慢性HCV感染者中分离的不同长度3′UTR-PolyU/UC段对IRES介导的翻译及NS5B合成RNA影响  

Effects of HCV 3′UTR containing different lengths of PolyU/UC tract isolated from chronic HCV infected patients on IRES-mediated translation and RNA synthesis by NS5B polymerase

作　　者：王华[1] 叶荣[1] 兰水云[1] 袁正宏[1] 

机构地区：[1]复旦大学上海医学院医学分子病毒学重点实验室,上海200032

出　　处：《中华微生物学和免疫学杂志》2004年第5期388-392,共5页Chinese Journal of Microbiology and Immunology

基　　金：上海市青年科技启明星计划资助项目 (0 0QMH14 0 4) ;国家自然科学基金资助项目 (3 0 2 70 0 68)

摘　　要：目的　研究丙型肝炎病毒 3′非编码区 (3′UTR)及不同长度PolyU UC段对内在核糖体进入位点 (IRES)介导翻译的影响以及对NS5B聚合酶合成RNA的影响。方法　通过构建含有HCVIRES、荧光素酶 (fireflyluciferase)报道基因和内含不同长度PolyU UC区的 3′UTR序列的系列重组质粒 ,采用体外翻译和细胞转染等方法检测报道基因表达的水平。结果　体外翻译实验和细胞转染实验显示 3′UTR对IRES介导的翻译具有增强作用 ,在体外翻译体系中这种增强作用与PolyU UC区的长度相关 ,而在细胞中则与PolyU UC区的长度无明显相关性 ;3′UTR对共转染的重组NS5B质粒的复制活性具有抑制作用 ,这种抑制作用也与PolyU UC区长度不成正比。结论　HCV 3′UTR与蛋白翻译及RNA合成有关 ,在细胞中并不与PolyU UC区的长度相关。Objective To investigate the effects of HCV 3′UTR containing different lengths of PolyU/UC tract on IRES-mediated translation and RNA synthesis by NS5B polymerase. Methods A variety of 3′UTRs containing different lengths of PolyU/UC tract were obtained from HCV chronic infected patients and cloned respectively to the downstream of the HCV internal ribosome entry site(IRES) linked to the firefly luciferase coding gene. In vitro translation and cell transfection assays were employed to detect the activities of reporter firefly luciferase. Results In both in vitro and cell transfection assays, the IRES-mediated translation could be only enhanced by 3′UTR. However, such effect was correlated with the length of PolyU/UC tract in in vitro system, but not in cell transfection assay. 3′UTR showed an inhibitory effect on the activity of NS5B polymerase in cell transfection assay, and the inhibitory effect was not correlated with the length of PolyU/UC tract. Conclusion HCV 3′UTR plays an important role in viral protein translation and RNA synthesis, but such effect was not regulated by the length of PolyU/UC tract in cells.

关 键 词：慢性HCV感染 3'UTR-PolyU/UC段 IRES介导 翻译 RNA NSSB聚合酶 丙型肝炎病毒 

分 类 号：R512.62[医药卫生—内科学]