Roles of trehalose phosphate synthase in yeast glycogen metabolism and sporulation

Mol Microbiol. 2001 Jun;40(6):1345-56. doi: 10.1046/j.1365-2958.2001.02477.x.


Trehalose is a major storage carbohydrate in budding yeast, Saccharomyces cerevisiae. Alterations in trehalose synthesis affect carbon source-dependent growth, accumulation of glycogen and sporulation. Trehalose is synthesized by trehalose phosphate synthase (TPS), which is a complex of at least four proteins. In this work, we show that the Tps1p subunit protein catalyses trehalose phosphate synthesis in the absence of other TPS components. The tps1-H223Y allele (glc6-1) that causes a semidominant decrease in glycogen accumulation exhibits greater enzyme activity than wild-type TPS1 because, unlike the wild-type enzyme, TPS activity in tps1-H223Y cells is not inhibited by phosphate. Poor sporulation in tps1 null diploids is caused by reduced expression of meiotic inducers encoded by IME1, IME2 and MCK1. Furthermore, high-copy MCK1 or heterozygous hxk2 mutations can suppress the tps1 sporulation trait. These results suggest that the trehalose-6-phosphate inhibition of hexokinase activity is required for full induction of MCK1 in sporulating yeast cells.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Fungal Proteins / genetics
  • Fungal Proteins / metabolism
  • Gene Expression Regulation, Fungal
  • Glucosyltransferases / genetics
  • Glucosyltransferases / metabolism*
  • Glutathione Transferase / genetics
  • Glutathione Transferase / metabolism
  • Glycogen / metabolism*
  • Glycogen Synthase Kinase 3
  • Hexokinase / genetics
  • Hexokinase / metabolism
  • Mutation
  • Nuclear Proteins / genetics
  • Nuclear Proteins / metabolism
  • Protein-Tyrosine Kinases / genetics
  • Protein-Tyrosine Kinases / metabolism
  • Recombinant Fusion Proteins / genetics
  • Recombinant Fusion Proteins / metabolism
  • Saccharomyces cerevisiae Proteins*
  • Spores, Fungal / physiology
  • Transcription Factors*
  • Trehalose / analogs & derivatives
  • Trehalose / biosynthesis
  • Yeasts / metabolism
  • Yeasts / physiology*


  • Fungal Proteins
  • IME1 protein, S cerevisiae
  • Nuclear Proteins
  • Recombinant Fusion Proteins
  • Saccharomyces cerevisiae Proteins
  • Transcription Factors
  • alpha,alpha-trehalose 6,6'-diphosphate
  • Glycogen
  • Trehalose
  • Glucosyltransferases
  • trehalose-6-phosphate synthase
  • Glutathione Transferase
  • Hexokinase
  • Protein-Tyrosine Kinases
  • Glycogen Synthase Kinase 3
  • MCK1 protein, S cerevisiae