通过与Gαα相关联的rap1GAP异型激活ERK/MAPK通路 (i)
N Mochizuki1, Y Ohba, E Kiyokawa
1Department of Pathology, Research Institute, International Medical Center of Japan, Tokyo.
Nature
|September 7, 1999
概括
通过招募rap1GAPII,G (i) 蛋白的α子单元激活了ERK/MAPK通路. 这降低了与GTP结合的Rap1,从而激活了Ras-ERK/MAPK的线索.
科学领域:
- 细胞信号传递途径 细胞信号传递途径
- 分子生物学分子生物学
- 与G蛋白结合的受体是G蛋白结合的受体.
背景情况:
- 异构三分子G (i) 蛋白对神经和激素受体信号传递至关重要.
- 蛋白质子单元 (α和β) 激活ERK/MAPK级联.
- 构成性活性G ((alpha) i2 (gip2) 通过未知的机制转化细胞并激活ERK/MAPK.
研究的目的:
- 阐明G(i) 蛋白α子单元激活ERK/MAPK级联的机制.
- 为了确定Ras-ERK/MAPK通路的新型调节剂.
- 研究Rap1 GTPase激活蛋白II (rap1GAPII) 在G(i) 信号传递中的作用.
主要方法:
- 同免疫沉以评估蛋白质结合.
- 细胞转位测试用于监测蛋白质定位.
- 与GTP结合的Rap1试验量化了Rap1的活性.
- 进行ERK/MAPK激活试验.
主要成果:
- rap1GAPII 特别结合于 G 蛋白的α 子单元.
- 刺激G(i) 结合的m2-肌糖蛋白受体会导致rap1GAPII转移到膜上.
- 这种转移导致GTP结合的Rap1水平降低.
- 减少的与GTP结合的Rap1激活了ERK/MAPK通路.
结论:
- G的α子单元 (i) 激活了Ras-ERK/MAPK的线粒生成途径.
- 这种激活发生于rap1GAPII的膜招募,从而减少与GTP结合的Rap1.
- rap1GAPII是G(i) α子单元与Ras-ERK/MAPK通路之间的关键纽带.
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