激活通道的激活的机制
Jingyi Shi1, Gayathri Krishnamoorthy, Yanwu Yang
1Cardiac Bioelectricity Research and Training Center and Department of Biomedical Engineering, Case Western Reserve University, Cleveland, Ohio 44106-7207, USA.
Nature
|August 23, 2002
概括
大导电依赖 (BK) 通道对于肌肉和神经功能至关重要. 这项研究揭示了BK通道中的新型 (Mg2+) 结合部位,证明了Mg2+和 (Ca2+) 的独特激活通路.
科学领域:
- 分子生物学分子生物学
- 生物物理学的生物物理.
- 离子通道功能 离子通道功能
背景情况:
- 大导电 (BK类型) 的Ca2+-依赖K2+) 通道调节重要生理过程.
- BK通道通过膜去极化和细胞内Ca2+和Mg2+被激活.
- 之前的研究表明,电压,Ca2+和Mg2+结合的添加激活能量,意味着独立的激活途径.
研究的目的:
- 研究BK通道的Mg2+) 依存激活的分子机制.
- 为了阐明Ca(2+) 和Mg(2+) 的不同激活路径的结构基础.
主要方法:
- BK通道组件的局部定向突变发生.
- 道域的结构分析.
- 道活动的生物物理特征.
主要成果:
- 在BK通道的RCK/Rossman折叠域内确定了一个新的Mg(2+) 结合位.
- 影响Mg2+) 敏感性的突变不会改变Ca2+) 敏感性,反之亦然.
- 发现了Mg2+和Ca2+依赖道激活的独立结构途径的证据.
结论:
- 结合RCK/Rossman折叠域中新确定的位点的Mg(2+) 直接介导Mg(2+) 依存的BK通道激活.
- 2+) 和2+) 通过不同的结构机制激活BK通道.
- 这提供了Mg(2+) 与BK通道关结合的合的洞察力.
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