ASH1 / YKL185W Overview

Standard Name
ASH1 1
Systematic Name
Feature Type
ORF , Verified
Component of the Rpd3L histone deacetylase complex; zinc-finger inhibitor of HO transcription; mRNA is localized and translated in the distal tip of anaphase cells, resulting in accumulation of Ash1p in daughter cell nuclei and inhibition of HO expression; potential Cdc28p substrate 1 2 3 4
Name Description
Asymmetric Synthesis of HO 1
Comparative Info
Sequence Details


The S. cerevisiae Reference Genome sequence is derived from laboratory strain S288C. Download DNA or protein sequence, view genomic context and coordinates. Click "Sequence Details" to view all sequence information for this locus, including that for other strains.

Protein Details


Basic sequence-derived (length, molecular weight, isoelectric point) and experimentally-determined (median abundance, median absolute deviation) protein information. Click "Protein Details" for further information about the protein such as half-life, abundance, domains, domains shared with other proteins, protein sequence retrieval for various strains, physico-chemical properties, protein modification sites, and external identifiers for the protein.

Length (a.a.)
Mol. Weight (Da)
Isoelectric Point
Median Abundance (molecules/cell)
889 +/- 443
Half-life (min)


Curated mutant alleles for the specified gene, listed alphabetically. Click on the allele name to open the allele page. Click "SGD search" to view all alleles in search results. Click "YeastMine" to view all alleles in YeastMine.

View all ASH1 alleles in SGD search | YeastMine

Gene Ontology Details

Gene Ontology

GO Annotations consist of four mandatory components: a gene product, a term from one of the three Gene Ontology (GO) controlled vocabularies (Molecular Function, Biological Process, and Cellular Component), a reference, and an evidence code. SGD has manually curated and high-throughput GO Annotations, both derived from the literature, as well as computational, or predicted, annotations. Click "Gene Ontology Details" to view all GO information and evidence for this locus as well as biological processes it shares with other genes.

Sequence-specific DNA binding RNA Pol II transcription factor that up and down regulates transcription; its role as transcription repressor negatively regulates mating type switching, G1/S transition of mitotic cell cycle; its role as transcription activator positively regulates pseudohyphal growth; subunit of the Rpd3L histone deacetylase complex; also localizes to the cellular bud

View computational annotations

Cellular Component

Manually Curated
Phenotype Details


Phenotype annotations for a gene are curated single mutant phenotypes that require an observable (e.g., "cell shape"), a qualifier (e.g., "abnormal"), a mutant type (e.g., null), strain background, and a reference. In addition, annotations are classified as classical genetics or high-throughput (e.g., large scale survey, systematic mutation set). Whenever possible, allele information and additional details are provided. Click "Phenotype Details" to view all phenotype annotations and evidence for this locus as well as phenotypes it shares with other genes.

Non-essential gene; null mutant shows decreased filamentous growth and increased mating type switching; overexpression leads to decreased mating type switching
Interaction Details


Interaction annotations are curated by BioGRID and include physical or genetic interactions observed between at least two genes. An interaction annotation is composed of the interaction type, name of the interactor, assay type (e.g., Two-Hybrid), annotation type (e.g., manual or high-throughput), and a reference, as well as other experimental details. Click "Interaction Details" to view all interaction annotations and evidence for this locus, including an interaction visualization.

257 total interactions for 169 unique genes

Physical Interactions

  • Affinity Capture-MS: 36
  • Affinity Capture-RNA: 27
  • Affinity Capture-Western: 2
  • Biochemical Activity: 10
  • Co-localization: 2
  • Co-purification: 2
  • Protein-peptide: 1
  • Protein-RNA: 28
  • Reconstituted Complex: 2

Genetic Interactions

  • Dosage Growth Defect: 1
  • Dosage Lethality: 1
  • Dosage Rescue: 2
  • Negative Genetic: 95
  • Phenotypic Enhancement: 10
  • Phenotypic Suppression: 8
  • Positive Genetic: 21
  • Synthetic Growth Defect: 6
  • Synthetic Rescue: 3
Regulation Details


The number of putative Regulators (genes that regulate it) and Targets (genes it regulates) for the given locus, based on experimental evidence. This evidence includes data generated through high-throughput techniques. Click "Regulation Details" to view all regulation annotations, shared GO enrichment among regulation Targets, and a regulator/target diagram for the locus.

ASH1 encodes a transcriptional repressor that is a member of the C4 or GATA class and has roles in mating type switching and cell cycle regulation. Its best characterized target is the HO (YDL227C) gene, which encodes an endonuclease involved in mating type switching. Repression by Ash1p is part of a complicated regulatory network that keeps HO expression tightly controlled, as expected for an endonuclease whose unregulated expression would be lethal. Ash1p binding to the HO promoter recruits the Rpd3L histone deacetylase complex, which associates with Ash1p during the G1 phase of the cell cycle. The resulting chromatin remodeling inhibits the binding of coactivators Swi/Snf, SAGA, and Mediator, and this effect persists even when Ash1p is no longer bound to the promoter. Ash1p also represses transcription of the G1 cyclin CLN3, regulating the length of the G1 phase. Genetic evidence shows that Ash1p is required for filamentous growth and that it positively regulates transcription of the FLO11 gene encoding a cell surface glycoprotein. However, it has not been established whether this positive regulation is a direct effect. The ASH1 mRNA is specifically transported to daughter cells, so that Ash1p is expressed and active only in daughters. Expression of Ash1p is also regulated at the levels of mRNA stability and translation.
Expression Details


Expression data are derived from records contained in the Gene Expression Omnibus (GEO), and are first log2 transformed and normalized. Referenced datasets may contain one or more condition(s), and as a result there may be a greater number of conditions than datasets represented in a single clickable histogram bar. The histogram division at 0.0 separates the down-regulated (green) conditions and datasets from those that are up-regulated (red). Click "Expression Details" to view all expression annotations and details for this locus, including a visualization of genes that share a similar expression pattern.

Summary Paragraph

A summary of the locus, written by SGD Biocurators following a thorough review of the literature. Links to gene names and curated GO terms are included within the Summary Paragraphs.

Last Updated: 2006-04-28

Literature Details


All manually curated literature for the specified gene, organized into topics according to their relevance to the gene (Primary Literature, Additional Literature, or Review). Click "Literature Details" to view all literature information for this locus, including shared literature between genes.