B3GAT3
Beta-1,3-Glucuronyltransferase 3 (Glucuronosyltransferase I)
Gene Information Card
| Symbol | B3GAT3 |
|---|---|
| Full Name | Beta-1,3-Glucuronyltransferase 3 (Glucuronosyltransferase I) |
| Gene Type | Protein coding |
| Chromosomal Location | 11q12.3 |
| NCBI Gene ID | 26229 ncbi.nlm.nih.gov/gene/26229 |
| Ensembl ID | ENSG00000149269 |
| UniProt ID | O94766 |
| OMIM ID | 606374 |
| HGNC ID | 923 |
| Aliases | GlcAT-I, GlcAT1, GLCATI |
Description
B3GAT3 encodes beta-1,3-glucuronyltransferase 3, also known as glucuronosyltransferase I. This enzyme catalyzes the transfer of glucuronic acid to the tetrasaccharide linker region of proteoglycans, a critical step in the biosynthesis of glycosaminoglycan (GAG) chains such as heparan sulfate and chondroitin sulfate. Mutations in B3GAT3 cause a form of linkeropathy known as Larsen-like syndrome or multiple joint dislocations with short stature, craniofacial dysmorphism, and congenital heart defects.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Larsen-like syndrome (B3GAT3-related linkeropathy) | Loss-of-function mutations impair glucuronyltransferase activity, disrupting GAG linker synthesis and extracellular matrix integrity. | PMID: 23453969, ClinVar |
| Multiple joint dislocations, short stature, craniofacial dysmorphism, and congenital heart defects | Biallelic missense/nonsense variants reduce enzyme activity, leading to proteoglycan deficiency in connective tissues. | OMIM 606374, PMID: 23453969 |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Heart | 8.2 | Medium |
| Brain | 5.1 | Low |
| Liver | 6.8 | Medium |
| Kidney | 7.4 | Medium |
| Lung | 4.9 | Low |
| Skeletal Muscle | 3.2 | Low |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| HEK 293 | 12.5 | High expression |
| HeLa | 9.8 | Medium expression |
| HepG2 | 7.1 | Medium expression |
| K562 | 4.3 | Low expression |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.830G>A (p.Arg277Gln) | Missense | Rare | Reduced enzymatic activity; associated with Larsen-like syndrome |
| c.1A>G (p.Met1?) | Start loss | Rare | Loss of protein expression; severe phenotype |
| c.103C>T (p.Arg35*) | Nonsense | Rare | Premature truncation; loss of function |
Mutation functional classification
Loss of Function (LOF)
Most reported B3GAT3 mutations are loss-of-function, leading to reduced glucuronyltransferase activity and impaired GAG linker synthesis.
Gain of Function (GOF)
No gain-of-function mutations have been reported.
Dominant Negative (DN)
No dominant-negative effects have been described; inheritance is autosomal recessive.
View complete mutation data：
Gene Ontology (GO)
Pathways
• Proteoglycan biosynthesis (Reactome: R-HSA-1793185)
• Chondroitin sulfate/dermatan sulfate biosynthesis (Reactome: R-HSA-1793185)
• Heparan sulfate/heparin biosynthesis (Reactome: R-HSA-1793185)
Protein Summary
Beta-1,3-glucuronyltransferase 3 (GlcAT-I) is a type II transmembrane protein localized to the Golgi apparatus. It catalyzes the transfer of glucuronic acid from UDP-glucuronic acid to the trisaccharide Gal-Gal-Xyl on the proteoglycan core protein, forming the tetrasaccharide linker essential for GAG chain elongation. The enzyme is ubiquitously expressed with highest levels in heart and kidney. Defects in this enzyme disrupt proteoglycan function in connective tissues, leading to skeletal and cardiac abnormalities.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| B3GAT3 Knockout HEK293 Cell Line | EDJ-KQ8462 | Human | 26229 | Details Get a Quote |
| B3GAT3 Knockout A-549 Cell Line | EDJ-KQ34578 | Human | 26229 | Details Get a Quote |
| B3GAT3 Knockout HCT 116 Cell Line | EDJ-KQ34579 | Human | 26229 | Details Get a Quote |
| B3GAT3 Knockout HeLa Cell Line | EDJ-KQ34580 | Human | 26229 | Details Get a Quote |
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