Reoxidation of the NADPH produced by the pentose phosphate pathway is necessary for the utilization of glucose by Kluyveromyces lactis rag2 mutants.
Kluyveromyces lactis mutants defective in the glycolytic enzyme phosphoglucose isomerase are able to grow in glucose media and to produce ethanol, but they depend on a functional respiratory chain and do not grow in glucose-antimycin media. We postulate that this is due to the necessity of reoxidizing, in the mitochondria, the NADPH produced by the pentose phosphate pathway, which may be highly active in these mutants in order to bypass the blockade in the phosphoglucose isomerase step. This oxidation would be mediated by a cytoplasmic-side mitochondrial NAD(P)H dehydrogenase that would pass the electrons to ubiquinone. Data supporting this hypothesis are provided.
González Siso
M I
MI
Department of Molecular and Cellular Biology, Faculty of Sciences, Campus da Zapateira s/n, University of A Coruña, Spain.
Freire Picos
M A
MA
Cerdán
M E
ME
D000968:Antimycin A / Q000031:analogs & derivatives / Q000494:pharmacology; D004352:Drug Resistance, Microbial / Q000235:genetics; D000431:Ethanol / Q000378:metabolism; D005947:Glucose / Q000378:metabolism*; D005956:Glucose-6-Phosphate Isomerase / Q000235:genetics / Q000378:metabolism*; D007716:Kluyveromyces / Q000187:drug effects / Q000201:enzymology / Q000235:genetics / Q000378:metabolism*; D008928:Mitochondria / Q000378:metabolism; D009154:Mutation; D009249:NADP / Q000378:metabolism*; D010084:Oxidation-Reduction; D010427:Pentose Phosphate Pathway; D014451:Ubiquinone / Q000378:metabolism
C032456:antimycin; D014451:Ubiquinone; D000431:Ethanol; D009249:NADP; D000968:Antimycin A; D005956:Glucose-6-Phosphate Isomerase; D005947:Glucose