晶体结构和Ras与其效应物酸3-酶玛酶结合的功能分析
M E Pacold1, S Suire, O Perisic
1MRC Laboratory of Molecular Biology Hills Road CB2 2QH, Cambridge, United Kingdom.
Cell
|January 4, 2001
概括
拉斯蛋白直接激活酸酸3-激酶 (PI3Kgamma),这对癌细胞生存至关重要. 结构分析揭示了这种激活必不可少的特定结合相互作用,提供了新的治疗点.
科学领域:
- 分子生物学分子生物学
- 细胞信号传输 细胞信号传输
- 结构生物学 结构生物学
背景情况:
- 对于转化细胞的存活来说,Ras激活氨酸 3-酶 (PI3K) 是至关重要的.
- 了解Ras和PI3K之间的直接分子相互作用是破译癌细胞增殖的关键.
研究的目的:
- 通过 Ras. 调查PI3Kgamma的直接激活机制.
- 为了确定Ras-PI3K玛相互作用的结构基础.
- 探索这些相互作用对癌细胞存活的影响.
主要方法:
- 在体内和体外激活测定使用H-Ras G12V和GTPgammaS载荷的H-Ras.
- 确定PI3Kgamma/Ras.GMPPNP复合物的晶体结构.
- 位点定向突变发生,以分析关键相互作用区域.
主要成果:
- PI3Kgamma被H-Ras.强烈和直接激活.
- 晶体结构显示了一个关键循环,通过其交换机I和交换机II区域将Ras定位为PI3K玛结合.
- 突变性证实了这些Ras区域对于PI3Kgamma相互作用的必要性,以及与催化域的直接接触.
结论:
- 特定的结构相互作用通过Ras. 介导PI3Kgamma的直接激活.
- 这些发现表明,一种保守的激活机制可能与PI3Kalpha.共享.
- 观察到的PI3Kgamma的形状变化表明Ras介导激活中有一种全成分,这与癌症治疗有关.
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