Ubiquinone is not required for proton conductance by uncoupling protein 1 in yeast mitochondria.

TitleUbiquinone is not required for proton conductance by uncoupling protein 1 in yeast mitochondria.
Publication TypeJournal Article
Year of Publication2004
AuthorsEsteves, TC, Echtay, KS, Jonassen, T, Clarke, CF, Brand, MD
JournalBiochem J
IssuePt 2
Date Published2004 Apr 15
KeywordsCarrier Proteins, Ion Channels, Ion Transport, Membrane Proteins, Mitochondria, Mitochondrial Proteins, Mutation, Protons, Saccharomyces cerevisiae, Transformation, Genetic, Ubiquinone, Uncoupling Protein 1

Q (coenzyme Q or ubiquinone) is reported to be a cofactor obligatory for proton transport by UCPs (uncoupling proteins) in liposomes [Echtay, Winkler and Klingenberg (2000) Nature (London) 408, 609-613] and for increasing the binding of the activator retinoic acid to UCP1 [Tomás, Ledesma and Rial (2002) FEBS Lett. 526, 63-65]. In the present study, yeast ( Saccharomyces cerevisiae ) mutant strains lacking Q and expressing UCP1 were used to determine whether Q was required for UCP function in mitochondria. Wild-type yeast strain and two mutant strains (CENDeltaCOQ3 and CENDeltaCOQ2), both not capable of synthesizing Q, were transformed with the mouse UCP1 gene. UCP1 activity was measured as fatty acid-dependent, GDP-sensitive proton conductance in mitochondria isolated from the cells. The activity of UCP1 was similar in both Q-containing and -deficient yeast mitochondria. We conclude that Q is neither an obligatory cofactor nor an activator of proton transport by UCP1 when it is expressed in yeast mitochondria.

Alternate JournalBiochem. J.
Citation Key10.1042/BJ20031682
PubMed ID14680474
PubMed Central IDPMC1224067
Grant ListGM45952 / GM / NIGMS NIH HHS / United States