Positive control of yeast meiotic genes by the negative regulator UME6

Mol Cell Biol. 1995 Jun;15(6):2955-61. doi: 10.1128/mcb.15.6.2955.


The yeast meiotic activator IME1 stimulates transcription of many early meiotic genes. These genes share a 5' sequence called URS1. URS1 sites function as repression sites in cells that lack IME1; we show here that URS1 sites are weak activation sequences in cells that express IME1. Repression through URS1 sites is known to depend upon the URS1-binding protein UME6. We have identified a UME6 allele (previously called rim16-12) that causes a defect in IME1-dependent activation of meiotic genes but not in repression through URS1 sites. In contrast, a ume6 null mutation causes defects in both IME1-dependent activation and in repression through URS1 sites. A LexA-UME6 fusion protein is an IME1-dependent transcriptional activator, whereas a LexA-UME6 fusion carrying the rim16-12 substitution cannot activate transcription. These findings argue that IME1 activates meiotic genes by converting UME6 from a negative regulator to a positive regulator; the rim16-12 mutant protein is defective in conversion to a positive regulator.

Publication types

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

MeSH terms

  • Alleles
  • Base Sequence
  • DNA-Binding Proteins / genetics
  • DNA-Binding Proteins / metabolism*
  • Fungal Proteins / genetics
  • Fungal Proteins / metabolism*
  • Gene Expression Regulation, Fungal
  • Meiosis / genetics*
  • Molecular Sequence Data
  • Mutation
  • Nuclear Proteins / genetics
  • Nuclear Proteins / metabolism*
  • Plasmids
  • Repressor Proteins*
  • Saccharomyces cerevisiae / genetics
  • Saccharomyces cerevisiae / metabolism
  • Saccharomyces cerevisiae Proteins*
  • Transcription Factors / genetics
  • Transcription Factors / metabolism*


  • DNA-Binding Proteins
  • Fungal Proteins
  • IME1 protein, S cerevisiae
  • Nuclear Proteins
  • Repressor Proteins
  • Saccharomyces cerevisiae Proteins
  • Transcription Factors
  • UME6 protein, S cerevisiae