Molecular mechanism of heme signaling in yeast: the transcriptional activator Hap1 serves as the key mediator

Cell Mol Life Sci. 1999 Oct 30;56(5-6):415-26. doi: 10.1007/s000180050442.


Heme is a key molecule in mediating the effects of oxygen on various molecular and cellular processes in many living organisms. In the yeast Saccharomyces cerevisiae, heme serves as a secondary signal for oxygen; intracellular heme synthesis directly correlates with oxygen tension in the environment. In yeast, oxygen sensing and heme signaling are primarily mediated by the heme activator protein Hap1, which, in response to heme, activates the transcription of genes required for respiration and for controlling oxidative damage. Heme regulation of many genes required for anaerobic growth is mediated by the aerobic repressor Rox1, whose expression is controlled by heme. In this review, we summarize recent knowledge about (i) how heme synthesis may be controlled by oxygen tension, (ii) how heme precisely and stringently controls Hap1 activity and (iii) whether other transcriptional activators can also mediate heme action.

Publication types

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

MeSH terms

  • Anaerobiosis
  • DNA-Binding Proteins / metabolism
  • Fungal Proteins / metabolism*
  • Gene Expression Regulation, Fungal / drug effects*
  • Heme / biosynthesis
  • Heme / chemistry
  • Heme / pharmacology*
  • Macromolecular Substances
  • Models, Biological
  • Molecular Chaperones / metabolism
  • Oxygen / pharmacology*
  • Repressor Proteins / metabolism
  • Saccharomyces cerevisiae Proteins*
  • Signal Transduction / drug effects*
  • Trans-Activators / metabolism*
  • Transcription Factors
  • Yeasts / drug effects*
  • Yeasts / genetics
  • Yeasts / metabolism


  • DNA-Binding Proteins
  • Fungal Proteins
  • HAP1 protein, S cerevisiae
  • Macromolecular Substances
  • Molecular Chaperones
  • ROX1 protein, S cerevisiae
  • Repressor Proteins
  • Saccharomyces cerevisiae Proteins
  • Trans-Activators
  • Transcription Factors
  • Heme
  • Oxygen