Help Privacy Policy Disclaimer
  Advanced SearchBrowse




Journal Article

Oma1, a novel membrane-bound metallopeptidase in mitochondria with activities overlapping with the m-AAA protease


Langer,  T.
Department Langer - Mitochondrial Proteostasis, Max Planck Institute for Biology of Ageing, Max Planck Society;

External Resource
Fulltext (restricted access)
There are currently no full texts shared for your IP range.
Fulltext (public)
There are no public fulltexts stored in PuRe
Supplementary Material (public)
There is no public supplementary material available

Kaser, M., Kambacheld, M., Kisters-Woike, B., & Langer, T. (2003). Oma1, a novel membrane-bound metallopeptidase in mitochondria with activities overlapping with the m-AAA protease. J Biol Chem, 278(47), 46414-23. doi:10.1074/jbc.M305584200.

Cite as: https://hdl.handle.net/21.11116/0000-000B-71DA-0
The integrity of the inner membrane of mitochondria is maintained by a membrane-embedded quality control system that ensures the removal of misfolded membrane proteins. Two ATP-dependent AAA proteases with catalytic sites at opposite membrane surfaces are key components of this proteolytic system. Here we describe the identification of a novel conserved metallopeptidase that exerts activities overlapping with the m-AAA protease and was therefore termed Oma1. Both peptidases are integral parts of the inner membrane and mediate the proteolytic breakdown of a misfolded derivative of the polytopic inner membrane protein Oxa1. The m-AAA protease cleaves off the matrix-exposed C-terminal domain of Oxa1 and processively degrades its transmembrane domain. In the absence of the m-AAA protease, proteolysis of Oxa1 is mediated in an ATP-independent manner by Oma1 and a yet unknown peptidase resulting in the accumulation of N- and C-terminal proteolytic fragments. Oma1 exposes its proteolytic center to the matrix side; however, mapping of Oma1 cleavage sites reveals clipping of Oxa1 in loop regions at both membrane surfaces. These results identify Oma1 as a novel component of the quality control system in the inner membrane of mitochondria. Proteins homologous to Oma1 are present in higher eukaryotic cells, eubacteria and archaebacteria, suggesting that Oma1 is the founding member of a conserved family of membrane-embedded metallopeptidases.