万安玻璃红鲤鱼PKR的克隆鉴定与系统进化分析

GENE CLONE,IDENTIFICATION AND PHYLOGENETIC ANALYSIS OF PKR FROM CYPRINUS CARPIO VAR.WANANENSIS

本研究以万安玻璃红鲤鱼为材料,通过同源克隆的方法克隆了万安玻璃红鲤鱼双链RNA激活的蛋白激酶(PKRCcvwPKR),并首次克隆到CcvwPKR的剪接异构体。CcvwPKR全长为2145 bp,编码714个氨基酸,CcvwPKR剪接异构体全长1431 bp,编码476个氨基酸。CcvwPKR的剪接异构体是CcvwPKR第477个密码子的G突变为T(gaa477taa),从而使得CcvwPKR的翻译提前终止。氨基酸序列比对和空间结构SMART预测显示,CcvwPKR和CcvwPKR剪接异构体都含有三个双链RNA结合模体(dsRBM),CcvwPKR剪接异构体缺失PKR的C端的激酶结构域。系统进化分析表明,万安玻璃红鲤鱼PKR在进化上与鲤鱼和鲫鱼密切相关。万安玻璃红鲤鱼和目前已有研究的鲤科鱼类PKR一样,分子结构都含有三个dsRBM,三个dsRBM使得其具有更强的结合dsRNA的作用,推测可能与其较强的抗病能力有关。

In this study,PKR(CcvwPKR)from Cyprinus carpio var.wananensis was cloned by homologous clone methods,and CcvwPKR transcript variant was cloned for the first time.The full-length of CcvwPKR was 2145 bp,coded 714 amino acids,and the full-length of CcvwPKR transcript variant was 1431 bp,coded 476 amino acids.The translation of CcvwPKR transcript variant was terminated ahead of CcvwPKR at codon 477 with a point mutation G to T(gaa477taa).Amino acids sequences alignment and protein space structures prediction by SMART indicated that they all harbored three dsRBMs.Furthermore,the C terminal kinase domain of CcvwPKR transcript variant was deleted at codon 477 with point mutation.Phylogenetic analysis indicated that CcvwPKR was closely related to common carp and crucian carp.Consistent with the studied PKR of other cyprinidae fishes,they all had three dsRBMs,it implied that they had stronger ability of dsRNA binding and robust antiviral features.