%0 Journal Article %J Comp Biochem Physiol B Biochem Mol Biol %D 2011 %T Identification of three singular glycosyl hydrolase family 18 members from the oyster Crassostrea gigas: Structural characterization, phylogenetic analysis and gene expression. %A Badariotti, Fabien %A Christophe Lelong %A Marie-Pierre Dubos %A Pascal Favrel %K Animals %K Crassostrea %K Gene Expression Regulation, Enzymologic %K Glycoside Hydrolases %K Phylogeny %K Protein Conformation %K Species Specificity %X

Glycoside hydrolase family 18 (GH18) includes chitinases and non-enzymatic chitinase-like proteins (CLPs) with representatives among eukaryotes (animals and plants), prokaryotes and viruses. In Lophotrochozoa, one of the three clades of bilaterian animals, only three members (Cg-Clp1, Cg-Clp2 and Cg-Chit) have been reported from the bivalve mollusc Crassostrea gigas. Here, we describe the cloning and the characterization of two additional chitinases (Cg-Chit2 and Cg-Chit3) and a new CLP (Cg-Clp3) from this species. Cg-Chit2 presents an atypical C-terminal hydrophobic region acting probably as a GPI-anchor signal for plasma membrane attachment. On the contrary, Cg-Chit3 displays a C-terminal truncated structure leading to a possible sequestration in lysosomes. Phylogenetic analyses suggest that CLPs have appeared independently in the three main branches of bilaterian animals, as a result of convergent evolution. Gene expression profiles analyzed by quantitative RT-PCR support the involvement of Cg-Clp3 in embryonic development, adult oyster growth and tissue remodelling during metamorphosis and gonadal restructuring.

%B Comp Biochem Physiol B Biochem Mol Biol %V 158 %P 56-63 %8 2011 Jan %G eng %N 1 %R 10.1016/j.cbpb.2010.09.009