UGT1A4
UDP Glucuronosyltransferase Family 1 Member A4
Gene Information Card
| Symbol | UGT1A4 |
|---|---|
| Full Name | UDP Glucuronosyltransferase Family 1 Member A4 |
| Gene Type | protein-coding |
| Chromosomal Location | 2q37.1 |
| NCBI Gene ID | 54657 ncbi.nlm.nih.gov/gene/54657 |
| Ensembl ID | ENSG00000241635 |
| UniProt ID | P22309 |
| OMIM ID | 606428 |
| HGNC ID | 12539 |
| Aliases | UGT1A, UGT1A4S, UGT1-04, UDPGT 1-4 |
Description
UGT1A4 is a member of the UDP-glucuronosyltransferase (UGT) family, which catalyzes the glucuronidation of endogenous compounds (e.g., bilirubin, steroid hormones) and xenobiotics (e.g., drugs, carcinogens). The enzyme is primarily expressed in the liver and gastrointestinal tract, and genetic polymorphisms in UGT1A4 can alter drug metabolism and toxicity.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Gilbert Syndrome | Reduced UGT1A4 activity leads to mild unconjugated hyperbilirubinemia | ClinVar, OMIM |
| Crigler-Najjar Syndrome | Severe deficiency of UGT1A4 activity causes life-threatening unconjugated hyperbilirubinemia | OMIM |
| Drug-Induced Hepatotoxicity | Polymorphisms in UGT1A4 affect glucuronidation of drugs (e.g., lamotrigine, olanzapine), increasing risk of toxicity | ClinVar, PubMed |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Liver | 12.5 | High |
| Small Intestine | 6.8 | Medium |
| Kidney | 3.2 | Low |
| Colon | 2.1 | Low |
| Stomach | 1.5 | Low |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| HepG2 | 8.9 | Hepatocellular carcinoma cell line |
| Caco-2 | 4.3 | Colorectal adenocarcinoma cell line |
| HEK293 | 1.2 | Embryonic kidney cell line |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.142T>G (p.Phe48Val) | Missense | 1-5% | Reduced enzyme activity; altered drug metabolism |
| c.181G>A (p.Gly61Arg) | Missense | <1% | Decreased glucuronidation capacity |
| c.448C>T (p.Arg150*) | Nonsense | Rare | Loss of function; associated with Crigler-Najjar syndrome |
Mutation functional classification
Loss of Function (LOF)
Nonsense and missense variants that reduce or abolish UGT1A4 enzymatic activity, leading to impaired glucuronidation of bilirubin and drugs.
Gain of Function (GOF)
Not reported for UGT1A4.
Dominant Negative (DN)
Not reported for UGT1A4.
View complete mutation data：
Gene Ontology (GO)
| • glucuronosyltransferase activity (GO:0015020) | • cellular glucuronidation (GO:0052695) |
| • endoplasmic reticulum (GO:0005783) | • xenobiotic metabolic process (GO:0006805) |
Pathways
• Bilirubin conjugation (Reactome: R-HSA-156588)
• Glucuronidation (Reactome: R-HSA-156588)
• Phase I - Functionalization of compounds (Reactome: R-HSA-211945)
Protein Summary
UGT1A4 is a 533-amino acid transmembrane protein localized to the endoplasmic reticulum. It catalyzes the transfer of glucuronic acid from UDP-glucuronic acid to a variety of substrates, including bilirubin, steroid hormones, and numerous drugs. The enzyme is critical for detoxification and elimination of lipophilic compounds.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| UGT1A4 Knockout HEK293 Cell Line | EDJ-KQ51383 | Human | 54657 | Details Get a Quote |
| UGT1A4 Knockout HeLa Cell Line | EDJ-KQ56453 | Human | 54657 | Details Get a Quote |
| UGT1A4 Knockout A-549 Cell Line | EDJ-KQ64946 | Human | 54657 | Details Get a Quote |
| UGT1A4 Knockout HCT 116 Cell Line | EDJ-KQ73389 | Human | 54657 | Details Get a Quote |
