结合的GTPase和重塑ATPase活动形成了核糖体出口检查点
Yoshitaka Matsuo1, Sander Granneman2,3, Matthias Thoms1
1Biochemie-Zentrum der Universität Heidelberg, Im Neuenheimer Feld 328, Heidelberg D-69120, Germany.
Nature
|November 19, 2013
概括
该GTPase Nug2作为一个关键的定时器为真核核糖核酶出口. 它从前核糖体中释放,对于招募出口机器至关重要,确保适当的成熟.
科学领域:
- 分子生物学分子生物学
- 细胞生物学 细胞生物学
- 生物化学 生物化学
背景情况:
- 欧核细胞核糖体生物发生是一个复杂的,能源密集的过程.
- 核出口是前核糖体成熟的关键,不可逆转的步骤.
- 控制出口能力的时间机制尚不清楚.
研究的目的:
- 调查Saccharomyces cerevisiae GTPase Nug2在调节60S前核糖体出口能力的时间表中的作用.
- 阐明Nug2与参与核糖体成熟和出口的其他因素的相互作用.
主要方法:
- 在Saccharomyces cerevisiae中Nug2的枯竭和突变.
- 对60S前颗粒组成和Nmd3结合的分析.
- 研究Rea1 ATPase和Rsa4.4的作用.
主要成果:
- Nug2 结合了前-60S 粒子的子单元间面,防止过早的 Nmd3 结合.
- Nug2的耗尽导致Nmd3的过早结合和出口缺陷.
- Nug2的释放需要其GTPase活动和Rea1 ATPase活动.
- Rea1和Rsa4与Nug2结合的粒子相关,并与Nug2突变体进行合成相互作用.
结论:
- Nug2充当监管GTPase,监控60S前成熟的作用.
- 释放Nug2是一个关键的检查点,与核出口机械的招聘有关.
- 这项研究阐明了核糖体生物发生和出口时间的关键步骤.
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