关闭高导电性Ca2+激活K+通道的结构基础
Richard K Hite1, Xiao Tao1, Roderick MacKinnon1
1Rockefeller University and Howard Hughes Medical Institute, 1230 York Avenue, New York, New York 10065, USA.
Nature
|December 16, 2016
概括
离子 (Ca2+) 和膜电压精确控制Slo1K+通道. 这项研究揭示了Ca2+结合是如何稳定道关环的,影响其孔隙和电压传感器来调节离子流.
科学领域:
- 分子生物学分子生物学
- 生物物理学的生物物理.
- 神经科学是一个神经科学.
背景情况:
- 离子通道对于细胞功能至关重要,具有精确的封闭机制.
- Slo1 K+通道是关键的调节器,将细胞内 (Ca2+) 与膜刺激性联系起来.
- 了解Slo1通道调节对于破译细胞信号通路至关重要.
研究的目的:
- 阐明通过Ca2+和膜电压调节Slo1 K+通道的结构基础.
- 为了比较Aplysia californica Slo1通道的Ca2+自由和Ca2+结合结构.
- 为了研究Ca2+结合影响道构成和门的机制.
主要方法:
- 用X射线晶体学来确定不同Ca2+状态下的Slo1 K+通道的结构.
- 对无Ca2+和有Ca2+结合的Slo1通道进行比较结构分析.
- 生物化学和生物物理技术分析形状变化和功能影响.
主要成果:
- 每个子单元在两个不同的位置结合Ca2+稳定了Ca2+传感器封闭环的扩展形状.
- 门环的形状变化通过共价连接器传递到通道孔.
- 直接的蛋白质接口连接着封闭环和电压传感器,使 Ca2+ 传感器的电压依赖调节成为可能.
结论:
- 2+结合会在Slo1通道的封闭环中引发显著的构造变化.
- 这些Ca2+诱导的变化与孔隙和电压感应领域相结合,整合了多个调节输入.
- 这些发现为了解Slo1通道如何将细胞内Ca2+水平和膜电压联系起来以控制K+流量的结构框架.
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