Li W, Brinton M A
Department of Biology, Georgia State University, Atlanta, Georgia 30302, USA.
Virology. 2001 Aug 15;287(1):49-61. doi: 10.1006/viro.2001.1015.
Cis-acting elements that regulate translation have been identified in the 3' noncoding regions (NCRs) of cellular and viral mRNAs. As one means of analyzing the effect on translation of the conserved 3' terminal RNA structure of the West Nile virus (WNV) genome, the translation efficiencies of chimeric mRNAs composed of a CAT reporter gene flanked by viral or nonviral 5' and 3' terminal sequences were compared. In vitro, the WNV 3'(+) stem loop (SL) RNA reduced the translation efficiencies of chimeric mRNAs with either viral or nonviral 5' NCRs, suggesting that a specific 3'-5' RNA-RNA interaction was not involved. In contrast, the 3' terminal sequence of a togavirus, rubella virus, enhanced translation efficiency. The WNV 3'(+)SL reduced translation efficiency both in cis and in trans and of both capped and uncapped chimeric mRNAs. We have previously reported that three cellular proteins bind specifically to the WNV 3'(+)SL RNA. Competition between the WNV 3'(+)SL and the 5' terminus of the chimeric mRNAs for proteins involved in translation initiation could explain the translation inhibition observed.
已在细胞和病毒mRNA的3'非编码区（NCR）中鉴定出调控翻译的顺式作用元件。作为分析西尼罗河病毒（WNV）基因组保守的3'末端RNA结构对翻译影响的一种方法，比较了由CAT报告基因两侧为病毒或非病毒5'和3'末端序列组成的嵌合mRNA的翻译效率。在体外，WNV 3'（+）茎环（SL）RNA降低了具有病毒或非病毒5' NCR的嵌合mRNA的翻译效率，这表明不涉及特定的3'-5' RNA-RNA相互作用。相比之下，披膜病毒风疹病毒的3'末端序列提高了翻译效率。WNV 3'（+）SL在顺式和反式中均降低了加帽和未加帽嵌合mRNA的翻译效率。我们之前报道过三种细胞蛋白特异性结合WNV 3'（+）SL RNA。WNV 3'（+）SL与嵌合mRNA的5'末端竞争参与翻译起始的蛋白质，这可以解释所观察到的翻译抑制现象。
