UFM1 E3 连接酶促进了 ER 中的 60S 核糖体子单元的回收
Paul A DaRosa1, Ivan Penchev2, Samantha C Gumbin1
1Department of Biology, Stanford University, Stanford, CA, USA.
Nature
|February 21, 2024
概括
乌比基和类似乌比基的蛋白质 (UBL) 调节细胞的行为. 这项研究揭示了UFM1连接酶如何修改核糖体蛋白L24,帮助从ER膜中拯救和回收60S子单元.
科学领域:
- 分子生物学
- 细胞生物学
- 结构生物学
背景情况:
- 通过可逆修饰蛋白质,乌比基和乌比基类蛋白质 (UBLs) 调解关键的细胞过程.
- UFM1主要在ER相关的核糖体上修改核糖体蛋白L24,帮助60S子单元的恢复.
- 对于UFM1的目标选择及其在60S救援中的作用的确切机制尚不清楚.
研究的目的:
- 通过UFM1 E3酶 (E3(UFM1) 阐明核糖体UFMylation的分子机制.
- 确定 E3 ((UFM1) 基质的结构基础,并将UFM1 转移到 uL24.
- 研究E3 ((UFM1) 在终结后释放和回收大型核糖体子单元中的作用.
主要方法:
- 电子显微镜 (cryo-EM) 用于捕捉与其基质相互作用的E3(UFM1) 的连续快照.
- 生物化学分析以评估UFMylation机器的功能和相互作用.
- 在体内研究以观察自由60S子单元上的核糖体UFMylation.
主要成果:
- 在体内自由的60S子单元上发生核糖体UFMylation.
- 低温-EM结构显示了E3 ((UFM1) 与L1茎和tRNA结合点的结合,在150 Å的距离上改变了UL24.
- 在催化后,E3 ((UFM1) 在UFMylated 60S子单元周围形成一个稳定的C形.
结论:
- 采用一个独特的机制,在60S子单元上实现精确的L24修改.
- E3 ((UFM1)-UFMylated 60S复合物可能促进大核糖体子单元从ER膜释放和回收.
- 这项研究提供了关于核糖体质量控制和蛋白质合成调节的结构性见解.
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