Mitochondrial protein quality control by the proteasome involves ubiquitination and the protease Omi.

ABSTRACT: We report here that blocking the activity of the 26 S proteasome results in drastic changes in the morphology of the mitochondria and accumulation of intermembrane space (IMS) proteins. Using endonuclease G (endoG) as a model IMS protein, we found that accumulation of wild-type but to a greater extent mutant endoG leads to changes in the morphology of the mitochondria similar to those observed following proteasomal inhibition. Further, we show that wild-type but to a greater extent mutant endoG is a substrate for ubiquitination, suggesting the presence of a protein quality control. Conversely, we also report that wild-type but not mutant endoG is a substrate for the mitochondrial protease Omi but only upon inhibition of the proteasome. These findings suggest that although elimination of mu

SUBMITTER: Radke S 

PROVIDER: S-EPMC2442309 | biostudies-literature | 2008 May

REPOSITORIES: biostudies-literature