SSN2 / YDR443C Overview


Standard Name
SSN2 1
Systematic Name
YDR443C
SGD ID
SGD:S000002851
Aliases
RYE3 , MED13 4 , NUT8 5 , SCA1 , SRB9 , UME2 , SSX5 6
Feature Type
ORF , Verified
Description
Subunit of the RNA polymerase II mediator complex; associates with core polymerase subunits to form the RNA polymerase II holoenzyme; required for stable association of Srb10p-Srb11p kinase; essential for transcriptional regulation 1 2 3
Name Description
Suppressor of SNf1 1
Comparative Info
Sequence Details

Sequence

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

Protein

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.)
1420
Mol. Weight (Da)
159965.3
Isoelectric Point
5.51
Median Abundance (molecules/cell)
1512 +/- 1107
Half-life (hr)
7.5

Alleles

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 SSN2 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.


Summary
Cyclin binding protein involved in negative and positive regulation of transcription by RNA polymerase II; subunit of mediator complex

View computational annotations

Molecular Function

Manually Curated

Cellular Component

Manually Curated

Complex

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

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.


Interaction Details

Interaction

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.


562 total interactions for 397 unique genes

Physical Interactions

  • Affinity Capture-MS: 156
  • Affinity Capture-RNA: 6
  • Affinity Capture-Western: 15
  • Biochemical Activity: 4
  • Co-localization: 3
  • Co-purification: 1
  • Reconstituted Complex: 10
  • Two-hybrid: 15

Genetic Interactions

  • Dosage Rescue: 4
  • Negative Genetic: 228
  • Phenotypic Enhancement: 8
  • Phenotypic Suppression: 6
  • Positive Genetic: 59
  • Synthetic Growth Defect: 25
  • Synthetic Lethality: 12
  • Synthetic Rescue: 10
Regulation Details

Regulation

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.


Summary
SSN2 (also known as SRB9 or MED13) encodes a subunit of the CDK8 kinase module (CKM) of the Mediator transcriptional regulation complex. The Mediator complex is highly conserved from yeast to human, and is a central player in the transcriptional regulation of protein-coding genes, being required for nearly all transcription by RNA polymerase II (RNAPII). Mediator bridges activators and the general transcription machinery. The core Mediator complex contains three distinct head, middle, and tail modules. The CKM is a dissociable subcomplex that represses basal transcription. The other three subunits of the CKM are encoded by SSN3/CDK8/SRB10, SSN8/SRB11, and SSN5/MED12/SRB8. the strongest Mediator-CKM interaction involved a discrete contact through subunit Ssn2p. Formation of a Mediator-RNAPII holoenzyme is largely blocked by association of the CKM with the core Mediator complex. Interaction of the CKM with Mediator's middle module interferes with C-terminal domain (CTD)-dependent RNA polymerase II (RNAPII) binding and with the holoenzyme formation process. A combination of competitive interactions and conformational changes facilitate holoenzyme formation and underlie the mechanism of transcription regulation by Mediator. Obstruction of CTD-dependent RNAPII interaction with the middle module explains the repressive effect of the CKM on transcription.
Regulators
6
Targets
27
Expression Details

Expression

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.


Literature Details

Literature

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.


Primary
45
Additional
50
Reviews
44

Resources