酸化会诱导改变的质子化状态,并以全学调节Rac1-RhoGDI复合体
Krishnendu Sinha1, Amit Kumawat2, Hyunbum Jang3
1Department of Chemical and Biological Sciences, S. N. Bose National Centre for Basic Sciences, Kolkata, India.
Protein science : a publication of the Protein Society
|December 22, 2025
概括
罗核酸解离抑制剂 (RhoGDI) 的特定位点酸化控制Rac1 GTPase的释放. 在Ser101/Ser174的双酸化通过改变质子化状态和破坏通信通路而使Rac1-RhoGDI结合异质弱化.
科学领域:
- 分子细胞生物学 分子细胞生物学
- 生物化学 生物化学
- 计算生物学 计算生物学
背景情况:
- 罗GTPases调节细胞的基本功能,包括细胞运动.
- 罗氨酸核酸解离抑制剂 (RhoGDI) 在不活跃的GDP-bound状态下将Rho GTPases隔离.
- 已知RhoGDI的特定位点酸化可触发选择性GTPase释放,但根本机制尚未完全理解.
研究的目的:
- 阐明RhoGDI在Ser101和Ser174的双酸化促进Rac1 GTPase解离的分子机制.
- 为了对比双化 (SP101/174) 与在Ser96处的惰性化对Rac1-RhoGDI相互作用的影响.
- 为了研究化介导调节中改变的胺质子化状态和全沟通的作用.
主要方法:
- 使用恒定pH的分子动力学模拟来建模RhoGDI酸化.
- 分析胺质子化状态,静电环境和结合亲和力变化.
- 进行了结构聚类,构造自由能源景观分析和全网络分析.
主要成果:
- SP101/174酸化诱导了RhoGDI西丁质子状态的明显变化,改变了当地的静电环境.
- 由于SP101/174,观察到Rac1-RhoGDI结合亲和力显著减少,这与破坏的键和界面接触有关.
- SP101/174促进了Rac1和RhoGDI中关键区域的变异性和位移的增加,破坏了复杂稳定性至关重要的全沟通通路径.
结论:
- 在RhoGDI的特定位点酸化,特别是在Ser101/Ser174的双酸化,可以全质调节Rac1相互作用.
- 酸化调节RhoGDI的质子化状态,减弱结合亲和力,诱导形状变化,并破坏全网络.
- 这些发现为控制Rac1 GTPase活动中的酸化代码的选择性提供了机制基础.
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