Open AccessAlterations of the α or β Subunits of the Mitochondria1 ATPase in Yeast Mutants
Author(s) -
BOUTRY Marc,
GOFFEAU Andrè
Publication year - 1982
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1111/j.1432-1033.1982.tb06707.x
Subject(s) - cytochrome c oxidase , protein subunit , mutant , biology , biochemistry , cytochrome , cytochrome b , coenzyme q – cytochrome c reductase , cytochrome c1 , mitochondrion , electron transport complex iv , cytochrome c , microbiology and biotechnology , enzyme , mitochondrial dna , gene
Among 979 non‐glycerol growers of the yeast Schizosaccharomyces pombe , 40 strains were found to be deficient in the mitochondrial ATPase activity. Three of them exhibited an alteration in either the α or β subunits of the F 1 ATPase. The α subunit was not immunodetected in the A23/13 mutant. The β subunit was not immuno‐ detected in the B59/1 mutant. The existence of these two mutants shows that the α and β subunits can be present independently of each other in the inner mitochondrial membrane. The β subunit of the mutant F25/28 had a slower electrophoretic mobility than that of the wild‐type β subunit. This phenotype indicates abnormal processing or specific modification of the β subunit. All mutants showed reduced activities of the NADH–cytochrome c reductase and of the cytochrome oxidase and a decreased synthesis of cytochrome aa 3 and cytochrome b . This pleiotropic phenotype appears to result from specific modifications in the mitochondrial protein synthesis. The mitochondrial synthesis of four polypeptides (three cytochrome oxidase and one cytochrome b subunits) was markedly decreased or absent while three new polypeptides ( M r = 54000, 20000 and 15000) were detected in all the mutants analysed. This observation suggests that a functional F 1 ATPase is necessary for the correct synthesis and/or assembly of the mitochondrially made complexes.