FABP2: Fatty Acid Binding Protein 2 (Intestinal)
A comprehensive biomedical overview of the FABP2 gene, including its structure, function, expression, associated diseases, and clinical significance.
Gene Information Card
| Symbol | FABP2 |
|---|---|
| Full Name | Fatty Acid Binding Protein 2 (Intestinal) |
| Gene Type | Protein coding |
| Chromosomal Location | 4q26 |
| NCBI Gene ID | 2169 ncbi.nlm.nih.gov/gene/2169 |
| Ensembl ID | ENSG00000145362 |
| UniProt ID | P12104 |
| OMIM ID | 134640 |
| HGNC ID | 3555 |
| Aliases | FABPI, I-FABP, I-FABP2 |
Description
FABP2 (Fatty Acid Binding Protein 2) encodes the intestinal fatty acid binding protein (I-FABP), a small cytosolic protein (15 kDa) expressed in enterocytes of the small intestine. I-FABP binds long-chain fatty acids and facilitates their intracellular transport, metabolism, and absorption. It plays a critical role in dietary lipid processing and energy homeostasis. Genetic variants in FABP2 have been associated with altered lipid metabolism, insulin sensitivity, and susceptibility to metabolic disorders such as type 2 diabetes and obesity.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Type 2 Diabetes Mellitus | The Ala54Thr variant (rs1799883) increases fatty acid binding and transport, leading to elevated postprandial triglycerides and insulin resistance. | Multiple association studies; meta-analyses confirm modest risk increase (OR ~1.2-1.5). |
| Obesity | Altered fatty acid absorption and metabolism due to FABP2 variants may contribute to increased adiposity and body mass index. | Reported in candidate gene studies; some replication in diverse populations. |
| Insulin Resistance | Enhanced fatty acid flux from intestine to liver and muscle promotes lipid accumulation and impairs insulin signaling. | Biochemical and animal model evidence; human studies show correlation with HOMA-IR. |
| Hypertriglyceridemia | Increased intestinal fatty acid uptake and chylomicron secretion associated with the Thr54 allele. | Observed in postprandial lipid studies and cohort analyses. |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Small Intestine | 1200.5 | High |
| Duodenum | 1100.3 | High |
| Jejunum | 1300.8 | High |
| Ileum | 900.2 | High |
| Colon | 50.1 | Low |
| Liver | 2.3 | Not detected |
| Pancreas | 1.5 | Not detected |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| Caco-2 | 850.0 | Enterocyte-like; high expression |
| HT-29 | 120.0 | Moderate expression |
| HCT 116 | 45.0 | Low expression |
| HepG2 | 1.2 | Not detected |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| Ala54Thr (rs1799883) | Missense | ~30% in Europeans; ~20-40% globally | Increased fatty acid binding affinity; associated with higher postprandial lipids and insulin resistance. |
| Thr54Thr (homozygous) | Missense | ~5-10% in Europeans | Enhanced effect; stronger association with metabolic traits. |
Mutation functional classification
Loss of Function (LOF)
No well-characterized loss-of-function mutations reported in FABP2; complete knockout in mice is viable but alters lipid absorption.
Gain of Function (GOF)
Ala54Thr variant is considered a gain-of-function mutation, increasing fatty acid binding affinity and transport efficiency.
Dominant Negative (DN)
No dominant-negative mutations described for FABP2.
View complete mutation data：
Gene Ontology (GO)
Pathways
• Fatty acid metabolism (Reactome: R-HSA-8978868)
• Absorption of dietary lipids (Reactome: R-HSA-8963896)
• PPAR signaling pathway (KEGG: hsa03320)
Protein Summary
The FABP2 protein (UniProt P12104) is a 132-amino acid cytosolic fatty acid binding protein expressed predominantly in intestinal enterocytes. It adopts a beta-barrel structure that encapsulates a single long-chain fatty acid molecule. I-FABP facilitates the intracellular diffusion of fatty acids from the apical membrane to the endoplasmic reticulum for re-esterification and chylomicron assembly. The protein is also released into circulation upon enterocyte damage and serves as a biomarker for intestinal ischemia and mucosal injury. The common Ala54Thr polymorphism alters the protein's binding properties and has been implicated in metabolic disease risk.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| FABP2 Knockout HEK293 Cell Line | EDJ-KQ3670 | Human | 2169 | Details Get a Quote |
| FABP2 Knockout HeLa Cell Line | EDJ-KQ53197 | Human | 2169 | Details Get a Quote |
| FABP2 Knockout A-549 Cell Line | EDJ-KQ61675 | Human | 2169 | Details Get a Quote |
| FABP2 Knockout HCT 116 Cell Line | EDJ-KQ70158 | Human | 2169 | Details Get a Quote |
Displaying Records 1 To 4 Of 4 Records
