Mga2p is a putative sensor for low temperature and oxygen to induce OLE1 transcription in Saccharomyces cerevisiae

Biochem Biophys Res Commun. 2002 Mar 1;291(3):707-13. doi: 10.1006/bbrc.2002.6507.


Various low-temperature-inducible genes such as fatty acid desaturase genes are essential for all living organisms to acclimate to low temperature. However, a low-temperature signal transduction pathway has not been identified in eukaryotes. In yeast Saccharomyces cerevisiae, the Delta9 fatty acid desaturase gene OLE1 is activated by ubiquitin/proteasome-dependent processing of two homologous endoplasmic reticulum membrane proteins, Spt23p and Mga2p. We found that OLE1 transcription was transiently activated with resultant increases in the degree of unsaturation of total fatty acids when culture temperature was downshifted from 30 degrees C to 10 degrees C. This activation was greatly depressed in Deltamga2 cells. Although Mga2p is essential for hypoxic activation of OLE1 transcription, and its hypoxic functions are repressed by unsaturated fatty acids (UFAs), low-temperature activation of the OLE1 gene was not repressed by UFAs. These observations suggest that low-temperature and hypoxic signal transduction pathways share some components, and Mga2p is the first identified eukaryotic sensor for low temperature and oxygen.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cell Hypoxia
  • Cold Temperature
  • Fatty Acid Desaturases / biosynthesis*
  • Fatty Acid Desaturases / genetics
  • Fungal Proteins / genetics
  • Fungal Proteins / physiology*
  • Gene Expression Regulation, Fungal*
  • Kinetics
  • Membrane Proteins
  • Models, Genetic
  • Mutation
  • RNA, Fungal / biosynthesis
  • Saccharomyces cerevisiae / genetics*
  • Saccharomyces cerevisiae / metabolism
  • Saccharomyces cerevisiae Proteins*
  • Signal Transduction
  • Stearoyl-CoA Desaturase
  • Trans-Activators*
  • Transcription Factors
  • Transcriptional Activation*


  • Fungal Proteins
  • Membrane Proteins
  • RNA, Fungal
  • SPT23 protein, S cerevisiae
  • Saccharomyces cerevisiae Proteins
  • Trans-Activators
  • Transcription Factors
  • Fatty Acid Desaturases
  • Stearoyl-CoA Desaturase
  • delta-9 fatty acid desaturase