Publications
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 |
Lagueux, Marie; Perrodou, E; Levashina, Elena A; Capovilla, Maria; Hoffmann, Jules A Constitutive expression of a complement-like protein in toll and JAK gain-of-function mutants of Drosophila Article de journal Proc. Natl. Acad. Sci. U.S.A., 97 (21), p. 11427–11432, 2000, ISSN: 0027-8424. Résumé | Liens | BibTeX | Étiquettes: alpha-Macroglobulins, Amino Acid, Animals, Cell Surface, Complement C3, Esters, Genetic, hoffmann, Insect Proteins, Janus Kinases, M3i, Membrane Glycoproteins, Mutation, Protein-Tyrosine Kinases, Proteins, Receptors, Sequence Homology, Sulfhydryl Compounds, Toll-Like Receptors, Transcription, Transcription Factors @article{lagueux_constitutive_2000, title = {Constitutive expression of a complement-like protein in toll and JAK gain-of-function mutants of Drosophila}, author = {Marie Lagueux and E Perrodou and Elena A Levashina and Maria Capovilla and Jules A Hoffmann}, doi = {10.1073/pnas.97.21.11427}, issn = {0027-8424}, year = {2000}, date = {2000-10-01}, journal = {Proc. Natl. Acad. Sci. U.S.A.}, volume = {97}, number = {21}, pages = {11427--11432}, abstract = {We show that Drosophila expresses four genes encoding proteins with significant similarities with the thiolester-containing proteins of the complement C3/alpha(2)-macroglobulin superfamily. The genes are transcribed at a low level during all stages of development, and their expression is markedly up-regulated after an immune challenge. For one of these genes, which is predominantly expressed in the larval fat body, we observe a constitutive expression in gain-of-function mutants of the Janus kinase (JAK) hop and a reduced inducibility in loss-of-function hop mutants. We also observe a constitutive expression in gain-of-function Toll mutants. We discuss the possible roles of these novel complement-like proteins in the Drosophila host defense.}, keywords = {alpha-Macroglobulins, Amino Acid, Animals, Cell Surface, Complement C3, Esters, Genetic, hoffmann, Insect Proteins, Janus Kinases, M3i, Membrane Glycoproteins, Mutation, Protein-Tyrosine Kinases, Proteins, Receptors, Sequence Homology, Sulfhydryl Compounds, Toll-Like Receptors, Transcription, Transcription Factors}, pubstate = {published}, tppubtype = {article} } We show that Drosophila expresses four genes encoding proteins with significant similarities with the thiolester-containing proteins of the complement C3/alpha(2)-macroglobulin superfamily. The genes are transcribed at a low level during all stages of development, and their expression is markedly up-regulated after an immune challenge. For one of these genes, which is predominantly expressed in the larval fat body, we observe a constitutive expression in gain-of-function mutants of the Janus kinase (JAK) hop and a reduced inducibility in loss-of-function hop mutants. We also observe a constitutive expression in gain-of-function Toll mutants. We discuss the possible roles of these novel complement-like proteins in the Drosophila host defense. |