The phylogenetically conserved molluscan chitinase-like protein 1 (Cg-Clp1), homologue of human HC-gp39, stimulates proliferation and regulates synthesis of extracellular matrix components of mammalian chondrocytes.
Members of chitinase-like proteins (CLPs) have attracted much attention because of their ability to promote cell proliferation in insects (imaginal disc growth factors) and mammals (YKL-40). To gain insights into the molecular processes underlying the physiological control of growth and development in Lophotrochozoa, we report here the cloning and biochemical characterization of the first Lophotrochozoan CLP from the oyster Crassostrea gigas (Cg-Clp1). Gene expression profiles monitored by real time quantitative reverse transcription-PCR in different adult tissues and during development support the involvement of this protein in the control of growth and development in C. gigas. Recombinant Cg-Clp1 demonstrates a strong affinity for chitin but no chitinolytic activity, as was described for the HC-gp39 mammalian homolog. Furthermore, transient expression of Cg-Clp1 in primary cultures of rabbit articular chondrocytes as well as the use of both purified recombinant protein and conditioned medium from Cg-Clp1-expressing rabbit articular chondrocytes established that Cg-Clp1 stimulates cell proliferation and regulates extracellular matrix component synthesis, showing for the first time a possible involvement of a CLP on type II collagen synthesis regulation. These observations together with the fact that Cg-Clp1 gene organization strongly resembles that of its mammalian homologues argue for an early evolutionary origin and a high conservation of this class of proteins at both the structural and functional levels.
Badariotti
Fabien
F
Institut de Biologie Fondamentale et Appliquée, UMR 100 Institut Français de Recherche pour l'Exploitation de la Mer-Université de Caen, Physiologie et Ecophysiologie des Mollusques Marins, 14032 Caen Cedex, France.
Kypriotou
Magdalini
M
Lelong
Christophe
C
Dubos
Marie-Pierre
MP
Renard
Emmanuelle
E
Galera
Philippe
P
Favrel
Pascal
P
D000595:Amino Acid Sequence; D000818:Animals; D016466:CHO Cells; D049109:Cell Proliferation; D002478:Cells, Cultured; D002688:Chitinases / Q000737:chemistry* / Q000235:genetics / Q000502:physiology*; D019902:Chondrocytes / Q000378:metabolism*; D024043:Collagen Type II / Q000037:antagonists & inhibitors / Q000096:biosynthesis; D017124:Conserved Sequence; D049896:Crassostrea; D006224:Cricetinae; D016326:Extracellular Matrix Proteins / Q000096:biosynthesis* / Q000378:metabolism; D006801:Humans; D008969:Molecular Sequence Data; D010802:Phylogeny; D011817:Rabbits; D017386:Sequence Homology, Amino Acid; D040681:Structural Homology, Protein
D024043:Collagen Type II; D016326:Extracellular Matrix Proteins; D002688:Chitinases