脂酶C-β1是Gq/11的GTPase激活蛋白,它是其生理调节器
G Berstein1, J L Blank, D Y Jhon
1Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas 75235-9041.
Cell
|August 7, 1992
概括
脂酶C-β1 (PLC-β1) 作为Gq/11的GTPase激活蛋白 (GAP),加速了GTP的水解. 这一发现解释了G蛋白信号如何在生理条件下迅速失活.
科学领域:
- 生物化学 生物化学
- 分子生物学分子生物学
- 细胞信号传递 细胞信号传递
背景情况:
- Gq/11 是一种异构三元的G蛋白,对于信号传导至关重要.
- 通过G蛋白进行GTP水解是信号终止的关键步骤.
- 在体内快速关闭G蛋白信号传递的机制尚不完全理解.
研究的目的:
- 调查脂酶C-β1 (PLC-β1) 在调节Gq/11活动中的作用.
- 确定PLC-β1是否可以直接调节Gq/11.1.的GTPase活性.
- 探索PLC-β1功能对G蛋白信号失活的影响.
主要方法:
- 在脂质囊泡中复制纯化的M1肌肉胆固醇受体和Gq/11.
- 在有或没有PLC-β1的情况下测定Gq/11的GTPase活性.
- 测量 GTP-GDP 交换率和 GTP 水解率.
主要成果:
- 纯化的PLC-β1显著刺激了Gq/11的基底GTPase活性,高达20倍.
- 这种刺激依赖于受体介导的GTP-GDP交换.
- PLC-β1加速了与Gq/11结合的GTP的水解超过50倍.
- PLC-β1的GTPase激活蛋白 (GAP) 活性是Gq/11.11的特异性.
结论:
- PLC-β1作为Gq/11.1.的生理GTPase激活蛋白 (GAP) 起作用.
- 这种 PLC-β 1 的 GAP 活性提供了一个快速关闭 G 蛋白介导信号传递的机制.
- 这些发现使G蛋白的缓慢内在GTPase活性与它们在细胞信号通路中的快速转换相协调.
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