需要多蛋白桥接因子1来强大激活对碰撞的核糖体的综合应激反应
Kyusik Q Kim1, Jeffrey J Li2, Ankanahalli N Nanjaraj Urs1
1Department of Biology, Washington University in St. Louis, St. Louis, MO 63130, USA.
Molecular cell
|November 20, 2024
概括
多蛋白桥接因子1 (Mbf1) 感知了核糖体碰撞,激活了综合应激反应 (ISR). 这种蛋白质对于压力诱导的eIF2α酸化至关重要,而不是Gcn4转录的协同激活.
科学领域:
- 分子生物学分子生物学
- 细胞应激反应的应激反应
- 基因规则 基因规则
背景情况:
- 以前假设多蛋白桥接因子1 (Mbf1) 在酵母的综合应激反应 (ISR) 中作为转录协活性剂.
- Mbf1及其人类同类 (EDF1) 被招募到碰撞的核糖体中,这是已知的ISR激活剂.
- Mbf1在ISR中的确切作用仍然不清楚,关于其功能的证据相互矛盾.
研究的目的:
- 阐明Mbf1在综合应激反应 (ISR) 途径中的特定功能.
- 为了协调拟议的转录辅激剂作用与Mbf1对碰撞的核糖体的招募.
- 为了确定Mbf1在应对细胞压力的作用机制.
主要方法:
- 生物化学分析来研究蛋白质相互作用.
- 结构分析以确定Mbf1的合和结合部位.
- 在酵母中进行功能性测试,以评估Mbf1在ISR信号传递和翻译中的作用.
主要成果:
- Mbf1直接与碰撞的核糖体相互作用以调解Gcn2的激活,将其确立为核心的ISR因子.
- Mbf1 不能作为 Gcn4 的转录协活性剂起作用.
- Mbf1对于高效的压力诱导的真核细胞启动因子2α (eIF2α) 酸化和随后的GCN4翻译去压缩至关重要.
结论:
- Mbf1作为压力诱导的核糖体碰撞的直接传感器,将核糖体状态与ISR信号联系起来.
- 在ISR中Mbf1的主要作用是促进Gcn2激活和eIF2α酸化,而不是Gcn4转录激活.
- 这些发现重新定义了Mbf1在细胞应激反应途径中的功能.
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