CAPNS1: Calpain Small Subunit 1
Regulatory subunit of calpain proteases involved in calcium-dependent signaling and cellular processes
Gene Information Card
| Symbol | CAPNS1 |
|---|---|
| Full Name | Calpain Small Subunit 1 |
| Gene Type | Protein coding |
| Chromosomal Location | 19q13.12 |
| NCBI Gene ID | 826 ncbi.nlm.nih.gov/gene/826 |
| Ensembl ID | ENSG00000126267 |
| UniProt ID | P04632 |
| OMIM ID | 114170 |
| HGNC ID | 1481 |
| Aliases | CAPN4, CDPS, CSS1, 30K, CANP, CANPS, calpain small subunit 1 |
Description
CAPNS1 encodes the small regulatory subunit of calpain proteases, which are calcium-dependent cysteine proteases involved in various cellular processes including cell motility, cell cycle progression, apoptosis, and signal transduction. The protein forms a heterodimer with the large catalytic subunit (e.g., CAPN1 or CAPN2) and is essential for calpain stability and activity.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Spastic paraplegia 76 (SPG76) | Loss-of-function mutations in CAPNS1 impair calpain activity, leading to axonal degeneration and motor neuron dysfunction. | ClinVar, OMIM |
| Cancer (various types) | Altered CAPNS1 expression affects calpain-mediated proteolysis of tumor suppressors and adhesion molecules, promoting invasion and metastasis. | COSMIC, NCBI |
| Cardiomyopathy | Dysregulation of calpain activity due to CAPNS1 mutations contributes to cardiac remodeling and contractile dysfunction. | UniProt, ClinVar |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Brain | 12.5 | Medium |
| Heart | 8.3 | Medium |
| Liver | 6.1 | Low |
| Kidney | 10.2 | Medium |
| Lung | 7.4 | Medium |
| Skeletal muscle | 15.8 | High |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| HeLa | 14.2 | Cervical cancer cell line |
| HEK293 | 11.5 | Embryonic kidney cells |
| A549 | 9.8 | Lung cancer cell line |
| MCF7 | 8.6 | Breast cancer cell line |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.1A>G (p.Met1Val) | Missense | Rare | Loss of start codon, reduced protein expression |
| c.232C>T (p.Arg78Trp) | Missense | <0.01% | Impaired heterodimer formation with catalytic subunit |
| c.487G>A (p.Gly163Arg) | Missense | <0.01% | Decreased calcium sensitivity and protease activity |
Mutation functional classification
Loss of Function (LOF)
Mutations that disrupt the start codon or impair heterodimer formation lead to reduced calpain activity, associated with spastic paraplegia.
Gain of Function (GOF)
Not well characterized; some cancer-associated variants may increase calpain activity promoting invasion.
Dominant Negative (DN)
Missense mutations that produce a defective regulatory subunit can interfere with wild-type calpain function in a dominant-negative manner.
View complete mutation data：
Gene Ontology (GO)
| • calcium-dependent cysteine-type endopeptidase activity | • calpain complex |
| • proteolysis | • cell adhesion |
| • apoptotic process | • regulation of cell migration |
Pathways
• Calpain signaling pathway
• Apoptosis
• Focal adhesion
• Neurotrophin signaling
Protein Summary
CAPNS1 encodes the 30 kDa regulatory subunit of calpain proteases. This protein contains a calmodulin-like domain that binds calcium and a glycine-rich region that interacts with the catalytic subunit. It is essential for the stability, calcium sensitivity, and substrate specificity of the calpain heterodimer. The protein is ubiquitously expressed and plays key roles in cytoskeletal remodeling, cell signaling, and cell death.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| CAPNS1 Knockout HEK293 Cell Line | EDJ-KQ12723 | Human | 826 | Details Get a Quote |
| CAPNS1 Knockout A-549 Cell Line | EDJ-KQ40546 | Human | 826 | Details Get a Quote |
| CAPNS1 Knockout HCT 116 Cell Line | EDJ-KQ41812 | Human | 826 | Details Get a Quote |
| CAPNS1 Knockout HeLa Cell Line | EDJ-KQ41813 | Human | 826 | Details Get a Quote |
| CAPNS1 Knockout SK-N-SH Cell Line | EDJ-KZ128 | Human | 826 | Details Get a Quote |
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