登革2型病毒中国株3′非编码区RNA元件对翻译的影响

[目的]探讨登革病毒(dengue virus,DEN)3′非编码区(untranslated region,UTR)RNA元件(VR、RCS2、CS2、CS1和SL)对基因组翻译的影响.[方法]首先构建登革2′型病毒中国株(DEN2-43)UTR与萤火虫荧光素酶基因(LUC)组成的病毒诱导报告基因(virus induced reportergene,VIRG),在此基础上分别构建包含DEN2-43 3′UTR不同RNA元件的VIRG,并通过LUC检测、实时RT-PCR和Western blot方法分析含有不同元件VIRG对翻译效率的影响.[结果]发现完整的3′UTR缺失可显著抑制翻译,含有病毒VR元件VIRG的翻译水平与完整3′UTR的VIRG相似,RCS2或CS2元件可提高VIRG的翻译效率,CS1或SL元件可降低VIRG的翻译效率.[结论]DEN 2-43病毒基因组3′UTR参与了报告基因的翻译,其不同元件具有可上调和下调报告基因翻译效率的作用.

Effects of RNA elements within 3'untranslated region on dengue virus translation

OBJECTIVE: To investigate the effect of the well-defined RNA elements (VR, RCS2, CS2, CS1 and SL) within the 3'untranslated region (UTR) on dengue virus (DEN) translation. METHODS: We constructed a virus induced reporter gene (VIRG) by inserting the firefly luciferase (LUC) gene between 5'- and 3'-UTRs of DEN2-43 genome. Subsequently, a series of modified VIRGs consisting of different RNA elements in the 3'UTR were constructed. A 3'UTR-deficient VIRG was also constructed. The translational efficiency of all VIRGs was then analyzed by LUC detection, real time RT-PCR and Western blot assays. RESULTS: The translation of 3'UTR-deficient VIRG was abolished. The translational efficiency of VIRG with RNA element VR was comparable with that of VIRG with unmodified 3'UTR. The translational efficiency of VIRG with RNA elements RCS2 or CS2 was significantly higher while the translational efficiency of VIRG with RNA elements CS1 or SL was substantially lower than that of VIRG with RNA element VR. CONCLUSION: These results suggested that 3'UTR was indispensable for DEN translation, and some RNA elements within 3'UTR might either up-regulate or down- regulate translation.