GKN1: Gastrokine-1 – A Gastric Mucosal Protective Protein
Comprehensive genomic and proteomic analysis of GKN1, a key regulator of gastric epithelial homeostasis and tumor suppression.
Gene Information Card
| Symbol | GKN1 |
|---|---|
| Full Name | gastrokine 1 |
| Gene Type | protein-coding |
| Chromosomal Location | 2p13.3 |
| NCBI Gene ID | 56287 ncbi.nlm.nih.gov/gene/56287 |
| Ensembl ID | ENSG00000169398 |
| UniProt ID | Q9NS71 |
| OMIM ID | 618188 |
| HGNC ID | 23217 |
| Aliases | AMP-18, CA11, foveolin, GKN1, BRICD1 |
Description
GKN1 (gastrokine 1) encodes a secreted protein predominantly expressed in the gastric mucosa. It plays a critical role in maintaining gastric epithelial integrity, promoting mucosal repair, and suppressing inflammation. Loss of GKN1 expression is frequently observed in gastric cancer, suggesting a tumor suppressor function. The protein contains a BRICHOS domain implicated in protein folding and antimicrobial activity.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Gastric Cancer | Loss of GKN1 expression leads to reduced mucosal protection, increased inflammation, and epithelial-mesenchymal transition. | Multiple studies show GKN1 downregulation in gastric adenocarcinoma; re-expression suppresses tumor growth (PMID: 21742772, 25670082). |
| Helicobacter pylori Infection | H. pylori infection downregulates GKN1, contributing to chronic gastritis and increased cancer risk. | In vitro and in vivo models demonstrate H. pylori-induced GKN1 silencing via promoter methylation (PMID: 23359668). |
| Gastric Ulcer | Reduced GKN1 impairs mucosal repair and wound healing. | Animal models show GKN1 accelerates gastric ulcer healing (PMID: 18632602). |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Stomach | 123.4 | High |
| Esophagus | 2.1 | Low |
| Duodenum | 1.5 | Low |
| Colon | 0.3 | Not detected |
| Liver | 0.1 | Not detected |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| AGS (gastric adenocarcinoma) | 0.2 | Low expression; often silenced |
| MKN45 (gastric carcinoma) | 0.1 | Low expression |
| NCI-N87 (gastric carcinoma) | 0.3 | Low expression |
| HEK293 (embryonic kidney) | 0.0 | Not expressed |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.1A>G (p.Met1?) | missense | Rare | Likely loss of start codon; predicted loss of protein |
| c.226C>T (p.Arg76Trp) | missense | Rare | Unknown significance; located in BRICHOS domain |
| c.340G>A (p.Glu114Lys) | missense | Rare | Unknown significance |
Mutation functional classification
Loss of Function (LOF)
Promoter hypermethylation and transcriptional silencing are the primary mechanisms of GKN1 loss in gastric cancer. Rare missense variants may disrupt protein folding or secretion.
Gain of Function (GOF)
No gain-of-function mutations reported for GKN1.
Dominant Negative (DN)
No dominant-negative mutations described for GKN1.
View complete mutation data：
Gene Ontology (GO)
Pathways
• Gastric mucosal protection pathway
• Innate immune response (antimicrobial peptides)
• Epithelial cell signaling in Helicobacter pylori infection
Protein Summary
Gastrokine-1 (GKN1) is a 185-amino-acid secreted protein containing a BRICHOS domain. It is highly expressed in normal gastric mucosa and functions as a protective factor by promoting cell migration, inhibiting apoptosis, and exerting antimicrobial activity. GKN1 is frequently silenced in gastric cancer via promoter methylation, and its re-expression suppresses tumorigenesis. The protein is also involved in maintaining epithelial barrier integrity and modulating inflammatory responses.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| GKN1 Knockout HEK293 Cell Line | EDJ-KQ13606 | Human | 56287 | Details Get a Quote |
| GKN1 Knockout HeLa Cell Line | EDJ-KQ43271 | Human | 56287 | Details Get a Quote |
| GKN1 Knockout A-549 Cell Line | EDJ-KQ65235 | Human | 56287 | Details Get a Quote |
| GKN1 Knockout HCT 116 Cell Line | EDJ-KQ73674 | Human | 56287 | Details Get a Quote |
