Atp10p assists assembly of Atp6p into the F0 unit of the yeast mitochondrial ATPase.
The F(0)F(1)-ATPase complex of yeast mitochondria contains three mitochondrial and at least 17 nuclear gene products. The coordinate assembly of mitochondrial and cytosolic translation products relies on chaperones and specific factors that stabilize the pools of some unassembled subunits. Atp10p was identified as a mitochondrial inner membrane component necessary for the biogenesis of the hydrophobic F(0) sector of the ATPase. Here we show that, following its synthesis on mitochondrial ribosomes, subunit 6 of the ATPase (Atp6p) can be cross-linked to Atp10p. This interaction is required for the integration of Atp6p into a partially assembled subcomplex of the ATPase. Pulse labeling and chase of mitochondrial translation products in vivo indicate that Atp6p is less stable and more rapidly degraded in an atp10 null mutant than in wild type. Based on these observations, we propose Atp10p to be an Atp6p-specific chaperone that facilitates the incorporation of Atp6p into an intermediate subcomplex of ATPase subunits.
Department of Biological Sciences, Columbia University, New York, NY 10027, USA.
Alexander
A
Tzagoloff
Antoni
A
Barrientos
Walter
W
Neupert
Johannes M
JM
Herrmann
D000251:Adenosine Triphosphatases / Q000737:chemistry*; D003432:Cross-Linking Reagents / Q000494:pharmacology; D003600:Cytosol / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D008928:Mitochondria / Q000378:metabolism / Q000473:pathology; D025261:Mitochondrial Proton-Translocating ATPases; D008954:Models, Biological; D018832:Molecular Chaperones / Q000737:chemistry* / Q000502:physiology*; D009154:Mutation; D011233:Precipitin Tests; D011485:Protein Binding; D014176:Protein Biosynthesis; D017434:Protein Structure, Tertiary; D006180:Proton-Translocating ATPases / Q000737:chemistry*; D012441:Saccharomyces cerevisiae / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry* / Q000502:physiology*; D013997:Time Factors
C486885:Atp10 protein, S cerevisiae; D003432:Cross-Linking Reagents; D018832:Molecular Chaperones; D029701:Saccharomyces cerevisiae Proteins; D000251:Adenosine Triphosphatases; D025261:Mitochondrial Proton-Translocating ATPases; D006180:Proton-Translocating ATPases