Membrane protein turnover by the m-AAA protease in mitochondria depends on the transmembrane domains of its subunits.
Korbel, Daniel;
Wurth, Stephanie;
Käser, Michael;
Langer, Thomas;
(2004)
Membrane protein turnover by the m-AAA protease in mitochondria depends on the transmembrane domains of its subunits.
EMBO reports, 5 (7).
pp. 698-703.
ISSN 1469-221X
DOI: https://doi.org/10.1038/sj.embor.7400186
Permanent Identifier
Use this Digital Object Identifier when citing or linking to this resource.
AAA proteases are membrane-bound ATP-dependent proteases that are present in eubacteria, mitochondria and chloroplasts and that can degrade membrane proteins. Recent evidence suggests dislocation of membrane-embedded substrates for proteolysis to occur in a hydrophilic environment; however, next to nothing is known about the mechanism of this process. Here, we have analysed the role of the membrane-spanning domains of Yta10 and Yta12, which are conserved subunits of the hetero-oligomeric m-AAA protease in the mitochondria of Saccharomyces cerevisiae. We demonstrate that the m-AAA protease retains proteolytic activity after deletion of the transmembrane segments of either Yta10 or Yta12. Although the mutant m-AAA protease is still capable of processing cytochrome c peroxidase and degrading a peripheral membrane protein, proteolysis of integral membrane proteins is impaired. We therefore propose that transmembrane segments of m-AAA protease subunits have a direct role in the dislocation of membrane-embedded substrates.