质子感知和激活一个检测质子的GPCR
Li-Nan Chen1, Hui Zhou1, Kun Xi1
1Department of Pathology of Sir Run Run Shaw Hospital, Department of Pharmacology, MOE Frontier Science Center for Brain Research and Brain-Machine Integration, and Liangzhu Laboratory, Zhejiang University School of Medicine, Hangzhou 310058, China.
Molecular cell
|April 11, 2025
概括
像人类的GPR4一样的质子感应G蛋白合受体 (GPCR) 使用histidine残留物来检测酸度. 这引发了结构变化,揭示了这些关键受体如何激活以及药物如何向它们.
科学领域:
- 生物化学 生化学
- 分子生物学分子生物学
- 结构生物学 结构生物学
背景情况:
- 细胞,组织和系统的pH平衡对于人类健康至关重要.
- 质子感应G蛋白合受体 (GPCRs) 检测细胞外酸性,影响生理和病理过程.
- 构成质子传感和GPCR激活的精确分子机制在很大程度上是未知的.
研究的目的:
- 阐明人类GPR4中质子感应和激活的分子机制,这是一个具有代表性的质子感应GPCR.
- 确定质子结合和随后的构造变化的结构基础.
- 研究特定残留物和结构动机在受体激活和G蛋白合中的作用.
主要方法:
- 低温电子显微镜 (cryo-EM) 用于确定人类GPR4.4的高分辨率结构.
- 不活性和活性受体状态的结构分析.
- 突变分析以确定参与质子传感的关键残留物.
主要成果:
- 确定了三种关键的细胞外歇斯蒂丁残留物,这些残留物对于人类GPR4中的质子感应至关重要.
- 观察到细胞外环 (ECLs) 中显著的构造变化,特别是ECL2,在质子结合时,从螺旋环结构过渡到β-转-β结构.
- 透露了键网络和疏水性包装中的重排,由非规范性动机促进,使G蛋白适应.
- 证明抗体NE52-QQ57通过破坏疏水性堆叠来抑制GPR4的激活.
结论:
- 为人类GPR4的激活机制提供了详细的分子框架,这是一种质子感应的GPCR.
- 突出了细胞外的关键作用和pH感应中的形态动态.
- 提供了对抗作用的结构基础的见解,这对未来针对质子感应GPCRs的药物发现有价值.
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