Publications
2010 |
Whisstock, James C; Silverman, Gary A; Bird, Phillip I; Bottomley, Stephen P; Kaiserman, Dion; Luke, Cliff J; Pak, Stephen C; Reichhart, Jean-Marc; Huntington, James A Serpins flex their muscle: II. Structural insights into target peptidase recognition, polymerization, and transport functions Article de journal J. Biol. Chem., 285 (32), p. 24307–24312, 2010, ISSN: 1083-351X. Résumé | Liens | BibTeX | Étiquettes: Animals, Biological, Biological Transport, Biophysics, Catalytic Domain, Hormones, Humans, Kinetics, M3i, Models, Peptide Hydrolases, Protein Binding, Protein Conformation, Protein Structure, reichhart, Serpins, Substrate Specificity, Tertiary, Thrombin @article{whisstock_serpins_2010, title = {Serpins flex their muscle: II. Structural insights into target peptidase recognition, polymerization, and transport functions}, author = {James C Whisstock and Gary A Silverman and Phillip I Bird and Stephen P Bottomley and Dion Kaiserman and Cliff J Luke and Stephen C Pak and Jean-Marc Reichhart and James A Huntington}, doi = {10.1074/jbc.R110.141408}, issn = {1083-351X}, year = {2010}, date = {2010-08-01}, journal = {J. Biol. Chem.}, volume = {285}, number = {32}, pages = {24307--24312}, abstract = {Inhibitory serpins are metastable proteins that undergo a substantial conformational rearrangement to covalently trap target peptidases. The serpin reactive center loop contributes a majority of the interactions that serpins make during the initial binding to target peptidases. However, structural studies on serpin-peptidase complexes reveal a broader set of contacts on the scaffold of inhibitory serpins that have substantial influence on guiding peptidase recognition. Structural and biophysical studies also reveal how aberrant serpin folding can lead to the formation of domain-swapped serpin multimers rather than the monomeric metastable state. Serpin domain swapping may therefore underlie the polymerization events characteristic of the serpinopathies. Finally, recent structural studies reveal how the serpin fold has been adapted for non-inhibitory functions such as hormone binding.}, keywords = {Animals, Biological, Biological Transport, Biophysics, Catalytic Domain, Hormones, Humans, Kinetics, M3i, Models, Peptide Hydrolases, Protein Binding, Protein Conformation, Protein Structure, reichhart, Serpins, Substrate Specificity, Tertiary, Thrombin}, pubstate = {published}, tppubtype = {article} } Inhibitory serpins are metastable proteins that undergo a substantial conformational rearrangement to covalently trap target peptidases. The serpin reactive center loop contributes a majority of the interactions that serpins make during the initial binding to target peptidases. However, structural studies on serpin-peptidase complexes reveal a broader set of contacts on the scaffold of inhibitory serpins that have substantial influence on guiding peptidase recognition. Structural and biophysical studies also reveal how aberrant serpin folding can lead to the formation of domain-swapped serpin multimers rather than the monomeric metastable state. Serpin domain swapping may therefore underlie the polymerization events characteristic of the serpinopathies. Finally, recent structural studies reveal how the serpin fold has been adapted for non-inhibitory functions such as hormone binding. |
2006 |
Pelte, Nadège; Robertson, Andrew S; Zou, Zhen; Belorgey, Didier; Dafforn, Timothy R; Jiang, Haobo; Lomas, David; Reichhart, Jean-Marc; Gubb, David Immune challenge induces N-terminal cleavage of the Drosophila serpin Necrotic Article de journal Insect Biochem. Mol. Biol., 36 (1), p. 37–46, 2006, ISSN: 0965-1748. Résumé | Liens | BibTeX | Étiquettes: Animals, Gene Expression Regulation, M3i, Protein Conformation, reichhart, Serpins, Signal Transduction @article{pelte_immune_2006, title = {Immune challenge induces N-terminal cleavage of the Drosophila serpin Necrotic}, author = {Nadège Pelte and Andrew S Robertson and Zhen Zou and Didier Belorgey and Timothy R Dafforn and Haobo Jiang and David Lomas and Jean-Marc Reichhart and David Gubb}, doi = {10.1016/j.ibmb.2005.10.004}, issn = {0965-1748}, year = {2006}, date = {2006-01-01}, journal = {Insect Biochem. Mol. Biol.}, volume = {36}, number = {1}, pages = {37--46}, abstract = {The Drosophila Necrotic protein is a serine proteinase inhibitor, which regulates the Toll-mediated innate immune response. Necrotic specifically inhibits an extracellular serine proteinase cascade leading to activation of the Toll ligand, Spätzle. Necrotic carries a polyglutamine extension amino-terminal to the core serpin structure. We show here that cleavage of this N-terminal extension occurs following immune challenge. This modification is blocked in PGRP-SA(semmelweiss) mutants after Gram-positive bacterial challenge and in persephone mutants after fungal or Gram-positive bacterial challenge, indicating that activation of either of the Toll pathway upstream branches induces N-terminal cleavage of the serpin. The absolute requirement of persephone gene product for this cleavage indicates that Gram-positive bacteria activate a redundant set of proteinases upstream of Toll. Both full-length Necrotic and the core serpin are active inhibitors of a range of serine proteinases: the highest affinity being for cathepsin G and elastases. We found a 13-fold increase in the specificity of the core serpin over that of full-length Necrotic for one of the tested proteinases (porcine pancreatic elastase). This finding indicates that cleavage of the Necrotic amino-terminal extension might modulate Toll activation following the initial immune response.}, keywords = {Animals, Gene Expression Regulation, M3i, Protein Conformation, reichhart, Serpins, Signal Transduction}, pubstate = {published}, tppubtype = {article} } The Drosophila Necrotic protein is a serine proteinase inhibitor, which regulates the Toll-mediated innate immune response. Necrotic specifically inhibits an extracellular serine proteinase cascade leading to activation of the Toll ligand, Spätzle. Necrotic carries a polyglutamine extension amino-terminal to the core serpin structure. We show here that cleavage of this N-terminal extension occurs following immune challenge. This modification is blocked in PGRP-SA(semmelweiss) mutants after Gram-positive bacterial challenge and in persephone mutants after fungal or Gram-positive bacterial challenge, indicating that activation of either of the Toll pathway upstream branches induces N-terminal cleavage of the serpin. The absolute requirement of persephone gene product for this cleavage indicates that Gram-positive bacteria activate a redundant set of proteinases upstream of Toll. Both full-length Necrotic and the core serpin are active inhibitors of a range of serine proteinases: the highest affinity being for cathepsin G and elastases. We found a 13-fold increase in the specificity of the core serpin over that of full-length Necrotic for one of the tested proteinases (porcine pancreatic elastase). This finding indicates that cleavage of the Necrotic amino-terminal extension might modulate Toll activation following the initial immune response. |
2005 |
Reichhart, Jean-Marc Tip of another iceberg: Drosophila serpins Article de journal Trends Cell Biol., 15 (12), p. 659–665, 2005, ISSN: 0962-8924. Résumé | Liens | BibTeX | Étiquettes: Animals, Immunity, M3i, Protein Conformation, reichhart, Serine Proteinase Inhibitors, Serpins @article{reichhart_tip_2005, title = {Tip of another iceberg: Drosophila serpins}, author = {Jean-Marc Reichhart}, doi = {10.1016/j.tcb.2005.10.001}, issn = {0962-8924}, year = {2005}, date = {2005-12-01}, journal = {Trends Cell Biol.}, volume = {15}, number = {12}, pages = {659--665}, abstract = {Serpins are serine protease inhibitors with a conserved structure that have been identified in nearly all species and act as suicide substrates by binding covalently to their target proteases. Serpins regulate various physiological processes and defence mechanisms. In humans, several serpin mutations are linked to diseases. The genome of Drosophila melanogaster encodes 29 serpins and even more serine proteases. To date, three serpins have been investigated in detail. Spn27A controls the Toll pathway during early development and is involved in defence reactions in adult flies. SPN42DaA is an inhibitor of furin, a subtilisin-like convertase that is required for pro-protein maturation. Spn43Ac controls the Toll pathway during the immune response. In each case, Drosophila genetics has shed new light on the function of these serine protease inhibitors.}, keywords = {Animals, Immunity, M3i, Protein Conformation, reichhart, Serine Proteinase Inhibitors, Serpins}, pubstate = {published}, tppubtype = {article} } Serpins are serine protease inhibitors with a conserved structure that have been identified in nearly all species and act as suicide substrates by binding covalently to their target proteases. Serpins regulate various physiological processes and defence mechanisms. In humans, several serpin mutations are linked to diseases. The genome of Drosophila melanogaster encodes 29 serpins and even more serine proteases. To date, three serpins have been investigated in detail. Spn27A controls the Toll pathway during early development and is involved in defence reactions in adult flies. SPN42DaA is an inhibitor of furin, a subtilisin-like convertase that is required for pro-protein maturation. Spn43Ac controls the Toll pathway during the immune response. In each case, Drosophila genetics has shed new light on the function of these serine protease inhibitors. |
2001 |
Lamberty, M; Zachary, Daniel; Lanot, R; Bordereau, C; Robert, A; Hoffmann, Jules A; Bulet, Philippe Insect immunity. Constitutive expression of a cysteine-rich antifungal and a linear antibacterial peptide in a termite insect. Article de journal J. Biol. Chem., 276 (6), p. 4085–4092, 2001, ISSN: 0021-9258. Résumé | Liens | BibTeX | Étiquettes: Amino Acid, Animals, Anti-Bacterial Agents, Antifungal Agents, Base Sequence, Chromatography, Cysteine, DNA Primers, High Pressure Liquid, hoffmann, Immunohistochemistry, Isoptera, M3i, Peptides, Protein Conformation, Recombinant Proteins, Sequence Homology @article{lamberty_insect_2001, title = {Insect immunity. Constitutive expression of a cysteine-rich antifungal and a linear antibacterial peptide in a termite insect.}, author = {M Lamberty and Daniel Zachary and R Lanot and C Bordereau and A Robert and Jules A Hoffmann and Philippe Bulet}, doi = {10.1074/jbc.M002998200}, issn = {0021-9258}, year = {2001}, date = {2001-02-01}, journal = {J. Biol. Chem.}, volume = {276}, number = {6}, pages = {4085--4092}, abstract = {Two novel antimicrobial peptides, which we propose to name termicin and spinigerin, have been isolated from the fungus-growing termite Pseudacanthotermes spiniger (heterometabole insect, Isoptera). Termicin is a 36-amino acid residue antifungal peptide, with six cysteines arranged in a disulfide array similar to that of insect defensins. In contrast to most insect defensins, termicin is C-terminally amidated. Spinigerin consists of 25 amino acids and is devoid of cysteines. It is active against bacteria and fungi. Termicin and spinigerin show no obvious sequence similarities with other peptides. Termicin is constitutively present in hemocyte granules and in salivary glands. The presence of termicin and spinigerin in unchallenged termites contrasts with observations in evolutionary recent insects or insects undergoing complete metamorphosis, in which antimicrobial peptides are induced in the fat body and released into the hemolymph after septic injury.}, keywords = {Amino Acid, Animals, Anti-Bacterial Agents, Antifungal Agents, Base Sequence, Chromatography, Cysteine, DNA Primers, High Pressure Liquid, hoffmann, Immunohistochemistry, Isoptera, M3i, Peptides, Protein Conformation, Recombinant Proteins, Sequence Homology}, pubstate = {published}, tppubtype = {article} } Two novel antimicrobial peptides, which we propose to name termicin and spinigerin, have been isolated from the fungus-growing termite Pseudacanthotermes spiniger (heterometabole insect, Isoptera). Termicin is a 36-amino acid residue antifungal peptide, with six cysteines arranged in a disulfide array similar to that of insect defensins. In contrast to most insect defensins, termicin is C-terminally amidated. Spinigerin consists of 25 amino acids and is devoid of cysteines. It is active against bacteria and fungi. Termicin and spinigerin show no obvious sequence similarities with other peptides. Termicin is constitutively present in hemocyte granules and in salivary glands. The presence of termicin and spinigerin in unchallenged termites contrasts with observations in evolutionary recent insects or insects undergoing complete metamorphosis, in which antimicrobial peptides are induced in the fat body and released into the hemolymph after septic injury. |
1995 |
Cornet, B; Bonmatin, J M; Hetru, Charles; Hoffmann, Jules A; Ptak, M; Vovelle, F Refined three-dimensional solution structure of insect defensin A Article de journal Structure, 3 (5), p. 435–448, 1995, ISSN: 0969-2126. Résumé | BibTeX | Étiquettes: Amino Acid, Animals, Bacteriolysis, Chemistry, Defensins, Diptera, Gram-Positive Bacteria, hoffmann, Hydrogen Bonding, Insect Hormones, M3i, Magnetic Resonance Spectroscopy, Models, Molecular, Physical, Physicochemical Phenomena, Protein Conformation, Recombinant Proteins, Sequence Homology, Solutions, Structure-Activity Relationship @article{cornet_refined_1995, title = {Refined three-dimensional solution structure of insect defensin A}, author = {B Cornet and J M Bonmatin and Charles Hetru and Jules A Hoffmann and M Ptak and F Vovelle}, issn = {0969-2126}, year = {1995}, date = {1995-05-01}, journal = {Structure}, volume = {3}, number = {5}, pages = {435--448}, abstract = {BACKGROUND: Insect defensin A is a basic 4 kDa protein secreted by Phormia terranovae larvae in response to bacterial challenges or injuries. Previous biological tests suggest that the bacterial cytoplasmic membrane is the target of defensin A. The structural study of this protein is the first step towards establishing a structure-activity relationship and forms the basis for understanding its antibiotic activity at the molecular level. RESULTS: We describe a refined model of the three-dimensional structure of defensin A derived from an extensive analysis of 786 inter-proton nuclear Overhauser effects. The backbone fold involves an N-terminal loop and an alpha-helical fragment followed by an antiparallel beta-structure. The helix and the beta-structure are connected by two of the three disulphide bridges present in defensin A, forming a so-called 'cysteine-stabilized alpha beta' (CS alpha beta) motif. The N-terminal loop, which is locally well defined, can occupy different positions with respect to the other moieties of the molecule. CONCLUSIONS: The CS alpha beta motif, which forms the core of the defensin A structure, appears to be a common organization for several families of small proteins with toxic properties. The distribution of amino acid side chains in the protein structure creates several hydrophobic or hydrophilic patches. This leads us to propose that the initial step in the action of positively charged defensin A molecules with cytoplasmic membranes may involve interactions with acidic phospholipids.}, keywords = {Amino Acid, Animals, Bacteriolysis, Chemistry, Defensins, Diptera, Gram-Positive Bacteria, hoffmann, Hydrogen Bonding, Insect Hormones, M3i, Magnetic Resonance Spectroscopy, Models, Molecular, Physical, Physicochemical Phenomena, Protein Conformation, Recombinant Proteins, Sequence Homology, Solutions, Structure-Activity Relationship}, pubstate = {published}, tppubtype = {article} } BACKGROUND: Insect defensin A is a basic 4 kDa protein secreted by Phormia terranovae larvae in response to bacterial challenges or injuries. Previous biological tests suggest that the bacterial cytoplasmic membrane is the target of defensin A. The structural study of this protein is the first step towards establishing a structure-activity relationship and forms the basis for understanding its antibiotic activity at the molecular level. RESULTS: We describe a refined model of the three-dimensional structure of defensin A derived from an extensive analysis of 786 inter-proton nuclear Overhauser effects. The backbone fold involves an N-terminal loop and an alpha-helical fragment followed by an antiparallel beta-structure. The helix and the beta-structure are connected by two of the three disulphide bridges present in defensin A, forming a so-called 'cysteine-stabilized alpha beta' (CS alpha beta) motif. The N-terminal loop, which is locally well defined, can occupy different positions with respect to the other moieties of the molecule. CONCLUSIONS: The CS alpha beta motif, which forms the core of the defensin A structure, appears to be a common organization for several families of small proteins with toxic properties. The distribution of amino acid side chains in the protein structure creates several hydrophobic or hydrophilic patches. This leads us to propose that the initial step in the action of positively charged defensin A molecules with cytoplasmic membranes may involve interactions with acidic phospholipids. |
1992 |
Bonmatin, J M; Bonnat, J L; Gallet, X; Vovelle, F; Ptak, M; Reichhart, Jean-Marc; Hoffmann, Jules A; Keppi, E; Legrain, M; Achstetter, T Two-dimensional 1H NMR study of recombinant insect defensin A in water: resonance assignments, secondary structure and global folding Article de journal J. Biomol. NMR, 2 (3), p. 235–256, 1992, ISSN: 0925-2738. Résumé | BibTeX | Étiquettes: Animals, Defensins, hoffmann, Hydrogen, Insect Hormones, insects, M3i, Magnetic Resonance Spectroscopy, Models, Molecular, Protein Conformation, Recombinant Proteins, reichhart, Saccharomyces cerevisiae, Thermodynamics @article{bonmatin_two-dimensional_1992, title = {Two-dimensional 1H NMR study of recombinant insect defensin A in water: resonance assignments, secondary structure and global folding}, author = {J M Bonmatin and J L Bonnat and X Gallet and F Vovelle and M Ptak and Jean-Marc Reichhart and Jules A Hoffmann and E Keppi and M Legrain and T Achstetter}, issn = {0925-2738}, year = {1992}, date = {1992-01-01}, journal = {J. Biomol. NMR}, volume = {2}, number = {3}, pages = {235--256}, abstract = {A 500 MHz 2D 1H NMR study of recombinant insect defensin A is reported. This defense protein of 40 residues contains 3 disulfide bridges, is positively charged and exhibits antibacterial properties. 2D NMR maps of recombinant defensin A were fully assigned and secondary structure elements were localized. The set of NOE connectivities, 3JNH-alpha H coupling constants as well as 1H/2H exchange rates and delta delta/delta T temperature coefficients of NH protons strongly support the existence of an alpha-helix (residues 14-24) and of an antiparallel beta-sheet (residues 27-40). Models of the backbone folding were generated by using the DISMAN program and energy refined by using the AMBER program. This was done on the basis of: (i) 133 selected NOEs, (ii) 21 dihedral restraints from 3JNH-alpha H coupling constants, (iii) 12 hydrogen bonds mostly deduced from 1H/2H exchange rates or temperature coefficients, in addition to 9 initial disulfide bridge covalent constraints. The two secondary structure elements and the two bends connecting them involve approximately 70% of the total number of residues, which impose some stability in the C-terminal part of the molecule. The remaining N-terminal fragment forms a less well defined loop. This spatial organization, in which a beta-sheet is linked to an alpha-helix by two disulfide bridges and to a large loop by a third disulfide bridge, is rather similar to that found in scorpion charybdotoxin and seems to be partly present in several invertebrate toxins.}, keywords = {Animals, Defensins, hoffmann, Hydrogen, Insect Hormones, insects, M3i, Magnetic Resonance Spectroscopy, Models, Molecular, Protein Conformation, Recombinant Proteins, reichhart, Saccharomyces cerevisiae, Thermodynamics}, pubstate = {published}, tppubtype = {article} } A 500 MHz 2D 1H NMR study of recombinant insect defensin A is reported. This defense protein of 40 residues contains 3 disulfide bridges, is positively charged and exhibits antibacterial properties. 2D NMR maps of recombinant defensin A were fully assigned and secondary structure elements were localized. The set of NOE connectivities, 3JNH-alpha H coupling constants as well as 1H/2H exchange rates and delta delta/delta T temperature coefficients of NH protons strongly support the existence of an alpha-helix (residues 14-24) and of an antiparallel beta-sheet (residues 27-40). Models of the backbone folding were generated by using the DISMAN program and energy refined by using the AMBER program. This was done on the basis of: (i) 133 selected NOEs, (ii) 21 dihedral restraints from 3JNH-alpha H coupling constants, (iii) 12 hydrogen bonds mostly deduced from 1H/2H exchange rates or temperature coefficients, in addition to 9 initial disulfide bridge covalent constraints. The two secondary structure elements and the two bends connecting them involve approximately 70% of the total number of residues, which impose some stability in the C-terminal part of the molecule. The remaining N-terminal fragment forms a less well defined loop. This spatial organization, in which a beta-sheet is linked to an alpha-helix by two disulfide bridges and to a large loop by a third disulfide bridge, is rather similar to that found in scorpion charybdotoxin and seems to be partly present in several invertebrate toxins. |
1991 |
Hetru, Charles; Li, K W; Bulet, Philippe; Lagueux, Marie; Hoffmann, Jules A Isolation and structural characterization of an insulin-related molecule, a predominant neuropeptide from Locusta migratoria Article de journal Eur. J. Biochem., 201 (2), p. 495–499, 1991, ISSN: 0014-2956. Résumé | BibTeX | Étiquettes: Animals, Chromatography, DNA, Female, Grasshoppers, High Pressure Liquid, hoffmann, Insect Hormones, Insulin, M3i, Mass Spectrometry, Neuropeptides, Proinsulin, Protein Conformation @article{hetru_isolation_1991, title = {Isolation and structural characterization of an insulin-related molecule, a predominant neuropeptide from Locusta migratoria}, author = {Charles Hetru and K W Li and Philippe Bulet and Marie Lagueux and Jules A Hoffmann}, issn = {0014-2956}, year = {1991}, date = {1991-10-01}, journal = {Eur. J. Biochem.}, volume = {201}, number = {2}, pages = {495--499}, abstract = {Neurohaemal lobes of corpora cardiaca of Locusta migratoria are an established storage site for neurohormones produced by the neurosecretory cells of the brain. As previously reported [Hietter, H., Van Dorsselaer, A., Green, B., Denoroy, L., Hoffmann, J.A. & Luu, B. (1990) Eur. J. Biochem. 187, 241-247], the isolation and characterization of a novel 5-kDa peptide from these lobes served as the basis for oligonucleotide screening of cDNA libraries prepared from poly(A) RNA from neurosecretory cells of the central nervous system. From subsequent cDNA cloning studies [Lagueux, M., Lwoff, L., Meister, M., Goltzené, F. & Hoffmann, J.A. (1990) Eur. J. Biochem. 187, 249-254], the existence of a 145-residue precursor protein was deduced, which contained, in addition to the 5-kDa peptide, amino-acid sequences with homology to the A and B chains of an insulin-related peptide. In the present study we have isolated the native molecule from corpora cardiaca of Locusta and characterized, by Edman degradation and plasma-desorption mass spectrometry, the two chains as follows: A chain, Gly-Val-Phe-Asp-Glu-Cys-Cys-Arg-Lys-Ser-Cys-Ser-Ile-Ser-Glu-Leu-Gln-Thr- Tyr-Cys - Gly (Ile, isoleucine); B chain, Ser-Gly-Ala-Pro-Gln-Pro-Val-Ala-Arg-Tyr-Cys-Gly-Glu-Lys-Leu-Ser-Asn-Ala- Leu-Lys - Leu-Val-Cys-Arg-Gly-Asn-Tyr-Asn-Thr-Met-Phe. Taken in conjunction with the previous cloning studies, our data lead to a clear picture of the processing of Locusta preproinsulin. They indicate that locusta corpora cardiaca contain remarkably large amounts of one single insulin form, in contrast to multiple insulin isoforms of Bombyx mori, the only other insect species from which insulin-related peptides have been isolated and characterized [Nagasawa, H., Kataoka, H., Isogai, A., Tamura, S., Suzuki, A., Mizoguchi, A., Fujiwara, Y., Suzuki, A., Takahashi, S. & Ishizaki, H. (1986) Proc. Natl Acad. Sci. USA 83, 5840-5843].}, keywords = {Animals, Chromatography, DNA, Female, Grasshoppers, High Pressure Liquid, hoffmann, Insect Hormones, Insulin, M3i, Mass Spectrometry, Neuropeptides, Proinsulin, Protein Conformation}, pubstate = {published}, tppubtype = {article} } Neurohaemal lobes of corpora cardiaca of Locusta migratoria are an established storage site for neurohormones produced by the neurosecretory cells of the brain. As previously reported [Hietter, H., Van Dorsselaer, A., Green, B., Denoroy, L., Hoffmann, J.A. & Luu, B. (1990) Eur. J. Biochem. 187, 241-247], the isolation and characterization of a novel 5-kDa peptide from these lobes served as the basis for oligonucleotide screening of cDNA libraries prepared from poly(A) RNA from neurosecretory cells of the central nervous system. From subsequent cDNA cloning studies [Lagueux, M., Lwoff, L., Meister, M., Goltzené, F. & Hoffmann, J.A. (1990) Eur. J. Biochem. 187, 249-254], the existence of a 145-residue precursor protein was deduced, which contained, in addition to the 5-kDa peptide, amino-acid sequences with homology to the A and B chains of an insulin-related peptide. In the present study we have isolated the native molecule from corpora cardiaca of Locusta and characterized, by Edman degradation and plasma-desorption mass spectrometry, the two chains as follows: A chain, Gly-Val-Phe-Asp-Glu-Cys-Cys-Arg-Lys-Ser-Cys-Ser-Ile-Ser-Glu-Leu-Gln-Thr- Tyr-Cys - Gly (Ile, isoleucine); B chain, Ser-Gly-Ala-Pro-Gln-Pro-Val-Ala-Arg-Tyr-Cys-Gly-Glu-Lys-Leu-Ser-Asn-Ala- Leu-Lys - Leu-Val-Cys-Arg-Gly-Asn-Tyr-Asn-Thr-Met-Phe. Taken in conjunction with the previous cloning studies, our data lead to a clear picture of the processing of Locusta preproinsulin. They indicate that locusta corpora cardiaca contain remarkably large amounts of one single insulin form, in contrast to multiple insulin isoforms of Bombyx mori, the only other insect species from which insulin-related peptides have been isolated and characterized [Nagasawa, H., Kataoka, H., Isogai, A., Tamura, S., Suzuki, A., Mizoguchi, A., Fujiwara, Y., Suzuki, A., Takahashi, S. & Ishizaki, H. (1986) Proc. Natl Acad. Sci. USA 83, 5840-5843]. |
1990 |
Dimarcq, Jean-Luc; Zachary, Daniel; Hoffmann, Jules A; Hoffmann, Danièle; Reichhart, Jean-Marc Insect immunity: expression of the two major inducible antibacterial peptides, defensin and diptericin, in Phormia terranovae Article de journal EMBO J., 9 (8), p. 2507–2515, 1990, ISSN: 0261-4189. Résumé | BibTeX | Étiquettes: Animals, Anti-Bacterial Agents, Base Sequence, Blood Proteins, Cloning, Defensins, Diptera, Gene Expression, hoffmann, Insect Hormones, Insect Proteins, Larva, M3i, Molecular, Nucleic Acid Hybridization, Oligonucleotide Probes, Protein Conformation, reichhart @article{dimarcq_insect_1990, title = {Insect immunity: expression of the two major inducible antibacterial peptides, defensin and diptericin, in Phormia terranovae}, author = {Jean-Luc Dimarcq and Daniel Zachary and Jules A Hoffmann and Danièle Hoffmann and Jean-Marc Reichhart}, issn = {0261-4189}, year = {1990}, date = {1990-08-01}, journal = {EMBO J.}, volume = {9}, number = {8}, pages = {2507--2515}, abstract = {Injections of low doses of bacteria into larvae of Phormia terranovae induce the appearance of potent bactericidal peptides in the blood, among which predominate the anti-Gram positive insect defensins and the anti-Gram negative diptericins. Insect defensins show significant homologies to mammalian (including human) microbicidal peptides present in polymorphonuclear leukocytes and macrophages. We report the molecular cloning of cDNAs and primer extension studies which indicate that insect defensin is produced as a prepro-peptide yielding mature defensin A (40 residues) after cleavage of a putative signal peptide (23 residues) and a prosequence (34 residues). Previous studies have established that diptericin (82 residues) is matured from a pre-peptide by cleavage of a putative signal peptide (19 residues) and C-terminal amidation. Using oligonucleotide probes complementary to the sequences of the mRNAs for defensin and diptericin, we show by in situ hybridization that both antibacterial peptides are concomitantly synthesized by the same cells: thrombocytoids, a specialized blood cell type, and adipocytes. Transcriptional studies based on hybridization of RNAs to cDNAs of defensin and diptericin indicate that the transcription of both genes is induced regardless of the nature of the stimulus (injection of Gram positive or Gram negative bacteria, lipopolysaccharides). Even a sterile injury applied to axenically raised larvae is efficient in inducing the transcription of both genes suggesting that the local disruption of the integument aspecifically initiates a signalling mechanism which the thrombocytoids and the adipocytes are able to interpret. The transcription of immune genes is relatively short lived and a second challenge yields a response similar to that of the first stimulus, indicating that the experimental insects do not keep a 'memory' of their first injection.}, keywords = {Animals, Anti-Bacterial Agents, Base Sequence, Blood Proteins, Cloning, Defensins, Diptera, Gene Expression, hoffmann, Insect Hormones, Insect Proteins, Larva, M3i, Molecular, Nucleic Acid Hybridization, Oligonucleotide Probes, Protein Conformation, reichhart}, pubstate = {published}, tppubtype = {article} } Injections of low doses of bacteria into larvae of Phormia terranovae induce the appearance of potent bactericidal peptides in the blood, among which predominate the anti-Gram positive insect defensins and the anti-Gram negative diptericins. Insect defensins show significant homologies to mammalian (including human) microbicidal peptides present in polymorphonuclear leukocytes and macrophages. We report the molecular cloning of cDNAs and primer extension studies which indicate that insect defensin is produced as a prepro-peptide yielding mature defensin A (40 residues) after cleavage of a putative signal peptide (23 residues) and a prosequence (34 residues). Previous studies have established that diptericin (82 residues) is matured from a pre-peptide by cleavage of a putative signal peptide (19 residues) and C-terminal amidation. Using oligonucleotide probes complementary to the sequences of the mRNAs for defensin and diptericin, we show by in situ hybridization that both antibacterial peptides are concomitantly synthesized by the same cells: thrombocytoids, a specialized blood cell type, and adipocytes. Transcriptional studies based on hybridization of RNAs to cDNAs of defensin and diptericin indicate that the transcription of both genes is induced regardless of the nature of the stimulus (injection of Gram positive or Gram negative bacteria, lipopolysaccharides). Even a sterile injury applied to axenically raised larvae is efficient in inducing the transcription of both genes suggesting that the local disruption of the integument aspecifically initiates a signalling mechanism which the thrombocytoids and the adipocytes are able to interpret. The transcription of immune genes is relatively short lived and a second challenge yields a response similar to that of the first stimulus, indicating that the experimental insects do not keep a 'memory' of their first injection. |
1989 |
Rosenthal, G A; Reichhart, Jean-Marc; Hoffmann, Jules A L-canavanine incorporation into vitellogenin and macromolecular conformation Article de journal J. Biol. Chem., 264 (23), p. 13693–13696, 1989, ISSN: 0021-9258. Résumé | BibTeX | Étiquettes: Animals, Antibodies, Canavanine, fluorescence, Grasshoppers, hoffmann, M3i, Monoclonal, Protein Conformation, reichhart, Spectrometry, Vitellogenins @article{rosenthal_l-canavanine_1989, title = {L-canavanine incorporation into vitellogenin and macromolecular conformation}, author = {G A Rosenthal and Jean-Marc Reichhart and Jules A Hoffmann}, issn = {0021-9258}, year = {1989}, date = {1989-01-01}, journal = {J. Biol. Chem.}, volume = {264}, number = {23}, pages = {13693--13696}, abstract = {L-Canavanine is a potentially deleterious arginine antimetabolite whose toxicity is expressed in canavanine-sensitive organisms ranging from viruses to humans. Canavanine, a substrate for arginyl-tRNA synthetase, is incorporated into nascent polypeptide chains in place of arginine. This substitution results in the production of structurally aberrant, canavanyl proteins. Chemical, physical, and immunological studies of native and canavanine-containing vitellogenin obtained from female migratory locusts (Locusta migratoria migratorioides (Orthoptera] provide the first experimental evidence that canavanine can disrupt the tertiary and/or quaternary structure that yields the three-dimensional conformation unique to the protein. These findings enhance our understanding of the biochemical basis for canavanine's antimetabolic and potent insecticidal properties.}, keywords = {Animals, Antibodies, Canavanine, fluorescence, Grasshoppers, hoffmann, M3i, Monoclonal, Protein Conformation, reichhart, Spectrometry, Vitellogenins}, pubstate = {published}, tppubtype = {article} } L-Canavanine is a potentially deleterious arginine antimetabolite whose toxicity is expressed in canavanine-sensitive organisms ranging from viruses to humans. Canavanine, a substrate for arginyl-tRNA synthetase, is incorporated into nascent polypeptide chains in place of arginine. This substitution results in the production of structurally aberrant, canavanyl proteins. Chemical, physical, and immunological studies of native and canavanine-containing vitellogenin obtained from female migratory locusts (Locusta migratoria migratorioides (Orthoptera] provide the first experimental evidence that canavanine can disrupt the tertiary and/or quaternary structure that yields the three-dimensional conformation unique to the protein. These findings enhance our understanding of the biochemical basis for canavanine's antimetabolic and potent insecticidal properties. |