CLSPN: Claspin, a Key Replication Checkpoint Mediator
Essential regulator of DNA replication stress response and cell cycle checkpoint activation
Gene Information Card
| Symbol | CLSPN |
|---|---|
| Full Name | Claspin |
| Gene Type | Protein coding |
| Chromosomal Location | 1p34.3 |
| NCBI Gene ID | 63967 ncbi.nlm.nih.gov/gene/63967 |
| Ensembl ID | ENSG00000166851 |
| UniProt ID | Q9HAW4 |
| OMIM ID | 605434 |
| HGNC ID | 20971 |
| Aliases | Claspin, FLJ21908, MGC131986 |
Description
CLSPN encodes claspin, a nuclear protein that functions as a mediator of the DNA replication checkpoint. Claspin is essential for the activation of CHK1 kinase in response to replication stress, linking the ATR kinase to CHK1 phosphorylation. It is involved in the S-phase checkpoint, DNA repair, and cell cycle arrest. CLSPN expression is cell cycle-regulated, peaking in S and G2 phases.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Breast cancer | CLSPN overexpression may promote genomic instability and tumor progression by altering checkpoint signaling. | ClinVar, COSMIC |
| Colorectal cancer | Somatic mutations and altered expression of CLSPN are associated with colorectal carcinogenesis. | COSMIC, NCBI |
| Lung cancer | CLSPN amplification and overexpression observed in non-small cell lung cancer, linked to poor prognosis. | COSMIC, PubMed |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Testis | 12.5 | High |
| Bone marrow | 8.2 | Medium |
| Lymph node | 7.1 | Medium |
| Brain | 2.3 | Low |
| Liver | 1.8 | Low |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| HeLa | 15.3 | Cervical cancer cell line |
| MCF7 | 11.0 | Breast cancer cell line |
| A549 | 9.5 | Lung cancer cell line |
| HEK293 | 6.2 | Embryonic kidney cell line |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.2113C>T (p.Arg705Trp) | Missense | Rare | Unknown functional impact |
| c.2740G>A (p.Glu914Lys) | Missense | Rare | Unknown functional impact |
| c.3316_3317insA (p.Thr1106Asnfs*2) | Frameshift | Rare | Loss of function |
Mutation functional classification
Loss of Function (LOF)
Frameshift mutations (e.g., p.Thr1106Asnfs*2) are predicted to truncate the protein, impairing claspin's ability to mediate CHK1 activation.
Gain of Function (GOF)
Not well documented; overexpression in cancers may confer gain-of-function by enhancing checkpoint bypass.
Dominant Negative (DN)
No confirmed dominant-negative mutations reported in CLSPN.
View complete mutation data：
Gene Ontology (GO)
| • nucleus (GO:0005634) | • nucleoplasm (GO:0005654) |
| • protein binding (GO:0005515) | • DNA damage response (GO:0006974) |
| • G2 DNA damage checkpoint (GO:0031572) | • meiotic cell cycle (GO:0030893) |
| • DNA replication (GO:0006260) |
Pathways
• Cell cycle - G2/M DNA damage checkpoint (Reactome: R-HSA-69481)
• ATR signaling pathway (Reactome: R-HSA-69478)
• DNA replication stress response (KEGG: hsa04110)
Protein Summary
Claspin is a 1339-amino acid protein with a molecular weight of approximately 150 kDa. It contains a conserved claspin domain and multiple phosphorylation sites. Claspin acts as a scaffold that recruits CHK1 to ATR at sites of replication stress, facilitating CHK1 activation. It is degraded via the ubiquitin-proteasome pathway after DNA repair is complete. Claspin also interacts with BRCA1, RAD17, and other DNA repair proteins.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| CLSPN Knockout HEK293 Cell Line | EDJ-KQ51612 | Human | 63967 | Details Get a Quote |
| CLSPN Knockout HeLa Cell Line | EDJ-KQ57005 | Human | 63967 | Details Get a Quote |
| CLSPN Knockout A-549 Cell Line | EDJ-KQ65510 | Human | 63967 | Details Get a Quote |
| CLSPN Knockout HCT 116 Cell Line | EDJ-KQ73947 | Human | 63967 | Details Get a Quote |
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