Publications
2005 |
Weber, Alexander N R; Moncrieffe, Martin C; Gangloff, Monique; Imler, Jean-Luc; Gay, Nicholas J Ligand-receptor and receptor-receptor interactions act in concert to activate signaling in the Drosophila toll pathway Article de journal The Journal of Biological Chemistry, 280 (24), p. 22793–22799, 2005, ISSN: 0021-9258. Résumé | Liens | BibTeX | Étiquettes: Amino Acid, Animals, Biophysical Phenomena, Biophysics, Body Patterning, Calorimetry, Cell Line, Cell Surface, Cross-Linking Reagents, Cytokines, dimerization, Electrophoresis, Humans, imler, ligands, Luciferases, M3i, Membrane Glycoproteins, Polyacrylamide Gel, Protein Binding, Protein Structure, Receptors, Recombinant Proteins, Sequence Homology, Signal Transduction, Tertiary, Time Factors, Toll-Like Receptors, Ultracentrifugation @article{weber_ligand-receptor_2005, title = {Ligand-receptor and receptor-receptor interactions act in concert to activate signaling in the Drosophila toll pathway}, author = {Alexander N R Weber and Martin C Moncrieffe and Monique Gangloff and Jean-Luc Imler and Nicholas J Gay}, doi = {10.1074/jbc.M502074200}, issn = {0021-9258}, year = {2005}, date = {2005-01-01}, journal = {The Journal of Biological Chemistry}, volume = {280}, number = {24}, pages = {22793--22799}, abstract = {In Drosophila, the signaling pathway mediated by the Toll receptor is critical for the establishment of embryonic dorso-ventral pattern and for innate immune responses to bacterial and fungal pathogens. Toll is activated by high affinity binding of the cytokine Spätzle, a dimeric ligand of the cystine knot family. In vertebrates, a related family of Toll-like receptors play a critical role in innate immune responses. Despite the importance of this family of receptors, little is known about the biochemical events that lead to receptor activation and signaling. Here, we show that Spätzle binds to the N-terminal region of Toll and, using biophysical methods, that the binding is complex. The two binding events that cause formation of the cross-linked complex are non-equivalent: the first Toll ectodomain binds Spätzle with an affinity 3-fold higher than the second molecule suggesting that pathway activation involves negative cooperativity. We further show that the Toll ectodomains are able to form low affinity dimers in solution and that juxtamembrane sequences of Toll are critical for the activation or derepression of the pathway. These results, taken together, suggest a mechanism of signal transduction that requires both ligand-receptor and receptor-receptor interactions.}, keywords = {Amino Acid, Animals, Biophysical Phenomena, Biophysics, Body Patterning, Calorimetry, Cell Line, Cell Surface, Cross-Linking Reagents, Cytokines, dimerization, Electrophoresis, Humans, imler, ligands, Luciferases, M3i, Membrane Glycoproteins, Polyacrylamide Gel, Protein Binding, Protein Structure, Receptors, Recombinant Proteins, Sequence Homology, Signal Transduction, Tertiary, Time Factors, Toll-Like Receptors, Ultracentrifugation}, pubstate = {published}, tppubtype = {article} } In Drosophila, the signaling pathway mediated by the Toll receptor is critical for the establishment of embryonic dorso-ventral pattern and for innate immune responses to bacterial and fungal pathogens. Toll is activated by high affinity binding of the cytokine Spätzle, a dimeric ligand of the cystine knot family. In vertebrates, a related family of Toll-like receptors play a critical role in innate immune responses. Despite the importance of this family of receptors, little is known about the biochemical events that lead to receptor activation and signaling. Here, we show that Spätzle binds to the N-terminal region of Toll and, using biophysical methods, that the binding is complex. The two binding events that cause formation of the cross-linked complex are non-equivalent: the first Toll ectodomain binds Spätzle with an affinity 3-fold higher than the second molecule suggesting that pathway activation involves negative cooperativity. We further show that the Toll ectodomains are able to form low affinity dimers in solution and that juxtamembrane sequences of Toll are critical for the activation or derepression of the pathway. These results, taken together, suggest a mechanism of signal transduction that requires both ligand-receptor and receptor-receptor interactions. |
2003 |
Goto, Akira; Blandin, Stéphanie A; Royet, Julien; Reichhart, Jean-Marc; Levashina, Elena A Silencing of Toll pathway components by direct injection of double-stranded RNA into Drosophila adult flies Article de journal Nucleic Acids Res., 31 (22), p. 6619–6623, 2003, ISSN: 1362-4962. Résumé | BibTeX | Étiquettes: Animals, blandin, Cell Surface, Double-Stranded, Epistasis, Female, Genetic, Green Fluorescent Proteins, Homeodomain Proteins, Luminescent Proteins, M3i, Phenotype, Receptors, reichhart, RNA, RNA Interference, Serpins, Signal Transduction, Time Factors, Toll-Like Receptors, Transcription Factors @article{goto_silencing_2003, title = {Silencing of Toll pathway components by direct injection of double-stranded RNA into Drosophila adult flies}, author = {Akira Goto and Stéphanie A Blandin and Julien Royet and Jean-Marc Reichhart and Elena A Levashina}, issn = {1362-4962}, year = {2003}, date = {2003-11-01}, journal = {Nucleic Acids Res.}, volume = {31}, number = {22}, pages = {6619--6623}, abstract = {Double-stranded RNA (dsRNA) gene interference is an efficient method to silence gene expression in a sequence-specific manner. Here we show that the direct injection of dsRNA can be used in adult Drosophila flies to disrupt function of endogenous genes in vivo. As a proof of principle, we have used this method to silence components of a major signaling cascade, the Toll pathway, which controls fruit fly resistance to fungal and Gram-positive bacterial infections. We demonstrate that the knockout is efficient only if dsRNA is injected in 4- or more day-old flies and that it lasts for at least 1 week. Furthermore, we report dsRNA-based epistatic gene analysis via injection of a mixture of two dsRNAs and propose that injection of dsRNA represents a powerful method for rapid functional analysis of genes in Drosophila melanogaster adults, particularly of those whose mutations are lethal during development.}, keywords = {Animals, blandin, Cell Surface, Double-Stranded, Epistasis, Female, Genetic, Green Fluorescent Proteins, Homeodomain Proteins, Luminescent Proteins, M3i, Phenotype, Receptors, reichhart, RNA, RNA Interference, Serpins, Signal Transduction, Time Factors, Toll-Like Receptors, Transcription Factors}, pubstate = {published}, tppubtype = {article} } Double-stranded RNA (dsRNA) gene interference is an efficient method to silence gene expression in a sequence-specific manner. Here we show that the direct injection of dsRNA can be used in adult Drosophila flies to disrupt function of endogenous genes in vivo. As a proof of principle, we have used this method to silence components of a major signaling cascade, the Toll pathway, which controls fruit fly resistance to fungal and Gram-positive bacterial infections. We demonstrate that the knockout is efficient only if dsRNA is injected in 4- or more day-old flies and that it lasts for at least 1 week. Furthermore, we report dsRNA-based epistatic gene analysis via injection of a mixture of two dsRNAs and propose that injection of dsRNA represents a powerful method for rapid functional analysis of genes in Drosophila melanogaster adults, particularly of those whose mutations are lethal during development. |
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 Proc. Natl. Acad. Sci. U.S.A., 95 (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. |
1975 |
Feyereisen, R; Lagueux, Marie; Hoffmann, Jules A The hemolymphatic transport of molting hormone during the development of Locusta migratoria L Article de journal C.R. Hebd. Seances Acad. Sci., Ser. D, Sci. Nat., 280 (14), p. 1709–1712, 1975. Résumé | BibTeX | Étiquettes: Age Factors, Animals, Carrier Proteins, Chromatography, Ecdysone, Ecdysterone, Gel, Grasshoppers, Hematopoietic System, hoffmann, Larva, M3i, Neurosecretory Systems, Protein Binding, Time Factors @article{feyereisen_hemolymphatic_1975, title = {The hemolymphatic transport of molting hormone during the development of Locusta migratoria L}, author = {R Feyereisen and Marie Lagueux and Jules A Hoffmann}, year = {1975}, date = {1975-04-01}, journal = {C.R. Hebd. Seances Acad. Sci., Ser. D, Sci. Nat.}, volume = {280}, number = {14}, pages = {1709--1712}, abstract = {Shortly after injection of radio-labelled ecdysone into fifth instar larvae of Locusta migratoria, 20-hydroxy-ecdysone (ecdysterone) is the main hormone found in the blood. Some 10% of the circulating hormone are bound to hemolymph macromolecules. The ratio of bound to free hormone is stage-dependent; it decreases considerably after previous injections of non-labelled ecdysone, but increases in insects in which ecdysone biosynthesis has been blocked by extirpation of the prothoracic glands or selective X-ray treatment of the hemocytopoietic tissue.}, keywords = {Age Factors, Animals, Carrier Proteins, Chromatography, Ecdysone, Ecdysterone, Gel, Grasshoppers, Hematopoietic System, hoffmann, Larva, M3i, Neurosecretory Systems, Protein Binding, Time Factors}, pubstate = {published}, tppubtype = {article} } Shortly after injection of radio-labelled ecdysone into fifth instar larvae of Locusta migratoria, 20-hydroxy-ecdysone (ecdysterone) is the main hormone found in the blood. Some 10% of the circulating hormone are bound to hemolymph macromolecules. The ratio of bound to free hormone is stage-dependent; it decreases considerably after previous injections of non-labelled ecdysone, but increases in insects in which ecdysone biosynthesis has been blocked by extirpation of the prothoracic glands or selective X-ray treatment of the hemocytopoietic tissue. |
1974 |
Hoffmann, Jules A; Koolman, J; Karlson, P; Joly, P Molting hormone titer and metabolic fate of injected ecdysone during the fifth larval instar and in adults of Locusta migratoria (Orthoptera) Article de journal Gen. Comp. Endocrinol., 22 (1), p. 90–97, 1974, ISSN: 0016-6480. BibTeX | Étiquettes: Age Factors, Animals, Chromatography, Ecdysone, Feces, Grasshoppers, hoffmann, Hydroxylation, Invertebrate Hormones, Larva, M3i, Thin Layer, Time Factors, Tritium @article{hoffmann_molting_1974, title = {Molting hormone titer and metabolic fate of injected ecdysone during the fifth larval instar and in adults of Locusta migratoria (Orthoptera)}, author = {Jules A Hoffmann and J Koolman and P Karlson and P Joly}, issn = {0016-6480}, year = {1974}, date = {1974-01-01}, journal = {Gen. Comp. Endocrinol.}, volume = {22}, number = {1}, pages = {90--97}, keywords = {Age Factors, Animals, Chromatography, Ecdysone, Feces, Grasshoppers, hoffmann, Hydroxylation, Invertebrate Hormones, Larva, M3i, Thin Layer, Time Factors, Tritium}, pubstate = {published}, tppubtype = {article} } |
1973 |
Koolman, J; Hoffmann, Jules A; Karlson, P Sulphage esters as inactivation products of ecdysone in Locusta migratoria Article de journal Hoppe-Seyler's Z. Physiol. Chem., 354 (9), p. 1043–1048, 1973, ISSN: 0018-4888. BibTeX | Étiquettes: Animals, Biological, Cattle, Chromatography, Ecdysone, Electrophoresis, Esterases, Glucosidases, Glucuronidase, Grasshoppers, hoffmann, Hydrogen-Ion Concentration, Hydrolysis, Ion Exchange, Isotope Labeling, Kinetics, Larva, Liver, M3i, Metamorphosis, Paper, Plants, Saccharomyces cerevisiae, Snails, Sulfatases, Sulfur Radioisotopes, Sulfuric Acids, Swine, Thin Layer, Time Factors, Tritium @article{koolman_sulphage_1973, title = {Sulphage esters as inactivation products of ecdysone in Locusta migratoria}, author = {J Koolman and Jules A Hoffmann and P Karlson}, issn = {0018-4888}, year = {1973}, date = {1973-09-01}, journal = {Hoppe-Seyler's Z. Physiol. Chem.}, volume = {354}, number = {9}, pages = {1043--1048}, keywords = {Animals, Biological, Cattle, Chromatography, Ecdysone, Electrophoresis, Esterases, Glucosidases, Glucuronidase, Grasshoppers, hoffmann, Hydrogen-Ion Concentration, Hydrolysis, Ion Exchange, Isotope Labeling, Kinetics, Larva, Liver, M3i, Metamorphosis, Paper, Plants, Saccharomyces cerevisiae, Snails, Sulfatases, Sulfur Radioisotopes, Sulfuric Acids, Swine, Thin Layer, Time Factors, Tritium}, pubstate = {published}, tppubtype = {article} } |