TY - JOUR T1 - First description of French V. tubiashii strains pathogenic to mollusk: II. Characterization of properties of the proteolytic fraction of extracellular products A1 - Mersni Achour,Rachida A1 - Imbert-Auvray,Nathalie A1 - Huet,Valerie A1 - Ben Cheick,Yosra A1 - Faury,Nicole A1 - Doghri,Ibtissem A1 - Rouatbi,Sonia A1 - Bordenave,Stéphanie A1 - Travers,Marie-Agnes A1 - Saulnier,Denis A1 - Fruitier-Arnaudin,Ingrid AD - UMR 7266 CNRS-Université de La Rochelle, LIENSs, Equipe Approches Moléculaires, Environnement-Santé, Avenue Michel Crépeau, 17000 La Rochelle, France AD - Ifremer, SG2M-LGPMM, Laboratoire de Génétique et Pathologie des Mollusques Marins, Avenue de Mus de Loup, 17390 La Tremblade, France AD - UMR 7266 CNRS-Université de La Rochelle, LIENSs, Equipe Animaux MARins à la variabilité Environnementale, 2 rue Olympe de Gouges, 17000 La Rochelle, France AD - UMR 7266 CNRS-Université de La Rochelle, 2 rue Olympe de Gouges, 17000 La Rochelle, France AD - Ifremer, Centre Ifremer du Pacifique, UMR 241 Ecosystèmes Insulaires Océaniens, Tahiti, 98719 Taravao, French Polynesia AD - Fédération de Recherche en Environnement et Développement Durable, FR CNRS 3097, Université de La Rochelle, France UR - https://doi.org/10.1016/j.jip.2014.09.006 DO - 10.1016/j.jip.2014.09.006 KW - ECPs KW - Oyster immune responses KW - Thermolysin-metalloprotease KW - Mass spectroscopy KW - ADAM substrate KW - Vibrio N2 - Extracellular products (ECPs) of the French V. tubiashii strain 07/118 T2 were previously reported to be toxic for the Pacific oyster Crassostrea gigas. In this study we now assessed host cellular immune responses and bacterial potential effectors by which these ECPs can be associated with host damages. The adhesion capacity (28% inhibition) and phagocytosis ability (56% inhibition) of oyster hemocytes were the main functions affected following in vitro contact between hemocytes and V. tubiashii ECPs. This may be linked to the demonstration of the capability of ECPs to cleave various cellular substrates as oyster collagen. Moreover, a strong metalloproteolytic activity was recorded with general (azocasein) and specific (ADAM) substrates and characterized by the use of standard inhibitors and metal ions. The addition of 1, 10-phenanthroline and Zn2+ decreased proteolytic activity by about 80% and 50% respectively, confirming the presence of zinc metalloproteolytic activity in the ECPs. Mass spectrometry analyses of crude ECPs identified an extracellular zinc metalloprotease encoded by a gene with an open reading frame of 1821 bp (606 aa). Consensus zinc-binding motifs specific to thermolysin family and some glycosylation and phosphorylation sites were located on the deduced protein sequence. Even if taken together, our results let us wonder if this (these) zinc metalloprotease(s) could be involved in the impairment of hemocyte immunological functions, the direct implication of this (these) protein(s) in ECPs toxicity still has to be demonstrated. Y1 - 2014/11 PB - Academic Press Inc Elsevier Science JF - Journal Of Invertebrate Pathology SN - 0022-2011 VL - 123 SP - 49 EP - 59 ID - 32203 ER -