八肋游仆虫中ECD1基因的克隆及序列分析  

Cloning and Sequence Analysis of ECD1 from Euplotes octocarinatus

作　　者：党旭红[1] 许静[1] 李江姣[1] 梁爱华[1] 王伟[1] 

机构地区：[1]山西大学生物技术研究所,化学生物学与分子工程教育部重点实验室,山西太原030006

出　　处：《山西大学学报（自然科学版）》2009年第2期273-279,共7页Journal of Shanxi University(Natural Science Edition)

基　　金：国家自然科学基金(30770295;30670282);山西省自然科学基金(2008011063);科技部国际合作重点项目(2006DFA31960)

摘　　要：含有CHROMO(chromatin organization modifier)结构域的蛋白参与了异染色质的形成及转录沉默复合物的形成.原生动物游仆虫细胞中既含有转录活跃的大核也含有转录沉默的小核.本实验应用PCR技术从八肋游仆虫(Euplotes octocarinatus)中获得了一个编码含有CHROMO结构域的基因ECD1(Euplotes chromo domain-con-taining protein 1)(GeneBank登录号为FJ357578).大核中含有该基因的微小染色体全长1105 bp.小核中该基因内无内部删除序列IES的存在.通过RT-PCR,证实该基因开放阅读框为645 bp.大核基因中含有三个内含子,转录过程中这些内含子均符合一类内含子GU-AG剪切规则.DNAstar软件分析,该基因编码的蛋白质包含214个氨基酸,分子量24.7 kDa,等电点为5.48.结构域聚类分析表明Ecd1蛋白可能执行与四膜虫异染色质蛋白Pdd1p和Pdd3p相似功能,参与大核发育过程中异染色质的形成和IES序列的删除.The proteins containing chromo domain participate in the assembly of heterochromatin and tran- scriptional silencing complexes. Euplotes exhibits nuclear dimorphism,each cell contains a transcriptionally inert germline micronucleus and transcriptionally active somatic macronucleus. ECD1 （Euplotes Chromo domain-contoing protein）, a new chromo domain-containing protein gene, was obtained from Euplotes octo- carinatus by PCR and RT-PCR. The macronuclear DNA molecule carrying the ECD1 gene is 1 105 bp long and shows the characteristics of macronuclear minichromosomes of hypotrichous ciliates. Macronuclear ECD1 contains three introns. RT-PCR showed that the opening reading frame of the ECD1 gene was 645 bp long,which encoded a 214-amino acide polypeptide with a predicted molecular mass of 24.7 kDa and iso- electric point of 5.48. Phylogenetic tree analysis of chromo domain suggested that the Ecdl protein proba- bly has the similar function to Pddlp or Pdd3p,which is involved in formation of heterochromatin and IES elimination.

关 键 词：CHROMO结构域 八肋游仆虫 ECD1基因 基因克隆 序列分析 

分 类 号：Q78[生物学—分子生物学]