哺乳动物CCR4-NOT对翻译核糖体的特定识别和无处不在
Eva Absmeier1,2, Viswanathan Chandrasekaran3, Francis J O'Reilly4
1MRC Laboratory of Molecular Biology (LMB), Cambridge, UK.
Nature structural & molecular biology
|August 31, 2023
概括
哺乳动物的CCR4-NOT死化复合体识别了停滞的核糖体,插入CNOT3来阻止翻译. 这种复合体还通过 CNOT4 无所不在的延伸信号停止翻译延伸,链接翻译和mRNA衰变.
科学领域:
- 分子生物学分子生物学
- 生物化学 生物化学
- 结构生物学 结构生物学
背景情况:
- 使者RNA (mRNA) 的稳定性受到翻译的影响,这是由酵母中的Ccr4-Not死化复合体调节的过程.
- 在哺乳动物中控制这种过程的精确机制尚未完全理解.
研究的目的:
- 阐明哺乳动物CCR4-NOT复合体在调节翻译和mRNA稳定性的作用和机制.
- 调查CCR4-NOT在翻译延长过程中如何与核糖体相互作用.
主要方法:
- 使用冷电子显微镜 (cryo-EM) 确定了CCR4-NOT与核糖体相互作用的结构基础.
- 交叉连接质谱法被用于识别重新构成的系统中的蛋白质相互作用.
- 使用子和人类组件的体外复制系统被使用.
主要成果:
- 哺乳动物的CCR4-NOT特别识别了在翻译延长过程中停滞的核糖体.
- CNOT3亚单元插入核糖体的E位点并锁定L1茎,抑制进一步的翻译.
- CCR4-NOT对于CNOT4的结合至关重要,该结合使核糖体无处不在,信号停滞延长.
结论:
- 人类CCR4-NOT检测并强制执行核糖体停滞,功能性合翻译与mRNA衰变.
- 这些发现提供了对哺乳动物中CCR4-NOT复合体对mRNA调节的机制性见解.
- 这项研究揭示了物种间Ccr4-Not复合体对核糖体相互作用的保存机制.
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