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活性线粒体蛋白门的分子结构

Takuya Shiota¹, Kenichiro Imai², Jian Qiu³

¹Biomedicine Discovery Institute and Department of Microbiology, Monash University, Melbourne, Victoria 3800, Australia. Department of Chemistry, Graduate School of Science, Nagoya University, Chikusa-ku, Nagoya 464-8602, Japan.

Science (New York, N.Y.)

|September 26, 2015

概括

研究人员绘制了线粒体TOM复合体,揭示了不同的蛋白质进口途径. 这揭示了Tom40通道和相关蛋白质如何动态地促进几乎所有线粒体蛋白质的运输.

科学领域:

线粒体生物学
蛋白质进口机械
细胞能量和新陈代谢

背景情况:

线粒体对于细胞能量,新陈代谢和信号传递至关重要.
外部线粒体膜的转位酶 (TOM) 复合体调解了大多数线粒体蛋白质的进口.
对于TOM复合体的精确架构和运输机制, 基本上是未知的.

研究的目的:

为了阐明活跃的TOM复合体的分子结构.
确定涉及蛋白质在外线粒体膜中转移的特定途径和机制.
了解蛋白质进口过程中TOM复合元件的动态相互作用.

主要方法:

使用交叉链接方法在单个氨基酸分辨率下绘制TOM复合体内的蛋白质相互作用.
分析了Tom40通道及其相关受体和调节蛋白的结构组织.
在生物发生过程中研究了TOM复杂异型的动态交换.

主要成果:

绘制了活跃的TOM复合体,通过Tom40通道揭示了前蛋白的独特运输路径.
识别了Tom40的N端段, 招募膜间空间护卫者进行疏水性蛋白质转移.
证明转位器包括三个Tom40β-桶通道,一个中央的Tom22受体集群和外部的调节性Tom蛋白.
展示了三合体和二合体TOM复合异形之间的动态交换.
揭示了一种涉及合α-螺旋受体,β-桶通道和约1000种不同蛋白质的伴侣的多功能机器.

结论:

该研究提供了TOM复杂架构及其功能单元的高分辨率地图.
通过Tom40道为促进蛋白质进口提供了一种新的辅助机制.
确定了TOM复合物的动态性质,强调其在蛋白质运输中的适应性.
这些发现提供了关于线粒体蛋白质进口和细胞平衡的基本过程的见解.

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