人类斯芬戈-1-酸盐受体3-Gq复合体揭示的G蛋白亚型选择性的结构洞察
Momono Yamauchi1, Dohyun Im2, Shintaro Maeda1
1Department of Drug Discovery Medicine, Graduate School of Medicine, Kyoto University, Sakyo-ku, Kyoto 606-8507, Japan.
概括
氨酸-1-酸盐 (S1P) 受体调解免疫和血管功能. 冷-EM结构揭示了S1P激动剂如何结合S1PR3,确定了差异激活和G蛋白选择性的关键残留物,这对药物开发至关重要.
科学领域:
- 生物化学和结构生物学
- 分子药理学分子药理学
- 免疫学 免疫学 免疫学
背景情况:
- 氨酸-1-酸盐 (S1P) 是一种生物活性脂质,通过其受体 (S1PRs) 调节关键的生理过程.
- 控制S1P受体 (S1PR) 信号特异性的精确机制,特别是G蛋白合,仍然不完全理解.
- 了解S1PR激活对于开发针对免疫和血管疾病的向疗法至关重要.
研究的目的:
- 通过使用低温电子显微镜 (cryo-EM) 阐明内源性激素激活S1P受体3 (S1PR3) 激活的结构基础.
- 确定负责差异性激动剂强度和G蛋白亚型选择性的分子决定因素.
- 为A类G蛋白结合受体 (GPCRs) 的激活机制提供见解.
主要方法:
- 低温电子显微镜 (cryo-EM) 用于确定与Gαq和不同S1P激动剂复合的S1PR3的结构.
- 地点定向突变发生,以调查已识别的氨基酸残留在受体激活和G蛋白合中的作用.
- 生物化学测试以评估信号强度和G蛋白选择性.
主要成果:
- 确定了与d18:1 S1P和d16:1 S1P结合的S1PR3-Gαq复合物的高分辨率冷EM结构.
- 确定了Phe1193.33和Arg1363.50作为差异激动剂识别和受体激活的关键残留物.
- 揭示了细胞内循环2 (ICL2) 内的特定氨基酸相互作用,特别是在34.50和34.53位置,这决定了G蛋白选择性 (Gαq与Gαi).
结论:
- 该研究揭示了保留的结合模式,但在S1PR3.3.不同的S1P激动因子不同的激活途径.
- 跨膜域和ICL2中的关键残留物对S1PR3的功能特异性和G蛋白合至关重要.
- 这些结构和机制见解为设计具有改进治疗配置文件的S1PR调节器提供了基础.
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