巴克斯晶体结构揭示了BH3域如何激活巴克斯并核化其寡合化以诱导亡
Peter E Czabotar1, Dana Westphal, Grant Dewson
1The Walter and Eliza Hall Institute of Medical Research, Melbourne, Victoria 3052, Australia. czabotar@wehi.edu.au
Cell
|February 5, 2013
概括
细胞亡涉及巴克斯或巴克斯的寡合化. 这项研究揭示了BH3-only蛋白如何通过解离其域触发巴克斯激活,促进线粒体外膜透和细胞死亡.
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:
- 细胞亡,或编程细胞死亡,对于发育和组织平衡至关重要.
- 亡的线粒体途径由Bcl-2家族蛋白调节,包括亲亡的Bax和Bak及其激活剂.
研究的目的:
- 阐明仅BH3蛋白激活Bax的结构机制.
- 了解导致巴克斯寡合化和线粒体外膜透性的构造变化.
主要方法:
- 使用X射线结晶学来确定BaxΔC21与BH3的复合体中的结构.
- 对BAX螺旋α2-α5进行了结构分析,以调查同质化.
主要成果:
- BH3与Bax的正规结合,诱导域解离.
- 确定了激活器BH3域的保存序列签名.
- 巴克斯螺旋体α2-α5形成一个对称的同位体,这表明一个核化机制的寡合化.
- 同位体上的一种脂性表面可能会调解膜相互作用.
结论:
- 只有BH3的蛋白质通过促进其域解离和释放其自己的BH3域来激活Bax.
- 通过相互BH3域参与的Bax同质化是启动Bax寡质化的一个关键步骤.
- 这些发现为巴克斯在诱导亡过程中的结构转变提供了关键的见解.
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