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2002
Gottar Marie, Gobert Vanessa, Michel Tatiana, Belvin Marcia, Duyk Geoffrey, Hoffmann Jules A, Ferrandon Dominique, Royet Julien
The Drosophila immune response against Gram-negative bacteria is mediated by a peptidoglycan recognition protein Article de journal
Dans: Nature, vol. 416, p. 640–644, 2002, ISBN: 0028-0836.
Résumé | Liens | BibTeX | Étiquettes: Animal, Anti-Infective Agents/metabolism, Carrier Proteins/biosynthesis/genetics/*immunology, Drosophila melanogaster/genetics/*immunology/*microbiology, Drosophila Proteins/genetics/metabolism, Epistasis, Female, ferrandon, Genes, Genetic, Genetic Predisposition to Disease, Gram-Negative Bacteria/*immunology/physiology, hoffmann, Human, Insect/genetics, M3i, Messenger/genetics/metabolism, Mutation, Non-U.S. Gov't, P.H.S., Phenotype, RNA, Signal Transduction, Support, Survival Rate, Transgenes/genetics, U.S. Gov't
@article{gottar_drosophila_2002b,
title = {The Drosophila immune response against Gram-negative bacteria is mediated by a peptidoglycan recognition protein},
author = {Marie Gottar and Vanessa Gobert and Tatiana Michel and Marcia Belvin and Geoffrey Duyk and Jules A Hoffmann and Dominique Ferrandon and Julien Royet},
doi = {10.1038/nature734},
isbn = {0028-0836},
year = {2002},
date = {2002-03-01},
journal = {Nature},
volume = {416},
pages = {640--644},
abstract = {The antimicrobial defence of Drosophila relies largely on the challenge-induced synthesis of an array of potent antimicrobial peptides by the fat body. The defence against Gram-positive bacteria and natural fungal infections is mediated by the Toll signalling pathway, whereas defence against Gram-negative bacteria is dependent on the Immune deficiency (IMD) pathway. Loss-of-function mutations in either pathway reduce the resistance to corresponding infections. The link between microbial infections and activation of these two pathways has remained elusive. The Toll pathway is activated by Gram-positive bacteria through a circulating Peptidoglycan recognition protein (PGRP-SA). PGRPs appear to be highly conserved from insects to mammals, and the Drosophila genome contains 13 members. Here we report a mutation in a gene coding for a putative transmembrane protein, PGRP-LC, which reduces survival to Gram-negative sepsis but has no effect on the response to Gram-positive bacteria or natural fungal infections. By genetic epistasis, we demonstrate that PGRP-LC acts upstream of the imd gene. The data on PGRP-SA with respect to the response to Gram-positive infections, together with the present report, indicate that the PGRP family has a principal role in sensing microbial infections in Drosophila.},
keywords = {Animal, Anti-Infective Agents/metabolism, Carrier Proteins/biosynthesis/genetics/*immunology, Drosophila melanogaster/genetics/*immunology/*microbiology, Drosophila Proteins/genetics/metabolism, Epistasis, Female, ferrandon, Genes, Genetic, Genetic Predisposition to Disease, Gram-Negative Bacteria/*immunology/physiology, hoffmann, Human, Insect/genetics, M3i, Messenger/genetics/metabolism, Mutation, Non-U.S. Gov't, P.H.S., Phenotype, RNA, Signal Transduction, Support, Survival Rate, Transgenes/genetics, U.S. Gov't},
pubstate = {published},
tppubtype = {article}
}
The antimicrobial defence of Drosophila relies largely on the challenge-induced synthesis of an array of potent antimicrobial peptides by the fat body. The defence against Gram-positive bacteria and natural fungal infections is mediated by the Toll signalling pathway, whereas defence against Gram-negative bacteria is dependent on the Immune deficiency (IMD) pathway. Loss-of-function mutations in either pathway reduce the resistance to corresponding infections. The link between microbial infections and activation of these two pathways has remained elusive. The Toll pathway is activated by Gram-positive bacteria through a circulating Peptidoglycan recognition protein (PGRP-SA). PGRPs appear to be highly conserved from insects to mammals, and the Drosophila genome contains 13 members. Here we report a mutation in a gene coding for a putative transmembrane protein, PGRP-LC, which reduces survival to Gram-negative sepsis but has no effect on the response to Gram-positive bacteria or natural fungal infections. By genetic epistasis, we demonstrate that PGRP-LC acts upstream of the imd gene. The data on PGRP-SA with respect to the response to Gram-positive infections, together with the present report, indicate that the PGRP family has a principal role in sensing microbial infections in Drosophila.
Cristofari G., Bampi C., Wilhelm M., Wilhelm F. X., Darlix J. L.
A 5'-3' long-range interaction in Ty1 RNA controls its reverse transcription and retrotransposition Article de journal
Dans: EMBO J, vol. 21, no. 16, p. 4368-79, 2002, (0261-4189 Journal Article).
Résumé | BibTeX | Étiquettes: *Gene, *Transcription, Acid, cerevisiae/*genetics, Complementary/biosynthesis, Conformation, DNA, Expression, Fungal, Fungal/chemistry/*metabolism, Genetic, Gov't, in, Messenger/chemistry/*metabolism, Non-U.S., Nucleic, Phylogeny, Regulation, Retroelements/*genetics, RNA, Saccharomyces, Support, vitro
@article{,
title = {A 5'-3' long-range interaction in Ty1 RNA controls its reverse transcription and retrotransposition},
author = { G. Cristofari and C. Bampi and M. Wilhelm and F. X. Wilhelm and J. L. Darlix},
year = {2002},
date = {2002-01-01},
journal = {EMBO J},
volume = {21},
number = {16},
pages = {4368-79},
abstract = {LTR-retrotransposons are abundant components of all eukaryotic genomes and appear to be key players in their evolution. They share with retroviruses a reverse transcription step during their replication cycle. To better understand the replication of retrotransposons as well as their similarities to and differences from retroviruses, we set up an in vitro model system to examine minus-strand cDNA synthesis of the yeast Ty1 LTR-retrotransposon. Results show that the 5' and 3' ends of Ty1 genomic RNA interact through 14 nucleotide 5'-3' complementary sequences (CYC sequences). This 5'-3' base pairing results in an efficient initiation of reverse transcription in vitro. Transposition of a marked Ty1 element and Ty1 cDNA synthesis in yeast rely on the ability of the CYC sequences to base pair. This 5'-3' interaction is also supported by phylogenic analysis of all full-length Ty1 and Ty2 elements present in the Saccharomyces cerevisiae genome. These novel findings lead us to propose that circularization of the Ty1 genomic RNA controls initiation of reverse transcription and may limit reverse transcription of defective retroelements.},
note = {0261-4189
Journal Article},
keywords = {*Gene, *Transcription, Acid, cerevisiae/*genetics, Complementary/biosynthesis, Conformation, DNA, Expression, Fungal, Fungal/chemistry/*metabolism, Genetic, Gov't, in, Messenger/chemistry/*metabolism, Non-U.S., Nucleic, Phylogeny, Regulation, Retroelements/*genetics, RNA, Saccharomyces, Support, vitro},
pubstate = {published},
tppubtype = {article}
}
LTR-retrotransposons are abundant components of all eukaryotic genomes and appear to be key players in their evolution. They share with retroviruses a reverse transcription step during their replication cycle. To better understand the replication of retrotransposons as well as their similarities to and differences from retroviruses, we set up an in vitro model system to examine minus-strand cDNA synthesis of the yeast Ty1 LTR-retrotransposon. Results show that the 5' and 3' ends of Ty1 genomic RNA interact through 14 nucleotide 5'-3' complementary sequences (CYC sequences). This 5'-3' base pairing results in an efficient initiation of reverse transcription in vitro. Transposition of a marked Ty1 element and Ty1 cDNA synthesis in yeast rely on the ability of the CYC sequences to base pair. This 5'-3' interaction is also supported by phylogenic analysis of all full-length Ty1 and Ty2 elements present in the Saccharomyces cerevisiae genome. These novel findings lead us to propose that circularization of the Ty1 genomic RNA controls initiation of reverse transcription and may limit reverse transcription of defective retroelements.
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, no. 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
Vizioli J, Bulet Philippe, Hoffmann Jules A, Kafatos Fotis C, Müller H M, Dimopoulos G
Gambicin: a novel immune responsive antimicrobial peptide from the malaria vector Anopheles gambiae Article de journal
Dans: Proc. Natl. Acad. Sci. U.S.A., vol. 98, no. 22, p. 12630–12635, 2001, ISSN: 0027-8424.
Résumé | Liens | BibTeX | Étiquettes: Animals, Anopheles, Anti-Bacterial Agents, Anti-Infective Agents, Base Sequence, Chromosome Mapping, hoffmann, Insect Proteins, Insect Vectors, M3i, Malaria, messenger, RNA
@article{vizioli_gambicin:_2001,
title = {Gambicin: a novel immune responsive antimicrobial peptide from the malaria vector Anopheles gambiae},
author = {J Vizioli and Philippe Bulet and Jules A Hoffmann and Fotis C Kafatos and H M Müller and G Dimopoulos},
doi = {10.1073/pnas.221466798},
issn = {0027-8424},
year = {2001},
date = {2001-10-01},
journal = {Proc. Natl. Acad. Sci. U.S.A.},
volume = {98},
number = {22},
pages = {12630--12635},
abstract = {A novel mosquito antimicrobial peptide, gambicin, and the corresponding gene were isolated in parallel through differential display-PCR, an expressed sequence tag (EST) project, and characterization of an antimicrobial activity in a mosquito cell line by reverse-phase chromatography. The 616-bp gambicin ORF encodes an 81-residue protein that is processed and secreted as a 61-aa mature peptide containing eight cysteines engaged in four disulfide bridges. Gambicin lacks sequence homology with other known proteins. Like other Anopheles gambiae antimicrobial peptide genes, gambicin is induced by natural or experimental infection in the midgut, fatbody, and hemocyte-like cell lines. Within the midgut, gambicin is predominantly expressed in the anterior part. Both local and systemic gambicin expression is induced during early and late stages of natural malaria infection. In vitro experiments showed that the 6.8-kDa mature peptide can kill both Gram-positive and Gram-negative bacteria, has a morphogenic effect on a filamentous fungus, and is marginally lethal to Plasmodium berghei ookinetes. An oxidized form of gambicin isolated from the cell line medium was more active against bacteria than the nonoxidized form from the same medium.},
keywords = {Animals, Anopheles, Anti-Bacterial Agents, Anti-Infective Agents, Base Sequence, Chromosome Mapping, hoffmann, Insect Proteins, Insect Vectors, M3i, Malaria, messenger, RNA},
pubstate = {published},
tppubtype = {article}
}
A novel mosquito antimicrobial peptide, gambicin, and the corresponding gene were isolated in parallel through differential display-PCR, an expressed sequence tag (EST) project, and characterization of an antimicrobial activity in a mosquito cell line by reverse-phase chromatography. The 616-bp gambicin ORF encodes an 81-residue protein that is processed and secreted as a 61-aa mature peptide containing eight cysteines engaged in four disulfide bridges. Gambicin lacks sequence homology with other known proteins. Like other Anopheles gambiae antimicrobial peptide genes, gambicin is induced by natural or experimental infection in the midgut, fatbody, and hemocyte-like cell lines. Within the midgut, gambicin is predominantly expressed in the anterior part. Both local and systemic gambicin expression is induced during early and late stages of natural malaria infection. In vitro experiments showed that the 6.8-kDa mature peptide can kill both Gram-positive and Gram-negative bacteria, has a morphogenic effect on a filamentous fungus, and is marginally lethal to Plasmodium berghei ookinetes. An oxidized form of gambicin isolated from the cell line medium was more active against bacteria than the nonoxidized form from the same medium.
Boutabout M., Wilhelm M., Wilhelm F. X.
DNA synthesis fidelity by the reverse transcriptase of the yeast retrotransposon Ty1 Article de journal
Dans: Nucleic Acids Res, vol. 29, no. 11, p. 2217-22, 2001, (1362-4962 Journal Article).
Résumé | BibTeX | Étiquettes: cerevisiae/*genetics/metabolism, DNA, Fungal/genetics, Fungal/genetics/*metabolism, Genetic, Gov't, Kinetics, Non-U.S., Nucleotides/genetics/metabolism, Polymerase/*metabolism, Retroelements/*genetics, RNA, RNA-Directed, Saccharomyces, Support, Templates
@article{,
title = {DNA synthesis fidelity by the reverse transcriptase of the yeast retrotransposon Ty1},
author = { M. Boutabout and M. Wilhelm and F. X. Wilhelm},
year = {2001},
date = {2001-01-01},
journal = {Nucleic Acids Res},
volume = {29},
number = {11},
pages = {2217-22},
abstract = {The fidelity of the yeast retrotransposon Ty1 reverse transcriptase (RT) was determined by an assay based on gel electrophoresis. Steady-state kinetics analyses of deoxyribonucleotide (dNTP) incorporation at a defined primer-template site indicate that Ty1 RT misincorporates dNTP at a frequency of 0.45 x 10(-5) for the A(t):A mispair in which dATP is misincorporated opposite a template A to 6.27 x 10(-5) for the C(t):A mispair. The G(t):G and T(t):T mispairs are formed with very low efficiency. The fidelity parameters of Ty1 RT do not depend on whether RNA or DNA are copied. Relative to lentiviral RTs (HIV-1, HIV-2 or EIAV) Ty1 RT is approximately 10-fold less error prone. Our data also show that the Ty1 RT is able to recapitulate two error-generating mechanisms: extension of mismatches and non-templated addition of nucleotides at the end of a blunt-end primer-template.},
note = {1362-4962
Journal Article},
keywords = {cerevisiae/*genetics/metabolism, DNA, Fungal/genetics, Fungal/genetics/*metabolism, Genetic, Gov't, Kinetics, Non-U.S., Nucleotides/genetics/metabolism, Polymerase/*metabolism, Retroelements/*genetics, RNA, RNA-Directed, Saccharomyces, Support, Templates},
pubstate = {published},
tppubtype = {article}
}
The fidelity of the yeast retrotransposon Ty1 reverse transcriptase (RT) was determined by an assay based on gel electrophoresis. Steady-state kinetics analyses of deoxyribonucleotide (dNTP) incorporation at a defined primer-template site indicate that Ty1 RT misincorporates dNTP at a frequency of 0.45 x 10(-5) for the A(t):A mispair in which dATP is misincorporated opposite a template A to 6.27 x 10(-5) for the C(t):A mispair. The G(t):G and T(t):T mispairs are formed with very low efficiency. The fidelity parameters of Ty1 RT do not depend on whether RNA or DNA are copied. Relative to lentiviral RTs (HIV-1, HIV-2 or EIAV) Ty1 RT is approximately 10-fold less error prone. Our data also show that the Ty1 RT is able to recapitulate two error-generating mechanisms: extension of mismatches and non-templated addition of nucleotides at the end of a blunt-end primer-template.
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, no. 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.
Moine H., Mandel J. L.
Biomedicine. Do G quartets orchestrate fragile X pathology? Article de journal
Dans: Science, vol. 294, no. 5551, p. 2487-8, 2001, (0036-8075 Journal Article).
BibTeX | Étiquettes: Acid, Analysis, Animals, Array, Binding, Brain/metabolism, Conformation, Crystallography, Expression, Fragile, Gene, Genetic, Human, Messenger/*chemistry/genetics/*metabolism, Mice, Nerve, Nucleic, Oligonucleotide, Protein, Proteins/chemistry/genetics/*metabolism, Regions, Regulation, RNA, Sequence, Sites, structure, Synapses/physiology, Syndrome/genetics/*metabolism, Tertiary, Tissue, Translation, Untranslated, X, X-Ray
@article{,
title = {Biomedicine. Do G quartets orchestrate fragile X pathology?},
author = { H. Moine and J. L. Mandel},
year = {2001},
date = {2001-01-01},
journal = {Science},
volume = {294},
number = {5551},
pages = {2487-8},
note = {0036-8075
Journal Article},
keywords = {Acid, Analysis, Animals, Array, Binding, Brain/metabolism, Conformation, Crystallography, Expression, Fragile, Gene, Genetic, Human, Messenger/*chemistry/genetics/*metabolism, Mice, Nerve, Nucleic, Oligonucleotide, Protein, Proteins/chemistry/genetics/*metabolism, Regions, Regulation, RNA, Sequence, Sites, structure, Synapses/physiology, Syndrome/genetics/*metabolism, Tertiary, Tissue, Translation, Untranslated, X, X-Ray},
pubstate = {published},
tppubtype = {article}
}
Levashina Elena A, Moita L F, Blandin Stéphanie A, Vriend G, Lagueux Marie, Kafatos F C
Conserved role of a complement-like protein in phagocytosis revealed by dsRNA knockout in cultured cells of the mosquito, Anopheles gambiae Article de journal
Dans: Cell, vol. 104, no. 5, p. 709–718, 2001, ISSN: 0092-8674.
Résumé | BibTeX | Étiquettes: alpha-Macroglobulins, Animals, Anopheles, blandin, Cells, Cloning, Complement C3, Cultured, DNA Fragmentation, Double-Stranded, Female, Genetic, Gram-Negative Bacteria, Hemocytes, Insect Proteins, M3i, Molecular, Nucleic Acid Denaturation, Phagocytosis, Protein Structure, RNA, Tertiary, Transcription
@article{levashina_conserved_2001,
title = {Conserved role of a complement-like protein in phagocytosis revealed by dsRNA knockout in cultured cells of the mosquito, Anopheles gambiae},
author = {Elena A Levashina and L F Moita and Stéphanie A Blandin and G Vriend and Marie Lagueux and F C Kafatos},
issn = {0092-8674},
year = {2001},
date = {2001-01-01},
journal = {Cell},
volume = {104},
number = {5},
pages = {709--718},
abstract = {We characterize a novel hemocyte-specific acute phase glycoprotein from the malaria vector, Anopheles gambiae. It shows substantial structural and functional similarities, including the highly conserved thioester motif, to both a central component of mammalian complement system, factor C3, and to a pan-protease inhibitor, alpha2-macroglobulin. Most importantly, this protein serves as a complement-like opsonin and promotes phagocytosis of some Gram-negative bacteria in a mosquito hemocyte-like cell line. Chemical inactivation by methylamine and depletion by double-stranded RNA knockout demonstrate that this function is dependent on the internal thioester bond. This evidence of a complement-like function in a protostome animal adds substantially to the accumulating evidence of a common ancestry of immune defenses in insects and vertebrates.},
keywords = {alpha-Macroglobulins, Animals, Anopheles, blandin, Cells, Cloning, Complement C3, Cultured, DNA Fragmentation, Double-Stranded, Female, Genetic, Gram-Negative Bacteria, Hemocytes, Insect Proteins, M3i, Molecular, Nucleic Acid Denaturation, Phagocytosis, Protein Structure, RNA, Tertiary, Transcription},
pubstate = {published},
tppubtype = {article}
}
We characterize a novel hemocyte-specific acute phase glycoprotein from the malaria vector, Anopheles gambiae. It shows substantial structural and functional similarities, including the highly conserved thioester motif, to both a central component of mammalian complement system, factor C3, and to a pan-protease inhibitor, alpha2-macroglobulin. Most importantly, this protein serves as a complement-like opsonin and promotes phagocytosis of some Gram-negative bacteria in a mosquito hemocyte-like cell line. Chemical inactivation by methylamine and depletion by double-stranded RNA knockout demonstrate that this function is dependent on the internal thioester bond. This evidence of a complement-like function in a protostome animal adds substantially to the accumulating evidence of a common ancestry of immune defenses in insects and vertebrates.
2000
Dumortier H, Monneaux F, Jahn-Schmid B, Briand J P, Skriner K, Cohen P L, Smolen J S, Steiner G, Muller S
B and Ŧ cell responses to the spliceosomal heterogeneous nuclear ribonucleoproteins A2 and B1 in normal and lupus mice Article de journal
Dans: Journal of Immunology (Baltimore, Md.: 1950), vol. 165, no. 4, p. 2297–2305, 2000, ISSN: 0022-1767.
Résumé | Liens | BibTeX | Étiquettes: Amino Acid Sequence, Animals, Autoantibodies, B-Lymphocytes, Dumortier, Epitope Mapping, Female, Heterogeneous Nuclear, Heterogeneous-Nuclear Ribonucleoprotein Group A-B, Heterogeneous-Nuclear Ribonucleoproteins, Humans, I2CT, Immunoglobulin G, Inbred BALB C, Inbred C57BL, Inbred CBA, Inbred MRL lpr, Injections, Lupus Nephritis, Lymphocyte Activation, Male, Mice, Molecular Sequence Data, Monneaux, Peptide Fragments, Recombinant Proteins, Ribonucleoproteins, RNA, Spliceosomes, Subcutaneous, T-Lymphocytes, Team-Dumortier, transgenic
@article{dumortier_b_2000,
title = {B and Ŧ cell responses to the spliceosomal heterogeneous nuclear ribonucleoproteins A2 and B1 in normal and lupus mice},
author = {H Dumortier and F Monneaux and B Jahn-Schmid and J P Briand and K Skriner and P L Cohen and J S Smolen and G Steiner and S Muller},
doi = {10.4049/jimmunol.165.4.2297},
issn = {0022-1767},
year = {2000},
date = {2000-08-01},
journal = {Journal of Immunology (Baltimore, Md.: 1950)},
volume = {165},
number = {4},
pages = {2297--2305},
abstract = {Autoantibodies directed against spliceosomal heterogeneous nuclear ribonucleoproteins (hnRNPs) are a typical feature of rheumatoid arthritis, systemic lupus erythematosus, and mixed-connective tissue disease. With the aim of investigating a potential pathogenic role of these Abs, we have studied the Ab response to A2/B1 hnRNPs in different murine models of lupus. The specificity of anti-A2/B1 Abs was tested with a series of 14 overlapping synthetic peptides covering the region 1-206 of A2 that contains most of the epitopes recognized by patients' Abs. A major epitope recognized very early during the course of the disease by Abs from most of MRL lpr/lpr mice but not from other lupus mice and from mice of different MHC haplotypes immunized against B1 was identified in residues 50-70. This peptide contains a highly conserved sequence RGFGFVTF also present in other hnRNPs and small nuclear ribonucleoproteins. Abs reacting with a second A2 epitope identified in residues 35-55 were detectable several weeks later, suggesting an intramolecular B cell epitope spreading during the course of the disease. We identified several T cell epitopes within the region 35-175 that generated an effective Th cell response with IL-2 and IFN-gamma secretion in nonautoimmune CBA/J mice sharing the same MHC haplotype H-2k as MRL/lpr mice. None of the peptides stimulated T cells primed in vivo with B1. Because Abs to peptide 50-70 were detected significantly earlier than Abs reacting with other A2 peptides and the protein itself, it is possible that within the protein, this segment contains residues playing an initiator role in the induction of the anti-A2/B1 and antispliceosome Ab response.},
keywords = {Amino Acid Sequence, Animals, Autoantibodies, B-Lymphocytes, Dumortier, Epitope Mapping, Female, Heterogeneous Nuclear, Heterogeneous-Nuclear Ribonucleoprotein Group A-B, Heterogeneous-Nuclear Ribonucleoproteins, Humans, I2CT, Immunoglobulin G, Inbred BALB C, Inbred C57BL, Inbred CBA, Inbred MRL lpr, Injections, Lupus Nephritis, Lymphocyte Activation, Male, Mice, Molecular Sequence Data, Monneaux, Peptide Fragments, Recombinant Proteins, Ribonucleoproteins, RNA, Spliceosomes, Subcutaneous, T-Lymphocytes, Team-Dumortier, transgenic},
pubstate = {published},
tppubtype = {article}
}
Autoantibodies directed against spliceosomal heterogeneous nuclear ribonucleoproteins (hnRNPs) are a typical feature of rheumatoid arthritis, systemic lupus erythematosus, and mixed-connective tissue disease. With the aim of investigating a potential pathogenic role of these Abs, we have studied the Ab response to A2/B1 hnRNPs in different murine models of lupus. The specificity of anti-A2/B1 Abs was tested with a series of 14 overlapping synthetic peptides covering the region 1-206 of A2 that contains most of the epitopes recognized by patients' Abs. A major epitope recognized very early during the course of the disease by Abs from most of MRL lpr/lpr mice but not from other lupus mice and from mice of different MHC haplotypes immunized against B1 was identified in residues 50-70. This peptide contains a highly conserved sequence RGFGFVTF also present in other hnRNPs and small nuclear ribonucleoproteins. Abs reacting with a second A2 epitope identified in residues 35-55 were detectable several weeks later, suggesting an intramolecular B cell epitope spreading during the course of the disease. We identified several T cell epitopes within the region 35-175 that generated an effective Th cell response with IL-2 and IFN-gamma secretion in nonautoimmune CBA/J mice sharing the same MHC haplotype H-2k as MRL/lpr mice. None of the peptides stimulated T cells primed in vivo with B1. Because Abs to peptide 50-70 were detected significantly earlier than Abs reacting with other A2 peptides and the protein itself, it is possible that within the protein, this segment contains residues playing an initiator role in the induction of the anti-A2/B1 and antispliceosome Ab response.
Delagoutte B., Keith G., Moras D., Cavarelli J.
Crystallization and preliminary X-ray crystallographic analysis of yeast arginyl-tRNA synthetase-yeast tRNAArg complexes Article de journal
Dans: Acta Crystallogr D Biol Crystallogr, vol. 56, no. Pt 4, p. 492-4, 2000, (0907-4449 Journal Article).
Résumé | BibTeX | Étiquettes: &, Arg/*chemistry/isolation, Arginine-tRNA, cerevisiae/enzymology/genetics, Crystallization, Crystallography, Fungal/chemistry/isolation, Gov't, Ligase/*chemistry/isolation, Non-U.S., purification/*metabolism, purification/metabolism, RNA, Saccharomyces, Support, Transfer, X-Ray
@article{,
title = {Crystallization and preliminary X-ray crystallographic analysis of yeast arginyl-tRNA synthetase-yeast tRNAArg complexes},
author = { B. Delagoutte and G. Keith and D. Moras and J. Cavarelli},
year = {2000},
date = {2000-01-01},
journal = {Acta Crystallogr D Biol Crystallogr},
volume = {56},
number = {Pt 4},
pages = {492-4},
abstract = {Three different crystal forms of complexes between arginyl-tRNA synthetase from the yeast Saccharomyces cerevisae (yArgRS) and the yeast second major tRNA(Arg) (tRNA(Arg)(ICG)) isoacceptor have been crystallized by the hanging-drop vapour-diffusion method in the presence of ammonium sulfate. Crystal form II, which diffracts beyond 2.2 A resolution at the European Synchrotron Radiation Facility ID14-4 beamline, belongs to the orthorhombic space group P2(1)2(1)2, with unit-cell parameters a = 129.64},
note = {0907-4449
Journal Article},
keywords = {&, Arg/*chemistry/isolation, Arginine-tRNA, cerevisiae/enzymology/genetics, Crystallization, Crystallography, Fungal/chemistry/isolation, Gov't, Ligase/*chemistry/isolation, Non-U.S., purification/*metabolism, purification/metabolism, RNA, Saccharomyces, Support, Transfer, X-Ray},
pubstate = {published},
tppubtype = {article}
}
Three different crystal forms of complexes between arginyl-tRNA synthetase from the yeast Saccharomyces cerevisae (yArgRS) and the yeast second major tRNA(Arg) (tRNA(Arg)(ICG)) isoacceptor have been crystallized by the hanging-drop vapour-diffusion method in the presence of ammonium sulfate. Crystal form II, which diffracts beyond 2.2 A resolution at the European Synchrotron Radiation Facility ID14-4 beamline, belongs to the orthorhombic space group P2(1)2(1)2, with unit-cell parameters a = 129.64
Jaeger L., Leontis N. B.
Tecto-RNA: One-Dimensional Self-Assembly through Tertiary Interactions Article de journal
Dans: Angew Chem Int Ed Engl, vol. 39, no. 14, p. 2521-2524, 2000.
Résumé | BibTeX | Étiquettes: Chemistry, RNA, self-organisation, supramolecular
@article{,
title = {Tecto-RNA: One-Dimensional Self-Assembly through Tertiary Interactions},
author = { L. Jaeger and N. B. Leontis},
year = {2000},
date = {2000-01-01},
journal = {Angew Chem Int Ed Engl},
volume = {39},
number = {14},
pages = {2521-2524},
abstract = {The modularity of natural RNA is the basis for the design of tecto-RNA, modular RNA units capable of directed self-assembly. One such modular association through specific RNA loopreceptor tertiary interactions, which leads to one-dimensional oligomer arrays, is demonstrated (see picture).},
keywords = {Chemistry, RNA, self-organisation, supramolecular},
pubstate = {published},
tppubtype = {article}
}
The modularity of natural RNA is the basis for the design of tecto-RNA, modular RNA units capable of directed self-assembly. One such modular association through specific RNA loopreceptor tertiary interactions, which leads to one-dimensional oligomer arrays, is demonstrated (see picture).
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, no. 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, no. 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.
Lowenberger C A, Kamal S, Chiles J, Paskewitz S, Bulet Philippe, Hoffmann Jules A, Christensen B M
Mosquito-Plasmodium interactions in response to immune activation of the vector Article de journal
Dans: Exp. Parasitol., vol. 91, no. 1, p. 59–69, 1999, ISSN: 0014-4894.
Résumé | Liens | BibTeX | Étiquettes: Aedes, Animals, Anopheles, Culicidae, Defensins, Digestive System, Escherichia coli, Female, Genetic, Hemolymph, hoffmann, Insect Vectors, M3i, messenger, Micrococcus luteus, Plasmodium, Plasmodium berghei, Plasmodium gallinaceum, Proteins, Reverse Transcriptase Polymerase Chain Reaction, RNA, Transcription
@article{lowenberger_mosquito-plasmodium_1999,
title = {Mosquito-Plasmodium interactions in response to immune activation of the vector},
author = {C A Lowenberger and S Kamal and J Chiles and S Paskewitz and Philippe Bulet and Jules A Hoffmann and B M Christensen},
doi = {10.1006/expr.1999.4350},
issn = {0014-4894},
year = {1999},
date = {1999-01-01},
journal = {Exp. Parasitol.},
volume = {91},
number = {1},
pages = {59--69},
abstract = {During the development of Plasmodium sp. within the mosquito midgut, the parasite undergoes a series of developmental changes. The elongated ookinete migrates through the layers of the midgut where it forms the oocyst under the basal lamina. We demonstrate here that if Aedes aegypti or Anopheles gambiae, normally susceptible to Plasmodium gallinaceum and P. berghei, respectively, are immune activated by the injection of bacteria into the hemocoel, and subsequently are fed on an infectious bloodmeal, there is a significant reduction in the prevalence and mean intensity of infection of oocysts on the midgut. Only those mosquitoes immune activated prior to, or immediately after, parasite ingestion exhibit this reduction in parasite development. Mosquitoes immune activated 2-5 days after bloodfeeding show no differences in parasite burdens compared with naive controls. Northern analyses reveal that transcriptional activity for mosquito defensins is not detected in the whole bodies of Ae. aegypti from 4 h to 10 days after ingesting P. gallinaceum, suggesting that parasite ingestion, passage from the food bolus through the midgut, oocyst formation, and subsequent release of sporozoites into the hemolymph do not induce the production of defensin. However, reverse transcriptase-PCR of RNA isolated solely from the midguts of Ae. aegypti indicates that transcription of mosquito defensins occurs in the midguts of naive mosquitoes and those ingesting an infectious or noninfectious bloodmeal. Bacteria-challenged Ae. aegypti showed high levels of mature defensin in the hemolymph that correlate with a lower prevalence and mean intensity of infection with oocysts. Because few oocysts were found on the midgut of immune-activated mosquitoes, the data suggest that some factor, induced by bacterial challenge, kills the parasite at a preoocyst stage.},
keywords = {Aedes, Animals, Anopheles, Culicidae, Defensins, Digestive System, Escherichia coli, Female, Genetic, Hemolymph, hoffmann, Insect Vectors, M3i, messenger, Micrococcus luteus, Plasmodium, Plasmodium berghei, Plasmodium gallinaceum, Proteins, Reverse Transcriptase Polymerase Chain Reaction, RNA, Transcription},
pubstate = {published},
tppubtype = {article}
}
During the development of Plasmodium sp. within the mosquito midgut, the parasite undergoes a series of developmental changes. The elongated ookinete migrates through the layers of the midgut where it forms the oocyst under the basal lamina. We demonstrate here that if Aedes aegypti or Anopheles gambiae, normally susceptible to Plasmodium gallinaceum and P. berghei, respectively, are immune activated by the injection of bacteria into the hemocoel, and subsequently are fed on an infectious bloodmeal, there is a significant reduction in the prevalence and mean intensity of infection of oocysts on the midgut. Only those mosquitoes immune activated prior to, or immediately after, parasite ingestion exhibit this reduction in parasite development. Mosquitoes immune activated 2-5 days after bloodfeeding show no differences in parasite burdens compared with naive controls. Northern analyses reveal that transcriptional activity for mosquito defensins is not detected in the whole bodies of Ae. aegypti from 4 h to 10 days after ingesting P. gallinaceum, suggesting that parasite ingestion, passage from the food bolus through the midgut, oocyst formation, and subsequent release of sporozoites into the hemolymph do not induce the production of defensin. However, reverse transcriptase-PCR of RNA isolated solely from the midguts of Ae. aegypti indicates that transcription of mosquito defensins occurs in the midguts of naive mosquitoes and those ingesting an infectious or noninfectious bloodmeal. Bacteria-challenged Ae. aegypti showed high levels of mature defensin in the hemolymph that correlate with a lower prevalence and mean intensity of infection with oocysts. Because few oocysts were found on the midgut of immune-activated mosquitoes, the data suggest that some factor, induced by bacterial challenge, kills the parasite at a preoocyst stage.
1998
Uttenweiler-Joseph S, Moniatte M, Lagueux Marie, Dorsselaer Van A, Hoffmann Jules A, Bulet Philippe
Differential display of peptides induced during the immune response of Drosophila: a matrix-assisted laser desorption ionization time-of-flight mass spectrometry study Article de journal
Dans: Proc. Natl. Acad. Sci. U.S.A., vol. 95, no. 19, p. 11342–11347, 1998, ISSN: 0027-8424.
Résumé | BibTeX | Étiquettes: Animals, bacteria, Chromatography, Cloning, Hemolymph, High Pressure Liquid, hoffmann, Immunity, Insect Proteins, M3i, Mass, Matrix-Assisted Laser Desorption-Ionization, messenger, Molecular, Peptides, Protein Precursors, RNA, Sequence Analysis, Spectrometry, Time Factors
@article{uttenweiler-joseph_differential_1998,
title = {Differential display of peptides induced during the immune response of Drosophila: a matrix-assisted laser desorption ionization time-of-flight mass spectrometry study},
author = {S Uttenweiler-Joseph and M Moniatte and Marie Lagueux and Van A Dorsselaer and Jules A Hoffmann and Philippe Bulet},
issn = {0027-8424},
year = {1998},
date = {1998-09-01},
journal = {Proc. Natl. Acad. Sci. U.S.A.},
volume = {95},
number = {19},
pages = {11342--11347},
abstract = {We have developed an approach based on a differential mass spectrometric analysis to detect molecules induced during the immune response of Drosophila, regardless of their biological activities. For this, we have applied directly matrix-assisted laser desorption/ionization MS to hemolymph samples from individual flies before and after an immune challenge. This method provided precise information on the molecular masses of immune-induced molecules and allowed the detection, in the molecular range of 1.5-11 kDa, of 24 Drosophila immune-induced molecules (DIMs). These molecules are all peptides, and four correspond to already characterized antimicrobial peptides. We have further analyzed the induction of the various peptides by immune challenge in wild-type flies and in mutants with a compromised antimicrobial response. We also describe a methodology combining matrix-assisted laser desorption ionization time-of-flight MS, HPLC, and Edman degradation, which yielded the peptide sequence of three of the DIMs. Finally, molecular cloning and Northern blot analyses revealed that one of the DIMs is produced as a prepropeptide and is inducible on a bacterial challenge.},
keywords = {Animals, bacteria, Chromatography, Cloning, Hemolymph, High Pressure Liquid, hoffmann, Immunity, Insect Proteins, M3i, Mass, Matrix-Assisted Laser Desorption-Ionization, messenger, Molecular, Peptides, Protein Precursors, RNA, Sequence Analysis, Spectrometry, Time Factors},
pubstate = {published},
tppubtype = {article}
}
We have developed an approach based on a differential mass spectrometric analysis to detect molecules induced during the immune response of Drosophila, regardless of their biological activities. For this, we have applied directly matrix-assisted laser desorption/ionization MS to hemolymph samples from individual flies before and after an immune challenge. This method provided precise information on the molecular masses of immune-induced molecules and allowed the detection, in the molecular range of 1.5-11 kDa, of 24 Drosophila immune-induced molecules (DIMs). These molecules are all peptides, and four correspond to already characterized antimicrobial peptides. We have further analyzed the induction of the various peptides by immune challenge in wild-type flies and in mutants with a compromised antimicrobial response. We also describe a methodology combining matrix-assisted laser desorption ionization time-of-flight MS, HPLC, and Edman degradation, which yielded the peptide sequence of three of the DIMs. Finally, molecular cloning and Northern blot analyses revealed that one of the DIMs is produced as a prepropeptide and is inducible on a bacterial challenge.
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, no. 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, no. 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, no. 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.
Motorin Y., Keith G., Simon C., Foiret D., Simos G., Hurt E., Grosjean H.
The yeast tRNA:pseudouridine synthase Pus1p displays a multisite substrate specificity Article de journal
Dans: RNA, vol. 4, no. 7, p. 856-69, 1998, (1355-8382 Journal Article).
Résumé | BibTeX | Étiquettes: *RNA, cerevisiae, Cloning, Fractions/metabolism, Fungal, Fungal/metabolism, Gov't, Hydro-Lyases/biosynthesis/genetics/*metabolism, Molecular, Mutation, Non-U.S., Plant/metabolism, post-transcriptional, Precursors/*metabolism, Processing, Proteins/biosynthesis, Proteins/biosynthesis/genetics/metabolism, Pseudouridine/*biosynthesis, Recombinant, RNA, Saccharomyces, Specificity, Subcellular, Substrate, Support, Transfer/*metabolism
@article{,
title = {The yeast tRNA:pseudouridine synthase Pus1p displays a multisite substrate specificity},
author = { Y. Motorin and G. Keith and C. Simon and D. Foiret and G. Simos and E. Hurt and H. Grosjean},
year = {1998},
date = {1998-01-01},
journal = {RNA},
volume = {4},
number = {7},
pages = {856-69},
abstract = {We have previously shown that the yeast gene PUS1 codes for a tRNA:pseudouridine synthase and that recombinant Pus1p catalyzes, in an intron-dependent way, the formation of psi34 and psi36 in the anticodon loop of the yeast minor tRNA(Ile) in vitro (Simos G et al., 1996, EMBO J 15:2270-2284). Using a set of T7 transcripts of different tRNA genes, we now demonstrate that yeast pseudouridine synthase 1 catalyzes in vitro pseudouridine formation at positions 27 and/or 28 in several yeast cytoplasmic tRNAs and at position 35 in the intron-containing tRNA(Tyr) (anticodon GUA). Thus, Pus1p not only displays a broad specificity toward the RNA substrates, but is also capable of catalyzing the pseudouridine (psi) formation at distinct noncontiguous sites within the same tRNA molecule. The cell-free extract prepared from the yeast strain bearing disrupted gene PUS1 is unable to catalyze the formation of psi27, psi28, psi34, and psi36 in vitro, however, psi35 formation in the intron-containing tRNA(Tyr)(GUA) remains unaffected. Thus, in yeast, only one gene product accounts for tRNA pseudouridylation at positions 27, 28, 34, and 36, whereas for position 35 in tRNA(Tyr), another site-specific tRNA:pseudouridine synthase with overlapping specificity exists. Mapping of pseudouridine residues present in various tRNAs extracted from the PUS1-disrupted strain confirms the in vitro data obtained with the recombinant Pus1p. In addition, they suggest that Pus1p is implicated in modification at positions U26, U65, and U67 in vivo.},
note = {1355-8382
Journal Article},
keywords = {*RNA, cerevisiae, Cloning, Fractions/metabolism, Fungal, Fungal/metabolism, Gov't, Hydro-Lyases/biosynthesis/genetics/*metabolism, Molecular, Mutation, Non-U.S., Plant/metabolism, post-transcriptional, Precursors/*metabolism, Processing, Proteins/biosynthesis, Proteins/biosynthesis/genetics/metabolism, Pseudouridine/*biosynthesis, Recombinant, RNA, Saccharomyces, Specificity, Subcellular, Substrate, Support, Transfer/*metabolism},
pubstate = {published},
tppubtype = {article}
}
We have previously shown that the yeast gene PUS1 codes for a tRNA:pseudouridine synthase and that recombinant Pus1p catalyzes, in an intron-dependent way, the formation of psi34 and psi36 in the anticodon loop of the yeast minor tRNA(Ile) in vitro (Simos G et al., 1996, EMBO J 15:2270-2284). Using a set of T7 transcripts of different tRNA genes, we now demonstrate that yeast pseudouridine synthase 1 catalyzes in vitro pseudouridine formation at positions 27 and/or 28 in several yeast cytoplasmic tRNAs and at position 35 in the intron-containing tRNA(Tyr) (anticodon GUA). Thus, Pus1p not only displays a broad specificity toward the RNA substrates, but is also capable of catalyzing the pseudouridine (psi) formation at distinct noncontiguous sites within the same tRNA molecule. The cell-free extract prepared from the yeast strain bearing disrupted gene PUS1 is unable to catalyze the formation of psi27, psi28, psi34, and psi36 in vitro, however, psi35 formation in the intron-containing tRNA(Tyr)(GUA) remains unaffected. Thus, in yeast, only one gene product accounts for tRNA pseudouridylation at positions 27, 28, 34, and 36, whereas for position 35 in tRNA(Tyr), another site-specific tRNA:pseudouridine synthase with overlapping specificity exists. Mapping of pseudouridine residues present in various tRNAs extracted from the PUS1-disrupted strain confirms the in vitro data obtained with the recombinant Pus1p. In addition, they suggest that Pus1p is implicated in modification at positions U26, U65, and U67 in vivo.
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, no. 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.
Wilhelm M., Heyman T., Friant S., Wilhelm F. X.
Heterogeneous terminal structure of Ty1 and Ty3 reverse transcripts Article de journal
Dans: Nucleic Acids Res, vol. 25, no. 11, p. 2161-6, 1997, (0305-1048 Journal Article).
Résumé | BibTeX | Étiquettes: *Nucleic, *Transcription, Acid, Calf, Chain, Conformation, DNA, Fungal/*chemistry/metabolism, Genetic, Gov't, H, Hybridization, Non-U.S., Nucleic, Plasmids/chemistry/genetics/metabolism, Polymerase, Reaction, Replication, Retroelements/*genetics, Ribonuclease, RNA, Support, Thymus/metabolism, Transfer/chemistry
@article{,
title = {Heterogeneous terminal structure of Ty1 and Ty3 reverse transcripts},
author = { M. Wilhelm and T. Heyman and S. Friant and F. X. Wilhelm},
year = {1997},
date = {1997-01-01},
journal = {Nucleic Acids Res},
volume = {25},
number = {11},
pages = {2161-6},
abstract = {A specific terminal structure of preintegrative DNA is required for transposition of retroviruses and LTR-retrotransposons. We have used an anchored PCR technique to map the 3'ends of DNA intermediates synthesized inside yeast Ty1 and Ty3 retrotransposon virus-like particles. We find that, unlike retroviruses, Ty1 replicated DNA does not have two extra base pairs at its 3'ends. In contrast some Ty3 preintegrative DNA molecules have two extra nucleotides at the 3'end of upstream and downstream long terminal repeats. Moreover we find that some molecules of replicated Ty3 DNA have more than two extra nucleotides at the 3'end of the upstream LTR. This observation could be accounted for by imprecise RNAse H cutting of the PPT sequence. The site of Ty1 and Ty3 plus-strand strong-stop DNA termination was also examined. Our results confirm that the prominent Ty1 and Ty3 plus-strand strong-stop molecules harbor 12 tRNA templated bases but also show that some Ty1 and Ty3 plus-strand strong-stop DNA molecules harbor less tRNA templated bases. We propose that these less than full length plus-strand molecules could be active intermediates in Ty retrotransposon replication.},
note = {0305-1048
Journal Article},
keywords = {*Nucleic, *Transcription, Acid, Calf, Chain, Conformation, DNA, Fungal/*chemistry/metabolism, Genetic, Gov't, H, Hybridization, Non-U.S., Nucleic, Plasmids/chemistry/genetics/metabolism, Polymerase, Reaction, Replication, Retroelements/*genetics, Ribonuclease, RNA, Support, Thymus/metabolism, Transfer/chemistry},
pubstate = {published},
tppubtype = {article}
}
A specific terminal structure of preintegrative DNA is required for transposition of retroviruses and LTR-retrotransposons. We have used an anchored PCR technique to map the 3'ends of DNA intermediates synthesized inside yeast Ty1 and Ty3 retrotransposon virus-like particles. We find that, unlike retroviruses, Ty1 replicated DNA does not have two extra base pairs at its 3'ends. In contrast some Ty3 preintegrative DNA molecules have two extra nucleotides at the 3'end of upstream and downstream long terminal repeats. Moreover we find that some molecules of replicated Ty3 DNA have more than two extra nucleotides at the 3'end of the upstream LTR. This observation could be accounted for by imprecise RNAse H cutting of the PPT sequence. The site of Ty1 and Ty3 plus-strand strong-stop DNA termination was also examined. Our results confirm that the prominent Ty1 and Ty3 plus-strand strong-stop molecules harbor 12 tRNA templated bases but also show that some Ty1 and Ty3 plus-strand strong-stop DNA molecules harbor less tRNA templated bases. We propose that these less than full length plus-strand molecules could be active intermediates in Ty retrotransposon replication.
1996
Lowenberger C A, Ferdig M T, Bulet Philippe, Khalili S, Hoffmann Jules A, Christensen B M
Aedes aegypti: induced antibacterial proteins reduce the establishment and development of Brugia malayi Article de journal
Dans: Exp. Parasitol., vol. 83, no. 2, p. 191–201, 1996, ISSN: 0014-4894.
Résumé | Liens | BibTeX | Étiquettes: Aedes, Analysis of Variance, Animals, Anti-Bacterial Agents, Base Sequence, Blood Proteins, Blotting, Brugia malayi, Culicidae, Defensins, DNA, Escherichia coli, Fat Body, Genetic, Gerbillinae, hoffmann, M3i, Micrococcus luteus, Microfilaria, Northern, RNA, Transcription
@article{lowenberger_aedes_1996,
title = {Aedes aegypti: induced antibacterial proteins reduce the establishment and development of Brugia malayi},
author = {C A Lowenberger and M T Ferdig and Philippe Bulet and S Khalili and Jules A Hoffmann and B M Christensen},
doi = {10.1006/expr.1996.0066},
issn = {0014-4894},
year = {1996},
date = {1996-07-01},
journal = {Exp. Parasitol.},
volume = {83},
number = {2},
pages = {191--201},
abstract = {The effect of host immune activation on the development of Brugia malayi in one susceptible and four refractory strains of Aedes aegypti and in Armigeres subalbatus was assessed. A. aegypti that were immune activated by the injection of saline or bacteria 24 hr before feeding on a B. malayi-infected gerbil had significantly reduced prevalences and mean intensities of infection from those of naive controls when exposed to bloodmeals with low (105 mf/20 microliters) and medium (160 mf/20 microliters) microfilaremias. At a higher microfilaremia (237 mf/20 microliters) there were no significant differences in mean intensities, suggesting that the number of parasites ingested may affect the host's ability to mount an effective defense response. Because the major immune proteins in A. aegypti are defensins, we did Northern analyses of fat body RNA 8 hr after immune activation or bloodfeeding. All mosquitoes demonstrated rapid transcriptional activity for defensins following immune activation by intrathoracic inoculation with either saline or bacteria. However, no strain of A. aegypti, susceptible or refractory to B. malayi, nor Ar. subalbatus produced defensin transcripts after bloodfeeding on an uninfected or a B. malayi-infected gerbil. These data suggest that inducible immune proteins of mosquitoes can reduce the prevalence and mean intensity of infections with ingested parasites, but these proteins are not expressed routinely after parasite ingestion and midgut penetration and probably do not contribute to existing refractory mechanisms. Immune proteins such as defensins, however, represent potential candidates to genetically engineer mosquitoes for resistance to filarial worms.},
keywords = {Aedes, Analysis of Variance, Animals, Anti-Bacterial Agents, Base Sequence, Blood Proteins, Blotting, Brugia malayi, Culicidae, Defensins, DNA, Escherichia coli, Fat Body, Genetic, Gerbillinae, hoffmann, M3i, Micrococcus luteus, Microfilaria, Northern, RNA, Transcription},
pubstate = {published},
tppubtype = {article}
}
The effect of host immune activation on the development of Brugia malayi in one susceptible and four refractory strains of Aedes aegypti and in Armigeres subalbatus was assessed. A. aegypti that were immune activated by the injection of saline or bacteria 24 hr before feeding on a B. malayi-infected gerbil had significantly reduced prevalences and mean intensities of infection from those of naive controls when exposed to bloodmeals with low (105 mf/20 microliters) and medium (160 mf/20 microliters) microfilaremias. At a higher microfilaremia (237 mf/20 microliters) there were no significant differences in mean intensities, suggesting that the number of parasites ingested may affect the host's ability to mount an effective defense response. Because the major immune proteins in A. aegypti are defensins, we did Northern analyses of fat body RNA 8 hr after immune activation or bloodfeeding. All mosquitoes demonstrated rapid transcriptional activity for defensins following immune activation by intrathoracic inoculation with either saline or bacteria. However, no strain of A. aegypti, susceptible or refractory to B. malayi, nor Ar. subalbatus produced defensin transcripts after bloodfeeding on an uninfected or a B. malayi-infected gerbil. These data suggest that inducible immune proteins of mosquitoes can reduce the prevalence and mean intensity of infections with ingested parasites, but these proteins are not expressed routinely after parasite ingestion and midgut penetration and probably do not contribute to existing refractory mechanisms. Immune proteins such as defensins, however, represent potential candidates to genetically engineer mosquitoes for resistance to filarial worms.
Friant S., Heyman T., Wilhelm F. X., Wilhelm M.
Role of RNA primers in initiation of minus-strand and plus-strand DNA synthesis of the yeast retrotransposon Ty1 Article de journal
Dans: Biochimie, vol. 78, no. 7, p. 674-80, 1996, (0300-9084 Journal Article).
Résumé | BibTeX | Étiquettes: *DNA, Acid, Bacterial/*metabolism, Complementary/metabolism, Conformation, Data, DNA, Elements, Gov't, Molecular, Mutagenesis, Non-U.S., Nucleic, Replication, RNA, RNA/*metabolism, Sequence, Support, Transposable
@article{,
title = {Role of RNA primers in initiation of minus-strand and plus-strand DNA synthesis of the yeast retrotransposon Ty1},
author = { S. Friant and T. Heyman and F. X. Wilhelm and M. Wilhelm},
year = {1996},
date = {1996-01-01},
journal = {Biochimie},
volume = {78},
number = {7},
pages = {674-80},
abstract = {The Ty1 retrotransposon of the yeast Saccharomyces cerevisiae is a long terminal repeat mobile genetic element that transposes through an RNA intermediate. Initiation of minus-strand and plus-strand DNA synthesis are two critical steps during reverse transcription of the retrotransposon genome. Initiation of minus-strand DNA synthesis of the Ty1 element is primed by the cytoplasmic initiator methionine tRNA base paired to the primer binding site near the 5' end of the genomic RNA. A structural probing study of the primer tRNA-Ty1 RNA binary complex reveals that besides interactions between the primer binding site and the last 10 nucleotides at the 3' end of the primer tRNA, three short regions of Ty1 RNA named box 0, box 1 and box 2.1 interact with the T and D stems and loops of the primer tRNA. Some in vivo results underline the functional importance of the nucleotide sequence of the boxes and suggest that extended interactions between genomic Ty1 RNA and the primer tRNA play a role in the reverse transcription pathway. Plus-strand DNA synthesis is initiated from an RNase H resistant oligoribonucleotide spanning a purine-rich sequence, the polypurine tract (PPT). Two sites of initiation located at the 5' boundary of the 3' long terminal repeat (PPT1) and near the middle of the TyB (pol) gene in the integrase coding sequence (PPT2) have been identified in the genome of Ty1. The two PPTs have an identical sequence, TGGGTGGTA. Mutations replacing purines by pyrimidines in this sequence significantly diminish or abolish initiation of plus-strand DNA synthesis. Ty1 elements bearing a mutated PPT2 sequence are not defective for transposition whereas mutations in PPT1 abolish transposition.},
note = {0300-9084
Journal Article},
keywords = {*DNA, Acid, Bacterial/*metabolism, Complementary/metabolism, Conformation, Data, DNA, Elements, Gov't, Molecular, Mutagenesis, Non-U.S., Nucleic, Replication, RNA, RNA/*metabolism, Sequence, Support, Transposable},
pubstate = {published},
tppubtype = {article}
}
The Ty1 retrotransposon of the yeast Saccharomyces cerevisiae is a long terminal repeat mobile genetic element that transposes through an RNA intermediate. Initiation of minus-strand and plus-strand DNA synthesis are two critical steps during reverse transcription of the retrotransposon genome. Initiation of minus-strand DNA synthesis of the Ty1 element is primed by the cytoplasmic initiator methionine tRNA base paired to the primer binding site near the 5' end of the genomic RNA. A structural probing study of the primer tRNA-Ty1 RNA binary complex reveals that besides interactions between the primer binding site and the last 10 nucleotides at the 3' end of the primer tRNA, three short regions of Ty1 RNA named box 0, box 1 and box 2.1 interact with the T and D stems and loops of the primer tRNA. Some in vivo results underline the functional importance of the nucleotide sequence of the boxes and suggest that extended interactions between genomic Ty1 RNA and the primer tRNA play a role in the reverse transcription pathway. Plus-strand DNA synthesis is initiated from an RNase H resistant oligoribonucleotide spanning a purine-rich sequence, the polypurine tract (PPT). Two sites of initiation located at the 5' boundary of the 3' long terminal repeat (PPT1) and near the middle of the TyB (pol) gene in the integrase coding sequence (PPT2) have been identified in the genome of Ty1. The two PPTs have an identical sequence, TGGGTGGTA. Mutations replacing purines by pyrimidines in this sequence significantly diminish or abolish initiation of plus-strand DNA synthesis. Ty1 elements bearing a mutated PPT2 sequence are not defective for transposition whereas mutations in PPT1 abolish transposition.
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, no. 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, no. 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
Dirheimer G., Baranowski W., Keith G.
Variations in tRNA modifications, particularly of their queuine content in higher eukaryotes. Its relation to malignancy grading Article de journal
Dans: Biochimie, vol. 77, no. 1-2, p. 99-103, 1995, (0300-9084 Journal Article Review Review, Tutorial).
Résumé | BibTeX | Étiquettes: &, Animals, Cell, derivatives/analysis, Female, Gov't, Guanine/*analogs, Human, Neoplasms/*genetics/pathology, Neoplastic/genetics, Non-U.S., Ovarian, post-transcriptional, Processing, Purines/analysis, Pyrimidines/analysis, RNA, Support, Transfer/*chemistry/metabolism, Transformation
@article{,
title = {Variations in tRNA modifications, particularly of their queuine content in higher eukaryotes. Its relation to malignancy grading},
author = { G. Dirheimer and W. Baranowski and G. Keith},
year = {1995},
date = {1995-01-01},
journal = {Biochimie},
volume = {77},
number = {1-2},
pages = {99-103},
abstract = {Literature references dealing with the variations in the modification level of nucleosides in total eukaryotic tRNAs as a function of different physiological status and after drug administration as well as in sequenced cytoplasmic tRNAs between normal and tumor cells and in SV40-transformed cells are reviewed. In addition, special attention is given to guanine replacement of queuine in the first position of the anticodon of tRNAs. A correlation between the level of this undermodification in cancer tissues and the malignancy grading could be found in human ovarian tumors, confirming the results reported in several laboratories for lymphomas and lung cancer tissues. Indeed tRNAs from primary and metastatic human ovarian malignant tumors are Q deficient as compared to tRNAs from normal tissues or benign tumors: thus queuine deficiency increases with malignancy and grading of differentiation.},
note = {0300-9084
Journal Article
Review
Review, Tutorial},
keywords = {&, Animals, Cell, derivatives/analysis, Female, Gov't, Guanine/*analogs, Human, Neoplasms/*genetics/pathology, Neoplastic/genetics, Non-U.S., Ovarian, post-transcriptional, Processing, Purines/analysis, Pyrimidines/analysis, RNA, Support, Transfer/*chemistry/metabolism, Transformation},
pubstate = {published},
tppubtype = {article}
}
Literature references dealing with the variations in the modification level of nucleosides in total eukaryotic tRNAs as a function of different physiological status and after drug administration as well as in sequenced cytoplasmic tRNAs between normal and tumor cells and in SV40-transformed cells are reviewed. In addition, special attention is given to guanine replacement of queuine in the first position of the anticodon of tRNAs. A correlation between the level of this undermodification in cancer tissues and the malignancy grading could be found in human ovarian tumors, confirming the results reported in several laboratories for lymphomas and lung cancer tissues. Indeed tRNAs from primary and metastatic human ovarian malignant tumors are Q deficient as compared to tRNAs from normal tissues or benign tumors: thus queuine deficiency increases with malignancy and grading of differentiation.
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, no. 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.
Keith G.
Mobilities of modified ribonucleotides on two-dimensional cellulose thin-layer chromatography Article de journal
Dans: Biochimie, vol. 77, no. 1-2, p. 142-4, 1995, (0300-9084 Journal Article).
BibTeX | Étiquettes: *Chromatography, Layer, Purines/chemistry, Pyrimidines/chemistry, Ribonucleases/metabolism, Ribonucleotides/*chemistry, RNA, Thin, Transfer/chemistry
@article{,
title = {Mobilities of modified ribonucleotides on two-dimensional cellulose thin-layer chromatography},
author = { G. Keith},
year = {1995},
date = {1995-01-01},
journal = {Biochimie},
volume = {77},
number = {1-2},
pages = {142-4},
note = {0300-9084
Journal Article},
keywords = {*Chromatography, Layer, Purines/chemistry, Pyrimidines/chemistry, Ribonucleases/metabolism, Ribonucleotides/*chemistry, RNA, Thin, Transfer/chemistry},
pubstate = {published},
tppubtype = {article}
}
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, no. 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
Ferrandon Dominique, Elphick L, Nüsslein-Volhard C, Johnston St D
Staufen protein associates with the 3'UTR of bicoid mRNA to form particles that move in a microtubule-dependent manner Article de journal
Dans: Cell, vol. 79, no. 7, p. 1221–1232, 1994, ISSN: 0092-8674.
Résumé | BibTeX | Étiquettes: Animals, Base Sequence, Cell Polarity, ferrandon, Homeodomain Proteins, Insect Hormones, M3i, messenger, Microtubules, Nucleic Acid Conformation, Oocytes, RNA, RNA-Binding Proteins, Trans-Activators
@article{ferrandon_staufen_1994b,
title = {Staufen protein associates with the 3'UTR of bicoid mRNA to form particles that move in a microtubule-dependent manner},
author = {Dominique Ferrandon and L Elphick and C Nüsslein-Volhard and St D Johnston},
issn = {0092-8674},
year = {1994},
date = {1994-12-01},
journal = {Cell},
volume = {79},
number = {7},
pages = {1221--1232},
abstract = {Staufen protein is required in order to anchor bicoid (bcd) mRNA at the anterior pole of the Drosophila egg. Here we show that staufen protein colocalizes with bcd mRNA at the anterior, and that this localization depends upon its association with the mRNA. Upon injection into the embryo, bcd transcripts specifically interact with staufen, and we have mapped the sequences required to three regions of the 3'UTR, each of which is predicted to form a long stem-loop. The resulting staufen-bcd 3'UTR complexes form particles that show a microtubule-dependent localization. Since staufen is also transported with oskar (osk) mRNA during oogenesis, staufen associates specifically with both osk and bcd mRNAs to mediate their localizations, but at two distinct stages of development.},
keywords = {Animals, Base Sequence, Cell Polarity, ferrandon, Homeodomain Proteins, Insect Hormones, M3i, messenger, Microtubules, Nucleic Acid Conformation, Oocytes, RNA, RNA-Binding Proteins, Trans-Activators},
pubstate = {published},
tppubtype = {article}
}
Staufen protein is required in order to anchor bicoid (bcd) mRNA at the anterior pole of the Drosophila egg. Here we show that staufen protein colocalizes with bcd mRNA at the anterior, and that this localization depends upon its association with the mRNA. Upon injection into the embryo, bcd transcripts specifically interact with staufen, and we have mapped the sequences required to three regions of the 3'UTR, each of which is predicted to form a long stem-loop. The resulting staufen-bcd 3'UTR complexes form particles that show a microtubule-dependent localization. Since staufen is also transported with oskar (osk) mRNA during oogenesis, staufen associates specifically with both osk and bcd mRNAs to mediate their localizations, but at two distinct stages of development.
Fehlbaum P, Bulet Philippe, Michaut L, Lagueux Marie, Broekaert W F, Hetru Charles, Hoffmann Jules A
Insect immunity. Septic injury of Drosophila induces the synthesis of a potent antifungal peptide with sequence homology to plant antifungal peptides Article de journal
Dans: J. Biol. Chem., vol. 269, no. 52, p. 33159–33163, 1994, ISSN: 0021-9258.
Résumé | BibTeX | Étiquettes: Amino Acid, Animals, Antifungal Agents, Base Sequence, Cloning, Complementary, DNA, hoffmann, Insect Proteins, M3i, Male, messenger, Microbial Sensitivity Tests, Molecular, Peptide Biosynthesis, Peptides, Plants, Protein Biosynthesis, Protein Precursors, Proteins, RNA, Sequence Homology
@article{fehlbaum_insect_1994,
title = {Insect immunity. Septic injury of Drosophila induces the synthesis of a potent antifungal peptide with sequence homology to plant antifungal peptides},
author = {P Fehlbaum and Philippe Bulet and L Michaut and Marie Lagueux and W F Broekaert and Charles Hetru and Jules A Hoffmann},
issn = {0021-9258},
year = {1994},
date = {1994-12-01},
journal = {J. Biol. Chem.},
volume = {269},
number = {52},
pages = {33159--33163},
abstract = {In response to a septic injury (pricking with a bacteria-soaked needle) larvae and adults of Drosophila produce considerable amounts of a 44-residue peptide containing 8 cysteines engaged in intramolecular disulfide bridges. The peptide is synthesized in the fat body, a functional homologue of the mammalian liver, and secreted into the blood of the insect. It exhibits potent antifungal activity but is inactive against bacteria. This novel inducible peptide, which we propose to name drosomycin, shows a significant homology with a family of 5-kDa cysteine-rich plant antifungal peptides recently isolated from seeds of Brassicaceae. This finding underlines that plants and insects can rely on similar molecules in their innate host defense.},
keywords = {Amino Acid, Animals, Antifungal Agents, Base Sequence, Cloning, Complementary, DNA, hoffmann, Insect Proteins, M3i, Male, messenger, Microbial Sensitivity Tests, Molecular, Peptide Biosynthesis, Peptides, Plants, Protein Biosynthesis, Protein Precursors, Proteins, RNA, Sequence Homology},
pubstate = {published},
tppubtype = {article}
}
In response to a septic injury (pricking with a bacteria-soaked needle) larvae and adults of Drosophila produce considerable amounts of a 44-residue peptide containing 8 cysteines engaged in intramolecular disulfide bridges. The peptide is synthesized in the fat body, a functional homologue of the mammalian liver, and secreted into the blood of the insect. It exhibits potent antifungal activity but is inactive against bacteria. This novel inducible peptide, which we propose to name drosomycin, shows a significant homology with a family of 5-kDa cysteine-rich plant antifungal peptides recently isolated from seeds of Brassicaceae. This finding underlines that plants and insects can rely on similar molecules in their innate host defense.
Baranowski W., Dirheimer G., Jakowicki J. A., Keith G.
Deficiency of queuine, a highly modified purine base, in transfer RNAs from primary and metastatic ovarian malignant tumors in women Article de journal
Dans: Cancer Res, vol. 54, no. 16, p. 4468-71, 1994, (0008-5472 Journal Article).
Résumé | BibTeX | Étiquettes: &, Adolescent, Adult, Aged, derivatives/analysis, Female, Gov't, Guanine/*analogs, Human, Middle, Neoplasm/*chemistry, Neoplasms/*chemistry/pathology, Non-U.S., Ovarian, RNA, Support, Transfer/*chemistry
@article{,
title = {Deficiency of queuine, a highly modified purine base, in transfer RNAs from primary and metastatic ovarian malignant tumors in women},
author = { W. Baranowski and G. Dirheimer and J. A. Jakowicki and G. Keith},
year = {1994},
date = {1994-01-01},
journal = {Cancer Res},
volume = {54},
number = {16},
pages = {4468-71},
abstract = {The tRNAs from rapidly growing tissues, particularly from neoplasia, often exhibit queuine deficiency. In order to check whether different kinds of ovarian tumors display queuine deficiencies we have analyzed tRNA samples from 16 ovarian malignancies. The tRNAs from histologically normal myometrium (4 samples) and myoma (6 samples) were taken as healthy tissue and benign tumor references. Queuine deficiency was determined by an exchange assay using [8-3H]guanine and tRNA:guanine transglycosylase from Escherichia coli. The mean values of queuine deficiencies in tRNAs were: 10.95 +/- 2.21 (SD) pmol/A260 in gonadal and germ cell tumors (5 cases); 23.75 +/- 7.89 pmol/A260 in primary epithelial tumors (9 cases); and 34.58 +/- 7.18 pmol/A260 in metastatic tumors (2 cases). These values displayed statistically significant differences (P = 0.0003, Kruskal-Wallis test). The queuine deficiencies in tRNAs significantly increased when moving from well-differentiated through moderately differentiated to poorly differentiated tumors, with the highest values found in poorly differentiated metastatic tumors (P = 0.0002, Kruskal-Wallis test). Queuine deficiency determination in tRNAs is proposed as a factor for clinical outcome prognosis of ovarian malignancies.},
note = {0008-5472
Journal Article},
keywords = {&, Adolescent, Adult, Aged, derivatives/analysis, Female, Gov't, Guanine/*analogs, Human, Middle, Neoplasm/*chemistry, Neoplasms/*chemistry/pathology, Non-U.S., Ovarian, RNA, Support, Transfer/*chemistry},
pubstate = {published},
tppubtype = {article}
}
The tRNAs from rapidly growing tissues, particularly from neoplasia, often exhibit queuine deficiency. In order to check whether different kinds of ovarian tumors display queuine deficiencies we have analyzed tRNA samples from 16 ovarian malignancies. The tRNAs from histologically normal myometrium (4 samples) and myoma (6 samples) were taken as healthy tissue and benign tumor references. Queuine deficiency was determined by an exchange assay using [8-3H]guanine and tRNA:guanine transglycosylase from Escherichia coli. The mean values of queuine deficiencies in tRNAs were: 10.95 +/- 2.21 (SD) pmol/A260 in gonadal and germ cell tumors (5 cases); 23.75 +/- 7.89 pmol/A260 in primary epithelial tumors (9 cases); and 34.58 +/- 7.18 pmol/A260 in metastatic tumors (2 cases). These values displayed statistically significant differences (P = 0.0003, Kruskal-Wallis test). The queuine deficiencies in tRNAs significantly increased when moving from well-differentiated through moderately differentiated to poorly differentiated tumors, with the highest values found in poorly differentiated metastatic tumors (P = 0.0002, Kruskal-Wallis test). Queuine deficiency determination in tRNAs is proposed as a factor for clinical outcome prognosis of ovarian malignancies.
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, no. 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, no. 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.
Santos M. A., el-Adlouni C., Cox A. D., Luz J. M., Keith G., Tuite M. F.
Transfer RNA profiling: a new method for the identification of pathogenic Candida species Article de journal
Dans: Yeast, vol. 10, no. 5, p. 625-36, 1994, (0749-503x Journal Article).
Résumé | BibTeX | Étiquettes: Candida/classification/*genetics/pathogenicity, Electrophoresis, Fungal, Gel, Genetic, Gov't, Markers, Non-U.S., Polyacrylamide, RNA, Support, Transfer/*analysis
@article{,
title = {Transfer RNA profiling: a new method for the identification of pathogenic Candida species},
author = { M. A. Santos and C. el-Adlouni and A. D. Cox and J. M. Luz and G. Keith and M. F. Tuite},
year = {1994},
date = {1994-01-01},
journal = {Yeast},
volume = {10},
number = {5},
pages = {625-36},
abstract = {A new molecular taxonomic method applicable to the identification of medically important Candida species and other yeast species has been developed. It is based on the electrophoretic pattern of total tRNA samples (a 'tRNA profile') isolated from Candida species and generated using high-resolution semi-denaturing urea-polyacrylamide gel electrophoresis and methylene blue staining. Species-specific tRNA profiles for the species C. albicans, C. tropicalis, C. parapsilosis, C. guillierm