Mdm10 as a dynamic constituent of the TOB/SAM complex directs coordinated assembly of Tom40.

ABSTRACT: The mitochondrial outer membrane contains two protein translocators: the TOM40 and TOB/SAM complexes. Mdm10 is distributed in the TOB complex for beta-barrel protein assembly and in the MMM1 complex for tethering of the endoplasmic reticulum and mitochondria. Here, we establish a system in which the Mdm10 level in the TOB complex--but not in the MMM1 complex--is altered to analyse its part in beta-barrel protein assembly. A decrease in the Mdm10 level results in accumulation of in vitro imported Tom40, which is a beta-barrel protein, at the level of the TOB complex. An increase in the Mdm10 level inhibits association not only of Tom40 but also of other beta-barrel proteins with the TOB complex. These results show that Mdm10 regulates the timing of release of unassembled Tom40 from the TOB

SUBMITTER: Yamano K 

PROVIDER: S-EPMC2838686 | biostudies-literature | 2010 Mar

REPOSITORIES: biostudies-literature