通过动态蛋白交换和有序酸化事件,mTOR和S6K1介于翻译预启动复合物的组装
Marina K Holz1, Bryan A Ballif, Steven P Gygi
1Department of Cell Biology, Harvard Medical School, Boston, Massachusetts 02115, USA.
Cell
|November 16, 2005
概括
该研究揭示了真核启动因子3 (eIF3) 复合体如何作为支架,协调S6激酶1 (S6K1) 的动态激活,以控制响应细胞信号的蛋白质合成.
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:
- 核糖体蛋白S6激酶1 (S6K1) 是翻译的关键调节者,酸化位参与蛋白质合成.
- 控制S6K1激活,基质相互作用的精确分子机制及其在翻译启动中的作用仍然不完全理解.
研究的目的:
- 阐明mTOR,S6K1和真核体启动因子3 (eIF3) 复合体在信号依赖转化启动过程中的动态相互作用.
- 研究细胞刺激如何调节eIF3复合体内S6K1的关联和激活.
主要方法:
- 使用生物化学分析来追踪mTOR,猛禽和S6K1与eIF3复合物的关联和解离.
- 在细胞刺激时研究了S6K1在其疏水动机的酸化状态.
- 研究了像eIF4B这样的转化因子对eIF3复合物的酸化依赖的招募.
主要成果:
- 证明不活跃的S6K1与eIF3复合体结合,而它的激活剂mTOR/猛禽则没有.
- 表明细胞刺激导致mTOR/猛禽与eIF3结合,促进S6K1酸化以及随后的解离和激活.
- 证实了激活的S6K1酸化物下游目标,如eIF4B,促进其招募到翻译启动复合体.
结论:
- eIF3复合体作为一个关键的支架,协调分子事件的动态序列的信号响应翻译启动.
- 这种机制通过精确调节S6K1激活和基质酸化以响应细胞线索,确保了高效的蛋白质合成.
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