Mim1, a protein required for the assembly of the TOM complex of mitochondria

被引:63
作者
Waizengger, T [1 ]
Schmitt, S [1 ]
Zivkovic, J [1 ]
Neupert, W [1 ]
Rapaport, D [1 ]
机构
[1] Univ Munich, Inst Physiol Chem, D-81377 Munich, Germany
关键词
mitochondria; TOM complex; TOB complex; assembly; mim1;
D O I
10.1038/sj.embor.7400318
中图分类号
Q5 [生物化学]; Q7 [分子生物学];
学科分类号
071010 ; 081704 ;
摘要
The translocase of the outer mitochondrial membrane (TOM complex) is the general entry site for newly synthesized proteins into mitochondria. This complex is essential for the formation and maintenance of mitochondria. Here, we report on the role of the integral outer membrane protein, Mim1 (mitochondrial import), in the biogenesis of mitochondria. Depletion of Mim1 abrogates assembly of the TOM complex and results in accumulation of Tom40, the principal constituent of the TOM complex, as a low-molecular-mass species. Like all mitochondrial beta-barrel proteins, the precursor of Tom40 is inserted into the outer membrane by the TOB complex. Mim1 is likely to be required for a step after this TOB-complex-mediated insertion. Mim1 is a constituent of neither the TOM complex nor the TOB complex; rather, it seems to be a subunit of another, as yet unidentified, complex. We conclude that Mim1 has a vital and specific function in the assembly of the TOM complex.
引用
收藏
页码:57 / 62
页数:6
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