HAA1 / YPR008W Overview

Standard Name
HAA1 1
Systematic Name
Feature Type
ORF , Verified
Transcriptional activator involved in adaptation to weak acid stress; activates transcription of TPO2, YRO2, and other genes encoding membrane stress proteins; HAA1 has a paralog, CUP2, that arose from the whole genome duplication; relocalizes from cytoplasm to nucleus upon DNA replication stress 1 2 3 4 5
Name Description
Homolog of Ace1 Activator 1
CUP2 4
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.

HAA1 is located on the right arm of chromosome XVI very near the centromere between tRNA-Gly and SUT2 Zn2Cys6 family transcription factor; coding sequence is 2085 nucleotides long with 20 SNPs, 11 of which cause amino acid polymorphisms; HAA1 has paralog CUP2 that arose from the whole genome duplication
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.

Haa1p is 694 amino acids long, shorter lived, low in abundance; contains a copper fist DNA-binding domain; middle of protein is asparagine-rich; phosphorylated on 44 residues
Length (a.a.)
Mol. Weight (Da)
Isoelectric Point
Median Abundance (molecules/cell)
1845 +/- 692
Half-life (hr)


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.

View all HAA1 alleles in SGD search

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 polymerase II transcription factor involved in positive regulation of transcription by RNA polymerase II in response to stress and acidic pH; localizes to cytoplasm and nucleus

View computational annotations

Molecular Function

Manually Curated

Biological Process

Manually Curated

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 resistance to weak acids, decreased heat sensitivity; overexpression slows growth, exacerbates toxicity of UV, metals, hydroxyurea, paraquat, and fluconazole
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.

Haa1p interacts physically with proteins involved in transcription and RNA catabolism; HAA1 interacts genetically with genes involved in transcription; the haa1 null mutant is viable, the null mutant of paralog cup2 is viable, the haa1 cup2 double mutant has not been annotated for phenotype

111 total interactions for 102 unique genes

Physical Interactions

  • Affinity Capture-MS: 45
  • Affinity Capture-RNA: 10
  • Proximity Label-MS: 1
  • Two-hybrid: 4

Genetic Interactions

  • Dosage Rescue: 1
  • Negative Genetic: 29
  • Phenotypic Enhancement: 4
  • Phenotypic Suppression: 6
  • Positive Genetic: 10
  • Synthetic Growth Defect: 1
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.

HAA1 encodes a transcription factor with similarity to the paralogous Cup2p, which is a member of the copper fist family. However, Haa1p is not known to bind copper or to have a role in copper metabolism. The major role of Haa1p is in regulation of genes involved in the response to acetic acid stress. In response to acetic or propionic acid, Haa1p activates transcription of genes involved in keeping acetate out of the cell or exporting it from the cell, such as YGP1, TPO2, TPO3, and HRK1. Consistent with this, Haa1p overexpression causes decreased intracellular levels of acetic acid and protects against acetic acid stress. Another target of Haa1p is SAP30, which encodes a subunit of the Rpd3L histone deacetylase complex.
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: 2024-06-25

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.