STN1: A Key Component of the CST Telomere Maintenance Complex
Essential for telomere replication, protection, and genome stability
Gene Information Card
| Symbol | STN1 |
|---|---|
| Full Name | STN1, CST complex subunit |
| Gene Type | Protein coding |
| Chromosomal Location | 10q24.33 |
| NCBI Gene ID | 79991 ncbi.nlm.nih.gov/gene/79991 |
| Ensembl ID | ENSG00000120071 |
| UniProt ID | Q9H668 |
| OMIM ID | 613128 |
| HGNC ID | 29387 |
| Aliases | OBFC1, bA541N10.2, hStn1, MGC10731 |
Description
STN1 encodes a component of the CST (CTC1-STN1-TEN1) complex, which is essential for telomere replication and protection. The CST complex binds to single-stranded DNA at telomeres and is involved in telomere C-strand fill-in, telomere end protection, and regulation of telomerase activity. STN1 also participates in DNA replication stress response and genome-wide replication restart.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Coats plus syndrome (Cerebroretinal microangiopathy with calcifications and cysts) | Biallelic loss-of-function mutations in STN1 impair CST complex function, leading to telomere dysfunction, defective DNA repair, and microvascular abnormalities. | OMIM #612199; PMID: 27053774 |
| Dyskeratosis congenita (DC) | Heterozygous mutations in STN1 may contribute to telomere shortening and bone marrow failure, though evidence is limited. | PMID: 32000529 |
| Pulmonary fibrosis | Telomere dysfunction due to STN1 mutations has been associated with familial pulmonary fibrosis in some cases. | PMID: 32000529 |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Testis | 12.5 | Medium |
| Bone marrow | 10.2 | Medium |
| Lymph node | 9.8 | Medium |
| Spleen | 8.5 | Medium |
| Brain | 6.3 | Low |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| HEK 293 | 15.0 | High expression |
| HeLa | 12.5 | High expression |
| K562 | 10.0 | Medium expression |
| HepG2 | 8.5 | Medium expression |
| A549 | 7.0 | Low expression |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.370C>T (p.Arg124*) | Nonsense | Rare | Loss of function; associated with Coats plus syndrome |
| c.451C>T (p.Arg151Trp) | Missense | Rare | Impaired CST complex formation; associated with Coats plus syndrome |
| c.574C>T (p.Arg192*) | Nonsense | Rare | Loss of function; associated with Coats plus syndrome |
| c.1A>G (p.Met1Val) | Missense | Rare | Loss of start codon; likely loss of function |
Mutation functional classification
Loss of Function (LOF)
Biallelic loss-of-function mutations in STN1 cause Coats plus syndrome, characterized by telomere dysfunction, microvascular abnormalities, and bone marrow failure.
Gain of Function (GOF)
No gain-of-function mutations have been reported for STN1.
Dominant Negative (DN)
Heterozygous missense mutations may exert dominant-negative effects by disrupting CST complex assembly, though evidence is limited.
View complete mutation data：
Gene Ontology (GO)
| • telomere maintenance (GO:0000723) | • single-stranded DNA binding (GO:0003697) |
| • nucleus (GO:0005634) | • DNA duplex unwinding (GO:0032508) |
| • telomeric DNA binding (GO:0042162) | • DNA replication (GO:0006260) |
Pathways
• Telomere C-strand fill-in (CST complex pathway)
• Telomere end protection
• DNA replication stress response
Protein Summary
STN1 is a 368-amino acid protein that forms the CST complex with CTC1 and TEN1. It contains an OB-fold domain that binds single-stranded DNA. The CST complex is recruited to telomeres via interaction with POT1-TPP1 and facilitates telomerase-mediated telomere elongation by promoting C-strand synthesis. STN1 also functions in genome-wide replication restart by interacting with DNA polymerase alpha-primase.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| STN1 Knockout HEK293 Cell Line | EDJ-KQ15545 | Human | 79991 | Details Get a Quote |
| STN1 Knockout A-549 Cell Line | EDJ-KQ46394 | Human | 79991 | Details Get a Quote |
| STN1 Knockout HCT 116 Cell Line | EDJ-KQ46395 | Human | 79991 | Details Get a Quote |
| STN1 Knockout HeLa Cell Line | EDJ-KQ46396 | Human | 79991 | Details Get a Quote |
