ALPI (Alkaline Phosphatase, Intestinal)
Gene encoding intestinal alkaline phosphatase, involved in gut homeostasis and lipid metabolism.
Gene Information Card
| Symbol | ALPI |
|---|---|
| Full Name | Alkaline Phosphatase, Intestinal |
| Gene Type | protein-coding |
| Chromosomal Location | 2q37.1 |
| NCBI Gene ID | 248 ncbi.nlm.nih.gov/gene/248 |
| Ensembl ID | ENSG00000163286 |
| UniProt ID | P09923 |
| OMIM ID | 171740 |
| HGNC ID | 438 |
| Aliases | IAP, IAP-I, ALPI-1 |
Description
The ALPI gene encodes intestinal alkaline phosphatase (IAP), a membrane-bound glycoprotein that hydrolyzes phosphate esters and plays a critical role in gut barrier function, lipid absorption, and regulation of inflammation. IAP is expressed primarily in the brush border of enterocytes and is involved in detoxifying bacterial lipopolysaccharides (LPS) and modulating the gut microbiome.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Hypophosphatasia (mild forms) | Loss-of-function mutations in ALPI reduce alkaline phosphatase activity, impairing bone mineralization and causing dental anomalies. | ClinVar, OMIM |
| Inflammatory Bowel Disease (IBD) | Reduced IAP activity compromises gut barrier integrity, leading to increased LPS translocation and chronic intestinal inflammation. | NCBI, PubMed |
| Metabolic syndrome | IAP deficiency alters lipid absorption and promotes endotoxemia, contributing to obesity and insulin resistance. | UniProt, PubMed |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Small intestine | 78.5 | High |
| Colon | 12.3 | Medium |
| Liver | 0.2 | Not detected |
| Kidney | 0.1 | Not detected |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| Caco-2 | 45.2 | Intestinal epithelial cell line, high IAP expression |
| HT-29 | 22.8 | Colorectal adenocarcinoma, moderate expression |
| HepG2 | 0.3 | Hepatocellular carcinoma, negligible expression |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.571G>A (p.Gly191Arg) | Missense | <0.01% | Reduced enzyme activity, associated with mild hypophosphatasia |
| c.1012C>T (p.Arg338Cys) | Missense | <0.01% | Impaired dimerization and catalytic function |
| c.1465G>A (p.Glu489Lys) | Missense | <0.01% | Decreased stability and activity |
Mutation functional classification
Loss of Function (LOF)
Missense mutations (e.g., p.Gly191Arg, p.Arg338Cys) reduce catalytic activity or protein stability, leading to hypophosphatasia or gut barrier dysfunction.
Gain of Function (GOF)
No gain-of-function mutations reported in ALPI.
Dominant Negative (DN)
No dominant-negative mutations reported; ALPI functions as a homodimer, but heterozygous missense variants may exert mild effects.
View complete mutation data：
Gene Ontology (GO)
| • GO:0004035 - alkaline phosphatase activity | • GO:0016791 - phosphatase activity |
| • GO:0005886 - plasma membrane | • GO:0016021 - integral component of membrane |
| • GO:0008152 - metabolic process | • GO:0042493 - response to drug |
Pathways
• Vitamin B6 metabolism
• Phosphate metabolism
• Lipopolysaccharide detoxification
Protein Summary
Intestinal alkaline phosphatase (IAP) is a 528-amino-acid homodimeric glycoprotein anchored to the brush border membrane of enterocytes. It hydrolyzes phosphate monoesters, including pyridoxal phosphate (vitamin B6) and bacterial LPS, thereby regulating nutrient absorption and innate immunity. IAP activity is modulated by dietary factors and gut microbiota.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| ALPI Knockout HEK293 Cell Line | EDJ-KQ4045 | Human | 248 | Details Get a Quote |
| ALPI Knockout HeLa Cell Line | EDJ-KQ26397 | Human | 248 | Details Get a Quote |
| ALPI Knockout A-549 Cell Line | EDJ-KQ61078 | Human | 248 | Details Get a Quote |
| ALPI Knockout HCT 116 Cell Line | EDJ-KQ69560 | Human | 248 | Details Get a Quote |
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