Control of Saccharomyces cerevisiae carboxypeptidase S (CPS1) gene expression under nutrient limitation

Yeast. 1993 Apr;9(4):339-49. doi: 10.1002/yea.320090404.

Abstract

Expression of the vacuolar carboxypeptidase S (CPS1) gene in Saccharomyces cerevisiae is regulated by the availability of nutrients. Enzyme production is sensitive to nitrogen catabolite repression; i.e. the presence of ammonium ions maintains expression of the gene at a low level. Transfer of ammonium-glucose pre-grown cells to a medium deprived of nitrogen causes a drastic increase in CPS1 RNA level provided that a readily usable carbon source, such as glucose or fructose, is available to the cells. Derepression of the gene by nitrogen limitation is cycloheximide-insensitive. Neither glycerol, ethanol, acetate nor galactose support derepression of CPS1 expression under nitrogen starvation conditions. Non-metabolizable sugar analogs (2-deoxyglucose, 6-methyl-glucose or glucosamine) do not allow derepression of CPS1, showing that the process is energy-dependent. Production of carboxypeptidase yscS also increases several-fold when ammonium-pregrown cells are transferred to media containing glucose and a non-readily metabolizable nitrogen source such as proline, leucine, valine or leucyl-glycine. Analysis of CPS1 expression in RAS2+ (high cAMP) and ras2 mutant (low cAMP) strains and in cells grown at low temperature (23 degrees C) and in heat-shocked cells (38 degrees C) shows that steady-state levels of CPS1 mRNA are not controlled by a low cAMP level-signalling pathway.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenylyl Cyclases / metabolism
  • Carbon / metabolism
  • Carboxypeptidases / biosynthesis*
  • Energy Metabolism
  • Enzyme Repression
  • Fungal Proteins / metabolism
  • Gene Expression Regulation, Enzymologic*
  • Gene Expression Regulation, Fungal*
  • Monosaccharides / metabolism
  • Nitrogen / metabolism
  • RNA, Messenger / analysis
  • Saccharomyces cerevisiae / enzymology
  • Saccharomyces cerevisiae / genetics*
  • Saccharomyces cerevisiae Proteins*
  • Vacuoles / enzymology
  • ras Proteins*

Substances

  • Fungal Proteins
  • Monosaccharides
  • RNA, Messenger
  • Saccharomyces cerevisiae Proteins
  • Carbon
  • Carboxypeptidases
  • CPS1 protein, S cerevisiae
  • RAS2 protein, S cerevisiae
  • ras Proteins
  • Adenylyl Cyclases
  • Nitrogen