NADP+-dependent glutamate dehydrogenase activity is impaired in mutants of Saccharomyces cerevisiae that lack aconitase.
A mutant of Saccharomyces cerevisiae lacking aconitase did not grow on minimal medium (MM) and had five- to tenfold less NADP+-dependent glutamate dehydrogenase (GDH) activity than the wild-type, although its glutamine synthetase (GS) activity was still inducible. When this mutant was incubated with glutamate as the sole nitrogen source, the 2-oxoglutarate content rose, and the NADP+-dependent GDH activity increased. Furthermore, carbon-limited cultures showed a direct relation between NADP+-dependent GDH activity and the intracellular 2-oxoglutarate content. We propose that the low NADP+-dependent GDH activity found in the mutant was due to the lack of 2-oxoglutarate or some other intermediate of the tricarboxylic acid cycle.
González
A
A
Rodríguez
L
L
Olivera
H
H
Soberón
M
M
D000154:Aconitate Hydratase / Q000172:deficiency*; D005969:Glutamate Dehydrogenase / Q000378:metabolism*; D005974:Glutamate-Ammonia Ligase / Q000378:metabolism; D005971:Glutamates / Q000378:metabolism; D018698:Glutamic Acid; D007656:Ketoglutaric Acids / Q000378:metabolism; D009154:Mutation; D009249:NADP / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000201:enzymology*
D005971:Glutamates; D007656:Ketoglutaric Acids; D018698:Glutamic Acid; D009249:NADP; D005969:Glutamate Dehydrogenase; D000154:Aconitate Hydratase; D005974:Glutamate-Ammonia Ligase