二维机械敏感的OSCA/TMEM63通道的激活机制
Yuanyue Shan1,2, Mengmeng Zhang1, Meiyu Chen1
1Laboratory of Cell Fate Control, School of Life Sciences, Westlake University, Hangzhou, 310000, China.
Nature communications
|August 29, 2024
概括
机械敏感的OSCA/TMEM63通道,对于感知机械力至关重要,通过独特的孔隙扩张机制激活. 酸胆 (Lyso-PC) 结合进一步调节这种激活,揭示了对传送器类通道功能的洞察力.
科学领域:
- 生物物理学的生物物理.
- 结构生物学 结构生物学
- 细胞生物学 细胞生物学
背景情况:
- OSCA/TMEM63通道是具有传送器样结构的机械敏感 (MS) 离子通道.
- 它们通过机械力量的激活机制仍然不太清楚.
- 这些通道对于感知真核细胞中高值机械力量至关重要.
研究的目的:
- 为了阐明OSCA/TMEM63通道的激活机制.
- 确定这些传送器类通道中机械感觉的结构基础.
- 调查脂质,特别是lysophosphatidylcholine (Lyso-PC) 在道关口中的作用.
主要方法:
- 低温电子显微镜 (cryo-EM) 用于确定高分辨率结构.
- 位点导向的突变发生 (OSCA1.1-F516A突变) 来探测通道功能.
- 脂质纳米盘复制,以研究在类似本地脂质环境中的道活性.
- 单通道电生理学来评估离子导电性.
主要成果:
- 化EM结构揭示了一个二维OSCA1.1-F516A突变体,其细胞外毛孔顺序扩张,类似于'开花的花'.
- 这种扩张与单体收缩和脂质挤出相结合,表明一种新的门机制.
- 发现酸胆 (Lyso-PC) 可以直接激活该通道,通过重新定位M6b螺旋来诱导细胞内孔径扩张.
- 完全的机械激活涉及细胞间和细胞外孔的协调打开.
结论:
- 这项研究为类似传送器的MS OSCA/TMEM63通道提供了一个基本的激活范式.
- 莱索-PC作为直接激活剂,通过特定的结构重组来调节通道门.
- 这些发现提供了适用于更广泛的TMEM63/TMEM16/TMC超级家族的见解,进步了我们对机械传导的理解.
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