Physiological role of yeasts NAD(P)+ and NADP+-linked aldehyde dehydrogenases.
The activity of NAD+ and NADP+-linked aldehyde dehydrogenases has been investigated in yeast cells grown under different conditions. As occurs in other dehydrogenase reactions the NAD(P)+-linked enzyme was strongly repressed in all hypoxic conditions; nervetheless, the NADP+-linked enzyme was active. The results suggest that the NAD(P)+ aldehyde dehydrogenase is involved in the oxidation of ethanol to acetyl-CoA, and that when the pyruvate dehydrogenase complex is repressed the NADP+-linked aldehyde dehydrogenase is operative as an alternative pathway from pyruvate to acetyl-CoA: pyruvate leads to acetaldehyde leads to acetate leads to acetyl-Coa. In these conditions the supply of NADPH is advantageous to the cellular economy for biosynthetic purposes. Short term adaptation experiments suggest that the regulation of the levels of the aldehyde dehydrogenase-NAD(P)+ takes place by the de novo synthesis of the enzyme.
D000445:Aldehyde Oxidoreductases / Q000378:metabolism; D001681:Biological Assay; D009243:NAD / Q000378:metabolism*; D009249:NADP / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000201:enzymology* / Q000378:metabolism
D009243:NAD; D009249:NADP; D000445:Aldehyde Oxidoreductases