用Gβγ媒介激活氏体3-酶 γ 的分子基础
Chun-Liang Chen1,2, Ramizah Syahirah1, Sandeep K Ravala1,2
1Department of Biological Sciences, Purdue University, West Lafayette, IN, USA.
Nature structural & molecular biology
|April 2, 2024
概括
由Gβγ激活的酸酸3-激酶 (PI3Kγ) 对细胞运动和癌症扩散至关重要. 结构研究揭示了两个调节PI3Kγ活动和膜招募的Gβγ结合位点.
科学领域:
- 生物化学 生物化学
- 细胞生物学 细胞生物学
- 结构生物学 结构生物学
背景情况:
- 酸丁醇3-酶 (PI3Kγ) 催化酸丁醇4,5-双酸盐转化为酸丁醇3,4,5-三酸盐.
- 这种反应对于中性粒细胞化学毒性和癌症转移至关重要.
- PI3Kγ的激活是由从G蛋白结合受体释放的Gβγ异体介导的.
研究的目的:
- 阐明由Gβγ激活PI3Kγ的结构基础.
- 了解Gβγ介导的全调节和PI3Kγ的膜招募的机制.
主要方法:
- 电子显微镜 (cryo-EM) 用于确定PI3Kγ-Gβγ复合物的结构.
- 生物化学测试以评估PI3Kγ变体的活性.
- 斑马鱼中性粒细胞迁移研究.
主要成果:
- 确定了两个不同的Gβγ结合位点:一个在p110γ螺旋域上,另一个在p101 C终端域上.
- Gβγ 结合诱导PI3Kγ 激酶域的结构变化,类似于Ras·GTP诱导的变化.
- Gβγ结合部位和域间接触的乱会影响酶活性和膜局部化.
- 这些发现得到了斑马鱼中性粒细胞迁移试验的证实.
结论:
- Gβγ与PI3Kγ的结合是一种多部位相互作用,促进了膜招募.
- 通过两种已识别的结合部位,Gβγ在全质上调节PI3Kγ的活性.
- 这项研究为了解PI3Kγ和相关酶的Gβγ介导激活提供了一个结构框架.
- 这些发现为针对PI3Kγ相关疾病的向药物开发开辟了道路.
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