tailieunhanh - Báo cáo khoa học: cDNA cloning and characterization of a novel calmodulinlike protein from pearl oyster Pinctada fucata

Calcium metabolism in oysters is a very complicated and highly controlled physiological and biochemical process. However, the regulation of calcium metabolism in oyster is poorly understood. Our previous study showed that calmodulin (CaM) seemed to play a regulatory role in the process of oyster calcium metabolism. In this study, a full-length cDNA encoding a novel calmodulin-like protein (CaLP) with a long C-terminal sequence was identi-fied from pearl oysterPinctada fucata, expressed in Escherichia coliand characterizedin vitro. . | ềFEBS Journal cDNA cloning and characterization of a novel calmodulin-like protein from pearl oyster Pinctada fucata Shuo Li1 Liping Xie1 2 Zhuojun Ma1 and Rongqing Zhang1 2 1 Institute of Marine Biotechnology Department of BiologicalSciences and Biotechnology Tsinghua University Beijing China 2 Protein Science Laboratory of the Ministry of Education Tsinghua University Beijing China Keywords Calmodulin calmodulin-like protein calcium oyster Pinctada fucata Correspondence R. Zhang Department of Biological Sciences and Biotechnology Tsinghua University Beijing 100084 China Fax 86 10 62772899 Tel 86 10 62772899 E-mail rqzhang@ Note The nucleotide sequence reported in this paper has been submitted to GenBank with the accession number AY663847 Received 26 May 2005 revised 14 July 2005 accepted 3 August 2005 doi Calcium metabolism in oysters is a very complicated and highly controlled physiological and biochemical process. However the regulation of calcium metabolism in oyster is poorly understood. Our previous study showed that calmodulin CaM seemed to play a regulatory role in the process of oyster calcium metabolism. In this study a full-length cDNA encoding a novel calmodulin-like protein CaLP with a long C-terminal sequence was identified from pearl oyster Pinctada fucata expressed in Escherichia coli and characterized in vitro. The oyster CaLP mRNA was expressed in all tissues tested with the highest levels in the mantle that is a key organ involved in calcium secretion. In situ hybridization analysis reveals that CaLP mRNA is expressed strongly in the outer and inner epithelial cells of the inner fold the outer epithelial cells of the middle fold and the dorsal region of the mantle. The oyster CaLP protein with four putative Ca2 -binding domains is highly heat-stable and has a potentially high affinity for calcium. CaLP also displays typical Ca2 -dependent electrophoretic shift Ca2 -binding activity and .