Journal article

Mitochondrial OXA Translocase Plays a Major Role in Biogenesis of Inner-Membrane Proteins

Sebastian B Stiller, Jan Hoepker, Silke Oeljeklaus, Conny Schuetze, Sandra G Schrempp, Jens Vent-Schmidt, Susanne E Horvath, Ann E Frazier, Natalia Gebert, Martin van der Laan, Maria Bohnert, Bettina Warscheid, Nikolaus Pfanner, Nils Wiedemann



The mitochondrial inner membrane harbors three protein translocases. Presequence translocase and carrier translocase are essential for importing nuclear-encoded proteins. The oxidase assembly (OXA) translocase is required for exporting mitochondrial-encoded proteins; however, different views exist about its relevance for nuclear-encoded proteins. We report that OXA plays a dual role in the biogenesis of nuclear-encoded mitochondrial proteins. First, a systematic analysis of OXA-deficient mitochondria led to an unexpected expansion of the spectrum of OXA substrates imported via the presequence pathway. Second, biogenesis of numerous metabolite carriers depends on OXA, although they are not im..

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Awarded by Deutsche Forschungsgemeinschaft

Awarded by Excellence Initiative of the German federal and state governments

Awarded by European Research Council (ERC)

Awarded by German Academy of Sciences Leopoldina

Funding Acknowledgements

We thank J.M. Herrmann, P. Rehling, and M. Andes for discussion, yeast strains, and basic import experiments and A. Schulze-Specking for expert technical assistance. Work included in this study has also been performed in partial fulfillment of the requirements for the doctoral theses of S.B.S., J.H., and S.G.S. at the University of Freiburg. This work was supported by the Deutsche Forschungsgemeinschaft (PF 202/8-1), the Sonderforschungsbereiche 746 and 1140, the Excellence Initiative of the German federal and state governments (EXC 294 BIOSS; GSC-4 Spemann Graduate School), the European Research Council (ERC) Consolidator Grant Number 648235, the German Academy of Sciences Leopoldina (LPDS 2013-08 to S.E.H.), and a Boehringer Ingelheim Fonds fellowship (to M.B.).