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| Registros recuperados: 57 | |
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| Zappa, Sebastien; Rolland, Jean-luc; Flament, Didier; Gueguen, Yannick; Boudrant, Joseph; Dietrich, Jacques. |
| This work reports the first isolation and characterization of an alkaline phosphatase (AP) from a hyperthermophilic archaeon. An AP gene from Pyrococcus abyssi, a euryarchaeon isolated from a deep-sea hydrothermal vent, was cloned and the enzyme expressed in Escherichia coli. Analysis of the sequence showed conservation of the active site and structural elements of the E. coli AP. The recombinant AP was purified and characterized. Monomeric and homodimeric active forms were detected, with a monomer molecular mass of 54 kDa. Apparent optimum pH and temperature were estimated at 11.0 and 70 degreesC, respectively. Thus far, P. abyssi AP has been demonstrated to be the most thermostable AP, with half-lives at 100 and 105 degreesC of 18 and 5 h, respectively.... |
| Tipo: Text |
Palavras-chave: Escherichia coli; Characterization; Isolation; Gene; Alkaline phosphatase; Pyrococcus abyssi; Archaeon. |
| Ano: 2001 |
URL: http://archimer.ifremer.fr/doc/2001/publication-1268.pdf |
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| Henneke, Ghislaine; Gueguen, Yannick; Flament, Didier; Azam, Philippe; Querellou, Joel; Dietrich, Jacques; Hubscher, Ulrich; Raffin, Jean-paul. |
| The molecular organization of the replication complex in archaea is similar to that in eukaryotes. Only two proteins homologous to subunits of eukaryotic replication factor C (RFC) have been detected in Pyrococcus abyssi (Pab). The genes encoding these two proteins are arranged in tandem. We cloned these two genes and co-expressed the corresponding recombinant proteins in Escherichia coli. Two inteins present in the gene encoding the small subunit (Pab RFC-small) were removed during cloning. The recombinant protein complex was purified by anion-exchange and hydroxyapatite chromatography. Also, the Pab RFC-small subunit could be purified, while the large subunit (Pab RFC-large) alone was completely insoluble. The highly purified Pab RFC complex possessed an... |
| Tipo: Text |
Palavras-chave: PCNA binding domain; Pyrococcus abyssi; Hyperthermophile; Archaea; Replication factor C. |
| Ano: 2002 |
URL: https://archimer.ifremer.fr/doc/2002/publication-675.pdf |
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| Gueguen, Yannick; Herpin, Amaury; Aumelas, André; Garnier, Julien; Fievet, Julie; Escoubas, Jean-michel; Bulet, Philippe; Gonzalez, Marcelo; Lelong, Christophe; Favrel, Pascal; Bachere, Evelyne. |
| In invertebrates, defensins were found in arthropods and in the mussels. Here, we report for the first time the identification and characterization of a defensin (Cg-Def) from an oyster. Cg-def mRNA was isolated from Crassostrea gigas mantle using an expressed sequence tag approach. To gain insight into potential roles of Cg-Def in oyster immunity, we produced the recombinant peptide in Escherichia coli, characterized its antimicrobial activities, determined its solution structure by NMR spectroscopy, and quantified its gene expression in vivo following bacterial challenge of oysters. Recombinant Cg-Def was active in vitro against Gram-positive bacteria but showed no or limited activities against Gram-negative bacteria and fungi. The activity of Cg-Def was... |
| Tipo: Text |
Palavras-chave: Crassostrea gigas; Genomic library; Microbiology; Defensin; Oyster. |
| Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/2006/publication-2127.pdf |
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| Gueguen, Yannick; Garnier, Julien; Robert, Lorenne; Lefranc, Marie-paule; Mougenot, Isabelle; De Lorgeril, Julien; Janech, Michael; Gross, Paul S.; Warr, Gregory W.; Cuthbertson, Brandon; Barracco, Margherita A.; Bulet, Philippe; Aumelas, André; Yang, Yinshan; Bo, Dong; Xiang, Jianhai; Tassanakajon, Anchalee; Piquemal, Piquemal; Bachere, Evelyne. |
| Antimicrobial peptides play a major role in innate immunity. The penaeidins, initially characterized from the shrimp Litopenaeus vannamei, are a family of antimicrobial peptides that appear to be expressed in all penaeid shrimps. As of recent, a large number of penaeid nucleotide sequences have been identified from a variety of penaeid shrimp species and these sequences currently reside in several databases under unique identifiers with no nomenclatural continuity. To facilitate research in this field and avoid potential confusion due to a diverse number of nomenclatural designations, we have made a systematic effort to collect, analyse, and classify all the penaeidin sequences available in every database. We have identified a common penaeidin signature... |
| Tipo: Text |
Palavras-chave: Nomenclature; Sequence database; Crustacea; Antimicrobial peptide; Penaeid shrimp; Penaeidin. |
| Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/2006/publication-2332.pdf |
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| Gonzalez, Marcelo; Gueguen, Yannick; Destoumieux Garzon, Delphine; Romestand, Bernard; Fievet, Julie; Pugniere, M; Roquet, F; Escoubas, Jean-michel; Vandenbulcke, F; Levy, O; Saune, Laure; Bulet, P; Bachere, Evelyne. |
| A cDNA sequence with homologies to members of the LPS-binding protein and bactericidal/permeability-increasing protein (BPI) family was identified in the oyster Crassostrea gigas. The recombinant protein was found to bind LIPS, to display bactericidal activity against Escherichia coli, and to increase the permeability of the bacterial cytoplasmic membrane. This indicated that it is a BPI rather than an LPS-binding protein. By in situ hybridization, the expression of the C gigas BPI (Cg-bpi) was found to be induced in hemocytes after oyster bacterial challenge and to be constitutive in various epithelia of unchallenged oysters. Thus, Cg-bpi transcripts were detected in the epithelial cells of tissues/organs in contact with the external environment (mantle,... |
| Tipo: Text |
Palavras-chave: Oyster innate immunity; Mollusk; Hemocyte; Epithelia; Antimicrobial. |
| Ano: 2007 |
URL: http://archimer.ifremer.fr/doc/2007/publication-3564.pdf |
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| De Lorgeril, Julien; Gueguen, Yannick; Goarant, Cyrille; Goyard, Emmanuel; Mugnier, Chantal; Fievet, Julie; Piquemal, D; Bachere, Evelyne. |
| Understanding of antimicrobial defence mechanisms of penaeid shrimp should help in the design of efficient strategies for the management and disease control in aquaculture. In this study, we have specifically analysed the expression in circulating hemocytes of antimicrobial peptides (AMPs) encoding genes, such as PEN2 and PEN3, ALF, crustin, lysozyme and a putative cysteine-rich peptide. We evidenced a relationship between the level of expression of some AMPs and the successful response of the shrimp, Litopenaeus stylirostris, to circumvent a pathogenic Vibrio penaeicida infection. Additionally, significant differences in some AMP transcript amounts are evidenced between control, non-selected shrimp line and the third generation breeding of shrimp selected... |
| Tipo: Text |
Palavras-chave: Real time PCR; Cysteine rich peptide; Crustin; Anti LPS factor; Lysozyme; Penaeidins; Immune response; Vibrio penaeicida; Penaeid; Decapoda; Crustacean. |
| Ano: 2008 |
URL: http://archimer.ifremer.fr/doc/2008/publication-4524.pdf |
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| Maamaatuaiahutapu, Moana; Joufoques, Vaiana; Tamata, Thiery; Dupieux, Sylvain; Teissier, Alexandre; Rarahu, David; Remoissenet, Georges; Gasset, Eric; Knockaert, Camille; Gueguen, Yannick; Coves, Denis. |
| Ce rapport traite de la poursuite de l’acquisition de connaissances, du début du transfert vers le secteur privé et des futurs travaux sur de l’élevage du Paraha peue (Platax orbicularis). Acquisition de connaissances porte sur (i) Grossissement en cages en fonction du site d’élevage, tests de produits immuno-stimulants, définition de traitements anti-parasitaires, mise au point des méthodes de transport d’alevins et la mise en cages précoces d’animaux de 1 g pour le transport par voie aérienne vers les îles (i.i.) Synchronisation des pontes et mise en place d’un plan de croisement de géniteurs diminuant le risque de consanguinité et permettant un progrès génétique par la domestication et/ou la sélection, ainsi que la mise au point d’outils de... |
| Tipo: Text |
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| Ano: 2008 |
URL: http://archimer.ifremer.fr/doc/00128/23887/21820.pdf |
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| Roberts, S; Gueguen, Yannick; De Lorgeril, Julien; Goetz, F. |
| Interleukin-17 (IL-17) gene models have been found in the sequenced genomes of Strongylocentrotus purpuratus and Caenorhabditis elegans. However, there have been no published reports on the empirical cloning and characterization of any interleukin cDNAs in invertebrates. From a Pacific oyster (Crossostrea gigas) hemocyte cDNA library, two clones were obtained that encoded a protein similar to vertebrate IL-17s. The putative oyster IL-17 homolog (CgIL-17) was 27% identical to rainbow trout IL-17D, 21% to human IL-17D and 24% to an IL-17D-like gene model obtained from the annotation of the sea urchin genome. IL-17s from the oyster, sea urchin, trout and human, contained conserved cysteine residues found in all forms of IL-17 in mammals. Injection of bacteria... |
| Tipo: Text |
Palavras-chave: Invertebrate innate immunity; Crassostrea gigas; Invertebrate cytokines; Hemocytes; Pacific oyster; Interleukin. |
| Ano: 2008 |
URL: http://archimer.ifremer.fr/doc/2008/publication-4151.pdf |
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| Fleury, Elodie; Huvet, Arnaud; Lelong, Christophe; De Lorgeril, Julien; Boulo, Viviane; Gueguen, Yannick; Bachere, Evelyne; Tanguy, Arnaud; Moraga, Dario; Fabioux, Caroline; Lindeque, Penelope; Shaw, Jenny; Reinhardt, Richard; Prunet, Patrick; Davey, Grace; Lapegue, Sylvie; Sauvage, Christopher; Corporeau, Charlotte; Moal, Jeanne; Gavory, Frederick; Wincker, Patrick; Moreews, Francois; Klopp, Christophe; Mathieu, Michel; Boudry, Pierre; Favrel, Pascal. |
| Background: Although bivalves are among the most-studied marine organisms because of their ecological role and economic importance, very little information is available on the genome sequences of oyster species. This report documents three large-scale cDNA sequencing projects for the Pacific oyster Crassostrea gigas initiated to provide a large number of expressed sequence tags that were subsequently compiled in a publicly accessible database. This resource allowed for the identification of a large number of transcripts and provides valuable information for ongoing investigations of tissue-specific and stimulus-dependant gene expression patterns. These data are crucial for constructing comprehensive DNA microarrays, identifying single nucleotide... |
| Tipo: Text |
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| Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/2009/publication-6770.pdf |
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| Gueguen, Yannick; Romestand, Bernard; Fievet, Julie; Schmitt, Paulina; Destoumieux Garzon, Delphine; Franck, Vandenbulcke; Philippe, Bulet; Bachere, Evelyne. |
| A cDNA sequence that encodes a 61-amino acid polypeptide precursor with homologies to proline-rich antimicrobial peptides (AMPs) was identified in the oyster Crassostrea gigas. After release of a hydrophobic signal peptide. the resulting 37-amino acid peptide, Cg-Prp, is composed of an acidic region and a cationic proline-rich region. To evaluate the biological properties of Cg-Prp, multiple proline-rich peptides corresponding to putative processing of the full-length Cg-Prp were synthesized. A limited antimicrobial activity was observed for two of them, which also showed strong synergistic antimicrobial activity with Cg-Def, a defensin from C gigas. To our knowledge, this is the first evidence of synergy between a defensin and another AMP in an... |
| Tipo: Text |
Palavras-chave: Antimicrobial peptide; Mollusk; Synergy; Invertebrate; Innate immunity; Pacific oyster. |
| Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/2009/publication-6232.pdf |
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| Yang, Yinshan; Boze, Helene; Chemardin, Patrick; Padilla, Andre; Moulin, Guy; Tassanakajon, Anchalee; Pugniere, Martine; Roquet, Francoise; Destoumieux Garzon, Delphine; Gueguen, Yannick; Bachere, Evelyne; Aumelas, Andre. |
| The anti-lipopolysaccharide factor ALF-Pm3 is a 98-residue protein identified in hemocytes from the black tiger shrimp Penaeus monodon. It was expressed in Pichia pastoris from the constitutive glyceraldehyde-3-phosphate dehydrogenase promoter as a folded and N-15 uniformly labeled rALF-Pm3 protein. Its 3D structure was established by NMR and consists of three alpha-helices packed against a four-stranded beta-sheet. The C-34-C-55 disulfide bond was shown to be essential for the structure stability. By using surface plasmon resonance, we demonstrated that rALF-Pm3 binds to LPS, lipid A and to OM(R)-174, a soluble analogue of lipid A. Biophysical studies of rALF-Pm3/LPS and rALF-Pm3/OM(R)-174 complexes indicated rather high molecular sized aggregates, which... |
| Tipo: Text |
Palavras-chave: Ultracentrifugation; Surface plasmon resonance; Septic shock; Structure; NMR; Lipid A; Lipopolysaccharide; Anti lipopolysaccharide factor. |
| Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/2009/publication-6320.pdf |
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| David, R.; Treguier, Cathy; Montagnani, Caroline; Belliard, Corinne; Levy, Peva; Nedelec, Georges; Joufoques, Vaiana; Remoissenet, G.; Gueguen, Yannick; Cochennec-laureau, Nathalie. |
| Tipo: Text |
Palavras-chave: Betanodavirus; Detection; French Polynesia; Genotype; Platax orbicularis. |
| Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/00003/11380/7972.pdf |
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| Joubert, Caroline; Piquemal, David; Marie, Benjamin; Manchon, Laurent; Pierrat, Fabien; Zanella-cleon, Isabelle; Cochennec-laureau, Nathalie; Gueguen, Yannick; Montagnani, Caroline. |
| Background: The shell of the pearl-producing bivalve Pinctada margaritifera is composed of an organic cell-free matrix that plays a key role in the dynamic process of biologically-controlled biomineralization. In order to increase genomic resources and identify shell matrix proteins implicated in biomineralization in P. margaritifera, high-throughput Expressed Sequence Tag (EST) pyrosequencing was undertaken on the calcifying mantle, combined with a proteomic analysis of the shell. Results: We report the functional analysis of 276 738 sequences, leading to the constitution of an unprecedented catalog of 82 P. margaritifera biomineralization-related mantle protein sequences. Components of the current "chitin-silk fibroin gel-acidic macromolecule" model of... |
| Tipo: Text |
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| Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/00020/13154/10202.pdf |
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| Schmitt, Paulina; Gueguen, Yannick; Desmarais, Erick; Bachere, Evelyne; De Lorgeril, Julien. |
| Background: To gain insight into the molecular diversity of antimicrobial peptides and proteins in the oyster Crassostrea gigas, we characterized and compared the sequence polymorphism of the antimicrobial peptides (AMPs), Cg-Defensins (Cg-Defs) and Cg-Proline Rich peptide (Cg-Prp), and of the bactericidal permeability increasing protein, Cg-BPI. For that, we analyzed genomic and transcript sequences obtained by specific PCR amplification and in silico searches. Results: High diversification among the three antimicrobial effectors was evidenced by this polymorphism survey. On the basis of sequence phylogenies, each AMP aggregates into clearly defined groups of variants and is the product of a multigenic family displaying a variety of gene structures. In... |
| Tipo: Text |
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| Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/00001/11182/6691.pdf |
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| Registros recuperados: 57 | |
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