SIN1/MIP1 保持了 rictor-mTOR 复合体的完整性,并调节了 Akt 酸化和基质特异性
Estela Jacinto1, Valeria Facchinetti, Dou Liu
1Department of Physiology and Biophysics, UMDNJ-Robert Wood Johnson Medical School, Piscataway, NJ 08854, USA.
Cell
|September 12, 2006
概括
SIN1是mTORC2的关键子单元,对于Akt Ser473酸化和细胞存活至关重要. 它的缺失会破坏TORC2的功能,但不会破坏TORC1的功能,影响特定的Akt目标,如FoxO1/3a.
科学领域:
- 细胞生物学 细胞生物学
- 分子生物学分子生物学
- 生物化学 生物化学
背景情况:
- 猛素的哺乳动物标 (mTOR) 通过TORC1和TORC2复合体调节细胞生长和增殖.
- 作为PDK2,TORC2参与了Ser473的Akt/PKB酸化,这是Akt完全激活的关键部位.
- 阿克特酸化场所的确切作用及其监管机制需要进一步阐明.
研究的目的:
- 为了确定参与Akt酸化的TORC2的基本子单元.
- 研究SIN1/MIP1在TORC2功能和Akt激活的作用.
- 确定受损Akt Ser473酸化对下游目标和细胞存活的生理后果.
主要方法:
- 哺乳动物细胞中SIN1/MIP1基因的遗传切除.
- 在mTOR复合体内对蛋白质-蛋白质相互作用的生物化学分析.
- 在Ser473和Thr308.8的Akt/PKB酸化的评估.
- 对已知Akt和TORC1标的酸化状态的评估 (FoxO1/3a,TSC2,GSK3,S6K,4E-BP1).
主要成果:
- 鉴定出SIN1/MIP1是TORC2的一个重要亚单元,对Rictor-mTOR相互作用至关重要.
- 对SIN1的基因切除取消了Akt Ser473酸化,同时保留了Thr308酸化.
- 损坏的Ser473酸化选择性地影响了像FoxO1/3a这样的Akt目标,使TSC2,GSK3和TORC1效应器 (S6K,4E-BP1) 没有受到影响.
- 在SIN1的介导下,TORC2在Akt Ser473酸化中的作用对于细胞生存至关重要.
结论:
- 在TORC2介导的Akt Ser473酸化中,SIN1是不可或缺的.
- 这种特定的酸化事件对于TORC2在细胞存活中的功能至关重要.
- 在Akt Ser473酸化中,TORC2的作用与TORC1的活性是不同的,并且不可或缺.
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