增长因子和营养信号集成在mTORC1的溶酶体膜上的结构基础
Zhicheng Cui1,2, Alessandra Esposito3,4, Gennaro Napolitano3,4,5
1Department of Molecular and Cell Biology, University of California Berkeley; Berkeley CA 94720, USA.
bioRxiv : the preprint server for biology
|November 28, 2024
概括
拉巴胺素复合体1 (mTORC1) 在溶酶体膜上激活的机械标需要mTOR和Raptor与膜直接接触. 这个过程整合了生长因子和营养信号,实现了完全的催化激活.
科学领域:
- 细胞信号传递途径 细胞信号传递途径
- 细胞生长的分子机制
- lysosome 的生物学和功能.
背景情况:
- 拉巴胺素复合体1 (mTORC1) 的机械标集成生长因子和营养信号.
- mTORC1的激活发生在溶酶体膜上,由Rheb和Rag GTPases介导.
- 了解mTORC1激活的结构基础对于破译细胞生长调节至关重要.
研究的目的:
- 在生物化学上复制并从结构上阐明mTORC1在溶酶体膜上的激活.
- 确定膜接触和GTPase信号在mTORC1激活中的作用.
- 为 lysosome 信号整合提供分子层次的解释.
主要方法:
- 使用纯化的成分进行mTORC1激活的生物化学复制.
- 电子显微镜 (cryo-EM) 用于结构的确定.
- 蛋白质膜相互作用和催化位点对齐的分析.
主要成果:
- mTORC1激活涉及三个步骤的过程:Rag-Ragulator的招募,Rheb介导的招募,以及mTOR和Raptor的直接膜接触.
- 通过距离高达230 Å的点直接的膜相互作用对于最大激活至关重要.
- 膜的完全接触使mTOR活性位点中的催化残留保持一致,从而导致激活.
结论:
- 融合的生长因子和营养信号通过逐步招募和膜参与机制在溶酶体中集成.
- 该结构揭示了Rheb和膜相互作用如何协同发挥作用,以完全激活mTORC1的催化功能.
- 这为了解mTORC1调节中的营养和生长因子信号提供了一个详细的结构框架.
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