B4GAT1
Function
Beta-1,4-glucuronyltransferase involved in O-mannosylation of alpha-dystroglycan (DAG1) (PubMed:19587235, PubMed:23359570, PubMed:25279697, PubMed:25279699). Transfers a glucuronic acid (GlcA) residue onto a xylose (Xyl) acceptor to produce the glucuronyl-beta-1,4-xylose-beta disaccharide primer, which is further elongated by LARGE1, during synthesis of phosphorylated O-mannosyl glycan (PubMed:25279697, PubMed:25279699). Phosphorylated O-mannosyl glycan is a carbohydrate structure present in alpha-dystroglycan (DAG1), which is required for binding laminin G-like domain-containing extracellular proteins with high affinity (PubMed:25279697, PubMed:25279699). Required for axon guidance; via its function in O-mannosylation of alpha-dystroglycan (DAG1) (By similarity).
Involvement in disease
Muscular dystrophy-dystroglycanopathy congenital with brain and eye anomalies A13
MDDGA13
An autosomal recessive disorder characterized by congenital muscular dystrophy associated with cobblestone lissencephaly and other brain anomalies, eye malformations, profound intellectual disability, and death usually in the first years of life. Included diseases are the more severe Walker-Warburg syndrome and the slightly less severe muscle-eye-brain disease.
None
The disease is caused by variants affecting the gene represented in this entry.
Pathway
Protein modification; protein glycosylation.
Sequence Similarities
Belongs to the glycosyltransferase 49 family.
Tissue Specificity
In the adult, highly expressed in heart, brain, skeletal muscle and kidney and to a lesser extent in placenta, pancreas, spleen, prostate, testis, ovary, small intestine and colon. Very weak expression in lung, liver, thymus and peripheral blood leukocytes. In fetal highly expressed in brain and kidney and to a lesser extent in lung and liver.
Cellular localization
- Golgi apparatus membrane
- Single-pass type II membrane protein
- Localizes near the trans-Golgi apparatus.
Alternative names
B3GNT1, B3GNT6, B4GAT1, Poly-N-acetyllactosamine extension enzyme, iGnT