玉米转录因子ZmbHLH5的分离、序列分析及原核表达  

Isolation,Sequence Analysis and Prokaryotic Expression of a Putative Transcriptional Factor ZmbHLH5 from Maize(Zea mays)

作　　者：王芳[1] 钟鸣宇[1] 宋任涛[1] 许政暟[1] 王桂凤[1] 

机构地区：[1]上海大学生命科学学院上海市能源作物育种及应用重点实验室,上海200444

出　　处：《上海大学学报（自然科学版）》2013年第6期623-630,共8页Journal of Shanghai University:Natural Science Edition

基　　金：国家自然科学基金资助项目(31370035;31000747);上海高校教师产学研践习资助项目

摘　　要：以玉米籽粒发育特异cDNA文库的表达序列标签（expressedsequencetag，EST）为基础，成功克隆了1条全长碱性螺旋．环一螺旋（basichelix—loop—helix，bHLH）转录因子ZmbHLH5，并对其DNA结构、编码的蛋白质序列和表达进行了分析．结构分析表明，ZmbHLH5的cDNA全长1398bp，具有编码211个氨基酸的开放阅读框（openreadingframe，ORF）区、329bp的3／非翻译区（untranslatedregions，UTR）及433bp的51非翻译区．蛋白序列分析结果表明，ZmbHLH5包含典型的60个氨基酸的bHLH结构域，与其他植物的bHLH转录因子具有很高的同源性（68％-87％）．表达分析结果表明，ZmbHLH5在雌穗和发育早期的籽粒中高丰度表达，并且在籽粒中通过选择性剪接编码至少3种完整蛋白．在原核表达系统中成功诱导表达了融合蛋白GST—ZmbHLH5，其分子量大小为58kD，与预测的蛋白分子量大小一致．Based on expressed sequence tags （ESTs） isolated from the cDNA library of maize developing kernels, a full-length putative basic helix-loop-helix （bHLH） transcription factor, named ZrnbHLH5 was cloned successfully. Sequence analysis showed that ZmbHLH5 cDNA was 1 389 bp in length with an open reading frame （ORF） encoding 211 amino acids and untranslated regions （UTR） of 329 and 433 bp at the 3＇ and 5qends, respectively. The protein encoded by ZmbHLH5 had high homology with bHLH transcription factors of other plants, ranging from 68% to 87%, with a conserved 60 amino acids bHLH domain. Expression pattern demonstrated that ZmbHLH5 was expressed at high level in ear and early developing kernels, and at least three ZmbHLH5 isoforms were produced by alternative splicing during kernel development. The fused protein GST-ZmbHLH5 was successfully expressed in prokaryotic expression system with an expected molecular weight of 58 kD.

关 键 词：玉米 转录因子ZmbHLH5 选择性剪接 蛋白表达 籽粒 

分 类 号：TU411[建筑科学—岩土工程]