title: Nuclearly inherited diuron-resistant mutations conferring a deficiency in the NADH--or succinate--ubiquinone oxidoreductase activity in Saccharomyces cerevisiae.
abstract: In Saccharomyces cerevisiae, diuron, antimycin and myxothiazol block the respiratory pathway at the bc1 complex level. Nuclearly inherited mutations located at the DIU3 and DIU4 loci confer in vitro resistance to diuron and cross-resistance to antimycin and myxothiazol at the NADH oxidase level. The mutant strains do not exhibit diuron resistance at the quinol-cytochrome-c oxidoreductase level. Thus, the apparent resistance does not seem to be the result of a modification of the inhibitory sites. Instead, the quinone reduction rate was found to be altered in the mutant. The diu3 mutations lead to a deficiency of the NADH--ubiquinone oxidoreductase activity, and the diu4 mutations to a deficiency of the succinate--ubiquinone oxidoreductase activity. On the basis of the model of Kröger and Klingenberg, a decrease of quinone reduction could explain the resistance to the bc1 complex inhibitors. Thus, the apparent resistance to the bc1 complex inhibitors was found to be due to a modification of the electron transfer kinetics.
authors.affiliation: Laboratoire de Génétique Microbienne, Université Catholique de Louvain, Louvain-la-Neuve, Belgium.
authors.forename: B
authors.initials: B
authors.lastname: Meunier
authors.forename: A M
authors.initials: AM
authors.lastname: Colson-Corbisier
authors.forename: D
authors.initials: D
authors.lastname: Lemesle-Meunier
mesh_terms: D000968:Antimycin A / Q000031:analogs & derivatives / Q000494:pharmacology; D004237:Diuron / Q000494:pharmacology*; D004351:Drug Resistance; D042963:Electron Transport Complex II; D008689:Methacrylates; D009097:Multienzyme Complexes; D009154:Mutation; D016660:NAD(P)H Dehydrogenase (Quinone); D009245:NADH Dehydrogenase / Q000037:antagonists & inhibitors; D010088:Oxidoreductases; D011808:Quinone Reductases; D012441:Saccharomyces cerevisiae / Q000201:enzymology*; D013385:Succinate Dehydrogenase; D013844:Thiazoles / Q000494:pharmacology
chemical_list: D008689:Methacrylates; D009097:Multienzyme Complexes; D013844:Thiazoles; C032456:antimycin; D000968:Antimycin A; C030517:myxothiazol; D004237:Diuron; D010088:Oxidoreductases; D042963:Electron Transport Complex II; D013385:Succinate Dehydrogenase; D016660:NAD(P)H Dehydrogenase (Quinone); D011808:Quinone Reductases; D009245:NADH Dehydrogenase