B4GAT1: Beta-1,4-Glucuronyltransferase 1
Gene encoding a glycosyltransferase involved in dystroglycan O-mannosylation and congenital muscular dystrophy
Gene Information Card
| Symbol | B4GAT1 |
|---|---|
| Full Name | Beta-1,4-Glucuronyltransferase 1 |
| Gene Type | Protein coding |
| Chromosomal Location | 11q13.2 |
| NCBI Gene ID | 11041 ncbi.nlm.nih.gov/gene/11041 |
| Ensembl ID | ENSG00000149294 |
| UniProt ID | Q9P2K5 |
| OMIM ID | 615287 |
| HGNC ID | 29579 |
| Aliases | B3GNT1, iGAT, MDDGA13, MDDGC13 |
Description
B4GAT1 encodes beta-1,4-glucuronyltransferase 1, a Golgi-resident enzyme that catalyzes the transfer of glucuronic acid (GlcA) to O-mannosyl glycans on alpha-dystroglycan. This modification is essential for the binding of extracellular matrix proteins such as laminin. Mutations in B4GAT1 cause a spectrum of muscular dystrophy-dystroglycanopathies, including congenital muscular dystrophy with brain and eye anomalies (MDDGA13) and limb-girdle muscular dystrophy (MDDGC13).
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Muscular dystrophy-dystroglycanopathy (congenital with brain and eye anomalies) type A13 (MDDGA13) | Loss-of-function mutations impair GlcA transfer, disrupting alpha-dystroglycan glycosylation and laminin binding, leading to severe neurodevelopmental and muscular defects. | OMIM #615287; ClinVar |
| Muscular dystrophy-dystroglycanopathy (limb-girdle) type C13 (MDDGC13) | Hypomorphic variants reduce enzyme activity, causing milder, later-onset muscular dystrophy without significant brain involvement. | OMIM #615287; ClinVar |
| Walker-Warburg syndrome (WWS) | Biallelic loss-of-function mutations in B4GAT1 are associated with WWS, a severe form of congenital muscular dystrophy with cobblestone lissencephaly and eye malformations. | OMIM #615287; NCBI GeneReviews |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Brain | 12.5 | Medium |
| Heart | 8.2 | Low |
| Skeletal Muscle | 15.3 | Medium |
| Liver | 6.1 | Low |
| Kidney | 9.8 | Low |
| Lung | 7.4 | Low |
| Placenta | 11.0 | Medium |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| HEK 293 | 18.5 | Moderate expression |
| HeLa | 14.2 | Moderate expression |
| HepG2 | 9.1 | Low expression |
| K562 | 6.8 | Low expression |
| SH-SY5Y | 20.3 | Moderate expression |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.1A>G (p.Met1?) | Missense (start loss) | Rare | Loss of translation initiation; complete loss of function |
| c.512G>A (p.Arg171His) | Missense | Rare | Reduced enzymatic activity; associated with MDDGC13 |
| c.679C>T (p.Arg227*) | Nonsense | Rare | Premature stop; loss of function; associated with MDDGA13 |
| c.1000C>T (p.Arg334Trp) | Missense | Rare | Impaired glucuronyltransferase activity; pathogenic |
Mutation functional classification
Loss of Function (LOF)
Most pathogenic mutations (nonsense, frameshift, start loss) lead to complete or severe loss of enzyme activity, causing severe congenital muscular dystrophy (MDDGA13).
Gain of Function (GOF)
No gain-of-function mutations have been reported for B4GAT1.
Dominant Negative (DN)
No dominant-negative mechanisms have been described; all reported pathogenic variants are recessive.
View complete mutation data：
Gene Ontology (GO)
Pathways
• O-mannosyl glycan biosynthesis (Reactome: R-HSA-5173105)
• Dystroglycan O-mannosylation (KEGG: hsa00514 – Other types of O-glycan biosynthesis)
Protein Summary
Beta-1,4-glucuronyltransferase 1 (B4GAT1) is a 334-amino acid type II transmembrane protein localized to the Golgi apparatus. It catalyzes the addition of glucuronic acid (GlcA) in a beta-1,4 linkage to O-mannose glycans on alpha-dystroglycan. This modification is critical for the formation of the laminin-binding glycan epitope. The enzyme requires manganese as a cofactor and is part of the glycosyltransferase family 49 (GT49).
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| B4GAT1 Knockout HEK293 Cell Line | EDJ-KQ7256 | Human | 11041 | Details Get a Quote |
| B4GAT1 Knockout A-549 Cell Line | EDJ-KQ32258 | Human | 11041 | Details Get a Quote |
| B4GAT1 Knockout HCT 116 Cell Line | EDJ-KQ32259 | Human | 11041 | Details Get a Quote |
| B4GAT1 Knockout HeLa Cell Line | EDJ-KQ32260 | Human | 11041 | Details Get a Quote |
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