Identification of asymmetrically localized determinant, Ash1p, required for lineage-specific transcription of the yeast HO gene

Cell. 1996 Mar 8;84(5):711-22. doi: 10.1016/s0092-8674(00)81049-1.


S. cerevisiae cells exhibit asymmetric determination of cell fate. Cell division yields a mother cell, which is competent to transcribe the HO gene and switch mating type, and a daughter cell, which is not. We have isolated a mutant in which daughters transcribe HO and switch mating type. This mutation defines the ASH1 gene (asymmetric synthesis of HO). Deletion and overexpression of ASH1 cause reciprocal cell fate transformations: im ash1delta strains, daughters switch mating type as efficiently as mothers. Conversely, overexpression of ASH1 inhibits switching in mother cells. Ash1p has a zinc finger motif related to those of GATA transcriptional regulators. Ash1p is localized to the daughter nucleus in cells that have undergone nuclear division. Thus, Ash1p is a cell fate determinant that is asymmetrically localized to the daughter nucleus where it inhibits HO transcription.

Publication types

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

MeSH terms

  • Amino Acid Sequence
  • Cloning, Molecular
  • DNA-Binding Proteins*
  • Deoxyribonucleases, Type II Site-Specific / biosynthesis*
  • Deoxyribonucleases, Type II Site-Specific / genetics
  • Ethyl Methanesulfonate
  • Genes, Fungal*
  • Genes, Mating Type, Fungal*
  • Genotype
  • Mitosis
  • Models, Biological
  • Molecular Sequence Data
  • Mutagenesis
  • Mutagens
  • Recombinant Proteins / biosynthesis
  • Recombinant Proteins / chemistry
  • Repressor Proteins*
  • Saccharomyces cerevisiae / cytology
  • Saccharomyces cerevisiae / enzymology*
  • Saccharomyces cerevisiae / genetics*
  • Saccharomyces cerevisiae Proteins*
  • Sequence Homology, Amino Acid
  • Transcription Factors / chemistry
  • Transcription Factors / genetics*
  • Transcription Factors / metabolism*
  • Transcription, Genetic*


  • ASH1 protein, S cerevisiae
  • DNA-Binding Proteins
  • Mutagens
  • Recombinant Proteins
  • Repressor Proteins
  • Saccharomyces cerevisiae Proteins
  • Transcription Factors
  • Ethyl Methanesulfonate
  • HO protein, S cerevisiae
  • SCEI protein, S cerevisiae
  • Deoxyribonucleases, Type II Site-Specific