Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.6.3.14 (ATP synthase)
 7,042 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Cytoplasmically synthesized precursors of mitochondrial polypeptides have previously been observed in trace amounts after pulse labeling of yeast spheroplasts or after in vitro translation of yeast mRNA (Maccecchini, M. L., Rudin, Y., Blobel, G., and Schatz, G. (1979) Proc. Natl. Acad. Sci. U. S. A. 76, 343-347). Some of these precursors are shown here to accumulate in large amounts (up to 150 micrograms/g of cell protein) during growth of a cytoplasmic petite (rho-) mutant in the presence of carbonyl cyanide m-chlorophenylhydrazone, an uncoupler of oxidative phosphorylation. Cytochrome c1 precursor accumulated under these conditions is unstable; it is degraded with a half-life of about 10 min. In contrast, the F1-ATPase beta-subunit precursor is degraded considerably more slowly and, following removal of the uncoupler, can be post-translationally imported into mitochondria where it is processed to the mature polypeptide.
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PMID:Import of proteins into mitochondria. Yeast cells grown in the presence of carbonyl cyanide m-chlorophenylhydrazone accumulate massive amounts of some mitochondrial precursor polypeptides. 629 Apr 91

Oxa1p is a mitochondrial inner membrane protein that is mainly required for the insertion/assembly of complex IV and ATP synthase and is functionally conserved in yeasts, humans, and plants. We have isolated several independent suppressors that compensate for the absence of Oxa1p. Molecular cloning and sequencing reveal that the suppressor mutations (CYT1-1 to -6) correspond to amino acid substitutions that are all located in the membrane anchor of cytochrome c1 and decrease the hydrophobicity of this anchor. Cytochrome c1 is a catalytic subunit of complex III, but the CYT1-1 mutation does not seem to affect the electron transfer activity. The double-mutant cyt1-1,164, which has a drastically reduced electron transfer activity, still retains the suppressor activity. Altogether, these results suggest that the suppressor function of cytochrome c1 is independent of its electron transfer activity. In addition to the membrane-bound cytochrome c1, carbonate-extractable forms accumulate in all the suppressor strains. We propose that these carbonate-extractable forms of cytochrome c1 are responsible for the suppressor function by preventing the degradation of the respiratory complex subunits that occur in the absence of Oxa1p.
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PMID:Mutations in the membrane anchor of yeast cytochrome c1 compensate for the absence of Oxa1p and generate carbonate-extractable forms of cytochrome c1. 975 93