A Pathway of Protein Translocation in Mitochondria Mediated by the AAA-ATPase Bcsl
A Pathway of Protein Translocation in Mitochondria Mediated by the AAA-ATPase Bcsl
复制标题
DOI：
10.1016/j.molcel.2011.07.036
复制
发表时间：
2011-10-21
期刊：
影响因子：
16
通讯作者：
Neupert, Walter
中科院分区：
文献类型：
--
作者：
Wegener, Nikola;Ackermann, Markus;Neupert, Walter
真核生物中的 AAA+ 家族在不同的细胞区室中拥有许多成员，在蛋白质解折叠和降解中发挥作用。我们发现线粒体 AAA-ATPase Bcs1 在蛋白质易位中具有不寻常的功能。 Bcs1 介导 Rieske 蛋白 Rip1 的拓扑发生，Rip1 是细菌、线粒体和叶绿体中呼吸链的组成部分。寡聚 AAA-ATPase Bcs1 参与 Rip1 的折叠 Fe-S 结构域穿过内膜的输出，并将其跨膜片段插入细胞色素 bc(1) 复合物的组装中间体中，从而揭示了蛋白质跨膜易位的意外机制概念。此外，我们描述了 AAA-ATP 酶识别和输出以及 ATP 依赖性横向释放所需的 Rip1 结构元件。在细菌和叶绿体中，Rip1 使用 Tat 机制进行拓扑发生；然而，线粒体在进化过程中失去了这种机制，AAA-ATP酶家族的一个成员接管了它的功能。
The AAA+ family in eukaryotes has many members in various cellular compartments with a role in protein unfolding and degradation. We show that the mitochondrial AAA-ATPase Bcs1 has an unusual function in protein translocation. Bcs1 mediates topogenesis of the Rieske protein, Rip1, a component of respiratory chains in bacteria, mitochondria, and chloroplasts. The oligomeric AAA-ATPase Bcs1 is involved in export of the folded Fe-S domain of Rip1 across the inner membrane and insertion of its transmembrane segment into an assembly intermediate of the cytochrome bc(1) complex, thus revealing an unexpected mechanistical concept of protein translocation across membranes. Furthermore, we describe structural elements of Rip1 required for recognition and export by as well as ATP-dependent lateral release from the AAA-ATPase. In bacteria and chloroplasts Rip1 uses the Tat machinery for topogenesis; however, mitochondria have lost this machinery during evolution and a member of the AAA-ATPase family has taken over its function.