Protein quality control in the intermembrane space of mitochondria
22.10.2012
Böttinger L, Becker T
J Mol Biol. 2012; 424(5):225-6
Protein import and homeostasis are essential for the development of functional mitochondria. Protein translocation machineries and several proteases in the mitochondrial matrix and inner membrane have been identified to fulfill both processes. In contrast, only little is known how misfolded proteins of the intermembrane space are removed. Recent publications revealed that the inner membrane AAA-protease Yme1 plays a central role in the protein quality control of intermembrane space localized proteins. Mutants of Yme1 leads to the accumulation and aggregation of unassembled and unfolded proteins in the intermembrane space. In particular, mutants of the small Tim proteins that fail to assemble into their functional hexameric complex are enriched in Yme1 mutant mitochondria. These observations indicate that Yme1 removes proteolytically misfolded proteins in the intermembrane space. Future work has to reveal whether additional factor are required for the intermembrane space protein quality control.
