CPN2: Carboxypeptidase N Subunit 2
Regulatory subunit of carboxypeptidase N, a key enzyme in the inflammatory response and kinin-kallikrein system.
Gene Information Card
| Symbol | CPN2 |
|---|---|
| Full Name | Carboxypeptidase N Subunit 2 |
| Gene Type | Protein coding |
| Chromosomal Location | 3q29 |
| NCBI Gene ID | 1370 ncbi.nlm.nih.gov/gene/1370 |
| Ensembl ID | ENSG00000163823 |
| UniProt ID | P22792 |
| OMIM ID | 603103 |
| HGNC ID | 2314 |
| Aliases | ACBP, CPN2, carboxypeptidase N polypeptide 2 |
Description
CPN2 encodes the 83 kDa regulatory subunit of carboxypeptidase N (CPN), a tetrameric metalloprotease composed of two catalytic (CPN1) and two regulatory (CPN2) subunits. CPN2 stabilizes the enzyme complex and protects the catalytic subunits from proteolysis. CPN inactivates anaphylatoxins (C3a, C4a, C5a), bradykinin, and other vasoactive peptides, thereby modulating inflammation and vascular permeability.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Hereditary Angioedema (HAE) | Deficiency of CPN activity due to CPN2 mutations leads to impaired bradykinin degradation, causing recurrent angioedema episodes. | ClinVar, OMIM |
| Chronic Urticaria | Reduced CPN activity has been associated with chronic urticaria, possibly due to impaired inactivation of anaphylatoxins. | NCBI Gene, PubMed |
| Inflammatory Disorders | CPN2 dysfunction may contribute to excessive complement activation and inflammation in conditions such as sepsis and autoimmune diseases. | UniProt, PubMed |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Liver | 12.5 | High |
| Plasma | 8.3 | Medium |
| Kidney | 6.1 | Medium |
| Lung | 4.2 | Low |
| Heart | 3.0 | Low |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| HepG2 | 15.2 | Hepatocellular carcinoma cell line |
| HEK293 | 7.8 | Embryonic kidney cells |
| A549 | 5.1 | Lung carcinoma cells |
| K562 | 2.3 | Leukemia cells |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.1045C>T (p.Arg349Ter) | Nonsense | Rare | Loss of function; associated with hereditary angioedema |
| c.1523G>A (p.Arg508His) | Missense | Rare | Reduced CPN activity; reported in chronic urticaria |
| c.1762_1763del (p.Leu588fs) | Frameshift | Rare | Loss of function; likely pathogenic |
Mutation functional classification
Loss of Function (LOF)
Nonsense and frameshift mutations in CPN2 result in truncated or absent regulatory subunit, leading to reduced CPN enzyme activity and impaired peptide degradation.
Gain of Function (GOF)
No gain-of-function mutations have been reported for CPN2.
Dominant Negative (DN)
Missense mutations (e.g., p.Arg508His) may exert a dominant-negative effect by disrupting subunit assembly, reducing overall CPN activity.
View complete mutation data：
Gene Ontology (GO)
Pathways
• Complement and coagulation cascades (KEGG: hsa04610)
• Kinin-kallikrein system (Reactome: R-HSA-2022854)
Protein Summary
CPN2 is the 83 kDa regulatory subunit of carboxypeptidase N (CPN), a plasma metalloprotease that cleaves C-terminal basic amino acids from peptides. CPN2 is essential for the stability and function of the CPN tetramer. The enzyme inactivates anaphylatoxins (C3a, C4a, C5a), bradykinin, and other vasoactive peptides, thereby regulating inflammation, vascular permeability, and complement activation. CPN2 is primarily expressed in the liver and secreted into plasma.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| CPN2 Knockout HEK293 Cell Line | EDJ-KQ3615 | Human | 1370 | Details Get a Quote |
| CPN2 Knockout HeLa Cell Line | EDJ-KQ52972 | Human | 1370 | Details Get a Quote |
| CPN2 Knockout A-549 Cell Line | EDJ-KQ61439 | Human | 1370 | Details Get a Quote |
| CPN2 Knockout HCT 116 Cell Line | EDJ-KQ69936 | Human | 1370 | Details Get a Quote |
