13C NMR analysis of a developmental pathway mutation in Saccharomyces cerevisiae reveals a cell derepressed for succinate dehydrogenase.
13C nuclear magnetic resonance (NMR) spectroscopy was used to study the metabolism of [2-13C]acetate in a diploid strain of Saccharomyces cerevisiae homozygous for the spo50 mutation. This mutation results in failure to initiate sporulation and suppresses spd mutations (which cause derepressed sporulation). By analysing the pattern of 13C-labelling in glutamate it was deduced that the glyoxylate cycle is responsible for most of the acetate utilization and that there is very little tricarboxylic acid cycle activity. The labelling of alpha,alpha'-trehalose indicated that gluconeogenesis and the hexose monophosphate pathway operate in a similar way to the wild-type. The mutant strain has higher levels of succinate dehydrogenase than the wild-type. All of the physiological alterations caused by the spo50 mutation can be explained by this difference.
Dickinson
J R
JR
School of Pure and Applied Biology, University of Wales College of Cardiff, UK.
Hewlins
M J
MJ
D000085:Acetates / Q000378:metabolism; D019342:Acetic Acid; D002952:Citric Acid Cycle / Q000235:genetics; D005943:Gluconeogenesis / Q000235:genetics; D005971:Glutamates / Q000378:metabolism; D018698:Glutamic Acid; D006038:Glyoxylates / Q000378:metabolism; D009682:Magnetic Resonance Spectroscopy; D009154:Mutation; D012441:Saccharomyces cerevisiae / Q000235:genetics* / Q000502:physiology; D013172:Spores, Fungal / Q000235:genetics / Q000502:physiology; D013385:Succinate Dehydrogenase / Q000235:genetics / Q000378:metabolism
D000085:Acetates; D005971:Glutamates; D006038:Glyoxylates; D018698:Glutamic Acid; D013385:Succinate Dehydrogenase; C031150:glyoxylic acid; D019342:Acetic Acid