在CaV通道的calmodulin调节中用于空间Ca2+选择性的模块化开关
Ivy E Dick1, Michael R Tadross, Haoya Liang
1Calcium Signals Laboratory, Departments of Biomedical Engineering and Neuroscience, The Johns Hopkins University School of Medicine, Ross Building, Room 713, 720 Rutland Avenue, Baltimore, Maryland 21205, USA.
Nature
|February 1, 2008
概括
在N端的空间Ca2+转换元件 (NSCaTE) 切换calmodulin.
科学领域:
- 分子和细胞生物学分子和细胞生物学
- 离子通道生理学 离子通道生理学
- 信号传递 信号传递
背景情况:
- 电压通道 (CaV) 对于细胞功能至关重要.
- 与CaV通道结合的卡尔莫杜林 (CaM) 调节了它们的活性.
- CaM表现出不同的Ca2+选择性模式 (本地与全球).
研究的目的:
- 研究CaV通道调节中的空间Ca2+选择性背后的机制.
- 通过CaM的N-叶确定确定局部与全球Ca2+传感的因素.
- 阐明新型NSCaTE元素在CaV通道调制中的作用.
主要方法:
- 部位定向突变发生,以引入/破坏CaV通道中的NSCaTE元素.
- 电生理学记录以评估通道活动和Ca2+敏感性.
- 对CaV1和CaV2通道异型的比较分析.
主要成果:
- 一个新的Ca2+/CaM结合位点NSCaTE位于CaV通道N端,将CaM的N叶选择性从全球转变为局部.
- 缺乏NSCaTE的CaV2.2通道表现出全球的N-叶选择性,NSCaTE引入后变得局部化.
- 具有NSCaTE的原生CaV1.2/CaV1.3通道显示了局部N-叶的选择性,当NSCaTE被移除时会被破坏到全局.
结论:
- NSCaTE的存在或不存在解释了CaV1和CaV2通道家族之间的空间选择性差异.
- NSCaTE的N端位置表明,CaM可以跨越通道N端和C端.
- NSCaTE提供了一个模块化机制,用于理解CaV通道中的全球Ca2+选择性.
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