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Immunologie, Immunopathologie et Chimie Thérapeutique
Publications
2008
Geary C., Baudrey S., Jaeger L.
Comprehensive features of natural and in vitro selected GNRA tetraloop-binding receptors Article de journal
Dans: Nucleic Acids Res, vol. 36, non 4, p. 1138-52, 2008, (1362-4962 (Electronic) Journal Article Research Support, N.I.H., Extramural Research Support, U.S. Gov't, Non-P.H.S.).
Résumé | BibTeX | Étiquettes: Acid, Adenine/chemistry, Analysis, Base, Conformation, Data, dimerization, directed, Evolution, KROL, Models, Molecular, Nucleic, RNA, RNA/*chemistry/classification, Sequence, Thermodynamics
@article{,
title = {Comprehensive features of natural and in vitro selected GNRA tetraloop-binding receptors},
author = { C. Geary and S. Baudrey and L. Jaeger},
year = {2008},
date = {2008-01-01},
journal = {Nucleic Acids Res},
volume = {36},
number = {4},
pages = {1138-52},
abstract = {Specific recognitions of GNRA tetraloops by small helical receptors are among the most widespread long-range packing interactions in large ribozymes. However, in contrast to GYRA and GAAA tetraloops, very few GNRA/receptor interactions have yet been identified to involve GGAA tetraloops in nature. A novel in vitro selection scheme based on a rigid self-assembling tectoRNA scaffold designed for isolation of intermolecular interactions with A-minor motifs has yielded new GGAA tetraloop-binding receptors with affinity in the nanomolar range. One of the selected receptors is a novel 12 nt RNA motif, (CCUGUG. AUCUGG), that recognizes GGAA tetraloop hairpin with a remarkable specificity and affinity. Its physical and chemical characteristics are comparable to those of the well-studied '11nt' GAAA tetraloop receptor motif. A second less specific motif (CCCAGCCC. GAUAGGG) binds GGRA tetraloops and appears to be related to group IC3 tetraloop receptors. Mutational, thermodynamic and comparative structural analysis suggests that natural and in vitro selected GNRA receptors can essentially be grouped in two major classes of GNRA binders. New insights about the evolution, recognition and structural modularity of GNRA and A-minor RNA-RNA interactions are proposed.},
note = {1362-4962 (Electronic)
Journal Article
Research Support, N.I.H., Extramural
Research Support, U.S. Gov't, Non-P.H.S.},
keywords = {Acid, Adenine/chemistry, Analysis, Base, Conformation, Data, dimerization, directed, Evolution, KROL, Models, Molecular, Nucleic, RNA, RNA/*chemistry/classification, Sequence, Thermodynamics},
pubstate = {published},
tppubtype = {article}
}
Specific recognitions of GNRA tetraloops by small helical receptors are among the most widespread long-range packing interactions in large ribozymes. However, in contrast to GYRA and GAAA tetraloops, very few GNRA/receptor interactions have yet been identified to involve GGAA tetraloops in nature. A novel in vitro selection scheme based on a rigid self-assembling tectoRNA scaffold designed for isolation of intermolecular interactions with A-minor motifs has yielded new GGAA tetraloop-binding receptors with affinity in the nanomolar range. One of the selected receptors is a novel 12 nt RNA motif, (CCUGUG. AUCUGG), that recognizes GGAA tetraloop hairpin with a remarkable specificity and affinity. Its physical and chemical characteristics are comparable to those of the well-studied '11nt' GAAA tetraloop receptor motif. A second less specific motif (CCCAGCCC. GAUAGGG) binds GGRA tetraloops and appears to be related to group IC3 tetraloop receptors. Mutational, thermodynamic and comparative structural analysis suggests that natural and in vitro selected GNRA receptors can essentially be grouped in two major classes of GNRA binders. New insights about the evolution, recognition and structural modularity of GNRA and A-minor RNA-RNA interactions are proposed.
2007
Mandin P., Repoila F., Vergassola M., Geissmann T., Cossart P.
Identification of new noncoding RNAs in Listeria monocytogenes and prediction of mRNA targets Article de journal
Dans: Nucleic Acids Res, vol. 35, non 3, p. 962-74, 2007, (1362-4962 (Electronic) Journal Article Research Support, Non-U.S. Gov't).
Résumé | BibTeX | Étiquettes: 5', Assay, Bacterial, Base, Biology, Computational, Data, DNA, Electrophoretic, Flanking, Genes, Genomics, Intergenic/chemistry, Listeria, Messenger/chemistry/*metabolism, Mobility, Molecular, monocytogenes/*genetics/metabolism, Region, RNA, ROMBY, Sequence, Shift, Untranslated/analysis/*genetics/metabolism
@article{,
title = {Identification of new noncoding RNAs in Listeria monocytogenes and prediction of mRNA targets},
author = { P. Mandin and F. Repoila and M. Vergassola and T. Geissmann and P. Cossart},
year = {2007},
date = {2007-01-01},
journal = {Nucleic Acids Res},
volume = {35},
number = {3},
pages = {962-74},
abstract = {To identify noncoding RNAs (ncRNAs) in the pathogenic bacterium Listeria monocytogenes, we analyzed the intergenic regions (IGRs) of strain EGD-e by in silico-based approaches. Among the twelve ncRNAs found, nine are novel and specific to the Listeria genus, and two of these ncRNAs are expressed in a growth-dependent manner. Three of the ncRNAs are transcribed in opposite direction to overlapping open reading frames (ORFs), suggesting that they act as antisense on the corresponding mRNAs. The other ncRNA genes appear as single transcription units. One of them displays five repeats of 29 nucleotides. Five of these new ncRNAs are absent from the non-pathogenic species L. innocua, raising the possibility that they might be involved in virulence. To predict mRNA targets of the ncRNAs, we developed a computational method based on thermodynamic pairing energies and known ncRNA-mRNA hybrids. Three ncRNAs, including one of the putative antisense ncRNAs, were predicted to have more than one mRNA targets. Several of them were shown to bind efficiently to the ncRNAs suggesting that our in silico approach could be used as a general tool to search for mRNA targets of ncRNAs.},
note = {1362-4962 (Electronic)
Journal Article
Research Support, Non-U.S. Gov't},
keywords = {5', Assay, Bacterial, Base, Biology, Computational, Data, DNA, Electrophoretic, Flanking, Genes, Genomics, Intergenic/chemistry, Listeria, Messenger/chemistry/*metabolism, Mobility, Molecular, monocytogenes/*genetics/metabolism, Region, RNA, ROMBY, Sequence, Shift, Untranslated/analysis/*genetics/metabolism},
pubstate = {published},
tppubtype = {article}
}
To identify noncoding RNAs (ncRNAs) in the pathogenic bacterium Listeria monocytogenes, we analyzed the intergenic regions (IGRs) of strain EGD-e by in silico-based approaches. Among the twelve ncRNAs found, nine are novel and specific to the Listeria genus, and two of these ncRNAs are expressed in a growth-dependent manner. Three of the ncRNAs are transcribed in opposite direction to overlapping open reading frames (ORFs), suggesting that they act as antisense on the corresponding mRNAs. The other ncRNA genes appear as single transcription units. One of them displays five repeats of 29 nucleotides. Five of these new ncRNAs are absent from the non-pathogenic species L. innocua, raising the possibility that they might be involved in virulence. To predict mRNA targets of the ncRNAs, we developed a computational method based on thermodynamic pairing energies and known ncRNA-mRNA hybrids. Three ncRNAs, including one of the putative antisense ncRNAs, were predicted to have more than one mRNA targets. Several of them were shown to bind efficiently to the ncRNAs suggesting that our in silico approach could be used as a general tool to search for mRNA targets of ncRNAs.
2004
Grosjean H., Keith G., Droogmans L.
Detection and quantification of modified nucleotides in RNA using thin-layer chromatography Book Section
Dans: Gott, J. M. (Ed.): RNA Interference, Editing, and Modification: Methods and Protocols, vol. 265, p. 357-91, Springer Protocols, Humana Press, 2004.
Résumé | BibTeX | Étiquettes: &, 5', acids, and, Base, Chromatography, Composition, Deoxyribonucleotides/chemistry/isolation, DNA/chemistry/genetics/isolation, Endoribonucleases, Gov't, Indicators, Isotope, KEITH, Labeling/methods, Layer/methods, Non-U.S., Nucleic, Oligoribonucleotides/chemistry/isolation, Peptide, purification, Radioisotopes, Reagents, Regions/chemistry, Ribonucleotides/*analysis, RNA/*genetics/isolation, Support, Thin, Untranslated
@incollection{,
title = {Detection and quantification of modified nucleotides in RNA using thin-layer chromatography},
author = { H. Grosjean and G. Keith and L. Droogmans},
editor = { J.M. Gott},
year = {2004},
date = {2004-01-01},
booktitle = {RNA Interference, Editing, and Modification: Methods and Protocols},
volume = {265},
pages = {357-91},
publisher = {Springer Protocols, Humana Press},
series = {Methods in Molecular Biology},
abstract = {Identification of a modified nucleotide and its localization within an RNA molecule is a difficult task. Only direct sequencing of purified RNA molecules and high-performance liquid chromatography mass spectrometry analysis of purified RNA fragments allow determination of both the type and location of a given modified nucleotide within an RNA of 50-150 nt in length. The objective of this chapter is to describe in detail a few simple procedures that we have found particularly suited for the detection, localization, and quantification of modified nucleotides within an RNA of known sequence. The methods can also be used to reveal the enzymatic activity of a particular RNA-modifying enzyme in vitro or in vivo. The procedures are based on the use of radiolabeled RNA (with [32P], [14C], or [3H]) or [32P]-postlabeled oligonucleotides and two-dimensional thin-layer chromatography of labeled nucleotides on cellulose plates. This chapter provides useful maps of the migration characteristics of 70 modified nucleotides on thin-layer cellulose plates.},
keywords = {&, 5', acids, and, Base, Chromatography, Composition, Deoxyribonucleotides/chemistry/isolation, DNA/chemistry/genetics/isolation, Endoribonucleases, Gov't, Indicators, Isotope, KEITH, Labeling/methods, Layer/methods, Non-U.S., Nucleic, Oligoribonucleotides/chemistry/isolation, Peptide, purification, Radioisotopes, Reagents, Regions/chemistry, Ribonucleotides/*analysis, RNA/*genetics/isolation, Support, Thin, Untranslated},
pubstate = {published},
tppubtype = {incollection}
}
Identification of a modified nucleotide and its localization within an RNA molecule is a difficult task. Only direct sequencing of purified RNA molecules and high-performance liquid chromatography mass spectrometry analysis of purified RNA fragments allow determination of both the type and location of a given modified nucleotide within an RNA of 50-150 nt in length. The objective of this chapter is to describe in detail a few simple procedures that we have found particularly suited for the detection, localization, and quantification of modified nucleotides within an RNA of known sequence. The methods can also be used to reveal the enzymatic activity of a particular RNA-modifying enzyme in vitro or in vivo. The procedures are based on the use of radiolabeled RNA (with [32P], [14C], or [3H]) or [32P]-postlabeled oligonucleotides and two-dimensional thin-layer chromatography of labeled nucleotides on cellulose plates. This chapter provides useful maps of the migration characteristics of 70 modified nucleotides on thin-layer cellulose plates.
Martineau Y., Bec C. Le, Monbrun L., Allo V., Chiu I. M., Danos O., Moine H., Prats H., Prats A. C.
Internal ribosome entry site structural motifs conserved among mammalian fibroblast growth factor 1 alternatively spliced mRNAs Article de journal
Dans: Mol Cell Biol, vol. 24, non 17, p. 7622-35, 2004, (0270-7306 Journal Article).
Résumé | BibTeX | Étiquettes: (Genetics), *5', *Alternative, *Nucleic, *Promoter, 1/*genetics, Acid, Alignment, Animals, Base, Cell, Conformation, Data, EHRESMANN, Factor, Fibroblast, Gene, Genes, Genetic, Gov't, Growth, Human, Line, Messenger/chemistry/*genetics/metabolism, Mice, Molecular, Muscle, Mutagenesis, Non-U.S., Regions, Ribosomes/*metabolism, RNA, Sequence, Site-Directed, Skeletal/cytology/physiology, Splicing, Structural/genetics, Support, Techniques, Transfer, Untranslated, Vectors
@article{,
title = {Internal ribosome entry site structural motifs conserved among mammalian fibroblast growth factor 1 alternatively spliced mRNAs},
author = { Y. Martineau and C. Le Bec and L. Monbrun and V. Allo and I. M. Chiu and O. Danos and H. Moine and H. Prats and A. C. Prats},
year = {2004},
date = {2004-01-01},
journal = {Mol Cell Biol},
volume = {24},
number = {17},
pages = {7622-35},
abstract = {Fibroblast growth factor 1 (FGF-1) is a powerful angiogenic factor whose gene structure contains four promoters, giving rise to a process of alternative splicing resulting in four mRNAs with alternative 5' untranslated regions (5' UTRs). Here we have identified, by using double luciferase bicistronic vectors, the presence of internal ribosome entry sites (IRESs) in the human FGF-1 5' UTRs, particularly in leaders A and C, with distinct activities in mammalian cells. DNA electrotransfer in mouse muscle revealed that the IRES present in the FGF-1 leader A has a high activity in vivo. We have developed a new regulatable TET OFF bicistronic system, which allowed us to rule out the possibility of any cryptic promoter in the FGF-1 leaders. FGF-1 IRESs A and C, which were mapped in fragments of 118 and 103 nucleotides, respectively, are flexible in regard to the position of the initiation codon, making them interesting from a biotechnological point of view. Furthermore, we show that FGF-1 IRESs A of murine and human origins show similar IRES activity profiles. Enzymatic and chemical probing of the FGF-1 IRES A RNA revealed a structural domain conserved among mammals at both the nucleotide sequence and RNA structure levels. The functional role of this structural motif has been demonstrated by point mutagenesis, including compensatory mutations. These data favor an important role of IRESs in the control of FGF-1 expression and provide a new IRES structural motif that could help IRES prediction in 5' UTR databases.},
note = {0270-7306
Journal Article},
keywords = {(Genetics), *5', *Alternative, *Nucleic, *Promoter, 1/*genetics, Acid, Alignment, Animals, Base, Cell, Conformation, Data, EHRESMANN, Factor, Fibroblast, Gene, Genes, Genetic, Gov't, Growth, Human, Line, Messenger/chemistry/*genetics/metabolism, Mice, Molecular, Muscle, Mutagenesis, Non-U.S., Regions, Ribosomes/*metabolism, RNA, Sequence, Site-Directed, Skeletal/cytology/physiology, Splicing, Structural/genetics, Support, Techniques, Transfer, Untranslated, Vectors},
pubstate = {published},
tppubtype = {article}
}
Fibroblast growth factor 1 (FGF-1) is a powerful angiogenic factor whose gene structure contains four promoters, giving rise to a process of alternative splicing resulting in four mRNAs with alternative 5' untranslated regions (5' UTRs). Here we have identified, by using double luciferase bicistronic vectors, the presence of internal ribosome entry sites (IRESs) in the human FGF-1 5' UTRs, particularly in leaders A and C, with distinct activities in mammalian cells. DNA electrotransfer in mouse muscle revealed that the IRES present in the FGF-1 leader A has a high activity in vivo. We have developed a new regulatable TET OFF bicistronic system, which allowed us to rule out the possibility of any cryptic promoter in the FGF-1 leaders. FGF-1 IRESs A and C, which were mapped in fragments of 118 and 103 nucleotides, respectively, are flexible in regard to the position of the initiation codon, making them interesting from a biotechnological point of view. Furthermore, we show that FGF-1 IRESs A of murine and human origins show similar IRES activity profiles. Enzymatic and chemical probing of the FGF-1 IRES A RNA revealed a structural domain conserved among mammals at both the nucleotide sequence and RNA structure levels. The functional role of this structural motif has been demonstrated by point mutagenesis, including compensatory mutations. These data favor an important role of IRESs in the control of FGF-1 expression and provide a new IRES structural motif that could help IRES prediction in 5' UTR databases.
2003
Bonnal S., Schaeffer C., Creancier L., Clamens S., Moine H., Prats A. C., Vagner S.
A single internal ribosome entry site containing a G quartet RNA structure drives fibroblast growth factor 2 gene expression at four alternative translation initiation codons Article de journal
Dans: J Biol Chem, vol. 278, non 41, p. 39330-6, 2003, (0021-9258 Journal Article).
Résumé | BibTeX | Étiquettes: 2/*genetics, Acid, Alternative, Base, Cell, Chain, Codon, Complementary/genetics, Conformation, Data, Deletion, DNA, Expression, Factor, Fibroblast, Gene, Gov't, Growth, Human, initiation, Initiator/genetics, Line, Messenger/*chemistry/*genetics, Molecular, Non-U.S., Nucleic, Peptide, Ribosomes/*metabolism, RNA, Sequence, Splicing, Support, Transfection
@article{,
title = {A single internal ribosome entry site containing a G quartet RNA structure drives fibroblast growth factor 2 gene expression at four alternative translation initiation codons},
author = { S. Bonnal and C. Schaeffer and L. Creancier and S. Clamens and H. Moine and A. C. Prats and S. Vagner},
year = {2003},
date = {2003-01-01},
journal = {J Biol Chem},
volume = {278},
number = {41},
pages = {39330-6},
abstract = {The 484-nucleotide (nt) alternatively translated region (ATR) of the human fibroblast growth factor 2 (FGF-2) mRNA contains four CUG and one AUG translation initiation codons. Although the 5'-end proximal CUG codon is initiated by a cap-dependent translation process, the other four initiation codons are initiated by a mechanism of internal entry of ribosomes. We undertook here a detailed analysis of the cis-acting elements defining the FGF-2 internal ribosome entry site (IRES). A thorough deletion analysis study within the 5'-ATR led us to define a 176-nt region as being necessary and sufficient for IRES function at four codons present in a downstream 308-nt RNA segment. Unexpectedly, a single IRES module is therefore responsible for translation initiation at four distantly localized codons. The determination of the FGF-2 5'-ATR RNA secondary structure by enzymatic and chemical probing experiments showed that the FGF-2 IRES contained two stem-loop regions and a G quartet motif that constitute novel structural determinants of IRES function.},
note = {0021-9258
Journal Article},
keywords = {2/*genetics, Acid, Alternative, Base, Cell, Chain, Codon, Complementary/genetics, Conformation, Data, Deletion, DNA, Expression, Factor, Fibroblast, Gene, Gov't, Growth, Human, initiation, Initiator/genetics, Line, Messenger/*chemistry/*genetics, Molecular, Non-U.S., Nucleic, Peptide, Ribosomes/*metabolism, RNA, Sequence, Splicing, Support, Transfection},
pubstate = {published},
tppubtype = {article}
}
The 484-nucleotide (nt) alternatively translated region (ATR) of the human fibroblast growth factor 2 (FGF-2) mRNA contains four CUG and one AUG translation initiation codons. Although the 5'-end proximal CUG codon is initiated by a cap-dependent translation process, the other four initiation codons are initiated by a mechanism of internal entry of ribosomes. We undertook here a detailed analysis of the cis-acting elements defining the FGF-2 internal ribosome entry site (IRES). A thorough deletion analysis study within the 5'-ATR led us to define a 176-nt region as being necessary and sufficient for IRES function at four codons present in a downstream 308-nt RNA segment. Unexpectedly, a single IRES module is therefore responsible for translation initiation at four distantly localized codons. The determination of the FGF-2 5'-ATR RNA secondary structure by enzymatic and chemical probing experiments showed that the FGF-2 IRES contained two stem-loop regions and a G quartet motif that constitute novel structural determinants of IRES function.
Heyman T., Wilhelm M., Wilhelm F. X.
The central PPT of the yeast retrotransposon Ty1 is not essential for transposition Article de journal
Dans: J Mol Biol, vol. 331, non 2, p. 315-20, 2003, (0022-2836 Journal Article).
Résumé | BibTeX | Étiquettes: Base, cerevisiae/genetics, Data, DNA/*biosynthesis, Genetic, Gov't, Models, Molecular, Mutation, Non-U.S., Purines/*chemistry, Retroelements/*genetics, Saccharomyces, Sequence, Support
@article{,
title = {The central PPT of the yeast retrotransposon Ty1 is not essential for transposition},
author = { T. Heyman and M. Wilhelm and F. X. Wilhelm},
year = {2003},
date = {2003-01-01},
journal = {J Mol Biol},
volume = {331},
number = {2},
pages = {315-20},
abstract = {The yeast retrotransposon Ty1 has structural and functional similarities to retroviruses. We report here that, as in retroviruses, the plus-strand DNA of Ty1 is synthesized as two segments. A central DNA flap is formed during reverse transcription consecutive to elongation (with strand displacement) of the upstream segment beyond the central polypurine tract (cPPT) until the replication machinery is stopped at the central termination sequence. Comparison of wild-type and cPPT-mutant Ty1 elements shows that the mutant element lacking the central DNA flap is only twofold defective in transposition.},
note = {0022-2836
Journal Article},
keywords = {Base, cerevisiae/genetics, Data, DNA/*biosynthesis, Genetic, Gov't, Models, Molecular, Mutation, Non-U.S., Purines/*chemistry, Retroelements/*genetics, Saccharomyces, Sequence, Support},
pubstate = {published},
tppubtype = {article}
}
The yeast retrotransposon Ty1 has structural and functional similarities to retroviruses. We report here that, as in retroviruses, the plus-strand DNA of Ty1 is synthesized as two segments. A central DNA flap is formed during reverse transcription consecutive to elongation (with strand displacement) of the upstream segment beyond the central polypurine tract (cPPT) until the replication machinery is stopped at the central termination sequence. Comparison of wild-type and cPPT-mutant Ty1 elements shows that the mutant element lacking the central DNA flap is only twofold defective in transposition.
Miturski R., Postawski K., Semczuk A., Bogusiewicz M., Baranowski W., Jakowicki J. A., Keith G.
Global DNA methylation in relation to hMLH1 and hMSH2 protein immunoreactivity in sporadic human endometrial carcinomas Article de journal
Dans: Int J Mol Med, vol. 11, non 5, p. 569-74, 2003, (1107-3756 Journal Article).
Résumé | BibTeX | Étiquettes: *DNA, Base, Carcinoma/genetics/*metabolism/pathology, DNA, Endometrial, Female, Gov't, Human, Immunohistochemistry, Methylation, Mismatch, Neoplasm, Neoplasms/genetics/*metabolism/pathology, Non-U.S., Pair, Proteins/*metabolism, Proto-Oncogene, Repair, Support
@article{,
title = {Global DNA methylation in relation to hMLH1 and hMSH2 protein immunoreactivity in sporadic human endometrial carcinomas},
author = { R. Miturski and K. Postawski and A. Semczuk and M. Bogusiewicz and W. Baranowski and J. A. Jakowicki and G. Keith},
year = {2003},
date = {2003-01-01},
journal = {Int J Mol Med},
volume = {11},
number = {5},
pages = {569-74},
abstract = {Overall DNA methylation status was studied in a group of 28 sporadic human endometrial carcinomas (ECs) using the [32P]-postlabeling technique. Moreover, expression of the DNA mismatch repair proteins (hMLH1 and hMSH2) was investigated in ECs using immunohistochemistry. Mean 5-methyldeoxycytosine (m5dC) content in the studied group was 3.48+/-0.37% (range, 2.89-4.12%). The mean m5dC scores were significantly different between early (3.35+/-0.33%) and advanced (3.66+/-0.36%) endometrial neoplasms (chi2-test; p=0.03). There was a markedly increased overall DNA methylation with the degree of histological differentiation and with the infiltration of the myometrium (p<0.05). Loss of hMLH1 and hMSH2 expression was reported in 7 (25%) and 5 (18%) tumors, respectively, but the immunoreactivity did not correlate with the known clinicopathological variables of cancer. In addition, no obvious correlation was found between global m5dC content and the lack of hMLH1 and hMSH2 protein expression in human uterine tumors (p=0.97 and p=0.19 for hMLH1 and hMSH2, respectively; Spearman's rank correlation test). Our results clearly show that alterations in global DNA methylation may influence tumor progression, but they are not directly associated with the inactivation of the mismatch-repair machinery in sporadic human ECs.},
note = {1107-3756
Journal Article},
keywords = {*DNA, Base, Carcinoma/genetics/*metabolism/pathology, DNA, Endometrial, Female, Gov't, Human, Immunohistochemistry, Methylation, Mismatch, Neoplasm, Neoplasms/genetics/*metabolism/pathology, Non-U.S., Pair, Proteins/*metabolism, Proto-Oncogene, Repair, Support},
pubstate = {published},
tppubtype = {article}
}
Overall DNA methylation status was studied in a group of 28 sporadic human endometrial carcinomas (ECs) using the [32P]-postlabeling technique. Moreover, expression of the DNA mismatch repair proteins (hMLH1 and hMSH2) was investigated in ECs using immunohistochemistry. Mean 5-methyldeoxycytosine (m5dC) content in the studied group was 3.48+/-0.37% (range, 2.89-4.12%). The mean m5dC scores were significantly different between early (3.35+/-0.33%) and advanced (3.66+/-0.36%) endometrial neoplasms (chi2-test; p=0.03). There was a markedly increased overall DNA methylation with the degree of histological differentiation and with the infiltration of the myometrium (p<0.05). Loss of hMLH1 and hMSH2 expression was reported in 7 (25%) and 5 (18%) tumors, respectively, but the immunoreactivity did not correlate with the known clinicopathological variables of cancer. In addition, no obvious correlation was found between global m5dC content and the lack of hMLH1 and hMSH2 protein expression in human uterine tumors (p=0.97 and p=0.19 for hMLH1 and hMSH2, respectively; Spearman's rank correlation test). Our results clearly show that alterations in global DNA methylation may influence tumor progression, but they are not directly associated with the inactivation of the mismatch-repair machinery in sporadic human ECs.
Wilhelm F. X., Wilhelm M., Gabriel A.
Extension and cleavage of the polypurine tract plus-strand primer by Ty1 reverse transcriptase Article de journal
Dans: J Biol Chem, vol. 278, non 48, p. 47678-84, 2003, (0021-9258 Journal Article).
Résumé | BibTeX | Étiquettes: Base, Calf, Data, DNA, DNA/chemistry, Genetic, Gov't, H, Messenger/metabolism, Models, Molecular, Non-U.S., P.H.S., Polymerase/*chemistry, Primers, Proteins/chemistry, Purines/*chemistry, Recombinant, Replication, Retroelements/*genetics, Ribonuclease, RNA, RNA-Directed, RNA/chemistry, Sequence, Support, Templates, Thymus/chemistry, U.S., Viral
@article{,
title = {Extension and cleavage of the polypurine tract plus-strand primer by Ty1 reverse transcriptase},
author = { F. X. Wilhelm and M. Wilhelm and A. Gabriel},
year = {2003},
date = {2003-01-01},
journal = {J Biol Chem},
volume = {278},
number = {48},
pages = {47678-84},
abstract = {Using hybrid RNA/DNA substrates containing the polypurine tract (PPT) plus-strand primer, we have examined the interaction between the Ty1 reverse transcriptase (RT) and the plus-strand initiation complex. We show here that, although the PPT sequence is relatively resistant to RNase H cleavage, it can be cleaved internally by the polymerase-independent RNase H activity of Ty1 RT. Alternatively, this PPT can be used to initiate plus-strand DNA synthesis. We demonstrate that cleavage at the PPT/DNA junction occurs only after at least 9 nucleotides are extended. Cleavage leaves a nick between the RNA primer and the nascent plus-strand DNA. We show that Ty1 RT has a strand displacement activity beyond a gap but that the PPT is not efficiently re-utilized in vitro for another round of DNA synthesis after a first plus-strand DNA has been synthesized and cleaved at the PPT/U3 junction.},
note = {0021-9258
Journal Article},
keywords = {Base, Calf, Data, DNA, DNA/chemistry, Genetic, Gov't, H, Messenger/metabolism, Models, Molecular, Non-U.S., P.H.S., Polymerase/*chemistry, Primers, Proteins/chemistry, Purines/*chemistry, Recombinant, Replication, Retroelements/*genetics, Ribonuclease, RNA, RNA-Directed, RNA/chemistry, Sequence, Support, Templates, Thymus/chemistry, U.S., Viral},
pubstate = {published},
tppubtype = {article}
}
Using hybrid RNA/DNA substrates containing the polypurine tract (PPT) plus-strand primer, we have examined the interaction between the Ty1 reverse transcriptase (RT) and the plus-strand initiation complex. We show here that, although the PPT sequence is relatively resistant to RNase H cleavage, it can be cleaved internally by the polymerase-independent RNase H activity of Ty1 RT. Alternatively, this PPT can be used to initiate plus-strand DNA synthesis. We demonstrate that cleavage at the PPT/DNA junction occurs only after at least 9 nucleotides are extended. Cleavage leaves a nick between the RNA primer and the nascent plus-strand DNA. We show that Ty1 RT has a strand displacement activity beyond a gap but that the PPT is not efficiently re-utilized in vitro for another round of DNA synthesis after a first plus-strand DNA has been synthesized and cleaved at the PPT/U3 junction.
2002
Perederina A., Nevskaya N., Nikonov O., Nikulin A., Dumas P., Yao M., Tanaka I., Garber M., Gongadze G., Nikonov S.
Detailed analysis of RNA-protein interactions within the bacterial ribosomal protein L5/5S rRNA complex Article de journal
Dans: RNA, vol. 8, non 12, p. 1548-57, 2002, (1355-8382 Journal Article).
Résumé | BibTeX | Étiquettes: 5S/*chemistry/*metabolism, Acid, Amino, Bacterial, Base, Binding, Bonding, coli/genetics, Conformation, Data, Escherichia, Fragments/chemistry/metabolism, Gov't, Hydrogen, Models, Molecular, Non-U.S., Nucleic, Peptide, Protein, Proteins/*chemistry/*metabolism, Proteins/chemistry/metabolism, Ribosomal, RNA, Sequence, Sites, Support
@article{,
title = {Detailed analysis of RNA-protein interactions within the bacterial ribosomal protein L5/5S rRNA complex},
author = { A. Perederina and N. Nevskaya and O. Nikonov and A. Nikulin and P. Dumas and M. Yao and I. Tanaka and M. Garber and G. Gongadze and S. Nikonov},
year = {2002},
date = {2002-01-01},
journal = {RNA},
volume = {8},
number = {12},
pages = {1548-57},
abstract = {The crystal structure of ribosomal protein L5 from Thermus thermophilus complexed with a 34-nt fragment comprising helix III and loop C of Escherichia coli 5S rRNA has been determined at 2.5 A resolution. The protein specifically interacts with the bulged nucleotides at the top of loop C of 5S rRNA. The rRNA and protein contact surfaces are strongly stabilized by intramolecular interactions. Charged and polar atoms forming the network of conserved intermolecular hydrogen bonds are located in two narrow planar parallel layers belonging to the protein and rRNA, respectively. The regions, including these atoms conserved in Bacteria and Archaea, can be considered an RNA-protein recognition module. Comparison of the T. thermophilus L5 structure in the RNA-bound form with the isolated Bacillus stearothermophilus L5 structure shows that the RNA-recognition module on the protein surface does not undergo significant changes upon RNA binding. In the crystal of the complex, the protein interacts with another RNA molecule in the asymmetric unit through the beta-sheet concave surface. This protein/RNA interface simulates the interaction of L5 with 23S rRNA observed in the Haloarcula marismortui 50S ribosomal subunit.},
note = {1355-8382
Journal Article},
keywords = {5S/*chemistry/*metabolism, Acid, Amino, Bacterial, Base, Binding, Bonding, coli/genetics, Conformation, Data, Escherichia, Fragments/chemistry/metabolism, Gov't, Hydrogen, Models, Molecular, Non-U.S., Nucleic, Peptide, Protein, Proteins/*chemistry/*metabolism, Proteins/chemistry/metabolism, Ribosomal, RNA, Sequence, Sites, Support},
pubstate = {published},
tppubtype = {article}
}
The crystal structure of ribosomal protein L5 from Thermus thermophilus complexed with a 34-nt fragment comprising helix III and loop C of Escherichia coli 5S rRNA has been determined at 2.5 A resolution. The protein specifically interacts with the bulged nucleotides at the top of loop C of 5S rRNA. The rRNA and protein contact surfaces are strongly stabilized by intramolecular interactions. Charged and polar atoms forming the network of conserved intermolecular hydrogen bonds are located in two narrow planar parallel layers belonging to the protein and rRNA, respectively. The regions, including these atoms conserved in Bacteria and Archaea, can be considered an RNA-protein recognition module. Comparison of the T. thermophilus L5 structure in the RNA-bound form with the isolated Bacillus stearothermophilus L5 structure shows that the RNA-recognition module on the protein surface does not undergo significant changes upon RNA binding. In the crystal of the complex, the protein interacts with another RNA molecule in the asymmetric unit through the beta-sheet concave surface. This protein/RNA interface simulates the interaction of L5 with 23S rRNA observed in the Haloarcula marismortui 50S ribosomal subunit.
2001
Carnicelli D., Brigotti M., Rizzi S., Keith G., Montanaro L., Sperti S.
Nucleotides U28-A42 and A37 in unmodified yeast tRNA(Trp) as negative identity elements for bovine tryptophanyl-tRNA synthetase Article de journal
Dans: FEBS Lett, vol. 492, non 3, p. 238-41, 2001, (0014-5793 Journal Article).
Résumé | BibTeX | Étiquettes: Acid, Adenine/chemistry, Animals, Base, Cattle, cerevisiae/genetics, Conformation, Data, Fungal/genetics/metabolism, Gov't, Kinetics, Ligase/*metabolism, Molecular, Non-U.S., Nucleic, RNA, Saccharomyces, Sequence, Species, Specificity, Substrate, Support, Transfer, Trp/chemistry/*metabolism, Tryptophan-tRNA, Uridine/chemistry
@article{,
title = {Nucleotides U28-A42 and A37 in unmodified yeast tRNA(Trp) as negative identity elements for bovine tryptophanyl-tRNA synthetase},
author = { D. Carnicelli and M. Brigotti and S. Rizzi and G. Keith and L. Montanaro and S. Sperti},
year = {2001},
date = {2001-01-01},
journal = {FEBS Lett},
volume = {492},
number = {3},
pages = {238-41},
abstract = {Wild-type bovine and yeast tRNA(Trp) are efficiently aminoacylated by tryptophanyl-tRNA synthetase both from beef and from yeast. Upon loss of modified bases in the synthetic transcripts, mammalian tRNA(Trp) retains the double recognition by the two synthetases, while yeast tRNA(Trp) loses its substrate properties for the bovine enzyme and is recognised only by the cognate synthetase. By testing chimeric bovine-yeast transcripts with tryptophanyl-tRNA synthetase purified from beef pancreas, the nucleotides responsible for the loss of charging of the synthetic yeast transcript have been localised in the anticodon arm. A complete loss of charging akin to that observed with the yeast transcript requires substitution in the bovine backbone of G37 in the anticodon loop with yeast A37 and of C28-G42 in the anticodon stem with yeast U28-A42. Since A37 does not prevent aminoacylation of the wild-type yeast tRNA(Trp) by the beef enzyme, a negative combination apparently emerges in the synthetic transcript after unmasking of U28 by loss of pseudourydilation.},
note = {0014-5793
Journal Article},
keywords = {Acid, Adenine/chemistry, Animals, Base, Cattle, cerevisiae/genetics, Conformation, Data, Fungal/genetics/metabolism, Gov't, Kinetics, Ligase/*metabolism, Molecular, Non-U.S., Nucleic, RNA, Saccharomyces, Sequence, Species, Specificity, Substrate, Support, Transfer, Trp/chemistry/*metabolism, Tryptophan-tRNA, Uridine/chemistry},
pubstate = {published},
tppubtype = {article}
}
Wild-type bovine and yeast tRNA(Trp) are efficiently aminoacylated by tryptophanyl-tRNA synthetase both from beef and from yeast. Upon loss of modified bases in the synthetic transcripts, mammalian tRNA(Trp) retains the double recognition by the two synthetases, while yeast tRNA(Trp) loses its substrate properties for the bovine enzyme and is recognised only by the cognate synthetase. By testing chimeric bovine-yeast transcripts with tryptophanyl-tRNA synthetase purified from beef pancreas, the nucleotides responsible for the loss of charging of the synthetic yeast transcript have been localised in the anticodon arm. A complete loss of charging akin to that observed with the yeast transcript requires substitution in the bovine backbone of G37 in the anticodon loop with yeast A37 and of C28-G42 in the anticodon stem with yeast U28-A42. Since A37 does not prevent aminoacylation of the wild-type yeast tRNA(Trp) by the beef enzyme, a negative combination apparently emerges in the synthetic transcript after unmasking of U28 by loss of pseudourydilation.
Wilhelm M., Uzun O., Mules E. H., Gabriel A., Wilhelm F. X.
Polypurine tract formation by Ty1 RNase H Article de journal
Dans: J Biol Chem, vol. 276, non 50, p. 47695-701, 2001, (0021-9258 Journal Article).
Résumé | BibTeX | Étiquettes: *Purines, *Retroelements, Base, Binding, Calf, Data, DNA, DNA/metabolism, Factors, Gov't, H, Hydrolysis, Molecular, Mutation, Non-U.S., P.H.S., Polymerase/*chemistry/*metabolism, Primers/pharmacology, Protein, Proteins/metabolism, Recombinant, Ribonuclease, RNA-Directed, RNA/metabolism, Sequence, Sites, Support, Thymus/*chemistry/*genetics/metabolism, time, U.S.
@article{,
title = {Polypurine tract formation by Ty1 RNase H},
author = { M. Wilhelm and O. Uzun and E. H. Mules and A. Gabriel and F. X. Wilhelm},
year = {2001},
date = {2001-01-01},
journal = {J Biol Chem},
volume = {276},
number = {50},
pages = {47695-701},
abstract = {To better understand the mechanism by which Ty1 RNase H creates the polypurine tract (PPT) primer, we have demonstrated the polymerase-dependent hydrolytic activity of Ty1 reverse transcriptase (RT) during minus-strand synthesis. Using RNase H and polymerase mutants of the recombinant Ty1 RT protein, we show that the two domains of Ty1 RT can act independently of one another. Our results indicate that RNA/DNA substrates containing a short RNA PPT, which serve as primers for plus-strand DNA synthesis, are relatively resistant to RNase H cleavage. RNA substrates with a correct 5' end but with 3' end extending beyond the plus-strand initiation site were cleaved specifically to generate the correct 3' end of the PPT. Using long RNA/DNA duplexes containing the PPT, we show that Ty1 RT is able to make specific internal cleavages that could generate the plus-strand primer with correct 5' and 3' ends. Long RNA/DNA duplexes with mutations in the PPT or in a U-rich region upstream of the PPT, which abolish plus-strand initiation in vivo, were not cleaved specifically at the 5' end of the PPT. Our work demonstrates that the in vitro enzyme can recapitulate key processes that control proper replication in vivo.},
note = {0021-9258
Journal Article},
keywords = {*Purines, *Retroelements, Base, Binding, Calf, Data, DNA, DNA/metabolism, Factors, Gov't, H, Hydrolysis, Molecular, Mutation, Non-U.S., P.H.S., Polymerase/*chemistry/*metabolism, Primers/pharmacology, Protein, Proteins/metabolism, Recombinant, Ribonuclease, RNA-Directed, RNA/metabolism, Sequence, Sites, Support, Thymus/*chemistry/*genetics/metabolism, time, U.S.},
pubstate = {published},
tppubtype = {article}
}
To better understand the mechanism by which Ty1 RNase H creates the polypurine tract (PPT) primer, we have demonstrated the polymerase-dependent hydrolytic activity of Ty1 reverse transcriptase (RT) during minus-strand synthesis. Using RNase H and polymerase mutants of the recombinant Ty1 RT protein, we show that the two domains of Ty1 RT can act independently of one another. Our results indicate that RNA/DNA substrates containing a short RNA PPT, which serve as primers for plus-strand DNA synthesis, are relatively resistant to RNase H cleavage. RNA substrates with a correct 5' end but with 3' end extending beyond the plus-strand initiation site were cleaved specifically to generate the correct 3' end of the PPT. Using long RNA/DNA duplexes containing the PPT, we show that Ty1 RT is able to make specific internal cleavages that could generate the plus-strand primer with correct 5' and 3' ends. Long RNA/DNA duplexes with mutations in the PPT or in a U-rich region upstream of the PPT, which abolish plus-strand initiation in vivo, were not cleaved specifically at the 5' end of the PPT. Our work demonstrates that the in vitro enzyme can recapitulate key processes that control proper replication in vivo.
Wilhelm M., Wilhelm F. X.
Reverse transcription of retroviruses and LTR retrotransposons Article de journal
Dans: Cell Mol Life Sci, vol. 58, non 9, p. 1246-62, 2001, (1420-682x Journal Article Review Review, Academic).
Résumé | BibTeX | Étiquettes: *Retroelements, *Terminal, Acid, Alignment, Amino, Animals, Base, Conformation, Data, DNA, Homology, Human, Molecular, Nucleic, Polymerase/*chemistry/*metabolism, Repeat, Retroviridae/*enzymology/*genetics, RNA-Directed, Sequence, Sequences
@article{,
title = {Reverse transcription of retroviruses and LTR retrotransposons},
author = { M. Wilhelm and F. X. Wilhelm},
year = {2001},
date = {2001-01-01},
journal = {Cell Mol Life Sci},
volume = {58},
number = {9},
pages = {1246-62},
abstract = {Retroelements are mobile genetic entities that replicate via reverse transcription of a template RNA. A key component to the life cycle of these elements is the enzyme reverse transcriptase (RT), which copies the single-stranded genomic RNA of the element into a linear double-stranded DNA that is ultimately integrated into the host genome by the element-encoded integrase. RT is a multifunctionnal enzyme which possesses RNA-dependent and DNA-dependent DNA polymerase activities as well as RNase H activity that specifically degrades the RNA strand of RNA-DNA duplexes. At some stages of the replication a strand-displacement activity of RT is also necessary. All activities are essential for the conversion of single-stranded genomic RNA into the double-stranded preintegrative DNA. This review focuses on the role of RT in the different steps of the replication process of retroelements. The features of retrotransposon replication which differ from the retroviral ones will be emphasized. In a second part of the review, the biochemical and enzymatic properties of two newly characterized retrotransposon RTs will be described. The role of the integrase domain in reverse transcriptase activity of some retroviral and retrotransposon RTs will be discussed.},
note = {1420-682x
Journal Article
Review
Review, Academic},
keywords = {*Retroelements, *Terminal, Acid, Alignment, Amino, Animals, Base, Conformation, Data, DNA, Homology, Human, Molecular, Nucleic, Polymerase/*chemistry/*metabolism, Repeat, Retroviridae/*enzymology/*genetics, RNA-Directed, Sequence, Sequences},
pubstate = {published},
tppubtype = {article}
}
Retroelements are mobile genetic entities that replicate via reverse transcription of a template RNA. A key component to the life cycle of these elements is the enzyme reverse transcriptase (RT), which copies the single-stranded genomic RNA of the element into a linear double-stranded DNA that is ultimately integrated into the host genome by the element-encoded integrase. RT is a multifunctionnal enzyme which possesses RNA-dependent and DNA-dependent DNA polymerase activities as well as RNase H activity that specifically degrades the RNA strand of RNA-DNA duplexes. At some stages of the replication a strand-displacement activity of RT is also necessary. All activities are essential for the conversion of single-stranded genomic RNA into the double-stranded preintegrative DNA. This review focuses on the role of RT in the different steps of the replication process of retroelements. The features of retrotransposon replication which differ from the retroviral ones will be emphasized. In a second part of the review, the biochemical and enzymatic properties of two newly characterized retrotransposon RTs will be described. The role of the integrase domain in reverse transcriptase activity of some retroviral and retrotransposon RTs will be discussed.
2000
Rihn B. H., Bottin M. C., Coulais C., Rouget R., Monhoven N., Baranowski W., Edorh A., Keith G.
Genotoxicity of 3-methylcholanthrene in liver of transgenic big Blue mice Article de journal
Dans: Environ Mol Mutagen, vol. 36, non 4, p. 266-73, 2000, (0893-6692 Journal Article).
Résumé | BibTeX | Étiquettes: *Escherichia, Adducts, Animals, Bacterial, Base, C57BL, Cell, coli, Division/drug, DNA, effects, Gov't, Inbred, Liver/cytology/*drug, Methylcholanthrene/*toxicity, Mice, Mutagens/*toxicity, Mutation, Non-U.S., Organ, Primers, Proteins, Proteins/genetics, Repressor, Sequence, Support, transgenic, Weight
@article{,
title = {Genotoxicity of 3-methylcholanthrene in liver of transgenic big Blue mice},
author = { B. H. Rihn and M. C. Bottin and C. Coulais and R. Rouget and N. Monhoven and W. Baranowski and A. Edorh and G. Keith},
year = {2000},
date = {2000-01-01},
journal = {Environ Mol Mutagen},
volume = {36},
number = {4},
pages = {266-73},
abstract = {Transgenic mice provide a unique tool for studying the tissue specificity and mutagenic potential of chemicals. Because 3-methylcholanthrene (3MC) was found mutagenic in bacteria, clastogenic in bone marrow, and induces DNA adducts in animals, we were interested to determinine whether this xenobiotic provokes (1) cell proliferation, (2) transcriptional activity changes, (3) DNA adducts, and (4) hepatic mutations in transgenic Big Blue mice carrying the lambdaLIZ phage shuttle vector. Big Blue C57/Bl male mice were treated with a single intraperitoneal dose of 80 mg/kg 3MC for 1, 3, 6, 14, or 30 days. Cell proliferation was checked by 5-bromo-2-deoxyuridine labeling and immunohistochemical detection. The maximal increase of the mitotic index was evidenced after 3 days (2.9 times the control value; P < 0.01). The relative nucleus area, reflecting the transcriptional activity, was also the highest in the treated group after 3 days: 1.86 times the control value, on average (P < 0.01). Four major DNA adducts, determined according to the [(32)P]-postlabeling method, were evidenced in liver DNA of treated mice, 6 days after the treatment: the spot intensities increased in a time-dependent manner. The mutant frequency of liver DNA was the highest after 14 days: 20.3 +/- 2.9 x 10(-5) in the treated vs. 7.6 +/- 2.7 x 10(-5) in the control mice (P < 0.01). Sequencing of the lambda lacI mutant plaques showed mainly G:C --> T:A and C:G --> A:T transversions. In conclusion, 3MC at first induced nuclear enlargement and a slight increase of cell proliferation in liver, followed by parallel formation of DNA adducts and mutations. This study shows how transgenic models allow in vivo evaluation of mechanistically simultaneous endpoints.},
note = {0893-6692
Journal Article},
keywords = {*Escherichia, Adducts, Animals, Bacterial, Base, C57BL, Cell, coli, Division/drug, DNA, effects, Gov't, Inbred, Liver/cytology/*drug, Methylcholanthrene/*toxicity, Mice, Mutagens/*toxicity, Mutation, Non-U.S., Organ, Primers, Proteins, Proteins/genetics, Repressor, Sequence, Support, transgenic, Weight},
pubstate = {published},
tppubtype = {article}
}
Transgenic mice provide a unique tool for studying the tissue specificity and mutagenic potential of chemicals. Because 3-methylcholanthrene (3MC) was found mutagenic in bacteria, clastogenic in bone marrow, and induces DNA adducts in animals, we were interested to determinine whether this xenobiotic provokes (1) cell proliferation, (2) transcriptional activity changes, (3) DNA adducts, and (4) hepatic mutations in transgenic Big Blue mice carrying the lambdaLIZ phage shuttle vector. Big Blue C57/Bl male mice were treated with a single intraperitoneal dose of 80 mg/kg 3MC for 1, 3, 6, 14, or 30 days. Cell proliferation was checked by 5-bromo-2-deoxyuridine labeling and immunohistochemical detection. The maximal increase of the mitotic index was evidenced after 3 days (2.9 times the control value; P < 0.01). The relative nucleus area, reflecting the transcriptional activity, was also the highest in the treated group after 3 days: 1.86 times the control value, on average (P < 0.01). Four major DNA adducts, determined according to the [(32)P]-postlabeling method, were evidenced in liver DNA of treated mice, 6 days after the treatment: the spot intensities increased in a time-dependent manner. The mutant frequency of liver DNA was the highest after 14 days: 20.3 +/- 2.9 x 10(-5) in the treated vs. 7.6 +/- 2.7 x 10(-5) in the control mice (P < 0.01). Sequencing of the lambda lacI mutant plaques showed mainly G:C --> T:A and C:G --> A:T transversions. In conclusion, 3MC at first induced nuclear enlargement and a slight increase of cell proliferation in liver, followed by parallel formation of DNA adducts and mutations. This study shows how transgenic models allow in vivo evaluation of mechanistically simultaneous endpoints.
1999
Auxilien S., Keith G., Grice S. F. Le, Darlix J. L.
Role of post-transcriptional modifications of primer tRNALys,3 in the fidelity and efficacy of plus strand DNA transfer during HIV-1 reverse transcription Article de journal
Dans: J Biol Chem, vol. 274, non 7, p. 4412-20, 1999, (0021-9258 Journal Article).
Résumé | BibTeX | Étiquettes: *RNA, *Transcription, Acid, Base, Calf, Conformation, Data, DNA, Genetic, Gov't, H, HIV-1, HIV-1/*physiology, Lys/*metabolism, Molecular, Non-U.S., Nucleic, post-transcriptional, Processing, Reverse, Ribonuclease, RNA, Sequence, Support, Templates, Thymus/metabolism, Transcriptase/metabolism, Transfer, Viral/*metabolism, Viral/metabolism
@article{,
title = {Role of post-transcriptional modifications of primer tRNALys,3 in the fidelity and efficacy of plus strand DNA transfer during HIV-1 reverse transcription},
author = { S. Auxilien and G. Keith and S. F. Le Grice and J. L. Darlix},
year = {1999},
date = {1999-01-01},
journal = {J Biol Chem},
volume = {274},
number = {7},
pages = {4412-20},
abstract = {During HIV reverse transcription, (+) strand DNA synthesis is primed by an RNase H-resistant sequence, the polypurine tract, and continues as far as a 18-nt double-stranded RNA region corresponding to the 3' end of tRNALys,3 hybridized to the viral primer binding site (PBS). Before (+) strand DNA transfer, reverse transcriptase (RT) needs to unwind the double-stranded tRNA-PBS RNA in order to reverse-transcribe the 3' end of primer tRNALys,3. Since the detailed mechanism of (+) strand DNA transfer remains incompletely understood, we developed an in vitro system to closely examine this mechanism, composed of HIV 5' RNA, natural modified tRNALys,3, synthetic unmodified tRNALys,3 or oligonucleotides (RNA or DNA) complementary to the PBS, as well as the viral proteins RT and nucleocapsid protein (NCp7). Prior to (+) strand DNA transfer, RT stalls at the double-stranded tRNA-PBS RNA complex and is able to reverse-transcribe modified nucleosides of natural tRNALys,3. Modified nucleoside m1A-58 of natural tRNALys,3 is only partially effective as a stop signal, as RT can transcribe as far as the hyper-modified adenosine (ms2t6A-37) in the anticodon loop. m1A-58 is almost always transcribed into A, whereas other modified nucleosides are transcribed correctly, except for m7G-46, which is sometimes transcribed into T. In contrast, synthetic tRNALys,3, an RNA PBS primer, and a DNA PBS primer are completely reverse-transcribed. In the presence of an acceptor template, (+) strand DNA transfer is efficient only with templates containing natural tRNALys,3 or the RNA PBS primer. Sequence analysis of transfer products revealed frequent errors at the transfer site with synthetic tRNALys,3, not observed with natural tRNALys,3. Thus, modified nucleoside m1A-58, present in all retroviral tRNA primers, appears to be important for both efficacy and fidelity of (+) strand DNA transfer. We show that other factors such as the nature of the (-) PBS of the acceptor template and the RNase H activity of RT also influence the efficacy of (+) strand DNA transfer.},
note = {0021-9258
Journal Article},
keywords = {*RNA, *Transcription, Acid, Base, Calf, Conformation, Data, DNA, Genetic, Gov't, H, HIV-1, HIV-1/*physiology, Lys/*metabolism, Molecular, Non-U.S., Nucleic, post-transcriptional, Processing, Reverse, Ribonuclease, RNA, Sequence, Support, Templates, Thymus/metabolism, Transcriptase/metabolism, Transfer, Viral/*metabolism, Viral/metabolism},
pubstate = {published},
tppubtype = {article}
}
During HIV reverse transcription, (+) strand DNA synthesis is primed by an RNase H-resistant sequence, the polypurine tract, and continues as far as a 18-nt double-stranded RNA region corresponding to the 3' end of tRNALys,3 hybridized to the viral primer binding site (PBS). Before (+) strand DNA transfer, reverse transcriptase (RT) needs to unwind the double-stranded tRNA-PBS RNA in order to reverse-transcribe the 3' end of primer tRNALys,3. Since the detailed mechanism of (+) strand DNA transfer remains incompletely understood, we developed an in vitro system to closely examine this mechanism, composed of HIV 5' RNA, natural modified tRNALys,3, synthetic unmodified tRNALys,3 or oligonucleotides (RNA or DNA) complementary to the PBS, as well as the viral proteins RT and nucleocapsid protein (NCp7). Prior to (+) strand DNA transfer, RT stalls at the double-stranded tRNA-PBS RNA complex and is able to reverse-transcribe modified nucleosides of natural tRNALys,3. Modified nucleoside m1A-58 of natural tRNALys,3 is only partially effective as a stop signal, as RT can transcribe as far as the hyper-modified adenosine (ms2t6A-37) in the anticodon loop. m1A-58 is almost always transcribed into A, whereas other modified nucleosides are transcribed correctly, except for m7G-46, which is sometimes transcribed into T. In contrast, synthetic tRNALys,3, an RNA PBS primer, and a DNA PBS primer are completely reverse-transcribed. In the presence of an acceptor template, (+) strand DNA transfer is efficient only with templates containing natural tRNALys,3 or the RNA PBS primer. Sequence analysis of transfer products revealed frequent errors at the transfer site with synthetic tRNALys,3, not observed with natural tRNALys,3. Thus, modified nucleoside m1A-58, present in all retroviral tRNA primers, appears to be important for both efficacy and fidelity of (+) strand DNA transfer. We show that other factors such as the nature of the (-) PBS of the acceptor template and the RNase H activity of RT also influence the efficacy of (+) strand DNA transfer.
Perreau V. M., Keith G., Holmes W. M., Przykorska A., Santos M. A., Tuite M. F.
The Candida albicans CUG-decoding ser-tRNA has an atypical anticodon stem-loop structure Article de journal
Dans: J Mol Biol, vol. 293, non 5, p. 1039-53, 1999, (0022-2836 Journal Article).
Résumé | BibTeX | Étiquettes: *Nucleic, Acid, albicans/*genetics, Anticodon/*chemistry/*genetics/metabolism, Base, Candida, cerevisiae/genetics, Code/genetics, Conformation, Evolution, Fungal/chemistry/genetics/metabolism, Genetic, Gov't, Imidazoles/metabolism, Lead/metabolism, Methylation, Methyltransferases/metabolism, Molecular, Mutation/genetics, Non-P.H.S., Non-U.S., Nucleosides/genetics/metabolism, P.H.S., Ribonucleases/metabolism, RNA, Saccharomyces, Sequence, Ser/*chemistry/*genetics/metabolism, Solutions, Support, Transfer, tRNA, U.S.
@article{,
title = {The Candida albicans CUG-decoding ser-tRNA has an atypical anticodon stem-loop structure},
author = { V. M. Perreau and G. Keith and W. M. Holmes and A. Przykorska and M. A. Santos and M. F. Tuite},
year = {1999},
date = {1999-01-01},
journal = {J Mol Biol},
volume = {293},
number = {5},
pages = {1039-53},
abstract = {In many Candida species, the leucine CUG codon is decoded by a tRNA with two unusual properties: it is a ser-tRNA and, uniquely, has guanosine at position 33 (G33). Using a combination of enzymatic (V1 RNase, RnI nuclease) and chemical (Pb(2+), imidazole) probing of the native Candida albicans ser-tRNACAG, we demonstrate that the overall tertiary structure of this tRNA resembles that of a ser-tRNA rather than a leu-tRNA, except within the anticodon arm where there is considerable disruption of the anticodon stem. Using non-modified in vitro transcripts of the C. albicans ser-tRNACAG carrying G, C, U or A at position 33, we demonstrate that it is specifically a G residue at this position that induces the atypical anticodon stem structure. Further quantitative evidence for an unusual structure in the anticodon arm of the G33-tRNA is provided by the observed change in kinetics of methylation of the G at position 37, by purified Escherichia coli m(1)G37 methyltransferase. We conclude that the anticodon arm distortion, induced by a guanosine base at position 33 in the anticodon loop of this novel tRNA, results in reduced decoding ability which has facilitated the evolution of this tRNA without extinction of the species encoding it.},
note = {0022-2836
Journal Article},
keywords = {*Nucleic, Acid, albicans/*genetics, Anticodon/*chemistry/*genetics/metabolism, Base, Candida, cerevisiae/genetics, Code/genetics, Conformation, Evolution, Fungal/chemistry/genetics/metabolism, Genetic, Gov't, Imidazoles/metabolism, Lead/metabolism, Methylation, Methyltransferases/metabolism, Molecular, Mutation/genetics, Non-P.H.S., Non-U.S., Nucleosides/genetics/metabolism, P.H.S., Ribonucleases/metabolism, RNA, Saccharomyces, Sequence, Ser/*chemistry/*genetics/metabolism, Solutions, Support, Transfer, tRNA, U.S.},
pubstate = {published},
tppubtype = {article}
}
In many Candida species, the leucine CUG codon is decoded by a tRNA with two unusual properties: it is a ser-tRNA and, uniquely, has guanosine at position 33 (G33). Using a combination of enzymatic (V1 RNase, RnI nuclease) and chemical (Pb(2+), imidazole) probing of the native Candida albicans ser-tRNACAG, we demonstrate that the overall tertiary structure of this tRNA resembles that of a ser-tRNA rather than a leu-tRNA, except within the anticodon arm where there is considerable disruption of the anticodon stem. Using non-modified in vitro transcripts of the C. albicans ser-tRNACAG carrying G, C, U or A at position 33, we demonstrate that it is specifically a G residue at this position that induces the atypical anticodon stem structure. Further quantitative evidence for an unusual structure in the anticodon arm of the G33-tRNA is provided by the observed change in kinetics of methylation of the G at position 37, by purified Escherichia coli m(1)G37 methyltransferase. We conclude that the anticodon arm distortion, induced by a guanosine base at position 33 in the anticodon loop of this novel tRNA, results in reduced decoding ability which has facilitated the evolution of this tRNA without extinction of the species encoding it.
Wilhelm M., Boutabout M., Heyman T., Wilhelm F. X.
Reverse transcription of the yeast Ty1 retrotransposon: the mode of first strand transfer is either intermolecular or intramolecular Article de journal
Dans: J Mol Biol, vol. 288, non 4, p. 505-10, 1999, (0022-2836 Journal Article).
Résumé | BibTeX | Étiquettes: *Retroelements, *Transcription, Acid, Base, cerevisiae/*genetics, DNA, Genetic, Gov't, Non-U.S., Nucleic, Repetitive, Saccharomyces, Sequence, Sequences, Single-Stranded/genetics, Support
@article{,
title = {Reverse transcription of the yeast Ty1 retrotransposon: the mode of first strand transfer is either intermolecular or intramolecular},
author = { M. Wilhelm and M. Boutabout and T. Heyman and F. X. Wilhelm},
year = {1999},
date = {1999-01-01},
journal = {J Mol Biol},
volume = {288},
number = {4},
pages = {505-10},
abstract = {Replication of the yeast Ty1 retrotransposon occurs by a mechanism similar to that of retroviruses. According to the current model of retroviral reverse transcription, two strand transfers (the so-called minus-strand and plus-strand strong-stop DNA transfers) are required to produce full-length preintegrative DNA. Because two genomic RNA molecules are packaged inside the viral particles, the strand transfers can be either intra- or intermolecular. To study the mode of transfer of minus-strand strong-stop DNA during reverse transcription of the yeast Ty1 retrotransposon, we have analyzed the cDNA products that accumulate in the cytoplasmic virus-like particles of yeast cells harboring two marked Ty1 elements. Our results indicate that Ty1 minus-strand transfer occurs in a random manner with approximately similar frequencies of intra- and intermolecular transfer. It has been observed recently that intra- and intermolecular minus-strand transfer occur at similar frequencies during replication of a complex retrovirus such as HIV-1. These results together with the observation that genetic recombination occurs with a high frequency during minus-strand synthesis suggest that both packaged RNA molecules are needed for the synthesis of one minus-strand DNA.},
note = {0022-2836
Journal Article},
keywords = {*Retroelements, *Transcription, Acid, Base, cerevisiae/*genetics, DNA, Genetic, Gov't, Non-U.S., Nucleic, Repetitive, Saccharomyces, Sequence, Sequences, Single-Stranded/genetics, Support},
pubstate = {published},
tppubtype = {article}
}
Replication of the yeast Ty1 retrotransposon occurs by a mechanism similar to that of retroviruses. According to the current model of retroviral reverse transcription, two strand transfers (the so-called minus-strand and plus-strand strong-stop DNA transfers) are required to produce full-length preintegrative DNA. Because two genomic RNA molecules are packaged inside the viral particles, the strand transfers can be either intra- or intermolecular. To study the mode of transfer of minus-strand strong-stop DNA during reverse transcription of the yeast Ty1 retrotransposon, we have analyzed the cDNA products that accumulate in the cytoplasmic virus-like particles of yeast cells harboring two marked Ty1 elements. Our results indicate that Ty1 minus-strand transfer occurs in a random manner with approximately similar frequencies of intra- and intermolecular transfer. It has been observed recently that intra- and intermolecular minus-strand transfer occur at similar frequencies during replication of a complex retrovirus such as HIV-1. These results together with the observation that genetic recombination occurs with a high frequency during minus-strand synthesis suggest that both packaged RNA molecules are needed for the synthesis of one minus-strand DNA.
Wilhelm M., Heyman T., Boutabout M., Wilhelm F. X.
A sequence immediately upstream of the plus-strand primer is essential for plus-strand DNA synthesis of the Saccharomyces cerevisiae Ty1 retrotransposon Article de journal
Dans: Nucleic Acids Res, vol. 27, non 23, p. 4547-52, 1999, (0305-1048 Journal Article).
Résumé | BibTeX | Étiquettes: *DNA, *Retroelements, Base, cerevisiae/*genetics, DNA, Elements, Fungal/*biosynthesis, Gov't, Mutation, Non-U.S., Primers, response, Saccharomyces, Sequence, Support
@article{,
title = {A sequence immediately upstream of the plus-strand primer is essential for plus-strand DNA synthesis of the Saccharomyces cerevisiae Ty1 retrotransposon},
author = { M. Wilhelm and T. Heyman and M. Boutabout and F. X. Wilhelm},
year = {1999},
date = {1999-01-01},
journal = {Nucleic Acids Res},
volume = {27},
number = {23},
pages = {4547-52},
abstract = {Priming of plus-strand DNA is a critical step in reverse transcription of retroviruses and retrotransposons. All retroelements use an RNase H-resistant oligoribonucleotide spanning a purine-rich sequence (the polypurine tract or PPT) to prime plus-strand DNA synthesis. Plus-strand DNA synthesis of the yeast Saccharomyces cerevisiae Ty1-H3 retrotransposon is initiated at two sites, PPT1 and PPT2, located at the upstream boundary of the 3'-long terminal repeat and near the middle of the pol gene in the integrase coding region. The two plus-strand primers have the same purine-rich sequence GGGTGGTA. This sequence is not sufficient by itself to generate a plus-strand origin since two identical sequences located upstream of PPT2 in the integrase coding region are not used efficiently as primers for plus-strand DNA synthesis. Thus, other factors must be involved in the formation of a specific plus-strand DNA primer. We show here that mutations upstream of the PPT in a highly conserved T-rich region severely alters plus-strand DNA priming of Ty1. Our results demonstrate the importance of sequences or structural elements upstream of the PPT for initiation of plus-strand DNA synthesis.},
note = {0305-1048
Journal Article},
keywords = {*DNA, *Retroelements, Base, cerevisiae/*genetics, DNA, Elements, Fungal/*biosynthesis, Gov't, Mutation, Non-U.S., Primers, response, Saccharomyces, Sequence, Support},
pubstate = {published},
tppubtype = {article}
}
Priming of plus-strand DNA is a critical step in reverse transcription of retroviruses and retrotransposons. All retroelements use an RNase H-resistant oligoribonucleotide spanning a purine-rich sequence (the polypurine tract or PPT) to prime plus-strand DNA synthesis. Plus-strand DNA synthesis of the yeast Saccharomyces cerevisiae Ty1-H3 retrotransposon is initiated at two sites, PPT1 and PPT2, located at the upstream boundary of the 3'-long terminal repeat and near the middle of the pol gene in the integrase coding region. The two plus-strand primers have the same purine-rich sequence GGGTGGTA. This sequence is not sufficient by itself to generate a plus-strand origin since two identical sequences located upstream of PPT2 in the integrase coding region are not used efficiently as primers for plus-strand DNA synthesis. Thus, other factors must be involved in the formation of a specific plus-strand DNA primer. We show here that mutations upstream of the PPT in a highly conserved T-rich region severely alters plus-strand DNA priming of Ty1. Our results demonstrate the importance of sequences or structural elements upstream of the PPT for initiation of plus-strand DNA synthesis.
1998
Brigotti M., Keith G., Pallanca A., Carnicelli D., Alvergna P., Dirheimer G., Montanaro L., Sperti S.
Identification of the tRNAs which up-regulate agrostin, barley RIP and PAP-S, three ribosome-inactivating proteins of plant origin Article de journal
Dans: FEBS Lett, vol. 431, non 2, p. 259-62, 1998, (0014-5793 Journal Article).
Résumé | BibTeX | Étiquettes: &, Acid, Adenosine, Base, Conformation, Data, effects/*metabolism, Gov't, Hordeum/metabolism, Hydrolases/*metabolism, Molecular, N-Glycosyl, Non-U.S., Nucleic, Plant, Plant/chemistry/isolation, Proteins/drug, purification/*metabolism, RNA, Sequence, Support, Transfer/chemistry/isolation, Triphosphate/pharmacology, Up-Regulation
@article{,
title = {Identification of the tRNAs which up-regulate agrostin, barley RIP and PAP-S, three ribosome-inactivating proteins of plant origin},
author = { M. Brigotti and G. Keith and A. Pallanca and D. Carnicelli and P. Alvergna and G. Dirheimer and L. Montanaro and S. Sperti},
year = {1998},
date = {1998-01-01},
journal = {FEBS Lett},
volume = {431},
number = {2},
pages = {259-62},
abstract = {Ribosome-inactivating proteins (RIP) are RNA-N-glycosidases widely diffused in plants which depurinate ribosomal RNA at a specific universally conserved position, A4324 in rat ribosomes. A small group of RIPs (cofactor-dependent RIPs) require ATP and tRNA to reach maximal activity on isolated ribosomes. The tRNA which stimulates gelonin was identified as tRNA(Trp). The present paper reports the identification of three other tRNAs which stimulate agrostin (tRNA(Ala)), barley RIP (tRNA(Ala), tRNA(Val)) and PAP-S (tRNA(Gly)), while for tritin-S no particular stimulating tRNA emerged. The sequences of tRNA(Val) and tRNA(Gly) correspond to the already known ones (rabbit and man, respectively). The tRNA(Ala) (anticodon IGC) identifies a new isoacceptor. Only the stimulating activity of the tRNA(Ala) for agrostin approaches the specificity previously observed for the couple gelonin-tRNA(Trp).},
note = {0014-5793
Journal Article},
keywords = {&, Acid, Adenosine, Base, Conformation, Data, effects/*metabolism, Gov't, Hordeum/metabolism, Hydrolases/*metabolism, Molecular, N-Glycosyl, Non-U.S., Nucleic, Plant, Plant/chemistry/isolation, Proteins/drug, purification/*metabolism, RNA, Sequence, Support, Transfer/chemistry/isolation, Triphosphate/pharmacology, Up-Regulation},
pubstate = {published},
tppubtype = {article}
}
Ribosome-inactivating proteins (RIP) are RNA-N-glycosidases widely diffused in plants which depurinate ribosomal RNA at a specific universally conserved position, A4324 in rat ribosomes. A small group of RIPs (cofactor-dependent RIPs) require ATP and tRNA to reach maximal activity on isolated ribosomes. The tRNA which stimulates gelonin was identified as tRNA(Trp). The present paper reports the identification of three other tRNAs which stimulate agrostin (tRNA(Ala)), barley RIP (tRNA(Ala), tRNA(Val)) and PAP-S (tRNA(Gly)), while for tritin-S no particular stimulating tRNA emerged. The sequences of tRNA(Val) and tRNA(Gly) correspond to the already known ones (rabbit and man, respectively). The tRNA(Ala) (anticodon IGC) identifies a new isoacceptor. Only the stimulating activity of the tRNA(Ala) for agrostin approaches the specificity previously observed for the couple gelonin-tRNA(Trp).
Friant S., Heyman T., Bystrom A. S., Wilhelm M., Wilhelm F. X.
Interactions between Ty1 retrotransposon RNA and the T and D regions of the tRNA(iMet) primer are required for initiation of reverse transcription in vivo Article de journal
Dans: Mol Cell Biol, vol. 18, non 2, p. 799-806, 1998, (0270-7306 Journal Article).
Résumé | BibTeX | Étiquettes: *Retroelements, *Transcription, Acid, Base, Binding, cerevisiae, Conformation, Data, DNA, Fungal/*metabolism, Fungal/biosynthesis, Genetic, Gov't, Met/*metabolism, Molecular, Mutagenesis, Non-U.S., Nucleic, Primers, Replication, RNA, Saccharomyces, Sequence, Sites, Support, Transfer
@article{,
title = {Interactions between Ty1 retrotransposon RNA and the T and D regions of the tRNA(iMet) primer are required for initiation of reverse transcription in vivo},
author = { S. Friant and T. Heyman and A. S. Bystrom and M. Wilhelm and F. X. Wilhelm},
year = {1998},
date = {1998-01-01},
journal = {Mol Cell Biol},
volume = {18},
number = {2},
pages = {799-806},
abstract = {Reverse transcription of the Saccharomyces cerevisiae Ty1 retrotransposon is primed by tRNA(iMet) base paired to the primer binding site (PBS) near the 5' end of Ty1 genomic RNA. The 10-nucleotide PBS is complementary to the last 10 nucleotides of the acceptor stem of tRNA(iMet). A structural probing study of the interactions between the Ty1 RNA template and the tRNA(iMet) primer showed that besides interactions between the PBS and the 3' end of tRNA(iMet), three short regions of Ty1 RNA, named boxes 0, 1, and 2.1, interact with the T and D stems and loops of tRNA(iMet). To determine if these sequences are important for the reverse transcription pathway of the Ty1 retrotransposon, mutant Ty1 elements and tRNA(iMet) were tested for the ability to support transposition. We show that the Ty1 boxes and the complementary sequences in the T and D stems and loops of tRNA(iMet) contain bases that are critical for Ty1 retrotransposition. Disruption of 1 or 2 bp between tRNA(iMet) and box 0, 1, or 2.1 dramatically decreases the level of transposition. Compensatory mutations which restore base pairing between the primer and the template restore transposition. Analysis of the reverse transcription intermediates generated inside Ty1 virus-like particles indicates that initiation of minus-strand strong-stop DNA synthesis is affected by mutations disrupting complementarity between Ty1 RNA and primer tRNA(iMet).},
note = {0270-7306
Journal Article},
keywords = {*Retroelements, *Transcription, Acid, Base, Binding, cerevisiae, Conformation, Data, DNA, Fungal/*metabolism, Fungal/biosynthesis, Genetic, Gov't, Met/*metabolism, Molecular, Mutagenesis, Non-U.S., Nucleic, Primers, Replication, RNA, Saccharomyces, Sequence, Sites, Support, Transfer},
pubstate = {published},
tppubtype = {article}
}
Reverse transcription of the Saccharomyces cerevisiae Ty1 retrotransposon is primed by tRNA(iMet) base paired to the primer binding site (PBS) near the 5' end of Ty1 genomic RNA. The 10-nucleotide PBS is complementary to the last 10 nucleotides of the acceptor stem of tRNA(iMet). A structural probing study of the interactions between the Ty1 RNA template and the tRNA(iMet) primer showed that besides interactions between the PBS and the 3' end of tRNA(iMet), three short regions of Ty1 RNA, named boxes 0, 1, and 2.1, interact with the T and D stems and loops of tRNA(iMet). To determine if these sequences are important for the reverse transcription pathway of the Ty1 retrotransposon, mutant Ty1 elements and tRNA(iMet) were tested for the ability to support transposition. We show that the Ty1 boxes and the complementary sequences in the T and D stems and loops of tRNA(iMet) contain bases that are critical for Ty1 retrotransposition. Disruption of 1 or 2 bp between tRNA(iMet) and box 0, 1, or 2.1 dramatically decreases the level of transposition. Compensatory mutations which restore base pairing between the primer and the template restore transposition. Analysis of the reverse transcription intermediates generated inside Ty1 virus-like particles indicates that initiation of minus-strand strong-stop DNA synthesis is affected by mutations disrupting complementarity between Ty1 RNA and primer tRNA(iMet).
Gabus C., Ficheux D., Rau M., Keith G., Sandmeyer S., Darlix J. L.
The yeast Ty3 retrotransposon contains a 5'-3' bipartite primer-binding site and encodes nucleocapsid protein NCp9 functionally homologous to HIV-1 NCp7 Article de journal
Dans: EMBO J, vol. 17, non 16, p. 4873-80, 1998, (0261-4189 Journal Article).
Résumé | BibTeX | Étiquettes: *Capsid, *Retroelements, Acid, Base, Binding, Capsid/*genetics, cerevisiae/*genetics, dimerization, gag/*genetics, Gene, Gov't, Homology, Met/genetics/*metabolism, Non-U.S., Nucleic, P.H.S., Products, Proteins, RNA, Saccharomyces, Sequence, Sites, Support, Transfer, U.S.
@article{,
title = {The yeast Ty3 retrotransposon contains a 5'-3' bipartite primer-binding site and encodes nucleocapsid protein NCp9 functionally homologous to HIV-1 NCp7},
author = { C. Gabus and D. Ficheux and M. Rau and G. Keith and S. Sandmeyer and J. L. Darlix},
year = {1998},
date = {1998-01-01},
journal = {EMBO J},
volume = {17},
number = {16},
pages = {4873-80},
abstract = {Retroviruses, including HIV-1 and the distantly related yeast retroelement Ty3, all encode a nucleoprotein required for virion structure and replication. During an in vitro comparison of HIV-1 and Ty3 nucleoprotein function in RNA dimerization and cDNA synthesis, we discovered a bipartite primer-binding site (PBS) for Ty3 composed of sequences located at opposite ends of the genome. Ty3 cDNA synthesis requires the 3' PBS for primer tRNAiMet annealing to the genomic RNA, and the 5' PBS, in cis or in trans, as the reverse transcription start site. Ty3 RNA alone is unable to dimerize, but formation of dimeric tRNAiMet bound to the PBS was found to direct dimerization of Ty3 RNA-tRNAiMet. Interestingly, HIV-1 nucleocapsid protein NCp7 and Ty3 NCp9 were interchangeable using HIV-1 and Ty3 RNA template-primer systems. Our findings impact on the understanding of non-canonical reverse transcription as well as on the use of Ty3 systems to screen for anti-NCp7 drugs.},
note = {0261-4189
Journal Article},
keywords = {*Capsid, *Retroelements, Acid, Base, Binding, Capsid/*genetics, cerevisiae/*genetics, dimerization, gag/*genetics, Gene, Gov't, Homology, Met/genetics/*metabolism, Non-U.S., Nucleic, P.H.S., Products, Proteins, RNA, Saccharomyces, Sequence, Sites, Support, Transfer, U.S.},
pubstate = {published},
tppubtype = {article}
}
Retroviruses, including HIV-1 and the distantly related yeast retroelement Ty3, all encode a nucleoprotein required for virion structure and replication. During an in vitro comparison of HIV-1 and Ty3 nucleoprotein function in RNA dimerization and cDNA synthesis, we discovered a bipartite primer-binding site (PBS) for Ty3 composed of sequences located at opposite ends of the genome. Ty3 cDNA synthesis requires the 3' PBS for primer tRNAiMet annealing to the genomic RNA, and the 5' PBS, in cis or in trans, as the reverse transcription start site. Ty3 RNA alone is unable to dimerize, but formation of dimeric tRNAiMet bound to the PBS was found to direct dimerization of Ty3 RNA-tRNAiMet. Interestingly, HIV-1 nucleocapsid protein NCp7 and Ty3 NCp9 were interchangeable using HIV-1 and Ty3 RNA template-primer systems. Our findings impact on the understanding of non-canonical reverse transcription as well as on the use of Ty3 systems to screen for anti-NCp7 drugs.
1997
Friant S., Heyman T., Poch O., Wilhelm M., Wilhelm F. X.
Sequence comparison of the Ty1 and Ty2 elements of the yeast genome supports the structural model of the tRNAiMet-Ty1 RNA reverse transcription initiation complex Article de journal
Dans: Yeast, vol. 13, non 7, p. 639-45, 1997, (0749-503x Journal Article).
Résumé | BibTeX | Étiquettes: *Sequence, Acid, Alignment, Amino, Analysis, Base, Data, DNA, Elements/*genetics, Fungal/genetics, Gov't, Met/*chemistry/*genetics, Molecular, Non-U.S., RNA, Sequence, structure, Support, Transfer, Transposable, Yeasts/*genetics
@article{,
title = {Sequence comparison of the Ty1 and Ty2 elements of the yeast genome supports the structural model of the tRNAiMet-Ty1 RNA reverse transcription initiation complex},
author = { S. Friant and T. Heyman and O. Poch and M. Wilhelm and F. X. Wilhelm},
year = {1997},
date = {1997-01-01},
journal = {Yeast},
volume = {13},
number = {7},
pages = {639-45},
abstract = {In the reverse transcription initiation complex of the yeast Ty1 retrotransposon, interaction between the template RNA and primer tRNAiMet is not limited to base pairing of the primer binding site (PBS) with ten nucleotides at the 3' end of tRNAiMet, but three regions named boxes O, 1 and 2.1 interact with the T and D stems and loops of tRNAiMet. Sequence comparison of 33 Ty1 elements and 13 closely related Ty2 elements found in the yeast genome shows that the nucleotide sequence of all elements is highly conserved in the region spanning the PBS and the three boxes. Since the domain of the template RNA encodes a portion of protein TyA, we have calculated its amino acid profile and its nucleotide profile to evaluate the role played by nucleotide sequence conservation in the selection for TyA function and in the maintenance of base pairing interactions for the priming function of Ty1 RNA. Our results show that the nucleotide sequence conservation of Ty1 RNA is constrained not only by selection for Ty1 function but also by maintenance of a given nucleotide sequence able to base pair with the tRNAiMet in the primer-template initiation complex.},
note = {0749-503x
Journal Article},
keywords = {*Sequence, Acid, Alignment, Amino, Analysis, Base, Data, DNA, Elements/*genetics, Fungal/genetics, Gov't, Met/*chemistry/*genetics, Molecular, Non-U.S., RNA, Sequence, structure, Support, Transfer, Transposable, Yeasts/*genetics},
pubstate = {published},
tppubtype = {article}
}
In the reverse transcription initiation complex of the yeast Ty1 retrotransposon, interaction between the template RNA and primer tRNAiMet is not limited to base pairing of the primer binding site (PBS) with ten nucleotides at the 3' end of tRNAiMet, but three regions named boxes O, 1 and 2.1 interact with the T and D stems and loops of tRNAiMet. Sequence comparison of 33 Ty1 elements and 13 closely related Ty2 elements found in the yeast genome shows that the nucleotide sequence of all elements is highly conserved in the region spanning the PBS and the three boxes. Since the domain of the template RNA encodes a portion of protein TyA, we have calculated its amino acid profile and its nucleotide profile to evaluate the role played by nucleotide sequence conservation in the selection for TyA function and in the maintenance of base pairing interactions for the priming function of Ty1 RNA. Our results show that the nucleotide sequence conservation of Ty1 RNA is constrained not only by selection for Ty1 function but also by maintenance of a given nucleotide sequence able to base pair with the tRNAiMet in the primer-template initiation complex.
1996
Friant S., Heyman T., Wilhelm M. L., Wilhelm F. X.
Extended interactions between the primer tRNAi(Met) and genomic RNA of the yeast Ty1 retrotransposon Article de journal
Dans: Nucleic Acids Res, vol. 24, non 3, p. 441-9, 1996, (0305-1048 Journal Article).
Résumé | BibTeX | Étiquettes: Acid, Base, cerevisiae, Conformation, Data, Gov't, Met/genetics/*metabolism, Molecular, Mutation, Non-U.S., Nucleic, Retroelements/*genetics, RNA, RNA/genetics/*metabolism, Saccharomyces, Sequence, structure, Support, Transfer
@article{,
title = {Extended interactions between the primer tRNAi(Met) and genomic RNA of the yeast Ty1 retrotransposon},
author = { S. Friant and T. Heyman and M. L. Wilhelm and F. X. Wilhelm},
year = {1996},
date = {1996-01-01},
journal = {Nucleic Acids Res},
volume = {24},
number = {3},
pages = {441-9},
abstract = {Reverse transcription of the yeast Ty1 retrotransposon is primed by tRNAi(Met) base paired to the primer binding site near the 5'-end of Ty1 genomic RNA. To understand the molecular basis of the tRNAi(Met)-Ty1 RNA interaction the secondary structure of the binary complex was analysed. Enzymatic probes were used to test the conformation of tRNAi(Met) and of Ty1 RNA in the free form and in the complex. A secondary structure model of the tRNAi(Met) Ty1 RNA complex consistent with the probing data was constructed with the help of a computer program. The model shows that besides interactions between the primer binding site and the last 10 nt at the 3'-end of tRNAi(Met), three short regions of Ty1 RNA named boxes 0, 1 and 2.1 interact with the T and D stems and loops of tRNAiMet. Mutations were made in the boxes or in the complementary sequences of tRNAi(Met) to study the contribution of these sequences to formation of the complex. We find that interaction with at least one of the two boxes 0 or 1 is absolutely required for efficient annealing of the two RNAs. Sequence comparison showing that the primary sequence of the boxes is strictly conserved in Ty1 and Ty2 elements and previously published in vivo results underline the functional importance of the primary sequence of the boxes and suggest that extended interactions between genomic Ty1 RNA and the primary tRNAi(Met) play a role in the reverse transcription pathway.},
note = {0305-1048
Journal Article},
keywords = {Acid, Base, cerevisiae, Conformation, Data, Gov't, Met/genetics/*metabolism, Molecular, Mutation, Non-U.S., Nucleic, Retroelements/*genetics, RNA, RNA/genetics/*metabolism, Saccharomyces, Sequence, structure, Support, Transfer},
pubstate = {published},
tppubtype = {article}
}
Reverse transcription of the yeast Ty1 retrotransposon is primed by tRNAi(Met) base paired to the primer binding site near the 5'-end of Ty1 genomic RNA. To understand the molecular basis of the tRNAi(Met)-Ty1 RNA interaction the secondary structure of the binary complex was analysed. Enzymatic probes were used to test the conformation of tRNAi(Met) and of Ty1 RNA in the free form and in the complex. A secondary structure model of the tRNAi(Met) Ty1 RNA complex consistent with the probing data was constructed with the help of a computer program. The model shows that besides interactions between the primer binding site and the last 10 nt at the 3'-end of tRNAi(Met), three short regions of Ty1 RNA named boxes 0, 1 and 2.1 interact with the T and D stems and loops of tRNAiMet. Mutations were made in the boxes or in the complementary sequences of tRNAi(Met) to study the contribution of these sequences to formation of the complex. We find that interaction with at least one of the two boxes 0 or 1 is absolutely required for efficient annealing of the two RNAs. Sequence comparison showing that the primary sequence of the boxes is strictly conserved in Ty1 and Ty2 elements and previously published in vivo results underline the functional importance of the primary sequence of the boxes and suggest that extended interactions between genomic Ty1 RNA and the primary tRNAi(Met) play a role in the reverse transcription pathway.
de Barros J. P. Pais, Keith G., Adlouni C. El, Glasser A. L., Mack G., Dirheimer G., Desgres J.
2'-O-methyl-5-formylcytidine (f5Cm), a new modified nucleotide at the 'wobble' of two cytoplasmic tRNAs Leu (NAA) from bovine liver Article de journal
Dans: Nucleic Acids Res, vol. 24, non 8, p. 1489-96, 1996, (0305-1048 Journal Article).
Résumé | BibTeX | Étiquettes: &, Acid, Acyl/*chemistry/isolation, Amino, Animals, Base, Borohydrides/chemistry, Cattle, Cells, Conformation, Cytidine/*analogs, Cytoplasm, Data, derivatives/chemistry/isolation, Fragmentography, Gov't, Hela, Human, Liver/*chemistry, Mass, Molecular, Non-U.S., Nucleic, purification, RNA, Sequence, structure, Support, Transfer
@article{,
title = {2'-O-methyl-5-formylcytidine (f5Cm), a new modified nucleotide at the 'wobble' of two cytoplasmic tRNAs Leu (NAA) from bovine liver},
author = { J. P. Pais de Barros and G. Keith and C. El Adlouni and A. L. Glasser and G. Mack and G. Dirheimer and J. Desgres},
year = {1996},
date = {1996-01-01},
journal = {Nucleic Acids Res},
volume = {24},
number = {8},
pages = {1489-96},
abstract = {The nucleotide analysis of a cytoplasmic tRNA(Leu) isolated from bovine liver revealed the presence of an unknown modified nucleotide N. The corresponding N nucleoside was isolated by different enzymatic and chromatographic protocols from a partially purified preparation of this tRNA(Leu). Its chemical characterization was determined from its chromatographic properties, UV-absorption spectroscopy and mass spectrometric measurements, as well as from those of the borohydride reduced N nucleoside and its etheno-trimethylsilyl derivative. The structure of N was established as 2'-O-methyl-5-formylcytidine (f5CM), and its reduced derivative as 2'-O-methyl-5-hydroxy-methylcytidine (om5Cm). By sequencing the bovine liver tRNA(Leu), the structure of the anticodon was determined as f5CmAA. In addition, the nucleotide sequence showed two primary structures differing only by the nucleotide 47c which is either uridine or adenosine. The two slightly differing bovine liver tRNAs-Leu(f5CmAA) are the only tRNAs so far sequenced which contain f5Cm. The role of such a modified cytidine at the first position of the anticodon is discussed in terms of decoding properties for the UUG and UUA leucine codons. Recently, precise evidence was obtained for the presence of f5Cm at the same position in tRNAs(Leu)(NAA) isolated from rabbit and lamb liver. Therefore, the 2'-O-methyl-5-formyl modification of cytidine at position 34 could be a general feature of cytoplasmic tRNAs(Leu)(NAA) in mammals.},
note = {0305-1048
Journal Article},
keywords = {&, Acid, Acyl/*chemistry/isolation, Amino, Animals, Base, Borohydrides/chemistry, Cattle, Cells, Conformation, Cytidine/*analogs, Cytoplasm, Data, derivatives/chemistry/isolation, Fragmentography, Gov't, Hela, Human, Liver/*chemistry, Mass, Molecular, Non-U.S., Nucleic, purification, RNA, Sequence, structure, Support, Transfer},
pubstate = {published},
tppubtype = {article}
}
The nucleotide analysis of a cytoplasmic tRNA(Leu) isolated from bovine liver revealed the presence of an unknown modified nucleotide N. The corresponding N nucleoside was isolated by different enzymatic and chromatographic protocols from a partially purified preparation of this tRNA(Leu). Its chemical characterization was determined from its chromatographic properties, UV-absorption spectroscopy and mass spectrometric measurements, as well as from those of the borohydride reduced N nucleoside and its etheno-trimethylsilyl derivative. The structure of N was established as 2'-O-methyl-5-formylcytidine (f5CM), and its reduced derivative as 2'-O-methyl-5-hydroxy-methylcytidine (om5Cm). By sequencing the bovine liver tRNA(Leu), the structure of the anticodon was determined as f5CmAA. In addition, the nucleotide sequence showed two primary structures differing only by the nucleotide 47c which is either uridine or adenosine. The two slightly differing bovine liver tRNAs-Leu(f5CmAA) are the only tRNAs so far sequenced which contain f5Cm. The role of such a modified cytidine at the first position of the anticodon is discussed in terms of decoding properties for the UUG and UUA leucine codons. Recently, precise evidence was obtained for the presence of f5Cm at the same position in tRNAs(Leu)(NAA) isolated from rabbit and lamb liver. Therefore, the 2'-O-methyl-5-formyl modification of cytidine at position 34 could be a general feature of cytoplasmic tRNAs(Leu)(NAA) in mammals.
1995
Gabryszuk J., Keith G., Monko M., Kuligowska E., Dirheimer G., Szarkowski J. W., Przykorska A.
Structural specificity of nuclease from wheat chloroplasts stroma Article de journal
Dans: Nucleic Acids Symp Ser, non 33, p. 115-9, 1995, (0261-3166 Journal Article).
Résumé | BibTeX | Étiquettes: &, Acid, Asp/chemistry/genetics/metabolism, Base, Binding, Chloroplasts/*enzymology, Conformation, Data, Endonucleases/isolation, Fungal/chemistry/genetics/metabolism, Gov't, Molecular, Non-U.S., Nucleic, Phe/chemistry/genetics/metabolism, purification/*metabolism, RNA, RNA/chemistry/metabolism, Sequence, Sites, Specificity, Substrate, Support, Transfer, Triticum/*enzymology
@article{,
title = {Structural specificity of nuclease from wheat chloroplasts stroma},
author = { J. Gabryszuk and G. Keith and M. Monko and E. Kuligowska and G. Dirheimer and J. W. Szarkowski and A. Przykorska},
year = {1995},
date = {1995-01-01},
journal = {Nucleic Acids Symp Ser},
number = {33},
pages = {115-9},
abstract = {A single-strand-specific nuclease from wheat chloroplasts (ChS nuclease) was tested as a tool for RNA secondary and tertiary structure investigations, using yeast tRNA(Phe) and yeast tRNA(Asp) as models. In tRNA(Phe) the nuclease introduced main primary cleavages at positions U33, A35 and A36 in the anticodon-loop and G18 and G19 in the D-loop. In tRNA(Asp) the main primary cleavages occurred at positions U33, G34 and U35 in the anticodon-loop and the lower one at position C20:1 in the D-loop. No primary cleavages were observed within the double-stranded stems. Because ChS nuclease has (i) a low molecular weight, (ii) a wide pH range of action (5.0 to 7.5) (iii) no divalent cation requirement in the reaction mixture and (iv) can be obtained as a pure protein in rather large quantities it appeared to be a very good tool for secondary and tertiary structural studies of RNAs.},
note = {0261-3166
Journal Article},
keywords = {&, Acid, Asp/chemistry/genetics/metabolism, Base, Binding, Chloroplasts/*enzymology, Conformation, Data, Endonucleases/isolation, Fungal/chemistry/genetics/metabolism, Gov't, Molecular, Non-U.S., Nucleic, Phe/chemistry/genetics/metabolism, purification/*metabolism, RNA, RNA/chemistry/metabolism, Sequence, Sites, Specificity, Substrate, Support, Transfer, Triticum/*enzymology},
pubstate = {published},
tppubtype = {article}
}
A single-strand-specific nuclease from wheat chloroplasts (ChS nuclease) was tested as a tool for RNA secondary and tertiary structure investigations, using yeast tRNA(Phe) and yeast tRNA(Asp) as models. In tRNA(Phe) the nuclease introduced main primary cleavages at positions U33, A35 and A36 in the anticodon-loop and G18 and G19 in the D-loop. In tRNA(Asp) the main primary cleavages occurred at positions U33, G34 and U35 in the anticodon-loop and the lower one at position C20:1 in the D-loop. No primary cleavages were observed within the double-stranded stems. Because ChS nuclease has (i) a low molecular weight, (ii) a wide pH range of action (5.0 to 7.5) (iii) no divalent cation requirement in the reaction mixture and (iv) can be obtained as a pure protein in rather large quantities it appeared to be a very good tool for secondary and tertiary structural studies of RNAs.
Heyman T., Agoutin B., Friant S., Wilhelm F. X., Wilhelm M. L.
Plus-strand DNA synthesis of the yeast retrotransposon Ty1 is initiated at two sites, PPT1 next to the 3' LTR and PPT2 within the pol gene. PPT1 is sufficient for Ty1 transposition Article de journal
Dans: J Mol Biol, vol. 253, non 2, p. 291-303, 1995, (0022-2836 Journal Article).
Résumé | BibTeX | Étiquettes: *DNA, *Genes, *Repetitive, *Retroelements, Acid, Base, C/analysis, cerevisiae/genetics/*virology, Chain, Cloning, Data, DNA, Fungal, Fungal/biosynthesis, Genes, Genetic, Genome, Gov't, Mapping, Molecular, Non-U.S., Nucleic, pol, Poly, Polymerase, Primers, Reaction, Replication, Restriction, Saccharomyces, Sequence, Sequences, Support, Transcription, Viral, Viral/*biosynthesis
@article{,
title = {Plus-strand DNA synthesis of the yeast retrotransposon Ty1 is initiated at two sites, PPT1 next to the 3' LTR and PPT2 within the pol gene. PPT1 is sufficient for Ty1 transposition},
author = { T. Heyman and B. Agoutin and S. Friant and F. X. Wilhelm and M. L. Wilhelm},
year = {1995},
date = {1995-01-01},
journal = {J Mol Biol},
volume = {253},
number = {2},
pages = {291-303},
abstract = {Long terminal repeat elements and retroviruses require primers for initiation of minus and plus-strand DNA synthesis by reverse transcriptase. Here we demonstrate genetically that plus-strand DNA synthesis of the yeast Ty1 element is initiated at two sites located at the 5' boundary of the 3' long terminal repeat (PPT1) and near the middle of the pol gene in the integrase coding sequence (PPT2). A consequence of the presence of two PPTs is that Ty1 plus-strand DNA exists as segments at some time during replication. Three fragments have been identified: the plus-strand strong-stop DNA initiated at PPT1, a downstream fragment initiated at PPT2 and an upstream fragment spanning the 5'-terminal part of Ty1 and a portion of the TyB gene. Characterization of the 3' ends of the plus-strand DNA fragments reveals (1) that the upstream fragment is elongated beyond PPT2 creating a plus-strand overlap and (2) that the majority of plus-strand strong-stop DNA fragments bear a copy of the minus-strand primer binding site in agreement with the accepted model of retroviral genomic RNA reverse transcription. The two polypurine tracts, PPT1 and PPT2, have an identical sequence GGGTGGTA. Mutations replacing purines by pyrimidines in this sequence significantly diminish or abolish initiation of plus-strand synthesis. Ty1 elements bearing a mutated PPT2 sequence are not defective for transposition whereas mutations in PPT1 abolish transposition.},
note = {0022-2836
Journal Article},
keywords = {*DNA, *Genes, *Repetitive, *Retroelements, Acid, Base, C/analysis, cerevisiae/genetics/*virology, Chain, Cloning, Data, DNA, Fungal, Fungal/biosynthesis, Genes, Genetic, Genome, Gov't, Mapping, Molecular, Non-U.S., Nucleic, pol, Poly, Polymerase, Primers, Reaction, Replication, Restriction, Saccharomyces, Sequence, Sequences, Support, Transcription, Viral, Viral/*biosynthesis},
pubstate = {published},
tppubtype = {article}
}
Long terminal repeat elements and retroviruses require primers for initiation of minus and plus-strand DNA synthesis by reverse transcriptase. Here we demonstrate genetically that plus-strand DNA synthesis of the yeast Ty1 element is initiated at two sites located at the 5' boundary of the 3' long terminal repeat (PPT1) and near the middle of the pol gene in the integrase coding sequence (PPT2). A consequence of the presence of two PPTs is that Ty1 plus-strand DNA exists as segments at some time during replication. Three fragments have been identified: the plus-strand strong-stop DNA initiated at PPT1, a downstream fragment initiated at PPT2 and an upstream fragment spanning the 5'-terminal part of Ty1 and a portion of the TyB gene. Characterization of the 3' ends of the plus-strand DNA fragments reveals (1) that the upstream fragment is elongated beyond PPT2 creating a plus-strand overlap and (2) that the majority of plus-strand strong-stop DNA fragments bear a copy of the minus-strand primer binding site in agreement with the accepted model of retroviral genomic RNA reverse transcription. The two polypurine tracts, PPT1 and PPT2, have an identical sequence GGGTGGTA. Mutations replacing purines by pyrimidines in this sequence significantly diminish or abolish initiation of plus-strand synthesis. Ty1 elements bearing a mutated PPT2 sequence are not defective for transposition whereas mutations in PPT1 abolish transposition.
Keith G., Dirheimer G.
Postlabeling: a sensitive method for studying DNA adducts and their role in carcinogenesis Article de journal
Dans: Curr Opin Biotechnol, vol. 6, non 1, p. 3-11, 1995, (0958-1669 Journal Article Review Review, Academic).
Résumé | BibTeX | Étiquettes: *Cell, *Genome, Adducts/*analysis, and, Animals, Base, Cell, Conditions/genetics/pathology, Data, Dilution, Division, DNA, Genetic, Gov't, Human, Models, Molecular, Mutagenesis, Neoplasms/*genetics/pathology, Neoplastic, Non-U.S., Phosphorus, Precancerous, Radioisotope, Radioisotopes, Sensitivity, Sequence, Specificity, Support, Technique, Transformation, Xenobiotics
@article{,
title = {Postlabeling: a sensitive method for studying DNA adducts and their role in carcinogenesis},
author = { G. Keith and G. Dirheimer},
year = {1995},
date = {1995-01-01},
journal = {Curr Opin Biotechnol},
volume = {6},
number = {1},
pages = {3-11},
abstract = {The covalent binding of xenobiotics to DNA is an important trigger of the multistage process that leads to carcinogenesis. 32P-postlabeling represents a highly sensitive method for biomonitoring exposure to genotoxic agents and for cancer risk assessment; it is capable of detecting less than one DNA adduct per human genome. Recent improvements to the technique have shown that the resistance of adducted DNA to enzyme digestion may lead to an overestimation of the number of different adducts present in a sample.},
note = {0958-1669
Journal Article
Review
Review, Academic},
keywords = {*Cell, *Genome, Adducts/*analysis, and, Animals, Base, Cell, Conditions/genetics/pathology, Data, Dilution, Division, DNA, Genetic, Gov't, Human, Models, Molecular, Mutagenesis, Neoplasms/*genetics/pathology, Neoplastic, Non-U.S., Phosphorus, Precancerous, Radioisotope, Radioisotopes, Sensitivity, Sequence, Specificity, Support, Technique, Transformation, Xenobiotics},
pubstate = {published},
tppubtype = {article}
}
The covalent binding of xenobiotics to DNA is an important trigger of the multistage process that leads to carcinogenesis. 32P-postlabeling represents a highly sensitive method for biomonitoring exposure to genotoxic agents and for cancer risk assessment; it is capable of detecting less than one DNA adduct per human genome. Recent improvements to the technique have shown that the resistance of adducted DNA to enzyme digestion may lead to an overestimation of the number of different adducts present in a sample.
O'Connor M., Brunelli C. A., Firpo M. A., Gregory S. T., Lieberman K. R., Lodmell J. S., Moine H., Ryk D. I. Van, Dahlberg A. E.
Genetic probes of ribosomal RNA function Article de journal
Dans: Biochem Cell Biol, vol. 73, non 11-12, p. 859-68, 1995, (0829-8211 Journal Article Review Review, Tutorial).
Résumé | BibTeX | Étiquettes: 16S/genetics, Acid, Base, Conformation, Data, Gov't, Messenger/genetics, Molecular, Mutation, Non-U.S., Nucleic, P.H.S., Probes, Ribosomal, Ribosomal/*genetics, RNA, Sequence, Support, Transfer/genetics, U.S.
@article{,
title = {Genetic probes of ribosomal RNA function},
author = { M. O'Connor and C. A. Brunelli and M. A. Firpo and S. T. Gregory and K. R. Lieberman and J. S. Lodmell and H. Moine and D. I. Van Ryk and A. E. Dahlberg},
year = {1995},
date = {1995-01-01},
journal = {Biochem Cell Biol},
volume = {73},
number = {11-12},
pages = {859-68},
abstract = {We have used a genetic approach to uncover the functional roles of rRNA in protein synthesis. Mutations were constructed in a cloned rrn operon by site-directed mutagenesis or isolated by genetic selections following random mutagenesis. We have identified mutations that affect each step in the process of translation. The data are consistent with the results of biochemical and phylogenetic analyses but, in addition, have provided novel information on regions of rRNA not previously investigated.},
note = {0829-8211
Journal Article
Review
Review, Tutorial},
keywords = {16S/genetics, Acid, Base, Conformation, Data, Gov't, Messenger/genetics, Molecular, Mutation, Non-U.S., Nucleic, P.H.S., Probes, Ribosomal, Ribosomal/*genetics, RNA, Sequence, Support, Transfer/genetics, U.S.},
pubstate = {published},
tppubtype = {article}
}
We have used a genetic approach to uncover the functional roles of rRNA in protein synthesis. Mutations were constructed in a cloned rrn operon by site-directed mutagenesis or isolated by genetic selections following random mutagenesis. We have identified mutations that affect each step in the process of translation. The data are consistent with the results of biochemical and phylogenetic analyses but, in addition, have provided novel information on regions of rRNA not previously investigated.
1994
Dumas P., Bergdoll M., Cagnon C., Masson J. M.
Crystal structure and site-directed mutagenesis of a bleomycin resistance protein and their significance for drug sequestering Article de journal
Dans: EMBO J, vol. 13, non 11, p. 2483-92, 1994, (0261-4189 Journal Article).
Résumé | BibTeX | Étiquettes: *Acetyltransferases, &, Acid, Amino, Bacterial, Bacterial/*genetics, Base, Binding, Bleomycin/*metabolism/pharmacology, Conformation, Crystallization, Crystallography, Data, Drug, Fusion, Genes, Gov't, Microbial/genetics, Models, Molecular, Mutagenesis, Non-U.S., Protein, Proteins/*chemistry/genetics/isolation, Proteins/isolation, purification, purification/metabolism, Recombinant, Relationship, Resistance, Secondary, Sequence, Site-Directed, Sites, Structural, structure, Structure-Activity, Support, X-Ray
@article{,
title = {Crystal structure and site-directed mutagenesis of a bleomycin resistance protein and their significance for drug sequestering},
author = { P. Dumas and M. Bergdoll and C. Cagnon and J. M. Masson},
year = {1994},
date = {1994-01-01},
journal = {EMBO J},
volume = {13},
number = {11},
pages = {2483-92},
abstract = {The antibiotic bleomycin, a strong DNA cutting agent, is naturally produced by actinomycetes which have developed a resistance mechanism against such a lethal compound. The crystal structure, at 2.3 A resolution, of a bleomycin resistance protein of 14 kDa reveals a structure in two halves with the same alpha/beta fold despite no sequence similarity. The crystal packing shows compact dimers with a hydrophobic interface and involved in mutual chain exchange. Two independent solution studies (analytical centrifugation and light scattering) showed that this dimeric form is not a packing artefact but is indeed the functional one. Furthermore, light scattering also showed that one dimer binds two antibiotic molecules as expected. A crevice located at the dimer interface, as well as the results of a site-directed mutagenesis study, led to a model wherein two bleomycin molecules are completely sequestered by one dimer. This provides a novel insight into antibiotic resistance due to drug sequestering, and probably also into drug transport and excretion.},
note = {0261-4189
Journal Article},
keywords = {*Acetyltransferases, &, Acid, Amino, Bacterial, Bacterial/*genetics, Base, Binding, Bleomycin/*metabolism/pharmacology, Conformation, Crystallization, Crystallography, Data, Drug, Fusion, Genes, Gov't, Microbial/genetics, Models, Molecular, Mutagenesis, Non-U.S., Protein, Proteins/*chemistry/genetics/isolation, Proteins/isolation, purification, purification/metabolism, Recombinant, Relationship, Resistance, Secondary, Sequence, Site-Directed, Sites, Structural, structure, Structure-Activity, Support, X-Ray},
pubstate = {published},
tppubtype = {article}
}
The antibiotic bleomycin, a strong DNA cutting agent, is naturally produced by actinomycetes which have developed a resistance mechanism against such a lethal compound. The crystal structure, at 2.3 A resolution, of a bleomycin resistance protein of 14 kDa reveals a structure in two halves with the same alpha/beta fold despite no sequence similarity. The crystal packing shows compact dimers with a hydrophobic interface and involved in mutual chain exchange. Two independent solution studies (analytical centrifugation and light scattering) showed that this dimeric form is not a packing artefact but is indeed the functional one. Furthermore, light scattering also showed that one dimer binds two antibiotic molecules as expected. A crevice located at the dimer interface, as well as the results of a site-directed mutagenesis study, led to a model wherein two bleomycin molecules are completely sequestered by one dimer. This provides a novel insight into antibiotic resistance due to drug sequestering, and probably also into drug transport and excretion.
Heyman T., Agoutin B., Fix C., Dirheimer G., Keith G.
Yeast serine isoacceptor tRNAs: variations of their content as a function of growth conditions and primary structure of the minor tRNA(Ser)GCU Article de journal
Dans: FEBS Lett, vol. 347, non 2-3, p. 143-6, 1994, (0014-5793 Journal Article).
Résumé | BibTeX | Étiquettes: &, Acid, Anticodon, Base, cerevisiae/*genetics/*growth, Conformation, Culture, Data, development, Fungal/*chemistry, Galactose, Hybridization, Media, Molecular, Nucleic, Probes, RNA, Saccharomyces, Sequence, Ser/analysis/*chemistry, Transfer, Transfer/*chemistry
@article{,
title = {Yeast serine isoacceptor tRNAs: variations of their content as a function of growth conditions and primary structure of the minor tRNA(Ser)GCU},
author = { T. Heyman and B. Agoutin and C. Fix and G. Dirheimer and G. Keith},
year = {1994},
date = {1994-01-01},
journal = {FEBS Lett},
volume = {347},
number = {2-3},
pages = {143-6},
abstract = {The primary structure of Saccharomyces cerevisiae tRNA(Ser)GCU is presented (EMBL database accession No. X74268 S. cerevisiae tRNA-Ser). In addition, quantitation of the relative amounts of serine isoaccepting tRNAs in yeast grown on different media showed that the minor tRNA(Ser)GCU decreased while the major tRNA(Ser)AGA increased as the growth rate and the cellular protein content increased. The minor species, tRNA(Ser)CGA and tRNA(Ser)UGA, were not separated by our gel system, however, taken together they appeared to vary in the same way as tRNA(Ser)GCU. These data suggest a growth rate dependence of yeast tRNAs similar to that previously described for E. coli tRNAs.},
note = {0014-5793
Journal Article},
keywords = {&, Acid, Anticodon, Base, cerevisiae/*genetics/*growth, Conformation, Culture, Data, development, Fungal/*chemistry, Galactose, Hybridization, Media, Molecular, Nucleic, Probes, RNA, Saccharomyces, Sequence, Ser/analysis/*chemistry, Transfer, Transfer/*chemistry},
pubstate = {published},
tppubtype = {article}
}
The primary structure of Saccharomyces cerevisiae tRNA(Ser)GCU is presented (EMBL database accession No. X74268 S. cerevisiae tRNA-Ser). In addition, quantitation of the relative amounts of serine isoaccepting tRNAs in yeast grown on different media showed that the minor tRNA(Ser)GCU decreased while the major tRNA(Ser)AGA increased as the growth rate and the cellular protein content increased. The minor species, tRNA(Ser)CGA and tRNA(Ser)UGA, were not separated by our gel system, however, taken together they appeared to vary in the same way as tRNA(Ser)GCU. These data suggest a growth rate dependence of yeast tRNAs similar to that previously described for E. coli tRNAs.
Moine H., Dahlberg A. E.
Mutations in helix 34 of Escherichia coli 16 S ribosomal RNA have multiple effects on ribosome function and synthesis Article de journal
Dans: J Mol Biol, vol. 243, non 3, p. 402-12, 1994, (0022-2836 Journal Article).
Résumé | BibTeX | Étiquettes: *Mutation, *Nucleic, *Translation, &, 16S/*chemistry/genetics, Acid, Base, beta-Galactosidase/genetics, Codon, coli/*genetics/growth, Conformation, Data, development, Escherichia, Genetic, Gov't, Molecular, Non-U.S., P.H.S., Ribosomal, Ribosomes/*metabolism, RNA, Sequence, Support, Terminator, U.S.
@article{,
title = {Mutations in helix 34 of Escherichia coli 16 S ribosomal RNA have multiple effects on ribosome function and synthesis},
author = { H. Moine and A. E. Dahlberg},
year = {1994},
date = {1994-01-01},
journal = {J Mol Biol},
volume = {243},
number = {3},
pages = {402-12},
abstract = {Helix 34 of E. coli 16 S rRNA (1046 to 1067 and 1189 to 1211) has been proposed to participate directly in the termination of translation at UGA stop codons. We have constructed mutations in this helix in plasmid-encoded rDNA to explore the specific functional roles of the sequence UCAUCA (1199 to 1204) and a secondary structure also involving positions 1054 and 1057-1058. The rRNA mutations were analyzed for their effects on in vivo translational accuracy (stop codon readthrough and frameshifting) as well as growth rate, ribosome synthesis and incorporation into polysomes. Mutations at positions 1054, 1057, 1058, 1199 and 1200 had significant effects on translational accuracy, causing non-specific readthrough of all three stop codons as well as enhanced +1 and -1 frameshifting. Mutations at 1202 and 1203, however, had no effect. The incorporation of deleterious mutant subunits into 70 S ribosomes and polysomes was severely reduced and was associated with a slower growth rate and increased synthesis of host-encoded ribosomes. These data support the proposal that helix 34 is an essential component of the decoding center of the 30 S ribosomal subunit and is not restricted in function to UGA-codon specific termination.},
note = {0022-2836
Journal Article},
keywords = {*Mutation, *Nucleic, *Translation, &, 16S/*chemistry/genetics, Acid, Base, beta-Galactosidase/genetics, Codon, coli/*genetics/growth, Conformation, Data, development, Escherichia, Genetic, Gov't, Molecular, Non-U.S., P.H.S., Ribosomal, Ribosomes/*metabolism, RNA, Sequence, Support, Terminator, U.S.},
pubstate = {published},
tppubtype = {article}
}
Helix 34 of E. coli 16 S rRNA (1046 to 1067 and 1189 to 1211) has been proposed to participate directly in the termination of translation at UGA stop codons. We have constructed mutations in this helix in plasmid-encoded rDNA to explore the specific functional roles of the sequence UCAUCA (1199 to 1204) and a secondary structure also involving positions 1054 and 1057-1058. The rRNA mutations were analyzed for their effects on in vivo translational accuracy (stop codon readthrough and frameshifting) as well as growth rate, ribosome synthesis and incorporation into polysomes. Mutations at positions 1054, 1057, 1058, 1199 and 1200 had significant effects on translational accuracy, causing non-specific readthrough of all three stop codons as well as enhanced +1 and -1 frameshifting. Mutations at 1202 and 1203, however, had no effect. The incorporation of deleterious mutant subunits into 70 S ribosomes and polysomes was severely reduced and was associated with a slower growth rate and increased synthesis of host-encoded ribosomes. These data support the proposal that helix 34 is an essential component of the decoding center of the 30 S ribosomal subunit and is not restricted in function to UGA-codon specific termination.
Wilhelm M., Wilhelm F. X., Keith G., Agoutin B., Heyman T.
Yeast Ty1 retrotransposon: the minus-strand primer binding site and a cis-acting domain of the Ty1 RNA are both important for packaging of primer tRNA inside virus-like particles Article de journal
Dans: Nucleic Acids Res, vol. 22, non 22, p. 4560-5, 1994, (0305-1048 Journal Article).
Résumé | BibTeX | Étiquettes: Acid, Amino, Base, Binding, cerevisiae/*genetics, Cloning, Data, Fungal/*genetics, Genetic, Gov't, Met/*genetics, Molecular, Mutation/physiology, Non-U.S., Retroelements/*genetics/physiology, Retroviridae/genetics, RNA, RNA/*genetics, Saccharomyces, Sequence, Sites, Support, Transcription, Transfer
@article{,
title = {Yeast Ty1 retrotransposon: the minus-strand primer binding site and a cis-acting domain of the Ty1 RNA are both important for packaging of primer tRNA inside virus-like particles},
author = { M. Wilhelm and F. X. Wilhelm and G. Keith and B. Agoutin and T. Heyman},
year = {1994},
date = {1994-01-01},
journal = {Nucleic Acids Res},
volume = {22},
number = {22},
pages = {4560-5},
abstract = {Reverse transcription of the yeast retrotransposon Ty1 is primed by the cytoplasmic initiator methionine tRNA (tRNA(iMet)). The primer tRNA(iMet) is packaged inside virus-like particles (VLPs) and binds to a 10 nucleotides minus-strand primer binding site, the (-)PBS, complementary to its 3' acceptor stem. We have found that three short sequences of the Ty1 RNA (box 1, box 2.1 and box 2.2) located 3' to the (-)PBS are complementary to other regions of the primer tRNA(iMet) (T psi C and DHU stems and loops). Reconstitution of reverse transcription in vitro with T7 transcribed Ty1 RNA species and tRNA(iMet) purified from yeast cells shows that the boxes do not affect the efficiency of reverse transcription. Thus the role of the boxes on packaging of the primer tRNA(iMet) into the VLPs was investigated by analysing the level of tRNA(iMet) packaged into mutant VLPs. Specific nucleotide changes in the (-)PBS or in the boxes that do not change the protein coding sequence but disrupt the complementarity with the primer tRNA(iMet) within the VLPs. We propose that base pairing between the primer tRNA(iMet) and the Ty1 RNA is of major importance for tRNA(iMet) packaging into the VLPs. Moreover the intactness of the boxes is essential for retrotransposition as shown by the transposition defect of a Ty1 element harboring an intact (-)PBS and mutated boxes.},
note = {0305-1048
Journal Article},
keywords = {Acid, Amino, Base, Binding, cerevisiae/*genetics, Cloning, Data, Fungal/*genetics, Genetic, Gov't, Met/*genetics, Molecular, Mutation/physiology, Non-U.S., Retroelements/*genetics/physiology, Retroviridae/genetics, RNA, RNA/*genetics, Saccharomyces, Sequence, Sites, Support, Transcription, Transfer},
pubstate = {published},
tppubtype = {article}
}
Reverse transcription of the yeast retrotransposon Ty1 is primed by the cytoplasmic initiator methionine tRNA (tRNA(iMet)). The primer tRNA(iMet) is packaged inside virus-like particles (VLPs) and binds to a 10 nucleotides minus-strand primer binding site, the (-)PBS, complementary to its 3' acceptor stem. We have found that three short sequences of the Ty1 RNA (box 1, box 2.1 and box 2.2) located 3' to the (-)PBS are complementary to other regions of the primer tRNA(iMet) (T psi C and DHU stems and loops). Reconstitution of reverse transcription in vitro with T7 transcribed Ty1 RNA species and tRNA(iMet) purified from yeast cells shows that the boxes do not affect the efficiency of reverse transcription. Thus the role of the boxes on packaging of the primer tRNA(iMet) into the VLPs was investigated by analysing the level of tRNA(iMet) packaged into mutant VLPs. Specific nucleotide changes in the (-)PBS or in the boxes that do not change the protein coding sequence but disrupt the complementarity with the primer tRNA(iMet) within the VLPs. We propose that base pairing between the primer tRNA(iMet) and the Ty1 RNA is of major importance for tRNA(iMet) packaging into the VLPs. Moreover the intactness of the boxes is essential for retrotransposition as shown by the transposition defect of a Ty1 element harboring an intact (-)PBS and mutated boxes.
1993
el Adlouni C., Keith G., Dirheimer G., Szarkowski J. W., Przykorska A.
Rye nuclease I as a tool for structural studies of tRNAs with large variable arms Article de journal
Dans: Nucleic Acids Res, vol. 21, non 4, p. 941-7, 1993, (0305-1048 Journal Article).
Résumé | BibTeX | Étiquettes: *Nucleotidases, Acid, Animals, Anticodon, Base, Cattle, cereale/*enzymology, cerevisiae, Conformation, Data, Gov't, Leu/chemistry, Molecular, Non-U.S., Nucleic, RNA, Saccharomyces, Secale, Sequence, Ser/chemistry, Support, Transfer, Transfer/*chemistry
@article{,
title = {Rye nuclease I as a tool for structural studies of tRNAs with large variable arms},
author = { C. el Adlouni and G. Keith and G. Dirheimer and J. W. Szarkowski and A. Przykorska},
year = {1993},
date = {1993-01-01},
journal = {Nucleic Acids Res},
volume = {21},
number = {4},
pages = {941-7},
abstract = {A single-strand-specific nuclease from rye germ (Rn nuclease I) was used for secondary and tertiary structure investigations of tRNAs with large variable arms (class II tRNAs). We have studied the structure in solution of two recently sequenced tRNA(Leu): yeast tRNA(Leu)(ncm5UmAA) and bovine tRNA(Leu)(XmAA) as well as yeast tRNA(Leu)(UAG), tRNA(Leu)(m5CAA) and tRNA(Ser)(IGA). The latter is the only tRNA with a long variable arm for which the secondary and tertiary structure has already been studied by use of chemical probes and computer modelling. The data obtained in this work showed that the general model of class II tRNAs proposed by others for tRNA(Ser) can be extended to tRNAs(Leu) as well. However interesting differences in the structure of tRNAs(Leu) versus tRNA(Ser)(IGA) were also noticed. The main difference was observed in the accessibility of the variable loops to nucleolytic attack of Rn nuclease I: variable loops of all studied tRNA(Leu) species were cut by Rn nuclease I, while that of yeast tRNA(Ser)(IGA) was not. This could be due to differences in stability of the variable arms and the lengths of their loops which are 3 and 4 nucleotides in tRNA(Ser)(IGA) and tRNAs(Leu) respectively.},
note = {0305-1048
Journal Article},
keywords = {*Nucleotidases, Acid, Animals, Anticodon, Base, Cattle, cereale/*enzymology, cerevisiae, Conformation, Data, Gov't, Leu/chemistry, Molecular, Non-U.S., Nucleic, RNA, Saccharomyces, Secale, Sequence, Ser/chemistry, Support, Transfer, Transfer/*chemistry},
pubstate = {published},
tppubtype = {article}
}
A single-strand-specific nuclease from rye germ (Rn nuclease I) was used for secondary and tertiary structure investigations of tRNAs with large variable arms (class II tRNAs). We have studied the structure in solution of two recently sequenced tRNA(Leu): yeast tRNA(Leu)(ncm5UmAA) and bovine tRNA(Leu)(XmAA) as well as yeast tRNA(Leu)(UAG), tRNA(Leu)(m5CAA) and tRNA(Ser)(IGA). The latter is the only tRNA with a long variable arm for which the secondary and tertiary structure has already been studied by use of chemical probes and computer modelling. The data obtained in this work showed that the general model of class II tRNAs proposed by others for tRNA(Ser) can be extended to tRNAs(Leu) as well. However interesting differences in the structure of tRNAs(Leu) versus tRNA(Ser)(IGA) were also noticed. The main difference was observed in the accessibility of the variable loops to nucleolytic attack of Rn nuclease I: variable loops of all studied tRNA(Leu) species were cut by Rn nuclease I, while that of yeast tRNA(Ser)(IGA) was not. This could be due to differences in stability of the variable arms and the lengths of their loops which are 3 and 4 nucleotides in tRNA(Ser)(IGA) and tRNAs(Leu) respectively.
Keith G., Heitzler J., el Adlouni C., Glasser A. L., Fix C., Desgres J., Dirheimer G.
The primary structure of cytoplasmic initiator tRNA(Met) from Schizosaccharomyces pombe Article de journal
Dans: Nucleic Acids Res, vol. 21, non 12, p. 2949, 1993, (0305-1048 Journal Article).
BibTeX | Étiquettes: Base, Data, Fungal/*chemistry, Met/*chemistry, Molecular, RNA, Schizosaccharomyces/*genetics, Sequence, Transfer
@article{,
title = {The primary structure of cytoplasmic initiator tRNA(Met) from Schizosaccharomyces pombe},
author = { G. Keith and J. Heitzler and C. el Adlouni and A. L. Glasser and C. Fix and J. Desgres and G. Dirheimer},
year = {1993},
date = {1993-01-01},
journal = {Nucleic Acids Res},
volume = {21},
number = {12},
pages = {2949},
note = {0305-1048
Journal Article},
keywords = {Base, Data, Fungal/*chemistry, Met/*chemistry, Molecular, RNA, Schizosaccharomyces/*genetics, Sequence, Transfer},
pubstate = {published},
tppubtype = {article}
}
Pfeiffer P., Jung J. L., Heitzler J., Keith G.
Unusual structure of the double-stranded RNA associated with the '447' cytoplasmic male sterility in Vicia faba Article de journal
Dans: J Gen Virol, vol. 74, non Pt 6, p. 1167-73, 1993, (0022-1317 Journal Article).
Résumé | BibTeX | Étiquettes: *Plants, &, Base, Bodies, Cytoplasm, Data, Extrachromosomal, Fabaceae/*genetics, Genetic, Inclusion, Infertility/genetics, Inheritance/*genetics, Medicinal, Molecular, Pollen/genetics, purification, Replicase/metabolism, RNA, RNA/*genetics/isolation, Sequence, Transcription, Viral
@article{,
title = {Unusual structure of the double-stranded RNA associated with the '447' cytoplasmic male sterility in Vicia faba},
author = { P. Pfeiffer and J. L. Jung and J. Heitzler and G. Keith},
year = {1993},
date = {1993-01-01},
journal = {J Gen Virol},
volume = {74},
number = {Pt 6},
pages = {1167-73},
abstract = {The 16.7 kbp dsRNA specific to the '447' cytoplasmic male sterility (CMS) line of Vicia faba was labelled in vitro with [alpha-32P]ATP and poly(A) polymerase, and by T4 RNA ligase-mediated addition of [32P]pCp. Analysis of the reaction products under denaturing conditions revealed in both cases extensive labelling of a 4.5 kb ssRNA, already detected in previous experiments in which the RNA-dependent RNA polymerase associated with the dsRNA was allowed to pursue RNA synthesis on preinitiated complexes. Mobility shift analysis of total pCp-labelled dsRNA revealed not two but three different 3' termini. The most prominent sequencing pattern corresponded to the 4.5 kb ssRNA, indicating that this RNA species has a preferentially accessible, free 3' OH extremity. Northern blot analysis of the denatured dsRNA confirmed that the 4.5 kb ssRNA is a subgenomic mRNA and detected its counterpart of about 12 kb. Nearly all 16.7 kbp dsRNA molecules featured an interrupted positive-sense strand, indicating a marked prevalence of transcription over replication complexes. This unusual strategy of transcription by a strand displacement mechanism, following initiation at an internal discontinuity, is compared with that of other dsRNA viruses or defective viruses, and is discussed in relation to the expression of the CMS trait.},
note = {0022-1317
Journal Article},
keywords = {*Plants, &, Base, Bodies, Cytoplasm, Data, Extrachromosomal, Fabaceae/*genetics, Genetic, Inclusion, Infertility/genetics, Inheritance/*genetics, Medicinal, Molecular, Pollen/genetics, purification, Replicase/metabolism, RNA, RNA/*genetics/isolation, Sequence, Transcription, Viral},
pubstate = {published},
tppubtype = {article}
}
The 16.7 kbp dsRNA specific to the '447' cytoplasmic male sterility (CMS) line of Vicia faba was labelled in vitro with [alpha-32P]ATP and poly(A) polymerase, and by T4 RNA ligase-mediated addition of [32P]pCp. Analysis of the reaction products under denaturing conditions revealed in both cases extensive labelling of a 4.5 kb ssRNA, already detected in previous experiments in which the RNA-dependent RNA polymerase associated with the dsRNA was allowed to pursue RNA synthesis on preinitiated complexes. Mobility shift analysis of total pCp-labelled dsRNA revealed not two but three different 3' termini. The most prominent sequencing pattern corresponded to the 4.5 kb ssRNA, indicating that this RNA species has a preferentially accessible, free 3' OH extremity. Northern blot analysis of the denatured dsRNA confirmed that the 4.5 kb ssRNA is a subgenomic mRNA and detected its counterpart of about 12 kb. Nearly all 16.7 kbp dsRNA molecules featured an interrupted positive-sense strand, indicating a marked prevalence of transcription over replication complexes. This unusual strategy of transcription by a strand displacement mechanism, following initiation at an internal discontinuity, is compared with that of other dsRNA viruses or defective viruses, and is discussed in relation to the expression of the CMS trait.
Pochart P., Agoutin B., Fix C., Keith G., Heyman T.
A very poorly expressed tRNA(Ser) is highly concentrated together with replication primer initiator tRNA(Met) in the yeast Ty1 virus-like particles Article de journal
Dans: Nucleic Acids Res, vol. 21, non 7, p. 1517-21, 1993, (0305-1048 Journal Article).
Résumé | BibTeX | Étiquettes: &, Acid, Base, cerevisiae/metabolism, Conformation, Data, development, DNA, Electrophoresis, Elements/*physiology, Gel, Met/metabolism, Molecular, Nucleic, Retroviridae/*growth, RNA, Saccharomyces, Sequence, Ser/*metabolism, Transfer, Transposable, Two-Dimensional, Viral/*metabolism
@article{,
title = {A very poorly expressed tRNA(Ser) is highly concentrated together with replication primer initiator tRNA(Met) in the yeast Ty1 virus-like particles},
author = { P. Pochart and B. Agoutin and C. Fix and G. Keith and T. Heyman},
year = {1993},
date = {1993-01-01},
journal = {Nucleic Acids Res},
volume = {21},
number = {7},
pages = {1517-21},
abstract = {The analysis of the tRNAs associated to the virus-like particles produced by the Ty1 element revealed the specific packaging of three major tRNA species, in about equal amounts: the replication primer initiator tRNA(Met), the tRNA(Ser)AGA and a tRNA undetected until now as an expressed species in yeast. The latter tRNA is coded by the already described tDNA(Ser)GCT. This tRNA is enriched more than 150 fold in the particles as compared to its content in total cellular tRNA where it represents less than 0.1% (initiator tRNA(Met) and tRNA(Ser)AGA being 11 and 4 fold enriched respectively). This tRNA is the only species coded by the tDNA(Ser)GCT gene which is found in three copies per genome since no other corresponding expressed tRNA could be detected. This gene is thus very poorly expressed. The high concentration of tRNA(Ser)GCU in the particles compared to its very low cellular content led us to consider its possible implication in Ty specific processes.},
note = {0305-1048
Journal Article},
keywords = {&, Acid, Base, cerevisiae/metabolism, Conformation, Data, development, DNA, Electrophoresis, Elements/*physiology, Gel, Met/metabolism, Molecular, Nucleic, Retroviridae/*growth, RNA, Saccharomyces, Sequence, Ser/*metabolism, Transfer, Transposable, Two-Dimensional, Viral/*metabolism},
pubstate = {published},
tppubtype = {article}
}
The analysis of the tRNAs associated to the virus-like particles produced by the Ty1 element revealed the specific packaging of three major tRNA species, in about equal amounts: the replication primer initiator tRNA(Met), the tRNA(Ser)AGA and a tRNA undetected until now as an expressed species in yeast. The latter tRNA is coded by the already described tDNA(Ser)GCT. This tRNA is enriched more than 150 fold in the particles as compared to its content in total cellular tRNA where it represents less than 0.1% (initiator tRNA(Met) and tRNA(Ser)AGA being 11 and 4 fold enriched respectively). This tRNA is the only species coded by the tDNA(Ser)GCT gene which is found in three copies per genome since no other corresponding expressed tRNA could be detected. This gene is thus very poorly expressed. The high concentration of tRNA(Ser)GCU in the particles compared to its very low cellular content led us to consider its possible implication in Ty specific processes.
Santos M. A., Keith G., Tuite M. F.
Non-standard translational events in Candida albicans mediated by an unusual seryl-tRNA with a 5'-CAG-3' (leucine) anticodon Article de journal
Dans: EMBO J, vol. 12, non 2, p. 607-16, 1993, (0261-4189 Journal Article).
Résumé | BibTeX | Étiquettes: *Anticodon, *Translation, &, Acid, albicans/*genetics, Base, Candida, Cloning, Conformation, Data, DNA, Fungal,