Functional studies of aldo-keto reductases in Saccharomyces cerevisiae.
We utilized the budding yeast Saccharomyces cerevisiae as a model to systematically explore physiological roles for yeast and mammalian aldo-keto reductases. Six open reading frames encoding putative aldo-keto reductases were identified when the yeast genome was queried against the sequence for human aldose reductase, the prototypical mammalian aldo-keto reductase. Recombinant proteins produced from five of these yeast open reading frames demonstrated NADPH-dependent reductase activity with a variety of aldehyde and ketone substrates. A triple aldo-keto reductase null mutant strain demonstrated a glucose-dependent heat shock phenotype which could be rescued by ectopic expression of human aldose reductase. Catalytically-inactive mutants of human or yeast aldo-keto reductases failed to effect a rescue of the heat shock phenotype, suggesting that the phenotype results from either an accumulation of one or more unmetabolized aldo-keto reductase substrates or a synthetic deficiency of aldo-keto reductase products generated in response to heat shock stress. These results suggest that multiple aldo-keto reductases fulfill functionally redundant roles in the stress response in yeast.
Chang
Qing
Q
Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, 660 South Euclid Avenue (Campus Box 8096), St. Louis, MO 63110, USA.
Griest
Terry A
TA
Harter
Theresa M
TM
Petrash
J Mark
JM
D000429:Alcohol Oxidoreductases / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D000449:Aldehyde Reductase; D000074408:Aldo-Keto Reductases; D017353:Gene Deletion; D015971:Gene Expression Regulation, Enzymologic; D015966:Gene Expression Regulation, Fungal; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D009154:Mutation; D010641:Phenotype; D012441:Saccharomyces cerevisiae / Q000201:enzymology* / Q000235:genetics
D000429:Alcohol Oxidoreductases; D000074408:Aldo-Keto Reductases; D000449:Aldehyde Reductase