遗传 ›› 2007, Vol. 29 ›› Issue (1): 87-87―91.doi: 10.1360/yc-007-0087

• 研究报告 • 上一篇    下一篇

八肋游仆虫一种富含三核苷酸重复序列的新基因GARP的克隆与序列分析

许静, 王伟, 柴宝峰, 梁爱华   

  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, 太原 030006
  • 收稿日期:2006-04-07 修回日期:2006-07-03 出版日期:2007-01-10 发布日期:2007-01-10
  • 通讯作者: 梁爱华

Cloning and characterization of a novel trinucleotide repeat- containing gene GARP from Euplotes octocarinatus

XU Jing, WANG Wei, CHAI Bao-Feng, LIANG Ai-Hua

  

  1. Key Laboratory of Chemical Biology and Molecular Engineering of Ministry of Education, Institute of Biotechnology, Shanxi University, Taiyuan 030006, China

  • Received:2006-04-07 Revised:2006-07-03 Online:2007-01-10 Published:2007-01-10
  • Contact: AiHua Liang

摘要:

人类基因中三核苷酸重复序列拷贝数的异常扩增, 可导致多种神经系统疾病。一种富含GAA三核苷酸的GARP (glutamic acid-rich protein)基因从八肋游仆虫(Euplotes octocarinatus)大核文库中筛选获得。大核中该基因的染色体全长460 bp, 基因两端具有下毛类纤毛虫大核特有的端粒序列(C4A4C4A4C4A4C4), 开放读框内含有一个TGA(88-99)密码子, 在游仆虫中编码为半胱氨酸。经DNA Star 软件分析, 该基因编码的蛋白质由112个氨基酸组成, 预测其分子量为13 kDa, 等电点为3.82, 含有四个 [[alpha]] 螺旋和一个 [[beta]] 折叠。小核中对应的该基因含有两个内部删除序列, IES1 和IES2。IES1和IES2分别长41 bp, IES1以GA二核苷酸直接重复为删除信号, IES2以TA二核苷酸直接重复为删除信号。RT- PCR 证明该基因具有转录活性。

关键词: GARP基因, 八肋游仆虫, 三核苷酸重复

Abstract:

The expansion of trinucleotide repeats in genome is related to the phthogenesis of several neurodegenerative deseases. A GARP (glutamic acid-rich protein) gene was isolated from the macronuclear plasmid mini library of Euplotes octocarinatus. A micronuclear version of the GARP gene was amplified by polymerase chain reaction. The macronuclear DNA molecule carrying the GARP gene is 460 bp long and shows the characteristics of macronuclear chromosomes of hypotrichous ciliates. One of the three cysteines is encoded by the opal codon TGA(88-90). The predicted open reading frame encodes a 112-amino acid polypeptide, with a predicted molecular mass of 13 kDa and an isoelectric point of 3.82. Micronuclear version of the GARP gene contains two internal eliminated sequences (IES), IES1 and IES2. IES1 is 41 bp long and is flanked by 5′-GA-3′ direct repeats. IES2 is 41 bp long and flanked by 5′-TA-3′ direct repeats. Transcriptional activity of GARP gene was confirmed by reverse transcription polymerase chain reaction (RT-PCR).