PGA5 Gene - Pepsinogen A5
A key gastric aspartic protease involved in protein digestion and gastric physiology
Gene Information Card
| Symbol | PGA5 |
|---|---|
| Full Name | Pepsinogen A5 |
| Gene Type | Protein coding |
| Chromosomal Location | 11q13.1 |
| NCBI Gene ID | 5222 ncbi.nlm.nih.gov/gene/5222 |
| Ensembl ID | ENSG00000196378 |
| UniProt ID | P00790 |
| OMIM ID | 169710 |
| HGNC ID | 8888 |
| Aliases | PGA, PGA4, pepsinogen A, pepsinogen A4 |
Description
PGA5 encodes pepsinogen A5, a precursor of pepsin A, an aspartic protease secreted by gastric chief cells. Pepsinogen A5 is activated to pepsin A in the acidic gastric lumen, where it plays a critical role in the digestion of dietary proteins. The gene is part of a cluster of pepsinogen genes on chromosome 11q13.1. Expression is primarily in the stomach, and alterations in PGA5 levels have been associated with gastric disorders, including gastritis and gastric cancer.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Gastric Cancer | Altered pepsinogen A5 expression may reflect gastric mucosal atrophy and increased cancer risk. | ClinVar; COSMIC |
| Chronic Gastritis | Reduced PGA5 levels are associated with gastric atrophy and chronic inflammation. | NCBI Gene; OMIM |
| Peptic Ulcer Disease | Pepsinogen A5 activity contributes to mucosal damage in H. pylori infection. | NCBI Gene |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Stomach | 127.5 | High |
| Esophagus | 1.2 | Low |
| Duodenum | 0.8 | Low |
| Pancreas | 0.1 | Not detected |
| Liver | 0.0 | Not detected |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| MKN45 (gastric cancer) | 45.3 | Moderate expression |
| KATO III (gastric cancer) | 32.1 | Moderate expression |
| AGS (gastric adenocarcinoma) | 28.7 | Moderate expression |
| HEK293 (embryonic kidney) | 0.0 | Not detected |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.67C>T (p.Arg23Cys) | Missense | <0.01% | Unknown functional impact |
| c.214G>A (p.Gly72Ser) | Missense | <0.01% | Unknown functional impact |
| c.389A>G (p.Asn130Ser) | Missense | <0.01% | Unknown functional impact |
Mutation functional classification
Loss of Function (LOF)
No confirmed loss-of-function mutations reported in ClinVar or COSMIC.
Gain of Function (GOF)
No confirmed gain-of-function mutations reported.
Dominant Negative (DN)
No evidence of dominant-negative effects.
View complete mutation data：
Gene Ontology (GO)
| • aspartic-type endopeptidase activity (GO:0004190) | • proteolysis (GO:0006508) |
| • digestion (GO:0007586) | • hydrolase activity (GO:0016787) |
| • extracellular region (GO:0005576) |
Pathways
• KEGG: hsa04974 - Protein digestion and absorption
• Reactome: R-HSA-8963748 - Digestion of dietary protein
Protein Summary
Pepsinogen A5 is a 388-amino-acid precursor protein (UniProt P00790) that undergoes autocatalytic cleavage in acidic conditions to yield active pepsin A. The mature enzyme is a monomeric aspartic protease with two catalytic aspartate residues (Asp32 and Asp215) in the active site. It is secreted by gastric chief cells and functions optimally at pH 1.5–2.5. Pepsin A5 preferentially cleaves peptide bonds between hydrophobic and aromatic amino acids. The protein is a key component of the gastric digestive system and its levels are used clinically as a biomarker for gastric mucosal status.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| PGA5 Knockout HEK293 Cell Line | EDJ-KQ50511 | Human | 5222 | Details Get a Quote |
| PGA5 Knockout HeLa Cell Line | EDJ-KQ54125 | Human | 5222 | Details Get a Quote |
| PGA5 Knockout A-549 Cell Line | EDJ-KQ62615 | Human | 5222 | Details Get a Quote |
| PGA5 Knockout HCT 116 Cell Line | EDJ-KQ71087 | Human | 5222 | Details Get a Quote |
