海刺参(Stichopus japonicus)电压依赖性钙离子通道β亚基基因及其编码产物的结构特点  

Characterization and Structure Analysis of a Gene Encoding Voltage-dependent Calcium Channel β Subunit from Sea Cucumber Stichopus japonicus

作　　者：杨冠科[1] 丛丽娜[1] 谢三群[1] 张宗申[1] 朱蓓薇[1] 

机构地区：[1]大连工业大学生物与食品工程学院,大连116034

出　　处：《中国生物化学与分子生物学报》2009年第2期137-145,共9页Chinese Journal of Biochemistry and Molecular Biology

基　　金：国家自然科学基金(No.30571449);国家重点基础研究发展规划(973计划前期研究;No.2006CB708210);大连工业大学研究生科技创新基金(No.2007012)资助项目~~

摘　　要：电压依赖性钙离子通道(voltage-dependent calcium channels,VDCC)是细胞膜上控制Ca2+进入胞内的特殊蛋白质,VDCCβ亚基具有调节其通道活性的作用.使用RT-PCR和RACE PCR技术,从海刺参(Stichopus japonicus)肠中克隆得到电压依赖性钙离子通道β亚基(SjCaβ)基因,所得序列提交GenBank,登录号EU853658.该基因全长1 867 bp,包含1个1 614 bp的开放阅读框(ORF),编码537个氨基酸.将SjCaβ与多种无脊椎动物钙离子通道β亚基进行分析比较,发现它们有较高的同源性,并具有钙离子通道β亚基基因内保守的2个功能区域,即SH3功能区(src-homology 3 domain)和GK功能区(guanylate kinase domain).在功能区域附近还具有电压依赖性钙离子通道β亚基特有的BID区(βinteraction domain),氨基酸保守序列为PYDVVP-RP---VGPSLKGYEVTDMMQKALFDF,进一步确定了得到的cDNA序列为海刺参电压依赖性钙离子通道β亚基.对SjCaβ的二级结构进行了预测,构建了系统进化发育树,并运用同源建模法构建了SjCaβ的三维结构模型.研究结果对深入研究海刺参离子通道的结构以及在信号传导过程中的作用有着重要意义,并为研究海刺参自溶等问题提供一定的理论基础.Voltage-dependent calcium channels （VDCC）are special proteins that are located in the plasma membrane of virtually all types of excitable cells and serve to control the cellular Ca^2＋ influx. The β subunit of VDCC is known to modulate the channel activities. The cDNA of VDCC β subunit from the intestine of sea cucumber Stichopus japonicus （SjCaβ） was cloned by （GenBank accession No. EU853658） was determined RT-PCR and RACE. The full length cDNA of SjCaβ to be 1 867 bp with a open reading frame of 1 614 bp, encoding 537 amino acid residues. The phylogenetic analysis of SjCaβ showed its significant homology with the subunit of calcium channels from other known invertebrates containing a highly conserved BID domain （ interaction domain）, a src-homology 3 domain and a guanylate kinase domain. The secondary structure of SjCaβ was predicted, and its three-dimensional molecular structure was generated by homologous modeling.These results are useful resources to expand the understanding of VDCC in Stichopus japonicus and may be used in future studies to elucidate its connection to the autolysis problem in sea cucumber productions.

关 键 词：海刺参 电压依赖性钙离子通道 Β亚基 RT—PCR 结构分析 

分 类 号：Q71[生物学—分子生物学] Q959.269