The morphology proteins Mdm12/Mmm1 function in the major β-barrel assembly pathway of mitochondria
The morphology proteins Mdm12/Mmm1 function in the major β-barrel assembly pathway of mitochondria
复制标题
DOI：
10.1038/sj.emboj.7601673
复制
发表时间：
2007-05-02
期刊：
影响因子：
11.4
通讯作者：
Wiedemann, Nils
中科院分区：
文献类型：
--
作者：
Meisinger, Chris;Pfannschmidt, Sylvia;Wiedemann, Nils
线粒体的β桶蛋白在胞质核糖体上合成。蛋白质通过外膜转位酶（TOM）和分选和组装机器（SAM）输入。据推测，SAM（核心）复合物与亚基Sam 35，Sam 37和Sam 50代表了最后的进口阶段共同所有的b-桶蛋白，其次是分裂的Tom 40特异性路线和路线的其他b-桶蛋白。我们已经确定了新的组件的B-桶组装机械，并表明，主要的B-桶途径延伸到SAMcore之外。Mdm 12/Mmm 1在SAM核心之后但在主要途径分裂之前发挥功能。Mdm 12/Mmm 1已被称为他们的作用，在维护线粒体形态，但我们揭示组装的b桶蛋白作为其主要功能。此外，在Tom 40特异性途径中起作用的Mdm 10可以与SAM核心以及Mdm 12/Mmm 1结合形成不同的组装复合物，这表明控制线粒体b桶组装的机制之间存在动态交换。我们的结论是，组装的线粒体b-桶蛋白的形态蛋白Mdm 12/Mmm 1的一个主要功能。
The beta-barrel proteins of mitochondria are synthesized on cytosolic ribosomes. The proteins are imported by the translocase of the outer membrane (TOM) and the sorting and assembly machinery (SAM). It has been assumed that the SAM(core) complex with the subunits Sam35, Sam37 and Sam50 represents the last import stage common to all b-barrel proteins, followed by splitting in a Tom40-specific route and a route for other b-barrel proteins. We have identified new components of the b-barrel assembly machinery and show that the major b-barrel pathway extends beyond SAMcore. Mdm12/ Mmm1 function after SAMcore yet before splitting of the major pathway. Mdm12/ Mmm1 have been known for their role in maintenance of mitochondrial morphology but we reveal assembly of b-barrel proteins as their primary function. Moreover, Mdm10, which functions in the Tom40- specific route, can associate with SAMcore as well as Mdm12/ Mmm1 to form distinct assembly complexes, indicating a dynamic exchange between the machineries governing mitochondrial b-barrel assembly. We conclude that assembly of mitochondrial b-barrel proteins represents a major function of the morphology proteins Mdm12/ Mmm1.