缺少终端编码子的mRNAs的外体介导的识别和降解
Ambro van Hoof1, Pamela A Frischmeyer, Harry C Dietz
1Howard Hughes Medical Institute, 4000 Jones Bridge Road, Chevy Chase, MD 20815, USA. : ambro@u.arizona.edu
概括
缺乏停止信号的信使RNA (mRNA) 被细胞复合体外体分解. 这一涉及Ski7p蛋白的过程通过消除错误的转录来确保精确的基因表达.
科学领域:
- 分子生物学分子生物学
- 基因表达规范 基因表达规范
- 在RNA代谢过程中.
背景情况:
- 传递 RNA (mRNA) 的降解对于保持基因表达的忠实性至关重要.
- 异常的转录,例如缺乏翻译终结子 (不间断mRNAs) 的转录,在真核细胞中通常是不稳定的.
研究的目的:
- 为了研究在真核细胞中不间断的mRNA的降解途径.
- 确定参与无休止mRNAs识别和降解的关键因素.
主要方法:
- 利用酵母突变体研究mRNA降解途径.
- 研究了外体及其相关蛋白质在不间断mRNA衰变中的作用.
主要成果:
- 证明了不间断的mRNAs在3到5的方向下被外体分解.
- 确定了Ski7p,一种与外体相关的蛋白质,对于不间断的转录分解至关重要.
- 提出了一个Ski7p与核糖体的A位点结合的模型,在不间断的mRNA上招募外核糖体到停滞的核糖体.
结论:
- 外体体-Ski7p通路有效降解不间断的mRNA,防止异常转录的表达.
- 这种机制有效地准并消除编码区域内的过早多基解的mRNA,确保适当的基因表达.
相关概念视频
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Ribosome profiling has many applications, including in vivo monitoring of translation inside a particular organ or tissue type and quantifying new protein synthesis levels.
The technique helps...
Nonsense-mediated mRNA Decay
The Upf proteins that carry out nonsense-mediated decay (NMD) are found in all eukaryotic organisms, including humans. Each protein has an individual role, but they need to work in collaboration. Upf1 is an ATP-dependent RNA helicase that unwinds the RNA helix. Because Upf1 can unwind any RNA, Upf2 and Upf3 are required to help Upf1 discriminate between nonsense and normal mRNAs.
Usually, Upf3 binds to an Exon Junction Complex (EJC) at mRNA splice sites. If a ribosome fully translates the mRNA,...
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