Plasma membrane-stimulated vanadate-dependent NADH oxidation is not the primary mediator of vanadate toxicity in Saccharomyces cerevisiae.
Interactions of oxyvanadium compounds with cellular metabolism have recently been demonstrated. Membrane-stimulated vanadate-dependent NADH oxidation has been hypothesized to involve the cellular accumulation of H2O2, which may cause the vanadate sensitivity of animals and microbes. This report shows that the vanadate-dependent NADH oxidation activity of the yeast plasma membrane requires oxygen and is present in vanadate-resistant mutants of Saccharomyces cerevisiae. In addition, the vanadate sensitivity of growth in S. cerevisiae is the same during aerobic and anaerobic growth. These results imply that neither plasma membrane-mediated vanadate-stimulated NADH oxidation, nor any other oxidative process, is the primary cause of vanadate sensitivity in yeast cells.
Minasi
L A
LA
Department of Biochemistry, State University of New York School of Medicine and Biochemical Sciences, Buffalo 14214.
Chang
A
A
Willsky
G R
GR
D000332:Aerobiosis; D000693:Anaerobiosis; D017301:Ca(2+) Mg(2+)-ATPase / Q000378:metabolism; D002462:Cell Membrane / Q000378:metabolism; D007700:Kinetics; D009243:NAD / Q000378:metabolism*; D010084:Oxidation-Reduction; D012441:Saccharomyces cerevisiae / Q000187:drug effects* / Q000254:growth & development / Q000378:metabolism; D014638:Vanadates / Q000494:pharmacology*
D009243:NAD; D014638:Vanadates; D017301:Ca(2+) Mg(2+)-ATPase