低效的SRP与新生链的相互作用触发了mRNA质量控制途径
Andrey L Karamyshev1, Anna E Patrick1, Zemfira N Karamysheva1
1Department of Physiology, UT Southwestern Medical Center at Dallas, Dallas, TX 75390, USA.
Cell
|January 21, 2014
概括
细胞系统可以防止有毒蛋白质的积累. 分泌蛋白质的缺陷会触发Argonaute2 (Ago2) 降解它们的mRNA,通过一种新的翻译质量控制机制防止异常蛋白质的产生.
科学领域:
- 分子生物学分子生物学
- 细胞生物学 细胞生物学
- 蛋白质平衡是蛋白质的平衡.
背景情况:
- 错误折叠的蛋白质可能是细胞毒性,如果细胞系统无法防止其积累.
- 分泌蛋白需要特定的途径来进行适当的折叠和转移.
- 现有的质量控制机制主要关注蛋白质折叠和降解.
研究的目的:
- 发现一种新的机制,通过这种机制,分泌蛋白质的缺陷会减少mRNA和蛋白质的表达.
- 阐明Argonaute2 (Ago2) 在对异常分泌蛋白质合成的反应中的作用.
- 描述一种新的翻译质量控制途径,以预防性方式调节异常蛋白质生产 (RAPP).
主要方法:
- 研究了新生分泌蛋白质链,信号识别粒子 (SRP) 和在核糖体退出部位的Argonaute2 (Ago2) 之间的相互作用.
- 利用Argonaute2 (Ago2) 淘汰和过度表达实验来评估其在mRNA降解中的作用.
- 进行SRP54的敲击,以评估其对分泌蛋白mRNA稳定性的影响.
主要成果:
- 突变信号序列未能结合SRP导致新生的链接与Ago2接触.
- 这种相互作用特别触发了突变分泌蛋白mRNAs的降解.
- 信号序列突变的严重程度与Ago2近距离和mRNA降解相关;Ago2淘汰抑制了降解,而Ago2过度表达或SRP54淘汰促进了降解.
结论:
- 一种新的翻译质量控制机制,称为预防性调节异常蛋白质生产 (RAPP),已被确定.
- Ago2在识别和降解编码异常分泌蛋白的mRNA中发挥着关键作用.
- 这一途径代表了以前未被理解的控制mRNA水平蛋白质生产的一般机制.
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