Role of mitochondrial inner membrane organizing system in protein biogenesis of the mitochondrial outer membrane
23.08.2012
Bohnert M, Wenz LS, Zerbes RM, Horvath SE, Stroud DA, von der Malsburg K, Müller JM, Oeljeklaus S, Perschil I, Warscheid B, Chacinska A, Veenhuis M, van der Klei IJ, Daum G, Wiedemann N, Becker T, Pfanner N, van der Laan M
Mol Biol Cell. 2012 Oct;23(20):3948-3956.
The conserved Mitochondrial Inner Membrane Organizing System (MINOS) is crucial for the maintenance of mitochondrial membrane architecture. MINOS is composed of the core components Mitofilin (Fcj1) and Mio10 and at least four further subunits, which are all mitochondrial inner membrane proteins. Mutations causing the loss of functional MINOS complexes lead to a detachment of mitochondrial cristae membranes from the boundary inner membrane due to a collapse of crista junctions. Moreover, MINOS components are involved in the formation of contact sites between mitochondrial outer and inner membranes. In this study, we show that the central MINOS component Fcj1 in the yeast Saccharomyces cerevisiae is required for the efficient biogenesis of mitochondrial outer membrane proteins with a beta-barrel transmembrane topology. This process is mediated by the Translocase of the Outer mitochondrial Membrane (TOM complex) together with the Sorting and Assembly Machinery (SAM complex) and is facilitated by Fcj1 that physically interacts with these two outer mitochondrial membrane protein complexes.
