SIR4 / YDR227W Overview
- Standard Name
- SIR4 1
- Systematic Name
- YDR227W
- SGD ID
- SGD:S000002635
- Aliases
- ASD1 , STE9 , UTH2
- Feature Type
- ORF , Verified
- Description
- SIR protein involved in assembly of silent chromatin domains; silent information regulator (SIR) along with SIR2 and SIR3; involved in assembly of silent chromatin domains at telomeres and the silent mating-type loci; some SIR4 alleles prolong lifespan; required for Ku-mediated telomerase recruitment, telomere lengthening, and telomere hypercluster formation in quiescent yeast cells 2 3 4 5 6
- Name Description
- Silent Information Regulator 1
- Comparative Info
-
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.
Analyze Sequence
S288C only
BLASTN | BLASTP | Design Primers | Restriction Fragment Map | Restriction Fragment Sizes | Six-Frame Translation
S288C vs. other species
BLASTN vs. fungi | BLASTP at NCBI | BLASTP vs. fungi
S288C vs. other strains
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.)
- 1358
- Mol. Weight (Da)
- 152084.6
- Isoelectric Point
- 9.63
- Median Abundance (molecules/cell)
- 1446 +/- 381
- Half-life (hr)
- 4.4
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.
View all SIR4 alleles in SGD search
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
- Subunit of the chromatin silencing complex that binds to double-stranded DNA and nucleosomes; involved in chromatin silencing and tethering telomeres at the nuclear periphery; localizes to the telomeric region of nuclear chromosomes and to nuclear telomeric heterochromatin
View computational annotations
Molecular Function
- Manually Curated
- enables double-stranded DNA binding (IDA, IMP)
- enables molecular adaptor activity (IMP)
- enables nucleosome binding (IDA)
Biological Process
- Manually Curated
- involved in double-strand break repair via nonhomologous end joining (IMP)
- involved in establishment of protein-containing complex localization to telomere (IMP)
- involved in positive regulation of heterochromatin formation (IMP)
- involved in silent mating-type cassette heterochromatin formation (IMP, IGI)
- involved in subtelomeric heterochromatin formation (IMP)
- involved in telomere tethering at nuclear periphery (IMP)
Cellular Component
- Manually Curated
- part of chromatin silencing complex (IDA)
- located in chromosome, telomeric region (IDA, IMP)
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
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.
- Summary
- Non-essential gene; null mutant has reduced replicative lifespan, while the gain-of-function mutant has increased lifespan, but the lifespan of the homozygous diploid null is unchanged; reduction-of-function mutant displays decreased silencing at the silent mating type cassettes, HMR and HML, and overexpression decreases silencing at HMR, HML and telomeres; null mutant has decreased filamentous growth and is unable to undergo invasive growth; null mutant has an increased rate of chromosome loss, and both null and overexpressor have decreased telomere length; null mutant does not respond to alpha factor and conditional mutant is sterile, unable to shmoo or arrest the cell cycle in the presence of pheromone and produces very low levels of mating pheromone; conditional mutant has a bipolar budding pattern like diploids
Classical Genetics
- conditional
- null
- chromosome/plasmid maintenance: decreased
- lipid particle morphology: abnormal
- mating response: absent
- replicative lifespan: decreased
- replicative lifespan: normal
- resistance to chemicals: decreased
- resistance to chemicals: increased
- RNA accumulation: decreased
- RNA accumulation: increased
- silencing: decreased
- silencing: increased
- telomere length: decreased
- toxin resistance: increased
- overexpression
- gain of function
- activation
- null
- chemical compound accumulation: abnormal
- chemical compound accumulation: increased
- filamentous growth: decreased
- heat sensitivity: decreased
- invasive growth: absent
- killer toxin resistance: increased
- liquid culture appearance: abnormal
- mating response: absent
- oxidative stress resistance: decreased
- protein transport: abnormal
- replicative lifespan: decreased
- resistance to chemicals: decreased
- resistance to chemicals: increased
- respiratory growth: absent
- sporulation: abnormal
- stress resistance: decreased
- telomere length: decreased
- viable
- overexpression
Large-scale Survey
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.
339 total interactions for 147 unique genes
Physical Interactions
- Affinity Capture-MS: 38
- Affinity Capture-RNA: 6
- Affinity Capture-Western: 60
- Biochemical Activity: 4
- Co-crystal Structure: 6
- Co-localization: 5
- Co-purification: 4
- Far Western: 1
- PCA: 1
- Proximity Label-MS: 2
- Reconstituted Complex: 35
- Two-hybrid: 69
Genetic Interactions
- Dosage Rescue: 9
- Negative Genetic: 4
- Phenotypic Enhancement: 18
- Phenotypic Suppression: 30
- Synthetic Growth Defect: 19
- Synthetic Rescue: 28
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.
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.
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: 1999-09-01
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.