STAG1 Gene - Cohesin Complex Subunit SA1
STAG1: A Key Regulator of Sister Chromatid Cohesion and Genomic Stability
Gene Information Card
| Symbol | STAG1 |
|---|---|
| Full Name | Stromal Antigen 1 |
| Gene Type | Protein coding |
| Chromosomal Location | 3q22.3 |
| NCBI Gene ID | 10274 ncbi.nlm.nih.gov/gene/10274 |
| Ensembl ID | ENSG00000118007 |
| UniProt ID | Q8WVM7 |
| OMIM ID | 604358 |
| HGNC ID | 11354 |
| Aliases | SA1, SCC3A, bA517O1.1 |
Description
STAG1 encodes stromal antigen 1 (SA1), a subunit of the cohesin complex that mediates sister chromatid cohesion, DNA repair, and transcriptional regulation. SA1 binds to chromatin and facilitates the loading of cohesin onto DNA. Mutations in STAG1 are associated with developmental disorders (cohesinopathies) and various cancers.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Cornelia de Lange syndrome 5 (CDLS5) | Loss-of-function mutations in STAG1 disrupt cohesin complex function, leading to impaired chromatid cohesion and transcriptional dysregulation during development. | ClinVar; OMIM #620568 |
| Colorectal cancer | Somatic mutations and copy number alterations in STAG1 contribute to chromosomal instability and aneuploidy. | COSMIC; PMID: 23535601 |
| Breast cancer | STAG1 overexpression or mutation may alter cohesin dynamics, promoting tumorigenesis. | COSMIC; PMID: 28481328 |
| Bladder cancer | Recurrent STAG1 mutations are associated with genomic instability and poor prognosis. | COSMIC; PMID: 24880630 |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Testis | 35.2 | High |
| Bone marrow | 18.5 | Medium |
| Lymph node | 15.1 | Medium |
| Brain | 8.3 | Low |
| Liver | 6.7 | Low |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| HeLa | 22.4 | Cervical cancer cell line |
| K562 | 19.8 | Leukemia cell line |
| MCF7 | 14.2 | Breast cancer cell line |
| A549 | 11.5 | Lung cancer cell line |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.2071C>T (p.Arg691*) | Nonsense | <0.1% | Loss of function; truncation of SA1 protein |
| c.1123G>A (p.Gly375Arg) | Missense | <0.1% | Impaired cohesin loading |
| c.2450_2451del (p.Glu817Valfs*2) | Frameshift | <0.1% | Loss of function; premature termination |
| c.3650G>A (p.Arg1217Gln) | Missense | <0.1% | Unknown significance |
Mutation functional classification
Loss of Function (LOF)
Nonsense, frameshift, and splice-site mutations that reduce STAG1 protein levels or disrupt its interaction with other cohesin subunits are classified as loss-of-function.
Gain of Function (GOF)
No well-characterized gain-of-function mutations have been reported for STAG1.
Dominant Negative (DN)
Some missense mutations (e.g., p.Gly375Arg) may exert dominant-negative effects by interfering with cohesin complex assembly.
View complete mutation data：
Gene Ontology (GO)
| • sister chromatid cohesion | • chromatin binding |
| • double-strand break repair via homologous recombination | • mitotic cell cycle |
| • nucleus | • cohesin complex |
Pathways
• Cell Cycle
• Mitotic
• Homologous Recombination Repair
• Cohesin Loading onto Chromatin
Protein Summary
STAG1 (SA1) is a 1258-amino acid protein that forms part of the cohesin ring complex. It contains a stromal antigen domain and interacts with SMC1A, SMC3, and RAD21. SA1 is essential for proper chromosome segregation, DNA damage repair, and gene expression regulation. Its N-terminal region mediates chromatin association, while the C-terminal region binds RAD21.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| STAG1 Knockout HEK293 Cell Line | EDJ-KQ6987 | Human | 10274 | Details Get a Quote |
| STAG1 Knockout HeLa Cell Line | EDJ-KQ30319 | Human | 10274 | Details Get a Quote |
| STAG1 Knockout A-549 Cell Line | EDJ-KQ31699 | Human | 10274 | Details Get a Quote |
| STAG1 Knockout HCT 116 Cell Line | EDJ-KQ31700 | Human | 10274 | Details Get a Quote |
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