Bcl-x(L) 在合成脂质膜中形成离子通道
A J Minn1, P Vélez, S L Schendel
1Gwen Knapp Center for Lupus and Immunology Research, The University of Chicago, Illinois 60637, USA.
Nature
|January 23, 1997
概括
反亡蛋白Bcl-xL在细胞膜中形成离子通道. 这一发现表明,Bcl-xL通过控制膜透性来调节细胞生存.
科学领域:
- 生物化学 生物化学
- 分子生物学分子生物学
- 细胞生物学 细胞生物学
背景情况:
- 与Bcl-2相关的蛋白质调节细胞生存,并且存在于关键的细胞内膜上.
- 包括Bcl-xL在内的这些蛋白质的精确生物化学功能尚未完全理解.
- Bcl-xL被称为亡的抑制剂.
研究的目的:
- 为了研究Bcl-xL.L.的生物化学功能.
- 要确定Bcl-xL是否像形成孔隙的细菌毒素一样可以形成离子通道.
- 阐明Bcl-xL在通过膜透性调节细胞存活中的作用.
主要方法:
- Bcl-xL与形成孔隙的细菌毒素的结构比较.
- 使用合成脂质囊泡和平面脂质双层的功能性测试.
- 电生理学测量以表征离子通道活动.
主要成果:
- 证明Bcl-xL与细菌毒素的孔隙形成域具有结构上的相似性.
- Bcl-xL成功地插入了脂质双层,形成了离子导体通道.
- Bcl-xL离子通道在生理pH下表现出pH敏感性和阴离子选择性,具有多个导电状态.
结论:
- Bcl-xL具有离子通道形成能力,类似于细菌毒素.
- 由Bcl-xL形成的离子通道表明了调节细胞存活的新机制.
- Bcl-xL可以通过调节线粒体,核和内分泌网膜的透性来控制细胞生存.
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