Glycogen metabolism in a Saccharomyces cerevisiae phosphoglucose isomerase (pgil) disruption mutant

FEBS Lett. 1992 Sep 28;310(2):182-6. doi: 10.1016/0014-5793(92)81325-g.


Disruption of the gene pgil of Saccharomyces cerevisiae, which codes for phosphoglucose isomerase, results in a dramatic increase in the amount of intracellular glycogen in early exponential cultures. The level of glucose 6-phosphate was much higher in mutant than in wild-type cells. Phosphorylase a activity and the state of activation of glycogen synthase were also investigated. Phosphorylase a activity was rather low along the culture in wild-type cells, whereas it was consistently higher in mutants. Glycogen synthase was mostly in the active form in early-medium exponential cultures in wild-type cells whereas the activation state of this enzyme in mutant cells, although lower at the earlier steps of the culture, did not differ from wild-type cells at later stages. The fact that the intracellular levels of UDP-glucose are markedly increased in mutant cells suggest that the observed accumulation of glycogen results from a rise in substrate availability rather than from the activation of the enzyme responsible for the synthesis of the polysaccharide.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Enzyme Activation
  • Glucose-6-Phosphate Isomerase / genetics
  • Glucose-6-Phosphate Isomerase / metabolism*
  • Glucosephosphates / metabolism
  • Glucosyltransferases / metabolism
  • Glycogen / metabolism*
  • Glycogen Synthase / metabolism
  • Mutation*
  • Phosphorylase a / metabolism
  • Saccharomyces cerevisiae / enzymology*


  • Glucosephosphates
  • Glycogen
  • Glucosyltransferases
  • Phosphorylase a
  • Glycogen Synthase
  • N-acetylglucosaminyldiphosphoundecaprenol glucosyltransferase
  • Glucose-6-Phosphate Isomerase