...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Molecular and Cellular Biology >Sendai Virus Y Proteins Are Initiated by a Ribosomal Shunt
【24h】

Sendai Virus Y Proteins Are Initiated by a Ribosomal Shunt

机译：仙台病毒Y蛋白是由核糖体分流引发的

获取原文
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

The Sendai virus P/C mRNA expresses eight primary translation products by using a combination of ribosomal choice and cotranscriptional mRNA editing. The longest open reading frame (ORF) of the mRNA starts at AUG104 (the second initiation site) and encodes the 568-amino-acid P protein, an essential subunit of the viral polymerase. The first (ACG81), third (ATG114), fourth (ATG183), and fifth (ATG201) initiation sites are used to express a C-terminal nested set of polypeptides (collectively named the C proteins) in the +1 ORF relative to P, namely, C′, C, Y1, and Y2, respectively. Leaky scanning accounts for translational initiation at the first three start sites (a non-ATG followed by ATGs in progressively stronger contexts). Consistent with this, changing ACG81/C′ to ATG (GCCATG81G) abrogates expression from the downstream ATG104/P and ATG114/C initiation codons. However, expression of the Y1 and Y2 proteins remains normal in this background. We now have evidence that initiation from ATG183/Y1 and ATG201/Y2 takes place via a ribosomal shunt or discontinuous scanning. Scanning complexes appear to assemble at the 5′ cap and then scan ca. 50 nucleotides (nt) of the 5′ untranslated region before being translocated to an acceptor site at or close to the Y initiation codons. No specific donor site sequences are required, and translation of the Y proteins continues even when their start codons are changed to ACG. Curiously, ATG codons (in good contexts) in the P ORF, placed either 16 nt upstream of Y1, 29 nt downstream of Y2, or between the Y1 and Y2 codons, are not expressed even in the ACGY1/ACGY2 background. This indicates that ATG183/Y1 and ATG201/Y2 are privileged start sites within the acceptor site. Our observations suggest that the shunt delivers the scanning complex directly to the Y start codons.
机译：仙台病毒P / C mRNA通过结合核糖体选择和共转录mRNA编辑来表达八个初级翻译产物。 mRNA的最长开放阅读框（ORF）从AUG 104 （第二个起始位点）开始，并编码568个氨基酸的P蛋白，这是病毒聚合酶的重要亚基。第一（ACG 81 ），第三（ATG 114 ），第四（ATG 183 ）和第五（ATG 201 ）起始位点用于在相对于P的+1 ORF中分别表达C末端嵌套的一组多肽（统称为C蛋白），即C'，C，Y1和Y2。泄漏扫描说明了在前三个起始位点（非ATG，然后是在逐渐增强的语境下的ATG）的翻译起始。与此相符，将ACG 81 / C'更改为ATG（GCCATG 81 G）会废除下游ATG 104 / P 和ATG < sup> 114 / C 起始密码子。但是，在这种背景下，Y1和Y2蛋白的表达仍然正常。我们现在有证据表明，ATG 183 / Y1 和ATG 201 / Y2 的启动是通过核糖体分流或不连续扫描发生的。扫描复合物似乎聚集在5'帽上，然后扫描约。 5'非翻译区的50个核苷酸（nt），然后转移到Y起始密码子处或附近的受体位点。不需要特定的供体位点序列，并且即使将其起始密码子更改为ACG，Y蛋白的翻译仍会继续。奇怪的是，即使在ACG Y1 / ACG Y2 背景。这表明ATG 183 / Y1 和ATG 201 / Y2 是受体站点内的特权起始站点。我们的观察结果表明，分流器将扫描复合物直接传递至Y起始密码子。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号