在超极化激活的K+通道KAT1中的电机械合
Michael David Clark1, Gustavo F Contreras1, Rong Shen1
1Department of Biochemistry and Molecular Biology, The University of Chicago, Chicago, IL, USA.
Nature
|May 29, 2020
概括
研究人员使用KAT1结构阐明了电压关闭 (Kv) 道的关闭极性机制. 直接的传感器-孔隙相互作用,而不是化,主要决定了通道门的方向.
科学领域:
- 分子生物学
- 生物物理
- 结构生物学
背景情况:
- 电压通道 (Kv) 对于电信号和细胞体积调节至关重要.
- 虽然电压传感器转导电场,但Kv通道隔离极性的决定因素尚未完全理解.
研究的目的:
- 阐明非域交换Kv通道中的电机械合和门极性的分子机制.
- 确定KAT1通道中的超极化激活的结构基础.
主要方法:
- 用冷电子显微镜测定KAT1通道的结构.
- 结构导向突变和功能电生理学来评估突变通道活动.
主要成果:
- 通过直接和间接接口与封闭孔域相互作用的脱极电压传感器.
- 突变分析确定了电压传感器和C-linker头针之间的直接相互作用是门极性的主要决定因素.
- 一个直接合机制涉及S4螺旋运动和C-linker重定向.
结论:
- 直接的传感器-孔隙相互作用,特别是电压传感器和相邻的孔隙子单元C-linker之间,决定了Kv通道门的极性.
- 这种直接合机制提供了一个与异质模型形成对比的新视角,并且可以将脱极化和超极化激活的通道连接起来.
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