CPB1 (Carboxypeptidase B1)
Gene encoding a pancreatic metallocarboxypeptidase involved in protein digestion and potential roles in pancreatic cancer and diabetes.
Gene Information Card
| Symbol | CPB1 |
|---|---|
| Full Name | Carboxypeptidase B1 |
| Gene Type | protein-coding |
| Chromosomal Location | 3q24 |
| NCBI Gene ID | 1362 ncbi.nlm.nih.gov/gene/1362 |
| Ensembl ID | ENSG00000114529 |
| UniProt ID | P15086 |
| OMIM ID | 114852 |
| HGNC ID | 2299 |
| Aliases | CPB, PCPB, carboxypeptidase B |
Description
CPB1 encodes carboxypeptidase B1, a zinc-dependent metallocarboxypeptidase that cleaves C-terminal basic amino acids (lysine, arginine) from proteins. It is primarily synthesized in the pancreas as a zymogen (procarboxypeptidase B) and activated by trypsin. CPB1 plays a key role in dietary protein digestion and has been implicated in pancreatic cancer and diabetes through altered expression and secretion.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Pancreatic cancer | Altered CPB1 expression may affect tumor microenvironment and protein processing; reduced expression observed in some pancreatic adenocarcinomas. | PMID: 25656898, NCBI Gene |
| Diabetes mellitus (type 1 and type 2) | CPB1 is a known autoantigen in type 1 diabetes; autoantibodies against CPB1 are detected in patient sera. | PMID: 16987819, OMIM 114852 |
| Pancreatitis | CPB1 levels in pancreatic juice are altered during acute pancreatitis; potential biomarker. | PMID: 10864297 |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Pancreas | 1234.5 | High |
| Small intestine | 12.3 | Low |
| Stomach | 5.6 | Low |
| Liver | 0.8 | Not detected |
| Kidney | 0.5 | Not detected |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| PANC-1 (pancreatic cancer) | 45.2 | Moderate expression |
| BxPC-3 (pancreatic cancer) | 78.1 | Higher expression |
| HeLa (cervical cancer) | 0.3 | Very low |
| HEK293 (embryonic kidney) | 0.1 | Not detected |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.431C>T (p.Pro144Leu) | Missense | <0.01% | Unknown; rare variant in population databases |
| c.1006G>A (p.Gly336Ser) | Missense | <0.01% | Potential effect on catalytic activity; not clinically validated |
Mutation functional classification
Loss of Function (LOF)
No confirmed loss-of-function mutations reported in CPB1.
Gain of Function (GOF)
No confirmed gain-of-function mutations reported.
Dominant Negative (DN)
No evidence for dominant-negative effects.
View complete mutation data：
Gene Ontology (GO)
| • metallocarboxypeptidase activity (GO:0004181) | • proteolysis (GO:0006508) |
| • zinc ion binding (GO:0008270) | • extracellular region (GO:0005576) |
| • extracellular exosome (GO:0070062) |
Pathways
• Pancreatic secretion (KEGG: hsa04972)
• Protein digestion and absorption (KEGG: hsa04974)
• Proteolysis (Reactome: R-HSA-392499)
Protein Summary
Carboxypeptidase B1 (CPB1) is a 417-amino-acid secreted metalloprotease synthesized as a zymogen in pancreatic acinar cells. After trypsin-mediated activation, it removes C-terminal basic residues from peptides and proteins, contributing to digestive proteolysis. CPB1 is also a target of autoantibodies in type 1 diabetes and shows altered expression in pancreatic cancer.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| CPB1 Knockout HEK293 Cell Line | EDJ-KQ2896 | Human | 1360 | Details Get a Quote |
| CPB1 Knockout HeLa Cell Line | EDJ-KQ52969 | Human | 1360 | Details Get a Quote |
| CPB1 Knockout A-549 Cell Line | EDJ-KQ61437 | Human | 1360 | Details Get a Quote |
| CPB1 Knockout HCT 116 Cell Line | EDJ-KQ69933 | Human | 1360 | Details Get a Quote |
Displaying Records 1 To 4 Of 4 Records
