异育银鲫GABA A受体γ2亚基全长克隆及生物信息学分析  

Cloning and Bioinformatics Analysis of GABA A Receptor γ2 Subunit Gene in Carassais auratus gibebiol

作　　者：赵依妮[1] 胡鲲[1] 孙琪[1,2] 杨先乐[1] 阮记明[1] 周爱玲[1] 

机构地区：[1]上海海洋大学国家水生动物病原库,上海201306 [2]上海黛龙生物科技工程有限公司,上海201414

出　　处：《生物技术通报》2015年第3期191-198,共8页Biotechnology Bulletin

基　　金：国家科学自然基金项目(31172430);"863"计划项目(2011AA10A216);公益性农业行业专项项目(201203085)

摘　　要：近年来GABA A受体亚基特异性在药物筛选、研发过程中的应用得到广泛地关注,其中有关α1、β2和γ2三种功能性亚基的研究最为深入。异育银鲫因其良好的生长、繁殖优势,在国内得到广泛养殖。采用RACE法克隆得到了异育银鲫GABA A受体γ2亚基基因全长cDNA,并进行了生物信息学分析。该基因长2 763 bp,其中CDS区长1437 bp,可编码477个氨基酸的前体蛋白。预测蛋白分子量55.3 k D,理论等电点9.13。异育银鲫体内GABA A受体γ2亚基氨基酸序列N端存在1个长度为35个氨基酸的信号肽,4个长度分别为23、20、23和23个氨基酸的跨膜区,3个N-糖基结合位点和2个O-糖基化位点,1个特异性结构域,其氨基酸序列具有明显的氯离子门控通道家族特征。氨基酸序列与其他物种氨基酸序列的同源性都在89%以上,表明该蛋白属于GABA A受体亚基家族。系统进化树表明异育银鲫与斑马鱼聚为一支,亲缘关系最近。The application of the specificity of GABA receptor subunits in drug screening and drug development got widely attention recently, of which three function subunits α1, β2 and γ2 studied deeply. Furthermore, Carassais auratus gibebiol as its good growth and reproduction had been widely farmed in china. In the present study, we cloned and characterized GABA A receptor γ2 subunit full-length gene. The full-length Carassais auratus gibebiol GABA A receptor γ2 subunit cDNA was 2 763 bp in length, contained a 1437 bp open reading frame（ORF）, and encoded 477 amino acids which constituting a 55.3 kD protein molecule with an isoelectric point of 9.13. The γ2 subunit protein was hydrophilic. The protein sequence had one signal peptide, consisting of 35 amino acid residue. The sequence of amino acids contained four transmembrane regions, which length of 23,20,23 and 23 aa, involving in electronic transfer catalysis between the internal and external membrane. We found three N-glycosylation sites, two O- glycosylation sites and an extracellular domain which had obvious ligand-gated ion channels＇ characteristics. Sequence comparison revealed that the similarity of the γ2 subunit protein all above 89% with other aquatic animals showed that it belongs to GABA A receptor subunits＇ family. We conducted a phylogenetic analysis using the neighbor joining（NJ）method. The evolutionary tree showed that the γ2 subunit protein was clustered with the zebra fish which indicated that they are the two most closely related species.

关 键 词：异育银鲫 GABA A受体γ2亚基 克隆 生物信息学分析 

分 类 号：Q78[生物学—分子生物学]