寄生性吸虫谷胱甘肽过氧化物酶生物信息学分析  

Bioinformatics analysis of glutathione peroxidase in parasitic trematodes

作　　者：章莹[1] 蔡国斌[2] 何立[2] 蒋明森[2] 

机构地区：[1]武汉大学基础医学院医学遗传学教研室,武汉430071 [2]武汉大学基础医学院寄生虫学教研室,武汉430071

出　　处：《中国人兽共患病学报》2010年第4期293-298,共6页Chinese Journal of Zoonoses

基　　金：湖北省卫生厅血防专项基金项目(No.XF2008-15)资助

摘　　要：目的分析几种重要医学吸虫谷胱甘肽过氧化物酶(glutathione peroxidase,GPx)基因及其编码蛋白的生物学信息,探讨吸虫GPx在生物系统发育中的进化地位。方法从网络数据库获取各类目标序列,用NCBI Blast、Clustal X、GeneDoc、PH YLIP和SECISearch等工具,以及比较基因组学方法进行信息学分析。结果获得来自6种不同吸虫共12个GPx基因,分析发现它们均属磷脂氢谷胱甘肽过氧化物酶(PHGPx)家族,各成员之间具有较高的序列同源性(35%～87%)。除卫氏并殖吸虫一PHGPx基因外,其他基因开放阅读框内均含有"TGA"密码子,编码硒半胱氨酸,且其3’-端非翻译区均含有硒半胱氨酸插入序列(SECIS)。除华支睾吸虫一GPx基因组结构由5个外显子和4个内含子组成外,其他均由6个外显子和5个内含子组成。而且,吸虫的GPx基因"内含子?外显子"结构和脊椎动物的PHGPx基因相似,高度保守。结论医学吸虫和脊椎动物宿主的PHGPx基因可能来源于共同的祖先,提示寄生虫与宿主之间的相容性和协同进化的特征。Glutathione peroxidase （GPx） is an antioxidant enzyme which plays a unique role in the protection of cells by catalyzing the reduction of lipid-peroxides in biomembrane directly. In this study, the sequence information of target GPx in different taxa of organisms including trematodes was retrieved from Web Databases. Bioinformatics analysis was conducted by comparative genomics and performed by NCBI Blast, ClustalX, GeneDoc, PHYLIP and SECISearch. A total of 12 GPx genes from six different trematodes were obtained and they were found to be members of phospholipid hydroperoxide glutathione peroxidase （PHGPx） family. They shared considerable degrees of sequence identities （35%-87%） with each other. Except a GPx gene from Paragonimus westermani, all of them were found to be selenium-dependent proteins. The selenium-dependent protein cDNA harbored an unusual TGA codon, which was responsible for encoding selenocysteine （Sec）. A Sec insertion sequence （SECIS） was concurrently identified within the 3′-untranslated region. Among these GPx genes, the chromosomal segments were composed of 6 exons interrupted by 5 introns, except for a GPx gene from Clonorchis sinensis which was split into 5 exons by 4 intervening introns. The intron-exon structures of the PHGPx genes were tightly conserved between trematodes and vertebrates, in terms of positions and phases of their intervening introns. These results suggested that the PHGPx genes of medical trematodes and vertebrate hosts have slowly evolved from the same ancestor. It also emphasized the characteristics of compatibility and coevolution between parasites and their hosts.

关 键 词：医学吸虫 谷胱甘肽过氧化物酶 生物信息学 协同进化 

分 类 号：R383.2[医药卫生—医学寄生虫学]