COMPLETE 5' NONCODING REGION IS NECESSARY FOR THE EFFICIENT INTERNAL INITIATION OF HEPATITIS-C VIRUS-RNA
COMPLETE 5' NONCODING REGION IS NECESSARY FOR THE EFFICIENT INTERNAL INITIATION OF HEPATITIS-C VIRUS-RNA
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DOI：
10.1006/bbrc.1994.1246
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发表时间：
1994-03-15
影响因子：
3.1
通讯作者：
OYA, A
中科院分区：
文献类型：
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作者：
FUKUSHI, S;KATAYAMA, K;OYA, A
分析了丙型肝炎病毒（HCV）基因组5′非编码区（5′ncr）启动翻译的机制。在不同KCl条件下，使用含有HCV修饰的5'NCR的人工RNA体外翻译系统，HCV 5'NCR的核苷酸（nt.） 62至341不作为内部核糖体进入位点（IRES）。然而，全长5'NCR （nt. 1 ~ 341）产生了有效的内部起始。为了确定HCV- ires的基本区域，通过HCV 5'NCR的二级结构分析预测的茎环被删除，产生了各种突变体。这些构念通过体外翻译进行分析。这些突变体之间的翻译效率比较表明，结构域II的α -分支或α -分支和β -分支对高效翻译至关重要。此外，5′ncr中I结构域的存在似乎稳定了IRES正确二级结构的形成。此外，HCV的无帽位5'NCR比有帽位截断的5'NCR更有效地促进翻译。我们的研究结果强烈表明，包含所有茎环结构的完整5'NCR对于HCV-IRES的启动是必要的。(C) 1994学术出版社，Inc.
The mechanism of translational initiation by the 5' noncoding region (5'NCR) of hepatitis C virus (HCV) genome was analyzed. Using an in vitro translation system with artificial RNA containing a modified 5' NCR of HCV under the various KCl conditions, nucleotides (nt.) 62 to 341 of the HCV 5'NCR were not functional as an internal ribosome entry site (IRES). However, the full-length 5'NCR (nt. 1 to 341) produced an efficient internal initiation. To identify the essential region of the HCV-IRES, various mutants were produced in which stem-loops, predicted by secondary structure analysis of the HCV 5'NCR, were deleted. These constructs were analyzed by in vitro translation. Comparison of translation efficiency among these mutants suggested that the alpha- or both alpha- and beta-branches of domain II are essential for efficient translation. Morever, the formation of correct secondary structure of IRES seems to be stabilized by the presence of domain I in 5'NCR. Furthermore, the uncapped 5'NCR of HCV promotes translation more efficiently than capped truncated 5'NCR constructs. Our results strongly suggested that complete 5'NCR containing all stem-loop structures is necessary for initiation by HCV-IRES. (C) 1994 Academic Press, Inc.