CPN1 Gene: Carboxypeptidase N Subunit 1
Key regulator of inflammatory peptide processing and complement system modulation
Gene Information Card
| Symbol | CPN1 |
|---|---|
| Full Name | Carboxypeptidase N Subunit 1 |
| Gene Type | protein-coding |
| Chromosomal Location | 10q24.2 |
| NCBI Gene ID | 1369 ncbi.nlm.nih.gov/gene/1369 |
| Ensembl ID | ENSG00000120054 |
| UniProt ID | P15169 |
| OMIM ID | 603103 |
| HGNC ID | 2312 |
| Aliases | CPN, SCPN, carboxypeptidase N small subunit |
Description
The CPN1 gene encodes the small subunit of carboxypeptidase N (CPN), a zinc-dependent metalloprotease that cleaves C-terminal basic amino acids (arginine or lysine) from peptides and proteins. CPN is a key enzyme in the inactivation of anaphylatoxins (C3a, C4a, C5a), bradykinin, and other inflammatory mediators, thereby regulating complement activation and vascular permeability. The enzyme circulates in plasma as a tetramer composed of two catalytic CPN1 subunits and two regulatory CPN2 subunits.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Angioedema (hereditary or acquired) | Deficiency or dysfunction of CPN leads to impaired inactivation of bradykinin and anaphylatoxins, resulting in increased vascular permeability and edema. | ClinVar, OMIM |
| Complement-mediated inflammatory disorders | Reduced CPN activity may prolong the half-life of anaphylatoxins, contributing to excessive complement activation and tissue inflammation. | NCBI Gene, PubMed |
| Sepsis and systemic inflammation | Altered CPN levels or activity may affect the clearance of inflammatory peptides, influencing disease severity. | PubMed |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Liver | 12.5 | Medium |
| Kidney | 8.3 | Medium |
| Lung | 5.1 | Low |
| Heart | 3.2 | Low |
| Brain | 1.0 | Not detected |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| HepG2 (liver) | 15.0 | Hepatocyte-derived cell line |
| HEK293 (embryonic kidney) | 6.5 | Commonly used for recombinant expression |
| A549 (lung) | 4.2 | Lung carcinoma cell line |
| K562 (leukemia) | 1.8 | Low expression |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.112G>A (p.Gly38Arg) | Missense | Rare | Reduced catalytic activity; associated with angioedema |
| c.421C>T (p.Arg141Trp) | Missense | Rare | Impaired substrate binding; potential loss of function |
| c.1A>G (p.Met1Val) | Start loss | Very rare | Complete loss of protein expression |
Mutation functional classification
Loss of Function (LOF)
Missense mutations (e.g., p.Gly38Arg, p.Arg141Trp) reduce or abolish enzymatic activity, leading to impaired peptide inactivation and increased susceptibility to angioedema.
Gain of Function (GOF)
No gain-of-function mutations have been reported for CPN1.
Dominant Negative (DN)
No dominant-negative mutations have been described; CPN1 deficiency is typically recessive or haploinsufficient.
View complete mutation data：
Gene Ontology (GO)
Pathways
• Complement cascade (Reactome: R-HSA-166658)
• Bradykinin/kallikrein pathway (Reactome: R-HSA-166662)
• Peptide hormone metabolism (Reactome: R-HSA-422356)
Protein Summary
Carboxypeptidase N (CPN) is a plasma metalloprotease composed of two catalytic CPN1 subunits and two regulatory CPN2 subunits. The CPN1 subunit contains the active site with a zinc-binding motif (HEXXH) and cleaves C-terminal basic residues from peptides such as anaphylatoxins (C3a, C5a), bradykinin, and fibrinopeptides. This activity is critical for terminating inflammatory responses and regulating vascular tone. CPN1 is primarily synthesized in the liver and secreted into the bloodstream. Mutations in CPN1 can lead to reduced enzymatic activity, contributing to angioedema and complement dysregulation.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| CPN1 Knockout HEK293 Cell Line | EDJ-KQ4334 | Human | 1369 | Details Get a Quote |
| CPN1 Knockout A-549 Cell Line | EDJ-KQ26833 | Human | 1369 | Details Get a Quote |
| CPN1 Knockout HeLa Cell Line | EDJ-KQ52971 | Human | 1369 | Details Get a Quote |
| CPN1 Knockout HCT 116 Cell Line | EDJ-KQ69935 | Human | 1369 | Details Get a Quote |
Displaying Records 1 To 4 Of 4 Records
