Within the yeast mitochondrial ATP synthase, subunit h is a small nuclear-encoded protein belonging to the so-called "peripheral stalk" that connects the enzyme catalytic F1 component to the mitochondrial inner membrane. This study examines the role of subunit h in ATP synthase function and assembly using a regulatable, doxycycline-repressible, subunit h gene, to overcome the strong instability of the mitochondrial DNA (mtDNA) previously observed in strains lacking the native subunit h gene. Yeast cells expressing less than 3% of subunit h, but still containing intact mitochondrial genomes, grew poorly on respiratory substrates because of a major impairment of ATP synthesis originating from the ATP synthase, whereas the respiratory chain complexes were not affected. The lack of ATP synthesis in the subunit h depleted (dh) mitochondria was attributed to defects in the assembly/stability of the ATP synthase. A main feature of dh mitochondria was a very low content (< 6%) in the mitochondrially encoded Atp6p subunit, an essential component of the enzyme proton channel, that was in large part due to a slowing down in translation. Interestingly, depletion of subunit h resulted in dramatic changes in mitochondrial cristae morphology, which further supports the existence of a link between the ATP synthase and the folding/biogenesis of the inner mitochondrial membrane.
|Evidence ID||Analyze ID||Interactor||Interactor Systematic Name||Interactor||Interactor Systematic Name||Type||Assay||Annotation||Action||Modification||Phenotype||Source||Reference||Note|
|Evidence ID||Analyze ID||Gene||Gene Systematic Name||Gene Ontology Term||Gene Ontology Term ID||Qualifier||Aspect||Method||Evidence||Source||Assigned On||Reference||Annotation Extension|
|Evidence ID||Analyze ID||Gene||Gene Systematic Name||Phenotype||Experiment Type||Experiment Type Category||Mutant Information||Strain Background||Chemical||Details||Reference|
|Evidence ID||Analyze ID||Regulator||Regulator Systematic Name||Target||Target Systematic Name||Experiment||Conditions||Strain||Source||Reference|