对于hERG1通道缓慢失活至关重要的细胞内疏水性结合
Whitney A Stevens-Sostre1, Lisandra Flores-Aldama1, Daniel Bustos2
1Department of Neuroscience, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin.
Biophysical journal
|January 14, 2024
概括
在hERG1通道中的一个关键的疏水连接点通过将PAS-cap尖端放置在电压传感器和门附近来控制缓慢的停用. 这种相互作用对于调节通道功能至关重要.
科学领域:
- 分子和细胞生物学分子和细胞生物学
- 生物物理学的生物物理.
- 心血管生理学心血管生理学
背景情况:
- 缓慢停用是电压关闭的K+通道的关键性质,特别是人类以太基因1 (hERG1) 通道.
- hERG1通道的失活是由细胞内域相互作用调节的,特别是N端的Per-Arnt-Sim (PAS) 和C端的循环核酸结合同质 (CNBh) 域之间.
- 该PAS域包括一个球状区域 (gPAS) 和一个PAS-cap,PAS-cap尖端以前被认为是缓慢停用的效应器,尽管它的位置控制不清楚.
研究的目的:
- 阐明如何控制PAS-cap尖端的位置来调节hERG1通道的停用.
- 确定负责维持hERG1通道缓慢失活的分子相互作用.
- 为了研究一个保存的疏水性连接在协调细胞内关机械中的作用.
主要方法:
- 序列分析以确定哺乳动物ERG和EAG1通道中的保护区域.
- 结构导向的突变发生,特别是在疏水性结合体内的极性血清替代.
- 电生理学来测量通道停机动力学.
- 分子动力学模拟用于分析结构变化和域移动.
主要成果:
- 一系列的疏水性相互作用,称为"疏水性结",涉及gPAS,PAS-cap α螺旋和CNBh域,对于hERG1缓慢停用至关重要.
- 北极血清替代或删除PAS-cap α螺旋导致中间停用模式,模仿彼此.
- 分子动力学模拟显示,这些替代破坏了疏水性结,导致域距离增加,改变了门环旋转和PAS-cap尖端收缩.
结论:
- 疏水性枢纽作为hERG1通道中的细胞内隔离环组件的关键协调者.
- 通过疏水性枢纽介导的PAS-cap尖端的精确定位,对于控制hERG1禁用门关键.
- 了解这种机制,可以了解心脏离子通道功能的调节以及潜在的治疗点.
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