作　　者： ; ; ; ; ;

机构地区： 中国药科大学生命科学与技术学院

出　　处： 《药物生物技术》 2012年第1期16-21,共6页

摘　　要： DNA结合抑制因子(Inhibitor of DNA binding,Id)又称分化抑制因子(Inhibitors of Differentiation,Id),属于负调控因子HLH家族的成员,其功能是与DNA结合并抑制细胞的分化和促进细胞的增殖。为揭示Id蛋白在鲨鱼肝脏再生过程中的作用,作者从前期构建的条纹斑竹鲨鱼肝脏cDNA文库中克隆到编码Id蛋白的cDNA全序列并预测了其编码产物(CpId)的结构,探讨了该基因在鲨鱼体内的时空表达方式,结果表明:CpId cDNA全长为1 074 bp,编码一个由135个氨基酸残基组成的无跨膜区的胞内蛋白,理论分子质量(Mr)为14 857.2,理论等电点(pI)为5.35。CpId蛋白序列与其他生物来源的Id蛋白的同源性介于42%～62%之间,其N端第31～87 aa组成一个相对保守的Myc型helix-loop-helix结构域。CpId基因在鲨鱼各种组织中均有表达,但以在肝脏、脑和生殖腺中的表达最高;肝部分切除后,CpId基因的表达迅速上调,在切除1 h后到达最高值(为正常肝组织的18倍左右),其后逐渐下降,并在24 h时恢复至正常肝组织中的水平;CpId基因的表达在肝部分切除后的第48 h出现第2个相对较高的表达峰。上述结果表明CpId基因参与了肝脏再生调控的过程,其作用可能与促进肝细胞的增殖再生过程有关。 Inhibitor of DNA binding（Id）,also known as the inhibitor of differentiation,is one member of the negative regulators of Helix-Loop-Helix（HLH） family.Its functions include binding with DNA,suppressing cell differentiation and promoting cell proliferation.To make better understanding of its role during shark liver regeneration,a full-length cDNA encoding Chiloscyllium plagiosum Id protein（CpId） was cloned from the cDNA library of liver.Subsequently,the structure of CpId was predicted by bioinformatics tools.The temporal and spatial expression patterns were analyzed.The results showed that the CpId cDNA,whose full-length was 1074 bp,encoded a protein composing of 135 amino acids without any trans-membrane area.Analysis of the predicted protein indicates a molecular weight of 14 857.2 and predicted pI 5.35.The protein has a similarity range from 42% to 62% with some other species.The 31st-87th amino acid in N-terminal formed a relative conserved Myc type HLH domain.Id protein mRNA is detected in all the tissues of shark,while the highest expression level appeared in liver,gonad and muscle.The mRNA expression level was up-regulated after parital hepatectomy and reached the peak after 1 h（18 fold to the normal）.Then it was down-regulated and recovered to a normal level at 24 hours but approached a second high level again at 48 h.All this implied that the Id protein involved in the regulate progress of liver regeneration.It may play an important role in promoting hepatocytes proliferation.

关 键 词： 条纹斑竹鲨鱼 结合抑制因子 时空表达 肝再生 肝细胞增殖

领　　域： [化学工程]