soluble and yielded crystals that are suitable for structure determination. This result underlines the importance of the N-terminal residue sequence for solubility. It suggests that additional criteria should be taken into account for the prediction of cleavage sites in mitochondrial targeting sequences.},
keywords = {FLORENTZ, FRUGIER, SISSLER, Unité ARN},
pubstate = {published},
tppubtype = {article}
}
Mitochondrial aminoacyl-tRNA synthetases are key enzymes in translation. They are encoded by the nuclear genome, synthesized as precursors in the cytosol and imported. Most are matured by cleavage of their N-terminal targeting sequence. The poor expression of mature proteins in prokaryotic systems, along with their low solubility and stability after purification are major obstacles for biophysical and crystallographic studies. The purpose of the present work was to analyze the influence of additives on a slightly soluble aspartyl-tRNA synthetase and of the N-terminal sequence of the protein on its expression and solubility. On the one hand, the solubility of the enzyme was augmented to some extent in the presence of a chemical analog of the intermediary product aspartyl-adenylate, 5'-O-[N-(L aspartyl) sulfamoyl] adenosine. On the other hand, expression was enhanced by extending the N-terminus by seven natural amino acids from the predicted targeting sequence. The re-designed enzyme was active, monodisperse, more soluble and yielded crystals that are suitable for structure determination. This result underlines the importance of the N-terminal residue sequence for solubility. It suggests that additional criteria should be taken into account for the prediction of cleavage sites in mitochondrial targeting sequences.
Fender A, Gaudry A, Jühling F, Sissler M, Florentz C
Adaptation of aminoacylation identity rules to mammalian mitochondria. Article de journal
Dans: Biochimie, vol. 94, non 5, p. 1090-1097, 2012, ISBN: 22402012, (Available online 1 March 2012).
Résumé | Liens | BibTeX | Étiquettes: FLORENTZ, Identity elements Mitochondrial tRNA Cross-aminoacylation Structural plasticity, SISSLER, Unité ARN
@article{,
title = {Adaptation of aminoacylation identity rules to mammalian mitochondria.},
author = {A Fender and A Gaudry and F Jühling and M Sissler and C Florentz},
url = {http://www.ncbi.nlm.nih.gov/pubmed/22402012?dopt=Abstract},
doi = {10.1016/j.biochi.2012.02.030},
isbn = {22402012},
year = {2012},
date = {2012-01-01},
journal = {Biochimie},
volume = {94},
number = {5},
pages = {1090-1097},
abstract = {Many mammalian mitochondrial aminoacyl-tRNA synthetases are of bacterial-type and share structural domains with homologous bacterial enzymes of the same specificity. Despite this high similarity, synthetases from bacteria are known for their inability to aminoacylate mitochondrial tRNAs, while mitochondrial enzymes do aminoacylate bacterial tRNAs. Here, the reasons for non-aminoacylation by a bacterial enzyme of a mitochondrial tRNA have been explored. A mutagenic analysis performed on in vitro transcribed human mitochondrial tRNA(Asp) variants tested for their ability to become aspartylated by Escherichia coli aspartyl-tRNA synthetase, reveals that full conversion cannot be achieved on the basis of the currently established tRNA/synthetase recognition rules. Integration of the full set of aspartylation identity elements and stabilization of the structural tRNA scaffold by restoration of D- and T-loop interactions, enable only a partial gain in aspartylation efficiency. The sequence context and high structural instability of the mitochondrial tRNA are additional features hindering optimal adaptation of the tRNA to the bacterial enzyme. Our data support the hypothesis that non-aminoacylation of mitochondrial tRNAs by bacterial synthetases is linked to the large sequence and structural relaxation of the organelle encoded tRNAs, itself a consequence of the high rate of mitochondrial genome divergence.},
note = {Available online 1 March 2012},
keywords = {FLORENTZ, Identity elements Mitochondrial tRNA Cross-aminoacylation Structural plasticity, SISSLER, Unité ARN},
pubstate = {published},
tppubtype = {article}
}
Many mammalian mitochondrial aminoacyl-tRNA synthetases are of bacterial-type and share structural domains with homologous bacterial enzymes of the same specificity. Despite this high similarity, synthetases from bacteria are known for their inability to aminoacylate mitochondrial tRNAs, while mitochondrial enzymes do aminoacylate bacterial tRNAs. Here, the reasons for non-aminoacylation by a bacterial enzyme of a mitochondrial tRNA have been explored. A mutagenic analysis performed on in vitro transcribed human mitochondrial tRNA(Asp) variants tested for their ability to become aspartylated by Escherichia coli aspartyl-tRNA synthetase, reveals that full conversion cannot be achieved on the basis of the currently established tRNA/synthetase recognition rules. Integration of the full set of aspartylation identity elements and stabilization of the structural tRNA scaffold by restoration of D- and T-loop interactions, enable only a partial gain in aspartylation efficiency. The sequence context and high structural instability of the mitochondrial tRNA are additional features hindering optimal adaptation of the tRNA to the bacterial enzyme. Our data support the hypothesis that non-aminoacylation of mitochondrial tRNAs by bacterial synthetases is linked to the large sequence and structural relaxation of the organelle encoded tRNAs, itself a consequence of the high rate of mitochondrial genome divergence.
2011
Messmer M, Florentz C, Schwenzer H, Scheper G C, van der Knaap M S, Marechal-Drouard L, Sissler M
A human pathology-related mutation prevents import of an aminoacyl-tRNA synthetase into mitochondria Article de journal
Dans: Biochem J, vol. 433, non 3, p. 441-446, 2011, ISSN: 1470-8728 (Electronic) 0264-6021 (Linking), (Messmer, Marie Florentz, Catherine Schwenzer, Hagen Scheper, Gert C van der Knaap, Marjo S Marechal-Drouard, Laurence Sissler, Marie Research Support, Non-U.S. Gov't England The Biochemical journal Biochem J. 2011 Jan 14;433(3):441-6.).
Résumé | Liens | BibTeX | Étiquettes: Aspartate-tRNA Ligase/*genetics/*metabolism Cell Line Humans Leukoencephalopathies/etiology/genetics Mitochondria/*metabolism *Mutation, FLORENTZ, Missense Protein Transport, SISSLER, Unité ARN
@article{,
title = {A human pathology-related mutation prevents import of an aminoacyl-tRNA synthetase into mitochondria},
author = {M Messmer and C Florentz and H Schwenzer and G C Scheper and M S van der Knaap and L Marechal-Drouard and M Sissler},
url = {http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=21121901},
doi = {10.1042/BJ20101902},
issn = {1470-8728 (Electronic) 0264-6021 (Linking)},
year = {2011},
date = {2011-01-01},
journal = {Biochem J},
volume = {433},
number = {3},
pages = {441-446},
abstract = {Mutations in the nuclear gene coding for the mitochondrial aspartyl-tRNA synthetase, a key enzyme for mitochondrial translation, are correlated with leukoencephalopathy. A Ser to Gly mutation is located in the predicted targeting signal of the protein. We demonstrate in the present study, by in vivo and in vitro approaches, that this pathology-related mutation impairs the import process across mitochondrial membranes.},
note = {Messmer, Marie
Florentz, Catherine
Schwenzer, Hagen
Scheper, Gert C
van der Knaap, Marjo S
Marechal-Drouard, Laurence
Sissler, Marie
Research Support, Non-U.S. Gov't
England
The Biochemical journal
Biochem J. 2011 Jan 14;433(3):441-6.},
keywords = {Aspartate-tRNA Ligase/*genetics/*metabolism Cell Line Humans Leukoencephalopathies/etiology/genetics Mitochondria/*metabolism *Mutation, FLORENTZ, Missense Protein Transport, SISSLER, Unité ARN},
pubstate = {published},
tppubtype = {article}
}
Mutations in the nuclear gene coding for the mitochondrial aspartyl-tRNA synthetase, a key enzyme for mitochondrial translation, are correlated with leukoencephalopathy. A Ser to Gly mutation is located in the predicted targeting signal of the protein. We demonstrate in the present study, by in vivo and in vitro approaches, that this pathology-related mutation impairs the import process across mitochondrial membranes.
2009
Messmer M, Putz J, Suzuki T, Sauter C, Sissler M, Florentz C
Tertiary network in mammalian mitochondrial tRNAAsp revealed by solution probing and phylogeny Article de journal
Dans: Nucleic Acids Res, vol. 37, non 20, p. 6881-6895, 2009, ISBN: 19767615, (1362-4962 (Electronic) 0305-1048 (Linking) Journal Article Research Support, Non-U.S. Gov't).
Résumé | Liens | BibTeX | Étiquettes: Asp/*chemistry/*metabolism Transcription, Base Sequence Databases, FLORENTZ, FRUGIER, Genetic, Nucleic Acid Humans Molecular Sequence Data Nucleic Acid Conformation Phylogeny RNA/*chemistry/*metabolism RNA, SISSLER, Transfer, Unité ARN
@article{,
title = {Tertiary network in mammalian mitochondrial tRNAAsp revealed by solution probing and phylogeny},
author = {M Messmer and J Putz and T Suzuki and C Sauter and M Sissler and C Florentz},
url = {http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=19767615},
isbn = {19767615},
year = {2009},
date = {2009-01-01},
journal = {Nucleic Acids Res},
volume = {37},
number = {20},
pages = {6881-6895},
abstract = {Primary and secondary structures of mammalian mitochondrial (mt) tRNAs are divergent from canonical tRNA structures due to highly skewed nucleotide content and large size variability of D- and T-loops. The nonconservation of nucleotides involved in the expected network of tertiary interactions calls into question the rules governing a functional L-shaped three-dimensional (3D) structure. Here, we report the solution structure of human mt-tRNA(Asp) in its native post-transcriptionally modified form and as an in vitro transcript. Probing performed with nuclease S1, ribonuclease V1, dimethylsulfate, diethylpyrocarbonate and lead, revealed several secondary structures for the in vitro transcribed mt-tRNA(Asp) including predominantly the cloverleaf. On the contrary, the native tRNA(Asp) folds into a single cloverleaf structure, highlighting the contribution of the four newly identified post-transcriptional modifications to correct folding. Reactivities of nucleotides and phosphodiester bonds in the native tRNA favor existence of a full set of six classical tertiary interactions between the D-domain and the variable region, forming the core of the 3D structure. Reactivities of D- and T-loop nucleotides support an absence of interactions between these domains. According to multiple sequence alignments and search for conservation of Leontis-Westhof interactions, the tertiary network core building rules apply to all tRNA(Asp) from mammalian mitochondria.},
note = {1362-4962 (Electronic)
0305-1048 (Linking)
Journal Article
Research Support, Non-U.S. Gov't},
keywords = {Asp/*chemistry/*metabolism Transcription, Base Sequence Databases, FLORENTZ, FRUGIER, Genetic, Nucleic Acid Humans Molecular Sequence Data Nucleic Acid Conformation Phylogeny RNA/*chemistry/*metabolism RNA, SISSLER, Transfer, Unité ARN},
pubstate = {published},
tppubtype = {article}
}
Primary and secondary structures of mammalian mitochondrial (mt) tRNAs are divergent from canonical tRNA structures due to highly skewed nucleotide content and large size variability of D- and T-loops. The nonconservation of nucleotides involved in the expected network of tertiary interactions calls into question the rules governing a functional L-shaped three-dimensional (3D) structure. Here, we report the solution structure of human mt-tRNA(Asp) in its native post-transcriptionally modified form and as an in vitro transcript. Probing performed with nuclease S1, ribonuclease V1, dimethylsulfate, diethylpyrocarbonate and lead, revealed several secondary structures for the in vitro transcribed mt-tRNA(Asp) including predominantly the cloverleaf. On the contrary, the native tRNA(Asp) folds into a single cloverleaf structure, highlighting the contribution of the four newly identified post-transcriptional modifications to correct folding. Reactivities of nucleotides and phosphodiester bonds in the native tRNA favor existence of a full set of six classical tertiary interactions between the D-domain and the variable region, forming the core of the 3D structure. Reactivities of D- and T-loop nucleotides support an absence of interactions between these domains. According to multiple sequence alignments and search for conservation of Leontis-Westhof interactions, the tertiary network core building rules apply to all tRNA(Asp) from mammalian mitochondria.
Messmer M, Gaudry A, Sissler M, Florentz C
Pathology-related mutation A7526G (A9G) helps in the understanding of the 3D structural core of human mitochondrial tRNA(Asp) Article de journal
Dans: RNA, vol. 15, non 8, p. 1462-1468, 2009, ISBN: 19535463, (1469-9001 (Electronic) Letter Research Support, Non-U.S. Gov't).
Résumé | Liens | BibTeX | Étiquettes: Asp/*chemistry/*genetics/metabolism Transfer RNA Aminoacylation/genetics, Binding Sites/genetics Humans Kinetics Mitochondrial Myopathies/genetics/metabolism/pathology Models, FLORENTZ, Missense Nucleic Acid Conformation RNA/*chemistry/*genetics/metabolism RNA, Molecular Mutation, SISSLER, Transfer, Unité ARN
@article{,
title = {Pathology-related mutation A7526G (A9G) helps in the understanding of the 3D structural core of human mitochondrial tRNA(Asp)},
author = {M Messmer and A Gaudry and M Sissler and C Florentz},
url = {http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=19535463},
isbn = {19535463},
year = {2009},
date = {2009-01-01},
journal = {RNA},
volume = {15},
number = {8},
pages = {1462-1468},
abstract = {More than 130 mutations in human mitochondrial tRNA (mt-tRNA) genes have been correlated with a variety of neurodegenerative and neuromuscular disorders. Their molecular impacts are of mosaic type, affecting various stages of tRNA biogenesis, structure, and/or functions in mt-translation. Knowledge of mammalian mt-tRNA structures per se remains scarce however. Primary and secondary structures deviate from classical tRNAs, while rules for three-dimensional (3D) folding are almost unknown. Here, we take advantage of a myopathy-related mutation A7526G (A9G) in mt-tRNA(Asp) to investigate both the primary molecular impact underlying the pathology and the role of nucleotide 9 in the network of 3D tertiary interactions. Experimental evidence is presented for existence of a 9-12-23 triple in human mt-tRNA(Asp) with a strongly conserved interaction scheme in mammalian mt-tRNAs. Mutation A7526G disrupts the triple interaction and in turn reduces aspartylation efficiency.},
note = {1469-9001 (Electronic)
Letter
Research Support, Non-U.S. Gov't},
keywords = {Asp/*chemistry/*genetics/metabolism Transfer RNA Aminoacylation/genetics, Binding Sites/genetics Humans Kinetics Mitochondrial Myopathies/genetics/metabolism/pathology Models, FLORENTZ, Missense Nucleic Acid Conformation RNA/*chemistry/*genetics/metabolism RNA, Molecular Mutation, SISSLER, Transfer, Unité ARN},
pubstate = {published},
tppubtype = {article}
}
More than 130 mutations in human mitochondrial tRNA (mt-tRNA) genes have been correlated with a variety of neurodegenerative and neuromuscular disorders. Their molecular impacts are of mosaic type, affecting various stages of tRNA biogenesis, structure, and/or functions in mt-translation. Knowledge of mammalian mt-tRNA structures per se remains scarce however. Primary and secondary structures deviate from classical tRNAs, while rules for three-dimensional (3D) folding are almost unknown. Here, we take advantage of a myopathy-related mutation A7526G (A9G) in mt-tRNA(Asp) to investigate both the primary molecular impact underlying the pathology and the role of nucleotide 9 in the network of 3D tertiary interactions. Experimental evidence is presented for existence of a 9-12-23 triple in human mt-tRNA(Asp) with a strongly conserved interaction scheme in mammalian mt-tRNAs. Mutation A7526G disrupts the triple interaction and in turn reduces aspartylation efficiency.
Messmer M, Blais S P, Balg C, Chenevert R, Grenier L, Lague P, Sauter C, Sissler M, Giege R, Lapointe J, Florentz C
Peculiar inhibition of human mitochondrial aspartyl-tRNA synthetase by adenylate analogs Article de journal
Dans: Biochimie, vol. 91, non 5, p. 596-603, 2009, ISBN: 19254750, (1638-6183 (Electronic) Journal Article Research Support, Non-U.S. Gov't).
Résumé | Liens | BibTeX | Étiquettes: Adenosine Monophosphate/*analogs & derivatives/*pharmacology Animals Aspartate-tRNA Ligase/*antagonists & inhibitors/*chemistry/metabolism Catalytic Domain Cattle Humans Mitochondria/*drug effects/*enzymology Molecular Structure Structure-Activity Relationship, FLORENTZ, SISSLER, Unité ARN
@article{,
title = {Peculiar inhibition of human mitochondrial aspartyl-tRNA synthetase by adenylate analogs},
author = {M Messmer and S P Blais and C Balg and R Chenevert and L Grenier and P Lague and C Sauter and M Sissler and R Giege and J Lapointe and C Florentz},
url = {http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=19254750},
isbn = {19254750},
year = {2009},
date = {2009-01-01},
journal = {Biochimie},
volume = {91},
number = {5},
pages = {596-603},
abstract = {Human mitochondrial aminoacyl-tRNA synthetases (mt-aaRSs), the enzymes which esterify tRNAs with the cognate specific amino acid, form mainly a different set of proteins than those involved in the cytosolic translation machinery. Many of the mt-aaRSs are of bacterial-type in regard of sequence and modular structural organization. However, the few enzymes investigated so far do have peculiar biochemical and enzymological properties such as decreased solubility, decreased specific activity and enlarged spectra of substrate tRNAs (of same specificity but from various organisms and kingdoms), as compared to bacterial aaRSs. Here the sensitivity of human mitochondrial aspartyl-tRNA synthetase (AspRS) to small substrate analogs (non-hydrolysable adenylates) known as inhibitors of Escherichia coli and Pseudomonas aeruginosa AspRSs is evaluated and compared to the sensitivity of eukaryal cytosolic human and bovine AspRSs. L-aspartol-adenylate (aspartol-AMP) is a competitive inhibitor of aspartylation by mitochondrial as well as cytosolic mammalian AspRSs, with K(i) values in the micromolar range (4-27 microM for human mt- and mammalian cyt-AspRSs). 5'-O-[N-(L-aspartyl)sulfamoyl]adenosine (Asp-AMS) is a 500-fold stronger competitive inhibitor of the mitochondrial enzyme than aspartol-AMP (10nM) and a 35-fold lower competitor of human and bovine cyt-AspRSs (300 nM). The higher sensitivity of human mt-AspRS for both inhibitors as compared to either bacterial or mammalian cytosolic enzymes, is not correlated with clear-cut structural features in the catalytic site as deduced from docking experiments, but may result from dynamic events. In the scope of new antibacterial strategies directed against aaRSs, possible side effects of such drugs on the mitochondrial human aaRSs should thus be considered.},
note = {1638-6183 (Electronic)
Journal Article
Research Support, Non-U.S. Gov't},
keywords = {Adenosine Monophosphate/*analogs & derivatives/*pharmacology Animals Aspartate-tRNA Ligase/*antagonists & inhibitors/*chemistry/metabolism Catalytic Domain Cattle Humans Mitochondria/*drug effects/*enzymology Molecular Structure Structure-Activity Relationship, FLORENTZ, SISSLER, Unité ARN},
pubstate = {published},
tppubtype = {article}
}
Human mitochondrial aminoacyl-tRNA synthetases (mt-aaRSs), the enzymes which esterify tRNAs with the cognate specific amino acid, form mainly a different set of proteins than those involved in the cytosolic translation machinery. Many of the mt-aaRSs are of bacterial-type in regard of sequence and modular structural organization. However, the few enzymes investigated so far do have peculiar biochemical and enzymological properties such as decreased solubility, decreased specific activity and enlarged spectra of substrate tRNAs (of same specificity but from various organisms and kingdoms), as compared to bacterial aaRSs. Here the sensitivity of human mitochondrial aspartyl-tRNA synthetase (AspRS) to small substrate analogs (non-hydrolysable adenylates) known as inhibitors of Escherichia coli and Pseudomonas aeruginosa AspRSs is evaluated and compared to the sensitivity of eukaryal cytosolic human and bovine AspRSs. L-aspartol-adenylate (aspartol-AMP) is a competitive inhibitor of aspartylation by mitochondrial as well as cytosolic mammalian AspRSs, with K(i) values in the micromolar range (4-27 microM for human mt- and mammalian cyt-AspRSs). 5'-O-[N-(L-aspartyl)sulfamoyl]adenosine (Asp-AMS) is a 500-fold stronger competitive inhibitor of the mitochondrial enzyme than aspartol-AMP (10nM) and a 35-fold lower competitor of human and bovine cyt-AspRSs (300 nM). The higher sensitivity of human mt-AspRS for both inhibitors as compared to either bacterial or mammalian cytosolic enzymes, is not correlated with clear-cut structural features in the catalytic site as deduced from docking experiments, but may result from dynamic events. In the scope of new antibacterial strategies directed against aaRSs, possible side effects of such drugs on the mitochondrial human aaRSs should thus be considered.
2008
Sissler M, Lorber B, Messmer M, Schaller A, Putz J, Florentz C
Handling mammalian mitochondrial tRNAs and aminoacyl-tRNA synthetases for functional and structural characterization Article de journal
Dans: Methods, vol. 44, non 2, p. 176-189, 2008, ISBN: 18241799, (1046-2023 (Print) Journal article).
Résumé | Liens | BibTeX | Étiquettes: FLORENTZ, FLORENTZ GIEGE, SISSLER, Unité ARN
@article{,
title = {Handling mammalian mitochondrial tRNAs and aminoacyl-tRNA synthetases for functional and structural characterization},
author = {M Sissler and B Lorber and M Messmer and A Schaller and J Putz and C Florentz},
url = {http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=18241799},
isbn = {18241799},
year = {2008},
date = {2008-01-01},
journal = {Methods},
volume = {44},
number = {2},
pages = {176-189},
abstract = {The mammalian mitochondrial (mt) genome codes for only 13 proteins, which are essential components in the process of oxidative phosphorylation of ADP into ATP. Synthesis of these proteins relies on a proper mt translation machinery. While 22 tRNAs and 2 rRNAs are also coded by the mt genome, all other factors including the set of aminoacyl-tRNA synthetases (aaRSs) are encoded in the nucleus and imported. Investigation of mammalian mt aminoacylation systems (and mt translation in general) gains more and more interest not only in regard of evolutionary considerations but also with respect to the growing number of diseases linked to mutations in the genes of either mt-tRNAs, synthetases or other factors. Here we report on methodological approaches for biochemical, functional, and structural characterization of human/mammalian mt-tRNAs and aaRSs. Procedures for preparation of native and in vitro transcribed tRNAs are accompanied by recommendations for specific handling of tRNAs incline to structural instability and chemical fragility. Large-scale preparation of mg amounts of highly soluble recombinant synthetases is a prerequisite for structural investigations that requires particular optimizations. Successful examples leading to crystallization of four mt-aaRSs and high-resolution structures are recalled and limitations discussed. Finally, the need for and the state-of-the-art in setting up an in vitro mt translation system are emphasized. Biochemical characterization of a subset of mammalian aminoacylation systems has already revealed a number of unprecedented peculiarities of interest for the study of evolution and forensic research. Further efforts in this field will certainly be rewarded by many exciting discoveries.},
note = {1046-2023 (Print)
Journal article},
keywords = {FLORENTZ, FLORENTZ GIEGE, SISSLER, Unité ARN},
pubstate = {published},
tppubtype = {article}
}
The mammalian mitochondrial (mt) genome codes for only 13 proteins, which are essential components in the process of oxidative phosphorylation of ADP into ATP. Synthesis of these proteins relies on a proper mt translation machinery. While 22 tRNAs and 2 rRNAs are also coded by the mt genome, all other factors including the set of aminoacyl-tRNA synthetases (aaRSs) are encoded in the nucleus and imported. Investigation of mammalian mt aminoacylation systems (and mt translation in general) gains more and more interest not only in regard of evolutionary considerations but also with respect to the growing number of diseases linked to mutations in the genes of either mt-tRNAs, synthetases or other factors. Here we report on methodological approaches for biochemical, functional, and structural characterization of human/mammalian mt-tRNAs and aaRSs. Procedures for preparation of native and in vitro transcribed tRNAs are accompanied by recommendations for specific handling of tRNAs incline to structural instability and chemical fragility. Large-scale preparation of mg amounts of highly soluble recombinant synthetases is a prerequisite for structural investigations that requires particular optimizations. Successful examples leading to crystallization of four mt-aaRSs and high-resolution structures are recalled and limitations discussed. Finally, the need for and the state-of-the-art in setting up an in vitro mt translation system are emphasized. Biochemical characterization of a subset of mammalian aminoacylation systems has already revealed a number of unprecedented peculiarities of interest for the study of evolution and forensic research. Further efforts in this field will certainly be rewarded by many exciting discoveries.
2007
Scheper G C, van der Klok T, van Andel R J, van Berkel C G, Sissler M, Smet J, Muravina T I, Serkov S V, Uziel G, Bugiani M, Schiffmann R, Krageloh-Mann I, Smeitink J A, Florentz C, Coster R Van, Pronk J C, van der Knaap M S
Mitochondrial aspartyl-tRNA synthetase deficiency causes leukoencephalopathy with brain stem and spinal cord involvement and lactate elevation Article de journal
Dans: Nat Genet, vol. 39, non 4, p. 534-539, 2007, ISBN: 17384640, (1061-4036 (Print) Journal Article).
Résumé | Liens | BibTeX | Étiquettes: FLORENTZ, SISSLER, Unité ARN
@article{,
title = {Mitochondrial aspartyl-tRNA synthetase deficiency causes leukoencephalopathy with brain stem and spinal cord involvement and lactate elevation},
author = {G C Scheper and T van der Klok and R J van Andel and C G van Berkel and M Sissler and J Smet and T I Muravina and S V Serkov and G Uziel and M Bugiani and R Schiffmann and I Krageloh-Mann and J A Smeitink and C Florentz and R Van Coster and J C Pronk and M S van der Knaap},
url = {http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=17384640},
isbn = {17384640},
year = {2007},
date = {2007-01-01},
journal = {Nat Genet},
volume = {39},
number = {4},
pages = {534-539},
abstract = {Leukoencephalopathy with brain stem and spinal cord involvement and lactate elevation (LBSL) has recently been defined based on a highly characteristic constellation of abnormalities observed by magnetic resonance imaging and spectroscopy. LBSL is an autosomal recessive disease, most often manifesting in early childhood. Affected individuals develop slowly progressive cerebellar ataxia, spasticity and dorsal column dysfunction, sometimes with a mild cognitive deficit or decline. We performed linkage mapping with microsatellite markers in LBSL families and found a candidate region on chromosome 1, which we narrowed by means of shared haplotypes. Sequencing of genes in this candidate region uncovered mutations in DARS2, which encodes mitochondrial aspartyl-tRNA synthetase, in affected individuals from all 30 families. Enzyme activities of mutant proteins were decreased. We were surprised to find that activities of mitochondrial complexes from fibroblasts and lymphoblasts derived from affected individuals were normal, as determined by different assays.},
note = {1061-4036 (Print)
Journal Article},
keywords = {FLORENTZ, SISSLER, Unité ARN},
pubstate = {published},
tppubtype = {article}
}
Leukoencephalopathy with brain stem and spinal cord involvement and lactate elevation (LBSL) has recently been defined based on a highly characteristic constellation of abnormalities observed by magnetic resonance imaging and spectroscopy. LBSL is an autosomal recessive disease, most often manifesting in early childhood. Affected individuals develop slowly progressive cerebellar ataxia, spasticity and dorsal column dysfunction, sometimes with a mild cognitive deficit or decline. We performed linkage mapping with microsatellite markers in LBSL families and found a candidate region on chromosome 1, which we narrowed by means of shared haplotypes. Sequencing of genes in this candidate region uncovered mutations in DARS2, which encodes mitochondrial aspartyl-tRNA synthetase, in affected individuals from all 30 families. Enzyme activities of mutant proteins were decreased. We were surprised to find that activities of mitochondrial complexes from fibroblasts and lymphoblasts derived from affected individuals were normal, as determined by different assays.
2006
Fender A, Sauter C, Messmer M, Putz J, Giege R, Florentz C, Sissler M
Loss of a primordial identity element for a mammalian mitochondrial aminoacylation system Article de journal
Dans: J Biol Chem, vol. 281, non 23, p. 15980-15986, 2006, ISBN: 16597625, (0021-9258 (Print) Journal Article).
Résumé | Liens | BibTeX | Étiquettes: Acylation Base Sequence Humans Kinetics Mutagenesis Nucleic Acid Conformation Plasmids RNA | Non-U.S. Gov't, Asp/chemistry/genetics/*metabolism Research Support, FLORENTZ, FRUGIER, Non-U.S. Gov't, SISSLER, Transfer, Unité ARN
@article{,
title = {Loss of a primordial identity element for a mammalian mitochondrial aminoacylation system},
author = {A Fender and C Sauter and M Messmer and J Putz and R Giege and C Florentz and M Sissler},
url = {http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=16597625},
isbn = {16597625},
year = {2006},
date = {2006-01-01},
journal = {J Biol Chem},
volume = {281},
number = {23},
pages = {15980-15986},
abstract = {In mammalian mitochondria the translational machinery is of dual origin with tRNAs encoded by a simplified and rapidly evolving mitochondrial (mt) genome and aminoacyl-tRNA synthetases (aaRS) coded by the nuclear genome, and imported. Mt-tRNAs are atypical with biased sequences, size variations in loops and stems, and absence of residues forming classical tertiary interactions, whereas synthetases appear typical. This raises questions about identity elements in mt-tRNAs and adaptation of their cognate mt-aaRSs. We have explored here the human mt-aspartate system in which a prokaryotic-type AspRS, highly similar to the Escherichia coli enzyme, recognizes a bizarre tRNA(Asp). Analysis of human mt-tRNA(Asp) transcripts confirms the identity role of the GUC anticodon as in other aspartylation systems but reveals the non-involvement of position 73. This position is otherwise known as the site of a universally conserved major aspartate identity element, G73, also known as a primordial identity signal. In mt-tRNA(Asp), position 73 can be occupied by any of the four nucleotides without affecting aspartylation. Sequence alignments of various AspRSs allowed placing Gly-269 at a position occupied by Asp-220, the residue contacting G73 in the crystallographic structure of E. coli AspRS-tRNA(Asp) complex. Replacing this glycine by an aspartate renders human mt-AspRS more discriminative to G73. Restriction in the aspartylation identity set, driven by a rapid mutagenic rate of the mt-genome, suggests a reverse evolution of the mt-tRNA(Asp) identity elements in regard to its bacterial ancestor.},
note = {0021-9258 (Print)
Journal Article},
keywords = {Acylation Base Sequence Humans Kinetics Mutagenesis Nucleic Acid Conformation Plasmids RNA | Non-U.S. Gov't, Asp/chemistry/genetics/*metabolism Research Support, FLORENTZ, FRUGIER, Non-U.S. Gov't, SISSLER, Transfer, Unité ARN},
pubstate = {published},
tppubtype = {article}
}
In mammalian mitochondria the translational machinery is of dual origin with tRNAs encoded by a simplified and rapidly evolving mitochondrial (mt) genome and aminoacyl-tRNA synthetases (aaRS) coded by the nuclear genome, and imported. Mt-tRNAs are atypical with biased sequences, size variations in loops and stems, and absence of residues forming classical tertiary interactions, whereas synthetases appear typical. This raises questions about identity elements in mt-tRNAs and adaptation of their cognate mt-aaRSs. We have explored here the human mt-aspartate system in which a prokaryotic-type AspRS, highly similar to the Escherichia coli enzyme, recognizes a bizarre tRNA(Asp). Analysis of human mt-tRNA(Asp) transcripts confirms the identity role of the GUC anticodon as in other aspartylation systems but reveals the non-involvement of position 73. This position is otherwise known as the site of a universally conserved major aspartate identity element, G73, also known as a primordial identity signal. In mt-tRNA(Asp), position 73 can be occupied by any of the four nucleotides without affecting aspartylation. Sequence alignments of various AspRSs allowed placing Gly-269 at a position occupied by Asp-220, the residue contacting G73 in the crystallographic structure of E. coli AspRS-tRNA(Asp) complex. Replacing this glycine by an aspartate renders human mt-AspRS more discriminative to G73. Restriction in the aspartylation identity set, driven by a rapid mutagenic rate of the mt-genome, suggests a reverse evolution of the mt-tRNA(Asp) identity elements in regard to its bacterial ancestor.
2005
Sissler M, Putz J, Fasiolo F, Florentz C
Mitochondrial aminoacyl-tRNA synthetases Chapitre d'ouvrage
Dans: Ibba, M; Francklyn, C; Cusak, S (Ed.): The Aminoacyl-tRNA Synthetases, Landes Bioscience, 2005.
Résumé | Liens | BibTeX | Étiquettes: FLORENTZ, FLORENTZ FASIOLO, SISSLER, Unité ARN
@inbook{,
title = {Mitochondrial aminoacyl-tRNA synthetases},
author = {M Sissler and J Putz and F Fasiolo and C Florentz},
editor = {M Ibba and C Francklyn and S Cusak},
url = {http://www.ncbi.nlm.nih.gov/books/NBK6033},
year = {2005},
date = {2005-01-01},
booktitle = {The Aminoacyl-tRNA Synthetases},
publisher = {Landes Bioscience},
abstract = {Mitochondria and chloroplasts have their own genomes that encode a small number of proteins whose synthesis depends on translation machineries of multiple origin. Whereas tRNAs, rRNAs and some ribosomal proteins are often encoded by the organellar genome, all other factors and in particular aminoacyl-tRNA synthetases (aaRSs) are nuclear encoded, synthesized in the cytosol and imported. Thus, two to three sets of aaRSs coexist in eukaryotic cells, namely cytosolic, mitochondrial and chloroplastic versions. Here, the diversity in the structural and functional properties of organellar aaRSs is illustrated by mammalian mitochondrial aaRSs (size, oligomeric structure, efficiency of aminoacylation, cross reactions, identity sets). Additionally, means by which nuclear genes encode cytosolic, mitochondrial and chloroplastic aaRSs are reviewed on the basis of database exploration on fully sequenced (although not completely annotated) genomes of Homo sapiens, Saccharomyces cerevisiae, Caenorabditis elegans, Drosophila melanogaster and Arabidopsis thaliana.},
keywords = {FLORENTZ, FLORENTZ FASIOLO, SISSLER, Unité ARN},
pubstate = {published},
tppubtype = {inbook}
}
Mitochondria and chloroplasts have their own genomes that encode a small number of proteins whose synthesis depends on translation machineries of multiple origin. Whereas tRNAs, rRNAs and some ribosomal proteins are often encoded by the organellar genome, all other factors and in particular aminoacyl-tRNA synthetases (aaRSs) are nuclear encoded, synthesized in the cytosol and imported. Thus, two to three sets of aaRSs coexist in eukaryotic cells, namely cytosolic, mitochondrial and chloroplastic versions. Here, the diversity in the structural and functional properties of organellar aaRSs is illustrated by mammalian mitochondrial aaRSs (size, oligomeric structure, efficiency of aminoacylation, cross reactions, identity sets). Additionally, means by which nuclear genes encode cytosolic, mitochondrial and chloroplastic aaRSs are reviewed on the basis of database exploration on fully sequenced (although not completely annotated) genomes of Homo sapiens, Saccharomyces cerevisiae, Caenorabditis elegans, Drosophila melanogaster and Arabidopsis thaliana.
Champagne K S, Sissler M, Larrabee Y, Doublie S, Francklyn C S
Activation of the hetero-octameric ATP phosphoribosyl transferase through subunit interface rearrangement by a tRNA synthetase paralog Article de journal
Dans: J Biol Chem, vol. 280, non 40, p. 34096-34104, 2005, ISBN: 16051603, (0021-9258 (Print) Journal Article).
Résumé | Liens | BibTeX | Étiquettes: Extramural Research Support, FLORENTZ ATP Phosphoribosyltransferase/*metabolism Allosteric Regulation Amino Acyl-tRNA Synthetases DNA Mutational Analysis Enzyme Activation *Models, N.I.H., Non-P.H.S. Research Support, P.H.S., SISSLER, Structural Phosphates/metabolism Research Support, U.S. Gov't, Unité ARN
@article{,
title = {Activation of the hetero-octameric ATP phosphoribosyl transferase through subunit interface rearrangement by a tRNA synthetase paralog},
author = {K S Champagne and M Sissler and Y Larrabee and S Doublie and C S Francklyn},
url = {http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=16051603},
isbn = {16051603},
year = {2005},
date = {2005-01-01},
journal = {J Biol Chem},
volume = {280},
number = {40},
pages = {34096-34104},
abstract = {ATP phosphoribosyl transferase (ATP-PRT) joins ATP and 5-phosphoribosyl-1-pyrophosphate (PRPP) in a highly regulated reaction that initiates histidine biosynthesis. The unusual hetero-octameric version of ATP-PRT includes four HisG(S) catalytic subunits based on the periplasmic binding protein fold and four HisZ regulatory subunits that resemble histidyl-tRNA synthetases. Here, we present the first structure of a PRPP-bound ATP-PRT at 2.9 A and provide a structural model for allosteric activation based on comparisons with other inhibited and activated ATP-PRTs from both the hetero-octameric and hexameric families. The activated state of the octameric enzyme is characterized by an interstitial phosphate ion in the HisZ-HisG interface and new contacts between the HisZ motif 2 loop and the HisG(S) dimer interface. These contacts restructure the interface to recruit conserved residues to the active site, where they activate pyrophosphate to promote catalysis. Additionally, mutational analysis identifies the histidine binding sites within a region highly conserved between HisZ and the functional HisRS. Through the oligomerization and functional re-assignment of protein domains associated with aminoacylation and phosphate binding, the HisZ-HisG octameric ATP-PRT acquired the ability to initiate the synthesis of a key metabolic intermediate in an allosterically regulated fashion.},
note = {0021-9258 (Print)
Journal Article},
keywords = {Extramural Research Support, FLORENTZ ATP Phosphoribosyltransferase/*metabolism Allosteric Regulation Amino Acyl-tRNA Synthetases DNA Mutational Analysis Enzyme Activation *Models, N.I.H., Non-P.H.S. Research Support, P.H.S., SISSLER, Structural Phosphates/metabolism Research Support, U.S. Gov't, Unité ARN},
pubstate = {published},
tppubtype = {article}
}
ATP phosphoribosyl transferase (ATP-PRT) joins ATP and 5-phosphoribosyl-1-pyrophosphate (PRPP) in a highly regulated reaction that initiates histidine biosynthesis. The unusual hetero-octameric version of ATP-PRT includes four HisG(S) catalytic subunits based on the periplasmic binding protein fold and four HisZ regulatory subunits that resemble histidyl-tRNA synthetases. Here, we present the first structure of a PRPP-bound ATP-PRT at 2.9 A and provide a structural model for allosteric activation based on comparisons with other inhibited and activated ATP-PRTs from both the hetero-octameric and hexameric families. The activated state of the octameric enzyme is characterized by an interstitial phosphate ion in the HisZ-HisG interface and new contacts between the HisZ motif 2 loop and the HisG(S) dimer interface. These contacts restructure the interface to recruit conserved residues to the active site, where they activate pyrophosphate to promote catalysis. Additionally, mutational analysis identifies the histidine binding sites within a region highly conserved between HisZ and the functional HisRS. Through the oligomerization and functional re-assignment of protein domains associated with aminoacylation and phosphate binding, the HisZ-HisG octameric ATP-PRT acquired the ability to initiate the synthesis of a key metabolic intermediate in an allosterically regulated fashion.
Bonnefond L, Fender A, Rudinger-Thirion J, Giege R, Florentz C, Sissler M
Toward the Full Set of Human Mitochondrial Aminoacyl-tRNA Synthetases: Characterization of AspRS and TyrRS Article de journal
Dans: Biochemistry, vol. 44, non 12, p. 4805-4816, 2005, ISBN: 15779907, (0006-2960 Journal Article).
Résumé | Liens | BibTeX | Étiquettes: FLORENTZ, FRUGIER, SISSLER, Unité ARN
@article{,
title = {Toward the Full Set of Human Mitochondrial Aminoacyl-tRNA Synthetases: Characterization of AspRS and TyrRS},
author = {L Bonnefond and A Fender and J Rudinger-Thirion and R Giege and C Florentz and M Sissler},
url = {http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=15779907},
isbn = {15779907},
year = {2005},
date = {2005-01-01},
journal = {Biochemistry},
volume = {44},
number = {12},
pages = {4805-4816},
abstract = {The human mitochondrion possesses a translational machinery devoted to the synthesis of 13 proteins. While the required tRNAs and rRNAs are produced by transcription of the mitochondrial genome, all other factors needed for protein synthesis are synthesized in the cytosol and imported. This is the case for aminoacyl-tRNA synthetases, the enzymes which esterify their cognate tRNA with the specific amino acid. The genes for the full set of cytosolic aaRSs are well defined, but only nine genes for mitochondrial synthetases are known. Here we describe the genes for human mitochondrial aspartyl- and tyrosyl-tRNA synthetases and the initial characterization of the enzymes. Both belong to the expected class of synthetases, have a dimeric organization, and aminoacylate Escherichia coli tRNAs as well as in vitro transcribed human mitochondrial tRNAs. Genes for the remaining missing synthetases were also found with the exception of glutaminyl-tRNA synthetase. Their sequence analysis confirms and further extends the view that, except for lysyl- and glycyl-tRNA synthetases, human mitochondrial and cytosolic enzymes are coded by two different sets of genes.},
note = {0006-2960
Journal Article},
keywords = {FLORENTZ, FRUGIER, SISSLER, Unité ARN},
pubstate = {published},
tppubtype = {article}
}
The human mitochondrion possesses a translational machinery devoted to the synthesis of 13 proteins. While the required tRNAs and rRNAs are produced by transcription of the mitochondrial genome, all other factors needed for protein synthesis are synthesized in the cytosol and imported. This is the case for aminoacyl-tRNA synthetases, the enzymes which esterify their cognate tRNA with the specific amino acid. The genes for the full set of cytosolic aaRSs are well defined, but only nine genes for mitochondrial synthetases are known. Here we describe the genes for human mitochondrial aspartyl- and tyrosyl-tRNA synthetases and the initial characterization of the enzymes. Both belong to the expected class of synthetases, have a dimeric organization, and aminoacylate Escherichia coli tRNAs as well as in vitro transcribed human mitochondrial tRNAs. Genes for the remaining missing synthetases were also found with the exception of glutaminyl-tRNA synthetase. Their sequence analysis confirms and further extends the view that, except for lysyl- and glycyl-tRNA synthetases, human mitochondrial and cytosolic enzymes are coded by two different sets of genes.
2004
Sohm B, Sissler M, Park H, King M P, Florentz C
Recognition of human mitochondrial tRNALeu(UUR) by its cognate leucyl-tRNA synthetase Article de journal
Dans: J Mol Biol, vol. 339, non 1, p. 17-29, 2004, ISBN: 15123417, (0022-2836 Journal Article).
Résumé | Liens | BibTeX | Étiquettes: Cultured, FLORENTZ, FLORENTZ *Acylation Base Sequence Comparative Study Human Kinetics Leucine/metabolism Leucine-tRNA Ligase/genetics/*metabolism Mitochondria/*metabolism Molecular Sequence Data Mutation Nucleic Acid Conformation Osteosarcoma/metabolism RNA/*genetics/metabolism RNA, Genetic/*genetics Tumor Cells, Leu/genetics/*metabolism Solutions Substrate Specificity Support, Non-U.S. Gov't Support, P.H.S. Transcription, SISSLER, Transfer, U.S. Gov't, Unité ARN
@article{,
title = {Recognition of human mitochondrial tRNALeu(UUR) by its cognate leucyl-tRNA synthetase},
author = {B Sohm and M Sissler and H Park and M P King and C Florentz},
url = {http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=15123417},
isbn = {15123417},
year = {2004},
date = {2004-01-01},
journal = {J Mol Biol},
volume = {339},
number = {1},
pages = {17-29},
abstract = {Accuracy of protein synthesis depends on specific recognition and aminoacylation of tRNAs by their cognate aminoacyl-tRNA synthetases. Rules governing these processes have been established for numerous prokaryotic and eukaryotic cytoplasmic systems, but only limited information is available for human mitochondrial systems. It has been shown that the in vitro transcribed human mitochondrial tRNA(Leu(UUR)) does not fold into the expected cloverleaf, but is however aminoacylated by the human mitochondrial leucyl-tRNA synthetase. Here, the role of the structure of the amino acid acceptor branch and the anticodon branch of tRNA(Leu(UUR)) in recognition by leucyl-tRNA synthetase was investigated. The kinetic parameters for aminoacylation of wild-type and mutant tRNA(Leu(UUR)) transcripts and of native tRNA(Leu(UUR)) were determined. Solution structure probing was performed in the presence or in the absence of leucyl-tRNA synthetase and correlated with the aminoacylation kinetics for each tRNA. Replacement of mismatches in either the anticodon-stem or D-stem that are present in the wild-type tRNA(Leu(UUR)) by G-C base-pairs is sufficient to induce (i) cloverleaf folding, (ii) improved aminoacylation efficiency, and (iii) interactions with the synthetase that are similar to those with the native tRNA(Leu(UUR)). Leucyl-tRNA synthetase contacts tRNA(Leu(UUR)) in the amino acid acceptor stem, the anticodon stem, and the D-loop, which is unprecedented for a leucine aminoacylation system.},
note = {0022-2836
Journal Article},
keywords = {Cultured, FLORENTZ, FLORENTZ *Acylation Base Sequence Comparative Study Human Kinetics Leucine/metabolism Leucine-tRNA Ligase/genetics/*metabolism Mitochondria/*metabolism Molecular Sequence Data Mutation Nucleic Acid Conformation Osteosarcoma/metabolism RNA/*genetics/metabolism RNA, Genetic/*genetics Tumor Cells, Leu/genetics/*metabolism Solutions Substrate Specificity Support, Non-U.S. Gov't Support, P.H.S. Transcription, SISSLER, Transfer, U.S. Gov't, Unité ARN},
pubstate = {published},
tppubtype = {article}
}
Accuracy of protein synthesis depends on specific recognition and aminoacylation of tRNAs by their cognate aminoacyl-tRNA synthetases. Rules governing these processes have been established for numerous prokaryotic and eukaryotic cytoplasmic systems, but only limited information is available for human mitochondrial systems. It has been shown that the in vitro transcribed human mitochondrial tRNA(Leu(UUR)) does not fold into the expected cloverleaf, but is however aminoacylated by the human mitochondrial leucyl-tRNA synthetase. Here, the role of the structure of the amino acid acceptor branch and the anticodon branch of tRNA(Leu(UUR)) in recognition by leucyl-tRNA synthetase was investigated. The kinetic parameters for aminoacylation of wild-type and mutant tRNA(Leu(UUR)) transcripts and of native tRNA(Leu(UUR)) were determined. Solution structure probing was performed in the presence or in the absence of leucyl-tRNA synthetase and correlated with the aminoacylation kinetics for each tRNA. Replacement of mismatches in either the anticodon-stem or D-stem that are present in the wild-type tRNA(Leu(UUR)) by G-C base-pairs is sufficient to induce (i) cloverleaf folding, (ii) improved aminoacylation efficiency, and (iii) interactions with the synthetase that are similar to those with the native tRNA(Leu(UUR)). Leucyl-tRNA synthetase contacts tRNA(Leu(UUR)) in the amino acid acceptor stem, the anticodon stem, and the D-loop, which is unprecedented for a leucine aminoacylation system.
Sissler M, Helm M, Frugier M, Giege R, Florentz C
Aminoacylation properties of pathology-related human mitochondrial tRNA(Lys) variants Article de journal
Dans: RNA, vol. 10, non 5, p. 841-853, 2004, ISBN: 15100439, (1355-8382 Journal Article).
Résumé | Liens | BibTeX | Étiquettes: ERIANI, FLORENTZ, FLORENTZ GIEGE Acylation Aminoacyltransferases/*genetics Human MERRF Syndrome/genetics Mitochondria/*genetics Mitochondrial Diseases/*genetics Mutation Nucleic Acid Conformation RNA, FRUGIER, Lys/*genetics Sequence Analysis, Non-U.S. Gov't Variation (Genetics), RNA Support, SISSLER, Transfer, Unité ARN
@article{,
title = {Aminoacylation properties of pathology-related human mitochondrial tRNA(Lys) variants},
author = {M Sissler and M Helm and M Frugier and R Giege and C Florentz},
url = {http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=15100439},
isbn = {15100439},
year = {2004},
date = {2004-01-01},
journal = {RNA},
volume = {10},
number = {5},
pages = {841-853},
abstract = {In vitro transcription has proven to be a successful tool for preparation of functional RNAs, especially in the tRNA field, in which, despite the absence of post-transcriptional modifications, transcripts are correctly folded and functionally active. Human mitochondrial (mt) tRNA(Lys) deviates from this principle and folds into various inactive conformations, due to the absence of the post-transcriptional modification m(1)A9 which hinders base-pairing with U64 in the native tRNA. Unavailability of a functional transcript is a serious drawback for structure/function investigations as well as in deciphering the molecular mechanisms by which point mutations in the mt tRNA(Lys) gene cause severe human disorders. Here, we show that an engineered in vitro transcribed "pseudo-WT" tRNA(Lys) variant is efficiently recognized by lysyl-tRNA synthetase and can substitute for the WT tRNA as a valuable reference molecule. This has been exploited in a systematic analysis of the effects on aminoacylation of nine pathology-related mutations described so far. The sole mutation located in a loop of the tRNA secondary structure, A8344G, does not affect aminoacylation efficiency. Out of eight mutations located in helical domains converting canonical Watson-Crick pairs into G-U pairs or C.A mismatches, six have no effect on aminoacylation (A8296G, U8316C, G8342A, U8356C, U8362G, G8363A), and two lead to drastic decreases (5000- to 7000-fold) in lysylation efficiencies (G8313A and G8328A). This screening, allowing for analysis of the primary impact level of all mutations affecting one tRNA under comparable conditions, indicates distinct molecular origins for different disorders.},
note = {1355-8382
Journal Article},
keywords = {ERIANI, FLORENTZ, FLORENTZ GIEGE Acylation Aminoacyltransferases/*genetics Human MERRF Syndrome/genetics Mitochondria/*genetics Mitochondrial Diseases/*genetics Mutation Nucleic Acid Conformation RNA, FRUGIER, Lys/*genetics Sequence Analysis, Non-U.S. Gov't Variation (Genetics), RNA Support, SISSLER, Transfer, Unité ARN},
pubstate = {published},
tppubtype = {article}
}
In vitro transcription has proven to be a successful tool for preparation of functional RNAs, especially in the tRNA field, in which, despite the absence of post-transcriptional modifications, transcripts are correctly folded and functionally active. Human mitochondrial (mt) tRNA(Lys) deviates from this principle and folds into various inactive conformations, due to the absence of the post-transcriptional modification m(1)A9 which hinders base-pairing with U64 in the native tRNA. Unavailability of a functional transcript is a serious drawback for structure/function investigations as well as in deciphering the molecular mechanisms by which point mutations in the mt tRNA(Lys) gene cause severe human disorders. Here, we show that an engineered in vitro transcribed "pseudo-WT" tRNA(Lys) variant is efficiently recognized by lysyl-tRNA synthetase and can substitute for the WT tRNA as a valuable reference molecule. This has been exploited in a systematic analysis of the effects on aminoacylation of nine pathology-related mutations described so far. The sole mutation located in a loop of the tRNA secondary structure, A8344G, does not affect aminoacylation efficiency. Out of eight mutations located in helical domains converting canonical Watson-Crick pairs into G-U pairs or C.A mismatches, six have no effect on aminoacylation (A8296G, U8316C, G8342A, U8356C, U8362G, G8363A), and two lead to drastic decreases (5000- to 7000-fold) in lysylation efficiencies (G8313A and G8328A). This screening, allowing for analysis of the primary impact level of all mutations affecting one tRNA under comparable conditions, indicates distinct molecular origins for different disorders.
Fender A, Sissler M, Florentz C, Giege R
Functional idiosyncrasies of tRNA isoacceptors in cognate and noncognate aminoacylation systems Article de journal
Dans: Biochimie, vol. 86, non 1, p. 21-29, 2004, ISBN: 14987797, (0300-9084 Journal Article).
Résumé | Liens | BibTeX | Étiquettes: Amino Acyl/genetics/*metabolism Saccharomyces cerevisiae Substrate Specificity/genetics/physiology Support, Chemical Molecular Sequence Data Mutation Nucleic Acid Conformation Protein Binding/physiology RNA, FLORENTZ, GIEGE FLORENTZ Amino Acid Activation/physiology Amino Acyl-tRNA Ligases/*metabolism Anticodon Bacterial Proteins/metabolism Base Sequence Cloning, Molecular Computer Simulation Escherichia coli Models, Non-U.S. Gov't Thermus thermophilus, SISSLER, Transfer, Transfer/genetics/*metabolism RNA, Unité ARN
@article{,
title = {Functional idiosyncrasies of tRNA isoacceptors in cognate and noncognate aminoacylation systems},
author = {A Fender and M Sissler and C Florentz and R Giege},
url = {http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=14987797},
isbn = {14987797},
year = {2004},
date = {2004-01-01},
journal = {Biochimie},
volume = {86},
number = {1},
pages = {21-29},
abstract = {The specificity of transfer RNA aminoacylation by cognate aminoacyl-tRNA synthetase is a crucial step for synthesis of functional proteins. It is established that the aminoacylation identity of a single tRNA or of a family of tRNA isoacceptors is linked to the presence of positive signals (determinants) allowing recognition by cognate synthetases and negative signals (antideterminants) leading to rejection by the noncognate ones. The completion of identity sets was generally tested by transplantation of the corresponding nucleotides into one or several host tRNAs which acquire as a consequence the new aminoacylation specificities. Such transplantation experiments were also useful to detect peculiar structural refinements required for optimal expression of a given aminoacylation identity set within a host tRNA. This study explores expression of the defined yeast aspartate identity set into different tRNA scaffolds of a same specificity, namely the four yeast tRNA(Arg) isoacceptors. The goal was to investigate whether expression of the new identity is similar due to the unique specificity of the host tRNAs or whether it is differently expressed due to their peculiar sequences and structural features. In vitro transcribed native tRNA(Arg) isoacceptors and variants bearing the aspartate identity elements were prepared and their aminoacylation properties established. The four wild-type isoacceptors are active in arginylation with catalytic efficiencies in a 20-fold range and are inactive in aspartylation. While transplanted tRNA(1)(Arg) and tRNA(4)(Arg) are converted into highly efficient substrates for yeast aspartyl-tRNA synthetase, transplanted tRNA(2)(Arg) and tRNA(3)(Arg) remain poorly aspartylated. Search for antideterminants in these two tRNAs reveals idiosyncratic features. Conversion of the single base-pair C6-G67 into G6-C67, the pair present in tRNA(Asp), allows full expression of the aspartate identity in the transplanted tRNA(2)(Arg), but not in tRNA(3)(Arg). It is concluded that the different isoacceptor tRNAs protect themselves from misaminoacylation by idiosyncratic pathways of antidetermination.},
note = {0300-9084
Journal Article},
keywords = {Amino Acyl/genetics/*metabolism Saccharomyces cerevisiae Substrate Specificity/genetics/physiology Support, Chemical Molecular Sequence Data Mutation Nucleic Acid Conformation Protein Binding/physiology RNA, FLORENTZ, GIEGE FLORENTZ Amino Acid Activation/physiology Amino Acyl-tRNA Ligases/*metabolism Anticodon Bacterial Proteins/metabolism Base Sequence Cloning, Molecular Computer Simulation Escherichia coli Models, Non-U.S. Gov't Thermus thermophilus, SISSLER, Transfer, Transfer/genetics/*metabolism RNA, Unité ARN},
pubstate = {published},
tppubtype = {article}
}
The specificity of transfer RNA aminoacylation by cognate aminoacyl-tRNA synthetase is a crucial step for synthesis of functional proteins. It is established that the aminoacylation identity of a single tRNA or of a family of tRNA isoacceptors is linked to the presence of positive signals (determinants) allowing recognition by cognate synthetases and negative signals (antideterminants) leading to rejection by the noncognate ones. The completion of identity sets was generally tested by transplantation of the corresponding nucleotides into one or several host tRNAs which acquire as a consequence the new aminoacylation specificities. Such transplantation experiments were also useful to detect peculiar structural refinements required for optimal expression of a given aminoacylation identity set within a host tRNA. This study explores expression of the defined yeast aspartate identity set into different tRNA scaffolds of a same specificity, namely the four yeast tRNA(Arg) isoacceptors. The goal was to investigate whether expression of the new identity is similar due to the unique specificity of the host tRNAs or whether it is differently expressed due to their peculiar sequences and structural features. In vitro transcribed native tRNA(Arg) isoacceptors and variants bearing the aspartate identity elements were prepared and their aminoacylation properties established. The four wild-type isoacceptors are active in arginylation with catalytic efficiencies in a 20-fold range and are inactive in aspartylation. While transplanted tRNA(1)(Arg) and tRNA(4)(Arg) are converted into highly efficient substrates for yeast aspartyl-tRNA synthetase, transplanted tRNA(2)(Arg) and tRNA(3)(Arg) remain poorly aspartylated. Search for antideterminants in these two tRNAs reveals idiosyncratic features. Conversion of the single base-pair C6-G67 into G6-C67, the pair present in tRNA(Asp), allows full expression of the aspartate identity in the transplanted tRNA(2)(Arg), but not in tRNA(3)(Arg). It is concluded that the different isoacceptor tRNAs protect themselves from misaminoacylation by idiosyncratic pathways of antidetermination.
Fender A, Geslain R, Eriani G, Giege R, Sissler M, Florentz C
A yeast arginine specific tRNA is a remnant aspartate acceptor Article de journal
Dans: Nucleic Acids Res, vol. 32, non 17, p. 5076-5086, 2004, ISBN: 15452274, (1362-4962 Journal Article).
Résumé | Liens | BibTeX | Étiquettes: Arg/*chemistry/genetics/metabolism RNA, Asp/*chemistry/genetics/metabolism Saccharomyces cerevisiae/*genetics Sequence Alignment Support, ERIANI, ERIANI FLORENTZ GIEGE Aspartic Acid/metabolism Base Sequence *Evolution, FLORENTZ, Fungal/*chemistry/genetics/metabolism RNA, Molecular Molecular Sequence Data Point Mutation RNA, Non-U.S. Gov't, SISSLER, Transfer, Unité ARN
@article{,
title = {A yeast arginine specific tRNA is a remnant aspartate acceptor},
author = {A Fender and R Geslain and G Eriani and R Giege and M Sissler and C Florentz},
url = {http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=15452274},
isbn = {15452274},
year = {2004},
date = {2004-01-01},
journal = {Nucleic Acids Res},
volume = {32},
number = {17},
pages = {5076-5086},
abstract = {High specificity in aminoacylation of transfer RNAs (tRNAs) with the help of their cognate aminoacyl-tRNA synthetases (aaRSs) is a guarantee for accurate genetic translation. Structural and mechanistic peculiarities between the different tRNA/aaRS couples, suggest that aminoacylation systems are unrelated. However, occurrence of tRNA mischarging by non-cognate aaRSs reflects the relationship between such systems. In Saccharomyces cerevisiae, functional links between arginylation and aspartylation systems have been reported. In particular, it was found that an in vitro transcribed tRNAAsp is a very efficient substrate for ArgRS. In this study, the relationship of arginine and aspartate systems is further explored, based on the discovery of a fourth isoacceptor in the yeast genome, tRNA4Arg. This tRNA has a sequence strikingly similar to that of tRNAAsp but distinct from those of the other three arginine isoacceptors. After transplantation of the full set of aspartate identity elements into the four arginine isoacceptors, tRNA4Arg gains the highest aspartylation efficiency. Moreover, it is possible to convert tRNA4Arg into an aspartate acceptor, as efficient as tRNAAsp, by only two point mutations, C38 and G73, despite the absence of the major anticodon aspartate identity elements. Thus, cryptic aspartate identity elements are embedded within tRNA4Arg. The latent aspartate acceptor capacity in a contemporary tRNAArg leads to the proposal of an evolutionary link between tRNA4Arg and tRNAAsp genes.},
note = {1362-4962
Journal Article},
keywords = {Arg/*chemistry/genetics/metabolism RNA, Asp/*chemistry/genetics/metabolism Saccharomyces cerevisiae/*genetics Sequence Alignment Support, ERIANI, ERIANI FLORENTZ GIEGE Aspartic Acid/metabolism Base Sequence *Evolution, FLORENTZ, Fungal/*chemistry/genetics/metabolism RNA, Molecular Molecular Sequence Data Point Mutation RNA, Non-U.S. Gov't, SISSLER, Transfer, Unité ARN},
pubstate = {published},
tppubtype = {article}
}
High specificity in aminoacylation of transfer RNAs (tRNAs) with the help of their cognate aminoacyl-tRNA synthetases (aaRSs) is a guarantee for accurate genetic translation. Structural and mechanistic peculiarities between the different tRNA/aaRS couples, suggest that aminoacylation systems are unrelated. However, occurrence of tRNA mischarging by non-cognate aaRSs reflects the relationship between such systems. In Saccharomyces cerevisiae, functional links between arginylation and aspartylation systems have been reported. In particular, it was found that an in vitro transcribed tRNAAsp is a very efficient substrate for ArgRS. In this study, the relationship of arginine and aspartate systems is further explored, based on the discovery of a fourth isoacceptor in the yeast genome, tRNA4Arg. This tRNA has a sequence strikingly similar to that of tRNAAsp but distinct from those of the other three arginine isoacceptors. After transplantation of the full set of aspartate identity elements into the four arginine isoacceptors, tRNA4Arg gains the highest aspartylation efficiency. Moreover, it is possible to convert tRNA4Arg into an aspartate acceptor, as efficient as tRNAAsp, by only two point mutations, C38 and G73, despite the absence of the major anticodon aspartate identity elements. Thus, cryptic aspartate identity elements are embedded within tRNA4Arg. The latent aspartate acceptor capacity in a contemporary tRNAArg leads to the proposal of an evolutionary link between tRNA4Arg and tRNAAsp genes.
2003
Florentz C, Sohm B, Tryoen-Toth P, Putz J, Sissler M
Human mitochondrial tRNAs in health and disease Article de journal
Dans: Cell Mol Life Sci, vol. 60, non 7, p. 1356-1375, 2003, ISBN: 12943225, (1420-682x Journal Article Review Review, Academic).
Résumé | Liens | BibTeX | Étiquettes: Base Sequence Genetic Diseases, FLORENTZ, Genetic, Inborn/*genetics Genome Human Mitochondria/*genetics Molecular Sequence Data Nucleic Acid Conformation RNA/chemistry/*genetics RNA, Messenger/genetics/metabolism RNA, Non-U.S. Gov't Translation, SISSLER, Transfer/chemistry/*genetics Reference Values Support, Unité ARN
@article{,
title = {Human mitochondrial tRNAs in health and disease},
author = {C Florentz and B Sohm and P Tryoen-Toth and J Putz and M Sissler},
url = {http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=12943225},
isbn = {12943225},
year = {2003},
date = {2003-01-01},
journal = {Cell Mol Life Sci},
volume = {60},
number = {7},
pages = {1356-1375},
abstract = {The human mitochondrial genome encodes 13 proteins, all subunits of the respiratory chain complexes and thus involved in energy metabolism. These genes are translated by 22 transfer RNAs (tRNAs), also encoded by the mitochondrial genome, which form the minimal set required for reading all codons. Human mitochondrial tRNAs gained interest with the rapid discovery of correlations between point mutations in their genes and various neuromuscular and neurodegenerative disorders. In this review, emerging fundamental knowledge on the structure/function relationships of these particular tRNAs and an overview of the large variety of mechanisms within translation, affected by mutations, are summarized. Also, initial results on wide-ranging molecular consequences of mutations outside the frame of mitochondrial translation are highlighted. While knowledge of mitochondrial tRNAs in both health and disease increases, deciphering the intricate network of events leading different genotypes to the variety of phenotypes requires further investigation using adapted model systems.},
note = {1420-682x
Journal Article
Review
Review, Academic},
keywords = {Base Sequence Genetic Diseases, FLORENTZ, Genetic, Inborn/*genetics Genome Human Mitochondria/*genetics Molecular Sequence Data Nucleic Acid Conformation RNA/chemistry/*genetics RNA, Messenger/genetics/metabolism RNA, Non-U.S. Gov't Translation, SISSLER, Transfer/chemistry/*genetics Reference Values Support, Unité ARN},
pubstate = {published},
tppubtype = {article}
}
The human mitochondrial genome encodes 13 proteins, all subunits of the respiratory chain complexes and thus involved in energy metabolism. These genes are translated by 22 transfer RNAs (tRNAs), also encoded by the mitochondrial genome, which form the minimal set required for reading all codons. Human mitochondrial tRNAs gained interest with the rapid discovery of correlations between point mutations in their genes and various neuromuscular and neurodegenerative disorders. In this review, emerging fundamental knowledge on the structure/function relationships of these particular tRNAs and an overview of the large variety of mechanisms within translation, affected by mutations, are summarized. Also, initial results on wide-ranging molecular consequences of mutations outside the frame of mitochondrial translation are highlighted. While knowledge of mitochondrial tRNAs in both health and disease increases, deciphering the intricate network of events leading different genotypes to the variety of phenotypes requires further investigation using adapted model systems.
Florentz C, Sissler M
Mitochondrial tRNA aminoacylation and human diseases. Chapitre d'ouvrage
Dans: Lapointe, J; Brakier-Gringas, L (Ed.): Translation Mechanisms, p. 129-143, Landes Bioscience, 2003.
Résumé | Liens | BibTeX | Étiquettes: FLORENTZ, SISSLER, Unité ARN
@inbook{,
title = {Mitochondrial tRNA aminoacylation and human diseases.},
author = {C Florentz and M Sissler},
editor = {J Lapointe and L Brakier-Gringas},
url = {http://www.landesbioscience.com/curie/chapter/911},
year = {2003},
date = {2003-01-01},
booktitle = {Translation Mechanisms},
pages = {129-143},
publisher = {Landes Bioscience},
abstract = {The human mitochondrial (mt) genome encodes for only 13 proteins which are all subunits of transmembranar respiratory chain complexes. These complexes contribute to a major mt functions namely the synthesis of energy in the way of ATP. Translation of the mRNAs is performed by a set of 22 tRNAs, also encoded by the mt genome, and aminoacylated by nuclear encoded aminoacyl-tRNA synthetases imported into the mitochondria. More and more point mutations affecting mt tRNA genes are reported as correlated to severe neurodegenerative disorders. Since these mutations generally lead to decreased mt protein synthesis, understanding the genotype/phenotype relationships is primarily based on investigation of the possible impacts of individual mutations on various aspects of tRNA structural and functional properties. Here, the present knowledge on human mt aminoacylation systems, as well as the strategies developed to investigate mt aminoacylation, and the effects of point mutations in tRNAs on this process are reviewed. The diversity in the effects observed so far, for a same mutation as well as for various mutations, highlights the ongoing technical limitations in studying human mt aminoacylation. They also suggest that aminoacylation may be a focus for therapeutic strategies for some mutations, while the impact of other mutations needs to be searched as well at other levels of the tRNA structure/function relationship as at unforeseen levels in mitochondria.},
keywords = {FLORENTZ, SISSLER, Unité ARN},
pubstate = {published},
tppubtype = {inbook}
}
The human mitochondrial (mt) genome encodes for only 13 proteins which are all subunits of transmembranar respiratory chain complexes. These complexes contribute to a major mt functions namely the synthesis of energy in the way of ATP. Translation of the mRNAs is performed by a set of 22 tRNAs, also encoded by the mt genome, and aminoacylated by nuclear encoded aminoacyl-tRNA synthetases imported into the mitochondria. More and more point mutations affecting mt tRNA genes are reported as correlated to severe neurodegenerative disorders. Since these mutations generally lead to decreased mt protein synthesis, understanding the genotype/phenotype relationships is primarily based on investigation of the possible impacts of individual mutations on various aspects of tRNA structural and functional properties. Here, the present knowledge on human mt aminoacylation systems, as well as the strategies developed to investigate mt aminoacylation, and the effects of point mutations in tRNAs on this process are reviewed. The diversity in the effects observed so far, for a same mutation as well as for various mutations, highlights the ongoing technical limitations in studying human mt aminoacylation. They also suggest that aminoacylation may be a focus for therapeutic strategies for some mutations, while the impact of other mutations needs to be searched as well at other levels of the tRNA structure/function relationship as at unforeseen levels in mitochondria.
1997
Sissler M, Eriani G, Martin F, Giege R, Florentz C
Mirror image alternative interaction patterns of the same tRNA with either class I arginyl-tRNA synthetase or class II aspartyl-tRNA synthetase Article de journal
Dans: Nucleic Acids Res, vol. 25, non 24, p. 4899-4906, 1997, ISBN: 9396794, (0305-1048 Journal Article).
Résumé | Liens | BibTeX | Étiquettes: Anticodon/chemistry Arginine-tRNA Ligase/classification/*metabolism Aspartate-tRNA Ligase/classification/*metabolism Base Sequence DNA Footprinting Escherichia coli Fungal Proteins/classification/*metabolism Models, Arg/chemistry/*metabolism RNA, Asp/chemistry/*metabolism Recombinant Fusion Proteins/metabolism Saccharomyces cerevisiae/metabolism Stereoisomerism Substrate Specificity Support, ERIANI, FLORENTZ, Fungal/chemistry/*metabolism RNA, Molecular Molecular Sequence Data *Nucleic Acid Conformation Protein Binding RNA, Non-U.S. Gov't, SISSLER, Transfer, Unité ARN
@article{,
title = {Mirror image alternative interaction patterns of the same tRNA with either class I arginyl-tRNA synthetase or class II aspartyl-tRNA synthetase},
author = {M Sissler and G Eriani and F Martin and R Giege and C Florentz},
url = {http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=9396794},
isbn = {9396794},
year = {1997},
date = {1997-01-01},
journal = {Nucleic Acids Res},
volume = {25},
number = {24},
pages = {4899-4906},
abstract = {Gene cloning, overproduction and an efficient purification protocol of yeast arginyl-tRNA synthetase (ArgRS) as well as the interaction patterns of this protein with cognate tRNAArgand non-cognate tRNAAspare described. This work was motivated by the fact that the in vitro transcript of tRNAAspis of dual aminoacylation specificity and is not only aspartylated but also efficiently arginylated. The crystal structure of the complex between class II aspartyl-tRNA synthetase (AspRS) and tRNAAsp, as well as early biochemical data, have shown that tRNAAspis recognized by its variable region side. Here we show by footprinting with enzymatic and chemical probes that transcribed tRNAAspis contacted by class I ArgRS along the opposite D arm side, as is homologous tRNAArg, but with idiosyncratic interaction patterns. Besides protection, footprints also show enhanced accessibility of the tRNAs to the structural probes, indicative of conformational changes in the complexed tRNAs. These different patterns are interpreted in relation to the alternative arginine identity sets found in the anticodon loops of tRNAArgand tRNAAsp. The mirror image alternative interaction patterns of unmodified tRNAAspwith either class I ArgRS or class II AspRS, accounting for the dual identity of this tRNA, are discussed in relation to the class defining features of the synthetases. This study indicates that complex formation between unmodified tRNAAspand either ArgRS and AspRS is solely governed by the proteins.},
note = {0305-1048
Journal Article},
keywords = {Anticodon/chemistry Arginine-tRNA Ligase/classification/*metabolism Aspartate-tRNA Ligase/classification/*metabolism Base Sequence DNA Footprinting Escherichia coli Fungal Proteins/classification/*metabolism Models, Arg/chemistry/*metabolism RNA, Asp/chemistry/*metabolism Recombinant Fusion Proteins/metabolism Saccharomyces cerevisiae/metabolism Stereoisomerism Substrate Specificity Support, ERIANI, FLORENTZ, Fungal/chemistry/*metabolism RNA, Molecular Molecular Sequence Data *Nucleic Acid Conformation Protein Binding RNA, Non-U.S. Gov't, SISSLER, Transfer, Unité ARN},
pubstate = {published},
tppubtype = {article}
}
Gene cloning, overproduction and an efficient purification protocol of yeast arginyl-tRNA synthetase (ArgRS) as well as the interaction patterns of this protein with cognate tRNAArgand non-cognate tRNAAspare described. This work was motivated by the fact that the in vitro transcript of tRNAAspis of dual aminoacylation specificity and is not only aspartylated but also efficiently arginylated. The crystal structure of the complex between class II aspartyl-tRNA synthetase (AspRS) and tRNAAsp, as well as early biochemical data, have shown that tRNAAspis recognized by its variable region side. Here we show by footprinting with enzymatic and chemical probes that transcribed tRNAAspis contacted by class I ArgRS along the opposite D arm side, as is homologous tRNAArg, but with idiosyncratic interaction patterns. Besides protection, footprints also show enhanced accessibility of the tRNAs to the structural probes, indicative of conformational changes in the complexed tRNAs. These different patterns are interpreted in relation to the alternative arginine identity sets found in the anticodon loops of tRNAArgand tRNAAsp. The mirror image alternative interaction patterns of unmodified tRNAAspwith either class I ArgRS or class II AspRS, accounting for the dual identity of this tRNA, are discussed in relation to the class defining features of the synthetases. This study indicates that complex formation between unmodified tRNAAspand either ArgRS and AspRS is solely governed by the proteins.
Putz J, Wientges J, Sissler M, Giege R, Florentz C, Schwienhorst A
Rapid selection of aminoacyl-tRNAs based on biotinylation of alpha-NH2 group of charged amino acids Article de journal
Dans: Nucleic Acids Res, vol. 25, non 9, p. 1862-1863, 1997, ISBN: 9162902, (0305-1048 Journal Article).
Résumé | Liens | BibTeX | Étiquettes: Amino Acids/*chemistry Biotin/*chemistry Polymerase Chain Reaction RNA, Amino Acyl/chemistry/*isolation & purification Support, FLORENTZ, Non-U.S. Gov't, SISSLER, Transfer, Unité ARN
@article{,
title = {Rapid selection of aminoacyl-tRNAs based on biotinylation of alpha-NH2 group of charged amino acids},
author = {J Putz and J Wientges and M Sissler and R Giege and C Florentz and A Schwienhorst},
url = {http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=9162902},
isbn = {9162902},
year = {1997},
date = {1997-01-01},
journal = {Nucleic Acids Res},
volume = {25},
number = {9},
pages = {1862-1863},
abstract = {A rapid selection procedure to separate low amounts of aminoacylated tRNAs from large pools of inactive variants is described. The procedure involves a three-step protocol. After initial aminoacylation of a tRNA pool, N-hydroxysuccinimide ester chemistry is applied to biotinylate the alpha-NH2 group of the amino acid bound to the 3'-end of a tRNA. The biotin tag is used to capture the derivatized tRNAs on streptavidin-conjugated magnetic beads. Variants bound to the solid phase can be amplified by RT-PCR and transcription, providing tRNAs for subsequent selection rounds.},
note = {0305-1048
Journal Article},
keywords = {Amino Acids/*chemistry Biotin/*chemistry Polymerase Chain Reaction RNA, Amino Acyl/chemistry/*isolation & purification Support, FLORENTZ, Non-U.S. Gov't, SISSLER, Transfer, Unité ARN},
pubstate = {published},
tppubtype = {article}
}
A rapid selection procedure to separate low amounts of aminoacylated tRNAs from large pools of inactive variants is described. The procedure involves a three-step protocol. After initial aminoacylation of a tRNA pool, N-hydroxysuccinimide ester chemistry is applied to biotinylate the alpha-NH2 group of the amino acid bound to the 3'-end of a tRNA. The biotin tag is used to capture the derivatized tRNAs on streptavidin-conjugated magnetic beads. Variants bound to the solid phase can be amplified by RT-PCR and transcription, providing tRNAs for subsequent selection rounds.
Becker H F, Motorin Y, Sissler M, Florentz C, Grosjean H
Major identity determinants for enzymatic formation of ribothymidine and pseudouridine in the T psi-loop of yeast tRNAs Article de journal
Dans: J Mol Biol, vol. 274, non 4, p. 505-518, 1997, ISBN: 9417931, (0022-2836 Journal Article).
Résumé | Liens | BibTeX | Étiquettes: Asp/chemistry/metabolism Saccharomyces cerevisiae/genetics Substrate Specificity Support, Base Sequence Conserved Sequence Intramolecular Lyases/metabolism Models, FLORENTZ, Fungal/*chemistry/metabolism RNA, Molecular Molecular Sequence Data Nucleic Acid Conformation Pseudouridine/chemistry/*metabolism RNA, Non-U.S. Gov't Uridine/*analogs & derivatives/chemistry/metabolism tRNA Methyltransferases/metabolism, SISSLER, Transfer, Transfer/*chemistry/*metabolism RNA, Unité ARN
@article{,
title = {Major identity determinants for enzymatic formation of ribothymidine and pseudouridine in the T psi-loop of yeast tRNAs},
author = {H F Becker and Y Motorin and M Sissler and C Florentz and H Grosjean},
url = {http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=9417931},
isbn = {9417931},
year = {1997},
date = {1997-01-01},
journal = {J Mol Biol},
volume = {274},
number = {4},
pages = {505-518},
abstract = {Almost all transfer RNA molecules sequenced so far contain two universal modified nucleosides at positions 54 and 55, respectively: ribothymidine (T54) and pseudouridine (psi 55). To identify the tRNA elements recognized by tRNA:m5uridine-54 methyltransferase and tRNA:pseudouridine-55 synthase from the yeast Saccharomyces cerevisiae, a set of 43 yeast tRNA(Asp) mutants were used. Some variants contained point mutations, while the others included progressive reductions in size down to a tRNA minisubstrate consisting of the T psi-loop with only one G.C base-pair as stem (9-mer). All substrates (full-sized tRNA(Asp) and various minihelices) were produced in vitro by T7 transcription and tested using yeast extract (S100) as a source of enzymatic activities and S-adenosyl-L-methionine as a methyl donor. The results indicate that the minimal substrate for enzymatic formation of psi 55 is a stem/loop structure with only four G.C base-pairs in the stem, while a longer stem is required for efficient T54 formation. None of the conserved nucleotides (G53, C56, A58 and C61) and U54 for psi 55 or U55 for T54 formation can be replaced by any of the other three canonical nucleotides. Yeast tRNA:m5uridine-54 methyltransferase additionally requires the presence of a pyrimidine-60 in the loop. Interestingly, in a tRNA(Asp) variant in which the T psi-loop was permuted with the anticodon-loop, the new U32 and U33 residues derived from the T psi-loop were quantitatively converted to T32 and psi 33, respectively. Structural mapping of this variant with ethylnitrosourea confirmed that the intrinsic characteristic structure of the T psi-loop was conserved upon permutation and that the displaced anticodon-loop did not acquire a T psi-loop structure. These results demonstrate that a local conformation rather than the exact location of the U-U sequence within the tRNA architecture is the important identity determinant for recognition by yeast tRNA:m5uridine-54 methyltransferase and tRNA:pseudouridine-55 synthase.},
note = {0022-2836
Journal Article},
keywords = {Asp/chemistry/metabolism Saccharomyces cerevisiae/genetics Substrate Specificity Support, Base Sequence Conserved Sequence Intramolecular Lyases/metabolism Models, FLORENTZ, Fungal/*chemistry/metabolism RNA, Molecular Molecular Sequence Data Nucleic Acid Conformation Pseudouridine/chemistry/*metabolism RNA, Non-U.S. Gov't Uridine/*analogs & derivatives/chemistry/metabolism tRNA Methyltransferases/metabolism, SISSLER, Transfer, Transfer/*chemistry/*metabolism RNA, Unité ARN},
pubstate = {published},
tppubtype = {article}
}
Almost all transfer RNA molecules sequenced so far contain two universal modified nucleosides at positions 54 and 55, respectively: ribothymidine (T54) and pseudouridine (psi 55). To identify the tRNA elements recognized by tRNA:m5uridine-54 methyltransferase and tRNA:pseudouridine-55 synthase from the yeast Saccharomyces cerevisiae, a set of 43 yeast tRNA(Asp) mutants were used. Some variants contained point mutations, while the others included progressive reductions in size down to a tRNA minisubstrate consisting of the T psi-loop with only one G.C base-pair as stem (9-mer). All substrates (full-sized tRNA(Asp) and various minihelices) were produced in vitro by T7 transcription and tested using yeast extract (S100) as a source of enzymatic activities and S-adenosyl-L-methionine as a methyl donor. The results indicate that the minimal substrate for enzymatic formation of psi 55 is a stem/loop structure with only four G.C base-pairs in the stem, while a longer stem is required for efficient T54 formation. None of the conserved nucleotides (G53, C56, A58 and C61) and U54 for psi 55 or U55 for T54 formation can be replaced by any of the other three canonical nucleotides. Yeast tRNA:m5uridine-54 methyltransferase additionally requires the presence of a pyrimidine-60 in the loop. Interestingly, in a tRNA(Asp) variant in which the T psi-loop was permuted with the anticodon-loop, the new U32 and U33 residues derived from the T psi-loop were quantitatively converted to T32 and psi 33, respectively. Structural mapping of this variant with ethylnitrosourea confirmed that the intrinsic characteristic structure of the T psi-loop was conserved upon permutation and that the displaced anticodon-loop did not acquire a T psi-loop structure. These results demonstrate that a local conformation rather than the exact location of the U-U sequence within the tRNA architecture is the important identity determinant for recognition by yeast tRNA:m5uridine-54 methyltransferase and tRNA:pseudouridine-55 synthase.
1996
Sissler M, Giege R, Florentz C
Arginine aminoacylation identity is context-dependent and ensured by alternate recognition sets in the anticodon loop of accepting tRNA transcripts Article de journal
Dans: EMBO J, vol. 15, non 18, p. 5069-5076, 1996, ISBN: 8890180, (0261-4189 Journal Article).
Résumé | Liens | BibTeX | Étiquettes: *Anticodon Arginine/*metabolism Base Sequence Kinetics Molecular Sequence Data Nucleic Acid Conformation RNA, Arg/*chemistry/metabolism RNA, Asp/chemistry/metabolism Saccharomyces cerevisiae Support, FLORENTZ, Fungal/*chemistry/metabolism RNA, Non-U.S. Gov't, SISSLER, Transfer, Unité ARN
@article{,
title = {Arginine aminoacylation identity is context-dependent and ensured by alternate recognition sets in the anticodon loop of accepting tRNA transcripts},
author = {M Sissler and R Giege and C Florentz},
url = {http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=8890180},
isbn = {8890180},
year = {1996},
date = {1996-01-01},
journal = {EMBO J},
volume = {15},
number = {18},
pages = {5069-5076},
abstract = {Yeast arginyl-tRNA synthetase recognizes the non-modified wild-type transcripts derived from both yeast tRNA(Arg) and tRNA(Asp) with equal efficiency. It discriminates its cognate natural substrate, tRNA(Arg), from non-cognate tRNA(Asp) by a negative discrimination mechanism whereby a single methyl group acts as an anti-determinant. Considering these facts, recognition elements responsible for specific arginylation in yeast have been searched by studying the in vitro arginylation properties of a series of transcripts derived from yeast tRNA(Asp), considered as an arginine isoacceptor tRNA. In parallel, experiments on similar tRNA(Arg) transcripts were performed. Unexpectedly, in the tRNA(Arg) context, arginylation is basically linked to the presence of residue C35, whereas in the tRNA(Asp) context, it is deeply related to that of C36 and G37 but is insensitive to the nucleotide at position 35. Each of these nucleotides present in one host, is absent in the other host tRNA. Thus, arginine identity is dependent on two different specific recognition sets according to the tRNA framework investigated.},
note = {0261-4189
Journal Article},
keywords = {*Anticodon Arginine/*metabolism Base Sequence Kinetics Molecular Sequence Data Nucleic Acid Conformation RNA, Arg/*chemistry/metabolism RNA, Asp/chemistry/metabolism Saccharomyces cerevisiae Support, FLORENTZ, Fungal/*chemistry/metabolism RNA, Non-U.S. Gov't, SISSLER, Transfer, Unité ARN},
pubstate = {published},
tppubtype = {article}
}
Yeast arginyl-tRNA synthetase recognizes the non-modified wild-type transcripts derived from both yeast tRNA(Arg) and tRNA(Asp) with equal efficiency. It discriminates its cognate natural substrate, tRNA(Arg), from non-cognate tRNA(Asp) by a negative discrimination mechanism whereby a single methyl group acts as an anti-determinant. Considering these facts, recognition elements responsible for specific arginylation in yeast have been searched by studying the in vitro arginylation properties of a series of transcripts derived from yeast tRNA(Asp), considered as an arginine isoacceptor tRNA. In parallel, experiments on similar tRNA(Arg) transcripts were performed. Unexpectedly, in the tRNA(Arg) context, arginylation is basically linked to the presence of residue C35, whereas in the tRNA(Asp) context, it is deeply related to that of C36 and G37 but is insensitive to the nucleotide at position 35. Each of these nucleotides present in one host, is absent in the other host tRNA. Thus, arginine identity is dependent on two different specific recognition sets according to the tRNA framework investigated.
