Intranet
Acces
Contact
Publications
2013 |
Quintin, Jessica; Asmar, Joelle; Matskevich, Alexey A; Lafarge, Marie-Céline; Ferrandon, Dominique The Drosophila Toll pathway controls but does not clear Candida glabrata infections Article de journal J. Immunol., 190 (6), p. 2818–2827, 2013, ISSN: 1550-6606. Résumé | Liens | BibTeX | Étiquettes: Adaptor Proteins, Animal, Animals, Antigens, Candida glabrata, Candidiasis, Cells, Cultured, Differentiation, Disease Models, ferrandon, Immunologic, M3i, Phagocytosis, Receptors, Signal Transducing, Signal Transduction, Toll-Like Receptors, Virulence @article{quintin_drosophila_2013b, title = {The Drosophila Toll pathway controls but does not clear Candida glabrata infections}, author = {Jessica Quintin and Joelle Asmar and Alexey A Matskevich and Marie-Céline Lafarge and Dominique Ferrandon}, doi = {10.4049/jimmunol.1201861}, issn = {1550-6606}, year = {2013}, date = {2013-03-01}, journal = {J. Immunol.}, volume = {190}, number = {6}, pages = {2818--2827}, abstract = {The pathogenicity of Candida glabrata to patients remains poorly understood for lack of convenient animal models to screen large numbers of mutants for altered virulence. In this study, we explore the minihost model Drosophila melanogaster from the dual perspective of host and pathogen. As in vertebrates, wild-type flies contain C. glabrata systemic infections yet are unable to kill the injected yeasts. As for other fungal infections in Drosophila, the Toll pathway restrains C. glabrata proliferation. Persistent C. glabrata yeasts in wild-type flies do not appear to be able to take shelter in hemocytes from the action of the Toll pathway, the effectors of which remain to be identified. Toll pathway mutant flies succumb to injected C. glabrata. In this immunosuppressed background, cellular defenses provide a residual level of protection. Although both the Gram-negative binding protein 3 pattern recognition receptor and the Persephone protease-dependent detection pathway are required for Toll pathway activation by C. glabrata, only GNBP3, and not psh mutants, are susceptible to the infection. Both Candida albicans and C. glabrata are restrained by the Toll pathway, yet the comparative study of phenoloxidase activation reveals a differential activity of the Toll pathway against these two fungal pathogens. Finally, we establish that the high-osmolarity glycerol pathway and yapsins are required for virulence of C. glabrata in this model. Unexpectedly, yapsins do not appear to be required to counteract the cellular immune response but are needed for the colonization of the wild-type host.}, keywords = {Adaptor Proteins, Animal, Animals, Antigens, Candida glabrata, Candidiasis, Cells, Cultured, Differentiation, Disease Models, ferrandon, Immunologic, M3i, Phagocytosis, Receptors, Signal Transducing, Signal Transduction, Toll-Like Receptors, Virulence}, pubstate = {published}, tppubtype = {article} } The pathogenicity of Candida glabrata to patients remains poorly understood for lack of convenient animal models to screen large numbers of mutants for altered virulence. In this study, we explore the minihost model Drosophila melanogaster from the dual perspective of host and pathogen. As in vertebrates, wild-type flies contain C. glabrata systemic infections yet are unable to kill the injected yeasts. As for other fungal infections in Drosophila, the Toll pathway restrains C. glabrata proliferation. Persistent C. glabrata yeasts in wild-type flies do not appear to be able to take shelter in hemocytes from the action of the Toll pathway, the effectors of which remain to be identified. Toll pathway mutant flies succumb to injected C. glabrata. In this immunosuppressed background, cellular defenses provide a residual level of protection. Although both the Gram-negative binding protein 3 pattern recognition receptor and the Persephone protease-dependent detection pathway are required for Toll pathway activation by C. glabrata, only GNBP3, and not psh mutants, are susceptible to the infection. Both Candida albicans and C. glabrata are restrained by the Toll pathway, yet the comparative study of phenoloxidase activation reveals a differential activity of the Toll pathway against these two fungal pathogens. Finally, we establish that the high-osmolarity glycerol pathway and yapsins are required for virulence of C. glabrata in this model. Unexpectedly, yapsins do not appear to be required to counteract the cellular immune response but are needed for the colonization of the wild-type host. |
2011 |
Ogawa, Michinaga; Yoshikawa, Yuko; Kobayashi, Taira; Mimuro, Hitomi; Fukumatsu, Makoto; Kiga, Kotaro; Piao, Zhenzi; Ashida, Hiroshi; Yoshida, Mitsutaka; Kakuta, Shigeru; Koyama, Tomohiro; Goto, Yoshiyuki; Nagatake, Takahiro; Nagai, Shinya; Kiyono, Hiroshi; Kawalec, Magdalena; Reichhart, Jean-Marc; Sasakawa, Chihiro A Tecpr1-dependent selective autophagy pathway targets bacterial pathogens Article de journal Cell Host Microbe, 9 (5), p. 376–389, 2011, ISSN: 1934-6069. Résumé | Liens | BibTeX | Étiquettes: Animals, Autophagy, Biological, Cells, Cultured, M3i, Membrane Proteins, Mice, Microtubule-Associated Proteins, Models, Phagosomes, Protein Interaction Mapping, reichhart, Shigella, Two-Hybrid System Techniques @article{ogawa_tecpr1-dependent_2011, title = {A Tecpr1-dependent selective autophagy pathway targets bacterial pathogens}, author = {Michinaga Ogawa and Yuko Yoshikawa and Taira Kobayashi and Hitomi Mimuro and Makoto Fukumatsu and Kotaro Kiga and Zhenzi Piao and Hiroshi Ashida and Mitsutaka Yoshida and Shigeru Kakuta and Tomohiro Koyama and Yoshiyuki Goto and Takahiro Nagatake and Shinya Nagai and Hiroshi Kiyono and Magdalena Kawalec and Jean-Marc Reichhart and Chihiro Sasakawa}, doi = {10.1016/j.chom.2011.04.010}, issn = {1934-6069}, year = {2011}, date = {2011-05-01}, journal = {Cell Host Microbe}, volume = {9}, number = {5}, pages = {376--389}, abstract = {Selective autophagy of bacterial pathogens represents a host innate immune mechanism. Selective autophagy has been characterized on the basis of distinct cargo receptors but the mechanisms by which different cargo receptors are targeted for autophagic degradation remain unclear. In this study we identified a highly conserved Tectonin domain-containing protein, Tecpr1, as an Atg5 binding partner that colocalized with Atg5 at Shigella-containing phagophores. Tecpr1 activity is necessary for efficient autophagic targeting of bacteria, but has no effect on rapamycin- or starvation-induced canonical autophagy. Tecpr1 interacts with WIPI-2, a yeast Atg18 homolog and PI(3)P-interacting protein required for phagophore formation, and they colocalize to phagophores. Although Tecpr1-deficient mice appear normal, Tecpr1-deficient MEFs were defective for selective autophagy and supported increased intracellular multiplication of Shigella. Further, depolarized mitochondria and misfolded protein aggregates accumulated in the Tecpr1-knockout MEFs. Thus, we identify a Tecpr1-dependent pathway as important in targeting bacterial pathogens for selective autophagy.}, keywords = {Animals, Autophagy, Biological, Cells, Cultured, M3i, Membrane Proteins, Mice, Microtubule-Associated Proteins, Models, Phagosomes, Protein Interaction Mapping, reichhart, Shigella, Two-Hybrid System Techniques}, pubstate = {published}, tppubtype = {article} } Selective autophagy of bacterial pathogens represents a host innate immune mechanism. Selective autophagy has been characterized on the basis of distinct cargo receptors but the mechanisms by which different cargo receptors are targeted for autophagic degradation remain unclear. In this study we identified a highly conserved Tectonin domain-containing protein, Tecpr1, as an Atg5 binding partner that colocalized with Atg5 at Shigella-containing phagophores. Tecpr1 activity is necessary for efficient autophagic targeting of bacteria, but has no effect on rapamycin- or starvation-induced canonical autophagy. Tecpr1 interacts with WIPI-2, a yeast Atg18 homolog and PI(3)P-interacting protein required for phagophore formation, and they colocalize to phagophores. Although Tecpr1-deficient mice appear normal, Tecpr1-deficient MEFs were defective for selective autophagy and supported increased intracellular multiplication of Shigella. Further, depolarized mitochondria and misfolded protein aggregates accumulated in the Tecpr1-knockout MEFs. Thus, we identify a Tecpr1-dependent pathway as important in targeting bacterial pathogens for selective autophagy. |
2010 |
Garcia, Alvaro Baeza; Pierce, Raymond J; Gourbal, Benjamin; Werkmeister, Elisabeth; Colinet, Dominique; Reichhart, Jean-Marc; Dissous, Colette; Coustau, Christine Involvement of the cytokine MIF in the snail host immune response to the parasite Schistosoma mansoni Article de journal PLoS Pathog., 6 (9), p. e1001115, 2010, ISSN: 1553-7374. Résumé | Liens | BibTeX | Étiquettes: Amino Acid, Animals, Apoptosis, Biomphalaria, Blotting, Cell Proliferation, Cells, Cricetinae, Cultured, Hemocytes, Host-Parasite Interactions, Humans, Liver, M3i, Macrophage Migration-Inhibitory Factors, messenger, Oocysts, Recombinant Proteins, reichhart, Reverse Transcriptase Polymerase Chain Reaction, RNA, Schistosoma mansoni, Schistosomiasis mansoni, Sequence Homology, Small Interfering, Western @article{baeza_garcia_involvement_2010, title = {Involvement of the cytokine MIF in the snail host immune response to the parasite Schistosoma mansoni}, author = {Alvaro Baeza Garcia and Raymond J Pierce and Benjamin Gourbal and Elisabeth Werkmeister and Dominique Colinet and Jean-Marc Reichhart and Colette Dissous and Christine Coustau}, doi = {10.1371/journal.ppat.1001115}, issn = {1553-7374}, year = {2010}, date = {2010-01-01}, journal = {PLoS Pathog.}, volume = {6}, number = {9}, pages = {e1001115}, abstract = {We have identified and characterized a Macrophage Migration Inhibitory Factor (MIF) family member in the Lophotrochozoan invertebrate, Biomphalaria glabrata, the snail intermediate host of the human blood fluke Schistosoma mansoni. In mammals, MIF is a widely expressed pleiotropic cytokine with potent pro-inflammatory properties that controls cell functions such as gene expression, proliferation or apoptosis. Here we show that the MIF protein from B. glabrata (BgMIF) is expressed in circulating immune defense cells (hemocytes) of the snail as well as in the B. glabrata embryonic (Bge) cell line that has hemocyte-like features. Recombinant BgMIF (rBgMIF) induced cell proliferation and inhibited NO-dependent p53-mediated apoptosis in Bge cells. Moreover, knock-down of BgMIF expression in Bge cells interfered with the in vitro encapsulation of S. mansoni sporocysts. Furthermore, the in vivo knock-down of BgMIF prevented the changes in circulating hemocyte populations that occur in response to an infection by S. mansoni miracidia and led to a significant increase in the parasite burden of the snails. These results provide the first functional evidence that a MIF ortholog is involved in an invertebrate immune response towards a parasitic infection and highlight the importance of cytokines in invertebrate-parasite interactions.}, keywords = {Amino Acid, Animals, Apoptosis, Biomphalaria, Blotting, Cell Proliferation, Cells, Cricetinae, Cultured, Hemocytes, Host-Parasite Interactions, Humans, Liver, M3i, Macrophage Migration-Inhibitory Factors, messenger, Oocysts, Recombinant Proteins, reichhart, Reverse Transcriptase Polymerase Chain Reaction, RNA, Schistosoma mansoni, Schistosomiasis mansoni, Sequence Homology, Small Interfering, Western}, pubstate = {published}, tppubtype = {article} } We have identified and characterized a Macrophage Migration Inhibitory Factor (MIF) family member in the Lophotrochozoan invertebrate, Biomphalaria glabrata, the snail intermediate host of the human blood fluke Schistosoma mansoni. In mammals, MIF is a widely expressed pleiotropic cytokine with potent pro-inflammatory properties that controls cell functions such as gene expression, proliferation or apoptosis. Here we show that the MIF protein from B. glabrata (BgMIF) is expressed in circulating immune defense cells (hemocytes) of the snail as well as in the B. glabrata embryonic (Bge) cell line that has hemocyte-like features. Recombinant BgMIF (rBgMIF) induced cell proliferation and inhibited NO-dependent p53-mediated apoptosis in Bge cells. Moreover, knock-down of BgMIF expression in Bge cells interfered with the in vitro encapsulation of S. mansoni sporocysts. Furthermore, the in vivo knock-down of BgMIF prevented the changes in circulating hemocyte populations that occur in response to an infection by S. mansoni miracidia and led to a significant increase in the parasite burden of the snails. These results provide the first functional evidence that a MIF ortholog is involved in an invertebrate immune response towards a parasitic infection and highlight the importance of cytokines in invertebrate-parasite interactions. |
2004 |
Costa, A; de Barros, Pais J P; Keith, G; Baranowski, W; Desgres, J Determination of queuosine derivatives by reverse-phase liquid chromatography for the hypomodification study of Q-bearing tRNAs from various mammal liver cells Article de journal J Chromatogr B Analyt Technol Biomed Life Sci, 801 (2), p. 237-47, 2004, (1570-0232 Journal Article). Résumé | BibTeX | Étiquettes: *Chromatography, &, Acyl/chemistry, Amino, Animals, Asn/chemistry, Cells, Chickens, Cultured, derivatives/*analysis, Experimental, Gov't, Hepatocytes/chemistry, high, KEITH, liquid, Liver, Liver/*chemistry, Neoplasms, Non-U.S., Nucleoside, Pressure, purification, Q/*analogs, Rats, RNA, Support, Transfer, Transfer/*chemistry/isolation, tumor @article{, title = {Determination of queuosine derivatives by reverse-phase liquid chromatography for the hypomodification study of Q-bearing tRNAs from various mammal liver cells}, author = { A. Costa and J. P. Pais de Barros and G. Keith and W. Baranowski and J. Desgres}, year = {2004}, date = {2004-01-01}, journal = {J Chromatogr B Analyt Technol Biomed Life Sci}, volume = {801}, number = {2}, pages = {237-47}, abstract = {Three queuosine derivatives (Q-derivatives) have been found at position 34 of four mammalian so-called Q-tRNAs: queuosine (Q) in tRNA(Asn) and tRNA(His), mannosyl-queuosine (manQ) in tRNA(Asp), and galactosyl-queuosine (galQ) in tRNA(Tyr). An analytical procedure based on the combined means of purified tRNA isolation from liver cells and ribonucleoside analysis by reverse-phase high performance liquid chromatography coupled with real-time UV-spectrometry (RPLC-UV) was developed for the quantitative analysis of the three Q-derivatives present in total tRNA from liver tissues and liver cell cultures. Using this analytical procedure, the rates of Q-tRNA modification were studied in total tRNAs from various mammalian hepatic cells. Our results show that the four Q-tRNAs are fully modified in liver tissues from adult mammals, regardless of the mammal species. However, a lack in the Q-modification level was observed in Q-tRNAs from newborn rat liver, as well in Q-tRNAs from normal rat liver cell cultures growing in a low queuine content medium, and from a rat hepatoma cell line. It is noteworthy that in all cases of Q-tRNA hypomodification, our analytical procedure showed that tRNA(Asp) is always the least affected by the hypomodification. The biological significance of this phenomenon is discussed.}, note = {1570-0232 Journal Article}, keywords = {*Chromatography, &, Acyl/chemistry, Amino, Animals, Asn/chemistry, Cells, Chickens, Cultured, derivatives/*analysis, Experimental, Gov't, Hepatocytes/chemistry, high, KEITH, liquid, Liver, Liver/*chemistry, Neoplasms, Non-U.S., Nucleoside, Pressure, purification, Q/*analogs, Rats, RNA, Support, Transfer, Transfer/*chemistry/isolation, tumor}, pubstate = {published}, tppubtype = {article} } Three queuosine derivatives (Q-derivatives) have been found at position 34 of four mammalian so-called Q-tRNAs: queuosine (Q) in tRNA(Asn) and tRNA(His), mannosyl-queuosine (manQ) in tRNA(Asp), and galactosyl-queuosine (galQ) in tRNA(Tyr). An analytical procedure based on the combined means of purified tRNA isolation from liver cells and ribonucleoside analysis by reverse-phase high performance liquid chromatography coupled with real-time UV-spectrometry (RPLC-UV) was developed for the quantitative analysis of the three Q-derivatives present in total tRNA from liver tissues and liver cell cultures. Using this analytical procedure, the rates of Q-tRNA modification were studied in total tRNAs from various mammalian hepatic cells. Our results show that the four Q-tRNAs are fully modified in liver tissues from adult mammals, regardless of the mammal species. However, a lack in the Q-modification level was observed in Q-tRNAs from newborn rat liver, as well in Q-tRNAs from normal rat liver cell cultures growing in a low queuine content medium, and from a rat hepatoma cell line. It is noteworthy that in all cases of Q-tRNA hypomodification, our analytical procedure showed that tRNA(Asp) is always the least affected by the hypomodification. The biological significance of this phenomenon is discussed. |
Sohm, B; Sissler, M; Park, H; King, M P; Florentz, C Recognition of human mitochondrial tRNALeu(UUR) by its cognate leucyl-tRNA synthetase Article de journal J Mol Biol, 339 (1), p. 17-29, 2004, ISBN: 15123417, (0022-2836 Journal Article). Résumé | Liens | BibTeX | Étiquettes: Cultured, FLORENTZ, FLORENTZ *Acylation Base Sequence Comparative Study Human Kinetics Leucine/metabolism Leucine-tRNA Ligase/genetics/*metabolism Mitochondria/*metabolism Molecular Sequence Data Mutation Nucleic Acid Conformation Osteosarcoma/metabolism RNA/*genetics/metabolism RNA, Genetic/*genetics Tumor Cells, Leu/genetics/*metabolism Solutions Substrate Specificity Support, Non-U.S. Gov't Support, P.H.S. Transcription, SISSLER, Transfer, U.S. Gov't, Unité ARN @article{, title = {Recognition of human mitochondrial tRNALeu(UUR) by its cognate leucyl-tRNA synthetase}, author = {B Sohm and M Sissler and H Park and M P King and C Florentz}, url = {http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=15123417}, isbn = {15123417}, year = {2004}, date = {2004-01-01}, journal = {J Mol Biol}, volume = {339}, number = {1}, pages = {17-29}, abstract = {Accuracy of protein synthesis depends on specific recognition and aminoacylation of tRNAs by their cognate aminoacyl-tRNA synthetases. Rules governing these processes have been established for numerous prokaryotic and eukaryotic cytoplasmic systems, but only limited information is available for human mitochondrial systems. It has been shown that the in vitro transcribed human mitochondrial tRNA(Leu(UUR)) does not fold into the expected cloverleaf, but is however aminoacylated by the human mitochondrial leucyl-tRNA synthetase. Here, the role of the structure of the amino acid acceptor branch and the anticodon branch of tRNA(Leu(UUR)) in recognition by leucyl-tRNA synthetase was investigated. The kinetic parameters for aminoacylation of wild-type and mutant tRNA(Leu(UUR)) transcripts and of native tRNA(Leu(UUR)) were determined. Solution structure probing was performed in the presence or in the absence of leucyl-tRNA synthetase and correlated with the aminoacylation kinetics for each tRNA. Replacement of mismatches in either the anticodon-stem or D-stem that are present in the wild-type tRNA(Leu(UUR)) by G-C base-pairs is sufficient to induce (i) cloverleaf folding, (ii) improved aminoacylation efficiency, and (iii) interactions with the synthetase that are similar to those with the native tRNA(Leu(UUR)). Leucyl-tRNA synthetase contacts tRNA(Leu(UUR)) in the amino acid acceptor stem, the anticodon stem, and the D-loop, which is unprecedented for a leucine aminoacylation system.}, note = {0022-2836 Journal Article}, keywords = {Cultured, FLORENTZ, FLORENTZ *Acylation Base Sequence Comparative Study Human Kinetics Leucine/metabolism Leucine-tRNA Ligase/genetics/*metabolism Mitochondria/*metabolism Molecular Sequence Data Mutation Nucleic Acid Conformation Osteosarcoma/metabolism RNA/*genetics/metabolism RNA, Genetic/*genetics Tumor Cells, Leu/genetics/*metabolism Solutions Substrate Specificity Support, Non-U.S. Gov't Support, P.H.S. Transcription, SISSLER, Transfer, U.S. Gov't, Unité ARN}, pubstate = {published}, tppubtype = {article} } Accuracy of protein synthesis depends on specific recognition and aminoacylation of tRNAs by their cognate aminoacyl-tRNA synthetases. Rules governing these processes have been established for numerous prokaryotic and eukaryotic cytoplasmic systems, but only limited information is available for human mitochondrial systems. It has been shown that the in vitro transcribed human mitochondrial tRNA(Leu(UUR)) does not fold into the expected cloverleaf, but is however aminoacylated by the human mitochondrial leucyl-tRNA synthetase. Here, the role of the structure of the amino acid acceptor branch and the anticodon branch of tRNA(Leu(UUR)) in recognition by leucyl-tRNA synthetase was investigated. The kinetic parameters for aminoacylation of wild-type and mutant tRNA(Leu(UUR)) transcripts and of native tRNA(Leu(UUR)) were determined. Solution structure probing was performed in the presence or in the absence of leucyl-tRNA synthetase and correlated with the aminoacylation kinetics for each tRNA. Replacement of mismatches in either the anticodon-stem or D-stem that are present in the wild-type tRNA(Leu(UUR)) by G-C base-pairs is sufficient to induce (i) cloverleaf folding, (ii) improved aminoacylation efficiency, and (iii) interactions with the synthetase that are similar to those with the native tRNA(Leu(UUR)). Leucyl-tRNA synthetase contacts tRNA(Leu(UUR)) in the amino acid acceptor stem, the anticodon stem, and the D-loop, which is unprecedented for a leucine aminoacylation system. |
Costa, A; de Barros, Pais J P; Keith, G; Baranowski, W; Desgres, J Determination of queuosine derivatives by reverse-phase liquid chromatography for the hypomodification study of Q-bearing tRNAs from various mammal liver cells Article de journal J Chromatogr B Analyt Technol Biomed Life Sci, 801 (2), p. 237-247, 2004, ISBN: 14751792, (1570-0232 Journal Article). Résumé | Liens | BibTeX | Étiquettes: Amino Acyl/chemistry RNA, Asn/chemistry Rats Support, Cultured, Cultured Chickens *Chromatography, Experimental Nucleoside Q/*analogs & derivatives/*analysis RNA, High Pressure Liquid Hepatocytes/chemistry Liver/*chemistry Liver Neoplasms, KEITH Animals Cells, Non-U.S. Gov't Tumor Cells, Transfer, Transfer/*chemistry/isolation & purification RNA, Unité ARN @article{, title = {Determination of queuosine derivatives by reverse-phase liquid chromatography for the hypomodification study of Q-bearing tRNAs from various mammal liver cells}, author = {A Costa and J P Pais de Barros and G Keith and W Baranowski and J Desgres}, url = {http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=14751792}, isbn = {14751792}, year = {2004}, date = {2004-01-01}, journal = {J Chromatogr B Analyt Technol Biomed Life Sci}, volume = {801}, number = {2}, pages = {237-247}, abstract = {Three queuosine derivatives (Q-derivatives) have been found at position 34 of four mammalian so-called Q-tRNAs: queuosine (Q) in tRNA(Asn) and tRNA(His), mannosyl-queuosine (manQ) in tRNA(Asp), and galactosyl-queuosine (galQ) in tRNA(Tyr). An analytical procedure based on the combined means of purified tRNA isolation from liver cells and ribonucleoside analysis by reverse-phase high performance liquid chromatography coupled with real-time UV-spectrometry (RPLC-UV) was developed for the quantitative analysis of the three Q-derivatives present in total tRNA from liver tissues and liver cell cultures. Using this analytical procedure, the rates of Q-tRNA modification were studied in total tRNAs from various mammalian hepatic cells. Our results show that the four Q-tRNAs are fully modified in liver tissues from adult mammals, regardless of the mammal species. However, a lack in the Q-modification level was observed in Q-tRNAs from newborn rat liver, as well in Q-tRNAs from normal rat liver cell cultures growing in a low queuine content medium, and from a rat hepatoma cell line. It is noteworthy that in all cases of Q-tRNA hypomodification, our analytical procedure showed that tRNA(Asp) is always the least affected by the hypomodification. The biological significance of this phenomenon is discussed.}, note = {1570-0232 Journal Article}, keywords = {Amino Acyl/chemistry RNA, Asn/chemistry Rats Support, Cultured, Cultured Chickens *Chromatography, Experimental Nucleoside Q/*analogs & derivatives/*analysis RNA, High Pressure Liquid Hepatocytes/chemistry Liver/*chemistry Liver Neoplasms, KEITH Animals Cells, Non-U.S. Gov't Tumor Cells, Transfer, Transfer/*chemistry/isolation & purification RNA, Unité ARN}, pubstate = {published}, tppubtype = {article} } Three queuosine derivatives (Q-derivatives) have been found at position 34 of four mammalian so-called Q-tRNAs: queuosine (Q) in tRNA(Asn) and tRNA(His), mannosyl-queuosine (manQ) in tRNA(Asp), and galactosyl-queuosine (galQ) in tRNA(Tyr). An analytical procedure based on the combined means of purified tRNA isolation from liver cells and ribonucleoside analysis by reverse-phase high performance liquid chromatography coupled with real-time UV-spectrometry (RPLC-UV) was developed for the quantitative analysis of the three Q-derivatives present in total tRNA from liver tissues and liver cell cultures. Using this analytical procedure, the rates of Q-tRNA modification were studied in total tRNAs from various mammalian hepatic cells. Our results show that the four Q-tRNAs are fully modified in liver tissues from adult mammals, regardless of the mammal species. However, a lack in the Q-modification level was observed in Q-tRNAs from newborn rat liver, as well in Q-tRNAs from normal rat liver cell cultures growing in a low queuine content medium, and from a rat hepatoma cell line. It is noteworthy that in all cases of Q-tRNA hypomodification, our analytical procedure showed that tRNA(Asp) is always the least affected by the hypomodification. The biological significance of this phenomenon is discussed. |
2003 |
Tryoen-Toth, P; Richert, S; Sohm, B; Mine, M; Marsac, C; Dorsselaer, Van A; Leize, E; Florentz, C Proteomic consequences of a human mitochondrial tRNA mutation beyond the frame of mitochondrial translation Article de journal J Biol Chem, 278 (27), p. 24314-24323, 2003, ISBN: 12714596, (0021-9258 Journal Article). Résumé | Liens | BibTeX | Étiquettes: Cultured, FLORENTZ, Genetic Tumor Cells, Human Mitochondria/genetics *Mutation Nuclear Proteins/*genetics Proteomics RNA/*genetics RNA, Non-U.S. Gov't Translation, Transfer/*genetics Structure-Activity Relationship Support, Unité ARN @article{, title = {Proteomic consequences of a human mitochondrial tRNA mutation beyond the frame of mitochondrial translation}, author = {P Tryoen-Toth and S Richert and B Sohm and M Mine and C Marsac and A Van Dorsselaer and E Leize and C Florentz}, url = {http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=12714596}, isbn = {12714596}, year = {2003}, date = {2003-01-01}, journal = {J Biol Chem}, volume = {278}, number = {27}, pages = {24314-24323}, abstract = {Numerous severe neurodegenerative and neuromuscular disorders, characterized biochemically by strong perturbations in energy metabolism, are correlated with single point mutations in mitochondrial genes coding for transfer RNAs. Initial comparative proteomics performed on wild-type and Myoclonic Epilepsy and Ragged Red Fibers (MERRF) mitochondria from sibling human cybrid cell lines revealed the potential of this approach. Here a quantitative analysis of several hundred silver-stained spots separated by two-dimensional gel electrophoresis was performed in the specific case of a couple of mitochondria, containing or not mutation A8344G in the gene for mitochondrial tRNALys, correlated with MERRF syndrome. Computer-assisted analysis allowed us to detect 38 spots with significant quantitative variations, of which 20 could be assigned by mass spectrometry. These include nuclear encoded proteins located in mitochondria such as respiratory chain subunits, metabolic enzymes, a protein of the mitochondrial translation machinery, and cytosolic contaminants. Furthermore, Western blotting combined with mass spectrometry revealed the occurrence of numerous isoforms of pyruvate dehydrogenase subunits, with subtle changes in post-translational modifications. This comparative proteomic approach gives the first insight for nuclear encoded proteins that undergo the largest quantitative changes, and pinpoints new potential molecular partners involved in the cascade of events that connect genotype to phenotype.}, note = {0021-9258 Journal Article}, keywords = {Cultured, FLORENTZ, Genetic Tumor Cells, Human Mitochondria/genetics *Mutation Nuclear Proteins/*genetics Proteomics RNA/*genetics RNA, Non-U.S. Gov't Translation, Transfer/*genetics Structure-Activity Relationship Support, Unité ARN}, pubstate = {published}, tppubtype = {article} } Numerous severe neurodegenerative and neuromuscular disorders, characterized biochemically by strong perturbations in energy metabolism, are correlated with single point mutations in mitochondrial genes coding for transfer RNAs. Initial comparative proteomics performed on wild-type and Myoclonic Epilepsy and Ragged Red Fibers (MERRF) mitochondria from sibling human cybrid cell lines revealed the potential of this approach. Here a quantitative analysis of several hundred silver-stained spots separated by two-dimensional gel electrophoresis was performed in the specific case of a couple of mitochondria, containing or not mutation A8344G in the gene for mitochondrial tRNALys, correlated with MERRF syndrome. Computer-assisted analysis allowed us to detect 38 spots with significant quantitative variations, of which 20 could be assigned by mass spectrometry. These include nuclear encoded proteins located in mitochondria such as respiratory chain subunits, metabolic enzymes, a protein of the mitochondrial translation machinery, and cytosolic contaminants. Furthermore, Western blotting combined with mass spectrometry revealed the occurrence of numerous isoforms of pyruvate dehydrogenase subunits, with subtle changes in post-translational modifications. This comparative proteomic approach gives the first insight for nuclear encoded proteins that undergo the largest quantitative changes, and pinpoints new potential molecular partners involved in the cascade of events that connect genotype to phenotype. |
2001 |
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 Cell, 104 (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 |
Rihn, B H; Mohr, S; McDowell, S A; Binet, S; Loubinoux, J; Galateau, F; Keith, G; Leikauf, G D Differential gene expression in mesothelioma Article de journal FEBS Lett, 480 (2-3), p. 95-100, 2000, (0014-5793 Journal Article). Résumé | BibTeX | Étiquettes: *Gene, Adhesion, Analysis/methods, Array, Cell, Cells, Chain, Cultured, Cycle, Division, Expression, Gene, Human, Invasiveness, Mesothelioma/*genetics/metabolism, Neoplasm, Neoplastic, Oligonucleotide, Oxidative, Polymerase, Profiling, Proteins/metabolism, Reaction, Regulation, Reverse, Sequence, Stress, Transcriptase, tumor, Xenobiotics @article{, title = {Differential gene expression in mesothelioma}, author = { B. H. Rihn and S. Mohr and S. A. McDowell and S. Binet and J. Loubinoux and F. Galateau and G. Keith and G. D. Leikauf}, year = {2000}, date = {2000-01-01}, journal = {FEBS Lett}, volume = {480}, number = {2-3}, pages = {95-100}, abstract = {To investigate the molecular events controlling malignant transformation of human pleural cells, we compared constitutive gene expression of mesothelioma cells to that of pleural cells. Using cDNA microarray and high-density filter array, we assessed expression levels of > 6500 genes. Most of the highly expressed transcripts were common to both cell lines and included genes associated with stress response and DNA repair, outcomes consistent with the radio- and chemo-resistance of mesothelioma. Interestingly, of the fewer than 300 genes that differed between cell lines, most functioned in (i) macromolecule stability, (ii) cell adhesion and recognition, (iii) cell migration (invasiveness), and (iv) extended cell division. Expression levels of several of these genes were confirmed by RT-PCR and could be useful as diagnostic markers of human mesothelioma.}, note = {0014-5793 Journal Article}, keywords = {*Gene, Adhesion, Analysis/methods, Array, Cell, Cells, Chain, Cultured, Cycle, Division, Expression, Gene, Human, Invasiveness, Mesothelioma/*genetics/metabolism, Neoplasm, Neoplastic, Oligonucleotide, Oxidative, Polymerase, Profiling, Proteins/metabolism, Reaction, Regulation, Reverse, Sequence, Stress, Transcriptase, tumor, Xenobiotics}, pubstate = {published}, tppubtype = {article} } To investigate the molecular events controlling malignant transformation of human pleural cells, we compared constitutive gene expression of mesothelioma cells to that of pleural cells. Using cDNA microarray and high-density filter array, we assessed expression levels of > 6500 genes. Most of the highly expressed transcripts were common to both cell lines and included genes associated with stress response and DNA repair, outcomes consistent with the radio- and chemo-resistance of mesothelioma. Interestingly, of the fewer than 300 genes that differed between cell lines, most functioned in (i) macromolecule stability, (ii) cell adhesion and recognition, (iii) cell migration (invasiveness), and (iv) extended cell division. Expression levels of several of these genes were confirmed by RT-PCR and could be useful as diagnostic markers of human mesothelioma. |
1996 |
Barillas-Mury, Carolina; Charlesworth, A; Gross, I; Richman, A; Hoffmann, Jules A; Kafatos, Fotis C Immune factor Gambif1, a new rel family member from the human malaria vector, Anopheles gambiae Article de journal EMBO J., 15 (17), p. 4691–4701, 1996, ISSN: 0261-4189. Résumé | BibTeX | Étiquettes: Amino Acid, Animals, Anopheles, Base Sequence, Biological Transport, Cell Nucleus, Cells, Complementary, Cultured, DNA, DNA-Binding Proteins, hoffmann, Insect Proteins, Insect Vectors, M3i, NF-kappa B, Proto-Oncogene Proteins, Proto-Oncogene Proteins c-rel, Sequence Homology, Trans-Activators, Transcriptional Activation @article{barillas-mury_immune_1996, title = {Immune factor Gambif1, a new rel family member from the human malaria vector, Anopheles gambiae}, author = {Carolina Barillas-Mury and A Charlesworth and I Gross and A Richman and Jules A Hoffmann and Fotis C Kafatos}, issn = {0261-4189}, year = {1996}, date = {1996-09-01}, journal = {EMBO J.}, volume = {15}, number = {17}, pages = {4691--4701}, abstract = {A novel rel family member, Gambif1 (gambiae immune factor 1), has been cloned from the human malaria vector, Anopheles gambiae, and shown to be most similar to Drosophila Dorsal and Dif. Gambif1 protein is translocated to the nucleus in fat body cells in response to bacterial challenge, although the mRNA is present at low levels at all developmental stages and is not induced by infection. DNA binding activity to the kappaB-like sites in the A.gambiae Defensin and the Drosophila Diptericin and Cecropin promoters is also induced in larval nuclear extracts following infection. Gambif1 has the ability to bind to kappaB-like sites in vitro. Co-transfection assays in Drosophila mbn-2 cells show that Gambif1 can activate transcription by interacting with the Drosophila Diptericin regulatory elements, but is not functionally equivalent to Dorsal in this assay. Gambif1 protein translocation to the nucleus and the appearance of kappaB-like DNA binding activity can serve as molecular markers of activation of the immune system and open up the possibility of studying the role of defence reactions in determining mosquito susceptibility/refractoriness to malaria infection.}, keywords = {Amino Acid, Animals, Anopheles, Base Sequence, Biological Transport, Cell Nucleus, Cells, Complementary, Cultured, DNA, DNA-Binding Proteins, hoffmann, Insect Proteins, Insect Vectors, M3i, NF-kappa B, Proto-Oncogene Proteins, Proto-Oncogene Proteins c-rel, Sequence Homology, Trans-Activators, Transcriptional Activation}, pubstate = {published}, tppubtype = {article} } A novel rel family member, Gambif1 (gambiae immune factor 1), has been cloned from the human malaria vector, Anopheles gambiae, and shown to be most similar to Drosophila Dorsal and Dif. Gambif1 protein is translocated to the nucleus in fat body cells in response to bacterial challenge, although the mRNA is present at low levels at all developmental stages and is not induced by infection. DNA binding activity to the kappaB-like sites in the A.gambiae Defensin and the Drosophila Diptericin and Cecropin promoters is also induced in larval nuclear extracts following infection. Gambif1 has the ability to bind to kappaB-like sites in vitro. Co-transfection assays in Drosophila mbn-2 cells show that Gambif1 can activate transcription by interacting with the Drosophila Diptericin regulatory elements, but is not functionally equivalent to Dorsal in this assay. Gambif1 protein translocation to the nucleus and the appearance of kappaB-like DNA binding activity can serve as molecular markers of activation of the immune system and open up the possibility of studying the role of defence reactions in determining mosquito susceptibility/refractoriness to malaria infection. |
1995 |
Levashina, Elena A; Ohresser, S; Bulet, Philippe; Reichhart, Jean-Marc; Hetru, Charles; Hoffmann, Jules A Metchnikowin, a novel immune-inducible proline-rich peptide from Drosophila with antibacterial and antifungal properties Article de journal Eur. J. Biochem., 233 (2), p. 694–700, 1995, ISSN: 0014-2956. Résumé | BibTeX | Étiquettes: Animals, Anti-Bacterial Agents, Antifungal Agents, Antimicrobial Cationic Peptides, bacteria, Base Sequence, Cells, Chromosome Mapping, Cloning, Cultured, Genetic, hoffmann, M3i, Molecular, Peptides, Proline, reichhart, Transcription @article{levashina_metchnikowin_1995, title = {Metchnikowin, a novel immune-inducible proline-rich peptide from Drosophila with antibacterial and antifungal properties}, author = {Elena A Levashina and S Ohresser and Philippe Bulet and Jean-Marc Reichhart and Charles Hetru and Jules A Hoffmann}, issn = {0014-2956}, year = {1995}, date = {1995-10-01}, journal = {Eur. J. Biochem.}, volume = {233}, number = {2}, pages = {694--700}, abstract = {One of the characteristics of the host defense of higher insects is the rapid and transient synthesis of a variety of potent antimicrobial peptides. To date, several distinct inducible antimicrobial peptides or peptide families have been totally or partially characterized. We present here the isolation and characterization of a novel 26-residue proline-rich immune-inducible peptide from Drosophila, which exhibits both antibacterial (Gram-positive) and antifungal activities. Peptide sequencing and cDNA cloning indicate the presense of two isoforms in our Drosophila Oregon strain, which differ by one residue (His compared to Arg) as a consequence of a single nucleotide change. The gene, which maps in position 52A1-2 on the right arm of the second chromosome, is expressed in the fat body after immune challenge. The novel peptide, which we propose to name metchnikowin, is a member of a family of proline-rich peptides, and we discuss the possible evolutionary relationships within this family.}, keywords = {Animals, Anti-Bacterial Agents, Antifungal Agents, Antimicrobial Cationic Peptides, bacteria, Base Sequence, Cells, Chromosome Mapping, Cloning, Cultured, Genetic, hoffmann, M3i, Molecular, Peptides, Proline, reichhart, Transcription}, pubstate = {published}, tppubtype = {article} } One of the characteristics of the host defense of higher insects is the rapid and transient synthesis of a variety of potent antimicrobial peptides. To date, several distinct inducible antimicrobial peptides or peptide families have been totally or partially characterized. We present here the isolation and characterization of a novel 26-residue proline-rich immune-inducible peptide from Drosophila, which exhibits both antibacterial (Gram-positive) and antifungal activities. Peptide sequencing and cDNA cloning indicate the presense of two isoforms in our Drosophila Oregon strain, which differ by one residue (His compared to Arg) as a consequence of a single nucleotide change. The gene, which maps in position 52A1-2 on the right arm of the second chromosome, is expressed in the fat body after immune challenge. The novel peptide, which we propose to name metchnikowin, is a member of a family of proline-rich peptides, and we discuss the possible evolutionary relationships within this family. |