Cloning, characterization and expression analysis of calcium channel beta subunit from pearl oyster (Pinctada fucata).
The absorption, transport and localization of calcium underlie the basis of biomineralization, and Ca(2+) entry into epithelial cell is the primary step in shell formation. However, the related mechanism of Ca(2+) transport is poorly documented at the gene or protein level. L-type voltage-dependent calcium channels may be involved in calcium transport for biomineralization in some marine invertebrates. In this study, a full-length cDNA of a voltage-dependent calcium channel beta subunit from Pinctada fucata (PCabeta) was cloned, and its amino acid sequence was deduced. PCabeta shared 51%-67% apparently sequence identity with voltage-dependent calcium channel beta subunits from other species. However, PCabeta was much shorter than other voltage-dependent calcium channel beta subunits particularly at the carboxyl terminus, indicating that it is likely a truncated beta subunit isoform. Semi-quantitative RT-PCR analysis showed that PCabeta was expressed in all the tested tissues and that it had a higher expression level in the gill tissue and hemolymph than in other tissues, suggesting that L-type voltage-dependent calcium channels are responsible for Ca(2+) absorption in the gill and Ca(2+) entry into hemocytes. In the mantle, PCabeta mRNA was predominantly expressed in the inner and middle folds of the mantle epithelium, suggesting that L-type voltage-dependent calcium channels are involved in Ca(2+) absorption from the ambient medium in the mantle. All these results suggest that voltage-dependent calcium channels are involved in Ca(2+) uptake and transport during oyster biomineralization.
Fan
Weimin
W
Institute of Marine Biotechnology, Department of Biological Sciences and Biotechnology, Tsinghua University, Beijing, China.
Li
Changzhong
C
Wang
Xue
X
Gong
Ningping
N
Xie
Liping
L
Zhang
Rongqing
R
D000595:Amino Acid Sequence; D000818:Animals; D002118:Calcium / Q000378:metabolism; D020746:Calcium Channels, L-Type / Q000737:chemistry* / Q000235:genetics*; D003001:Cloning, Molecular; D017403:In Situ Hybridization; D017136:Ion Transport; D008969:Molecular Sequence Data; D049911:Pinctada / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D021122:Protein Subunits / Q000737:chemistry / Q000235:genetics; D012333:RNA, Messenger / Q000032:analysis / Q000096:biosynthesis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D020539:Sequence Analysis, Protein; D040681:Structural Homology, Protein
D020746:Calcium Channels, L-Type; D021122:Protein Subunits; D012333:RNA, Messenger; D002118:Calcium