Properties of yeast cells depleted of the OSCP subunit of mitochondrial ATP synthase by regulated expression of the ATP5 gene.
OSCP is a subunit of the FA stalk sector of yeast mitochondrial ATP synthase complex. Cells of a null mutant for OSCP, constructed by disruption of the chromosomal ATP5 gene of Saccharomyces cerevisiae, exhibited a high level of genetic instability (petite formation). Study of the effects of ablation of OSCP required the development of a progressive depletion strategy. Introduction of a vector bearing an ATP5 gene cassette under GAL1 transcriptional control into null mutant cells gave rise to a stable yeast strain from which OSCP could be depleted in a controlled manner by manipulation of the level of galactose in the growth medium. Cells progressively depleted of OSCP exhibited properties of cellular respiration indicative of a decline in the functional coupling of the catalytic F1 sector to the proton channel F0 sector (normally linked by FA). Cells depleted of OSCP also exhibited a physical uncoupling of F1 from other subunits of the complex such that other FA subunits and F0 subunit 6 were not recovered in immunoprecipitates of ATP synthase complexes. Thus, OSCP plays a role in the assembly as well as function of the enzyme complex.
Prescott
M
M
Department of Biochemistry, Monash University, Clayton, Victoria, Australia.
Bush
N C
NC
Nagley
P
P
Devenish
R J
RJ
D000251:Adenosine Triphosphatases / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D001483:Base Sequence; D002352:Carrier Proteins; D004271:DNA, Fungal / Q000737:chemistry / Q000235:genetics; D004272:DNA, Mitochondrial / Q000737:chemistry / Q000235:genetics; D015870:Gene Expression; D005786:Gene Expression Regulation; D007163:Immunosorbent Techniques; D008565:Membrane Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D008928:Mitochondria / Q000201:enzymology*; D025261:Mitochondrial Proton-Translocating ATPases; D008969:Molecular Sequence Data; D016254:Mutagenesis, Insertional; D016133:Polymerase Chain Reaction; D006180:Proton-Translocating ATPases / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000201:enzymology* / Q000235:genetics*; D013329:Structure-Activity Relationship
D002352:Carrier Proteins; D004271:DNA, Fungal; D004272:DNA, Mitochondrial; D008565:Membrane Proteins; D000251:Adenosine Triphosphatases; D025261:Mitochondrial Proton-Translocating ATPases; D006180:Proton-Translocating ATPases; C020439:oligomycin sensitivity-conferring protein