SSA1 / YAL005C Overview

Standard Name
SSA1 1
Systematic Name
YG100 35
Feature Type
ORF , Verified
ATPase involved in protein folding and NLS-directed nuclear transport; HSP70 family member; required for ubiquitin-dependent degradation of short-lived proteins; forms a chaperone complex with Ydj1p; localizes to the nucleus, cytoplasm and cell wall; unique functional specificity in the propagation of yeast [URE3] prions and vacuolar-mediated degradation of gluconeogenic enzymes; general targeting factor of Hsp104p to prion fibrils; 98% identity with paralog Ssa2p 2 3 4 5 6 7 8 9
Name Description
Stress-Seventy subfamily A 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.

SSA1 is located on the left arm of chromosome I between TRN1 tRNA-Pro and EFB1 translation elongation factor 1 beta; coding sequence is 1929 nucleotides long with 70 nonsynonymous SNPs, 31 synonymous SNPs
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.

Ssa1p is 642 amino acids long, long-lived and highly abundant; contains nine 70kDa heat shock protein signature domains; acetylated on 4 lysines, succinylated on 4 lysines, phosphorylated on 34 residues, sumoylated on 4 lysines, ubiquitinylated on 22 lysines
Length (a.a.)
Mol. Weight (Da)
Isoelectric Point
Median Abundance (molecules/cell)
255901 +/- 159925
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 SSA1 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.

ATPase involved in protein folding, nuclear import, stress granule disassembly, and clathrin coat disassembly; localizes to many places in the cell, including the cell wall, vacuolar and plasma membranes, and the nucleus

View computational annotations

Molecular Function

Manually Curated

Cellular Component

Manually Curated


Macromolecular complex annotations are imported from the Complex Portal. These annotations have been derived from physical molecular interaction evidence extracted from the literature and cross-referenced in the entry, or by curator inference from information on homologs in closely related species or by inference from scientific background.

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; both null and dominant negative mutants have an increased accumulation of prions; overexpression results in larger aggregates in fewer numbers; heterozygous diploid mutant had decreased fitness
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.

Ssa1p interacts physically with proteins involved in transcription; SSA1 interacts genetically with genes involved in protein folding

1861 total interactions for 1083 unique genes

Physical Interactions

  • Affinity Capture-MS: 1480
  • Affinity Capture-RNA: 12
  • Affinity Capture-Western: 105
  • Biochemical Activity: 7
  • Co-crystal Structure: 4
  • Co-fractionation: 3
  • Co-localization: 3
  • Co-purification: 8
  • FRET: 2
  • PCA: 2
  • Protein-peptide: 2
  • Protein-RNA: 1
  • Proximity Label-MS: 4
  • Reconstituted Complex: 58
  • Two-hybrid: 10

Genetic Interactions

  • Dosage Growth Defect: 3
  • Dosage Lethality: 2
  • Dosage Rescue: 12
  • Negative Genetic: 64
  • Phenotypic Enhancement: 27
  • Phenotypic Suppression: 21
  • Positive Genetic: 7
  • Synthetic Growth Defect: 8
  • Synthetic Lethality: 10
  • Synthetic Rescue: 6
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.

SSA1 promoter is bound by Spt3p, Spt7p, Rgr1p, Srb5p, Sua7p, Tfc7p, and Ume6p in response to heat; SSA1 transcription is upregulated by Msn2p/Msn4p and Hsf1p in response to heat; SSA1 transcription is regulated by Sfp1p in response to stress
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: 2006-02-06

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.