B3GALNT2

This gene encodes a member of the glycosyltransferase 31 family. The encoded protein synthesizes GalNAc:beta-1,3GlcNAc, a novel carbohydrate structure, on N- and O-glycans. Alternatively spliced transcript variants that encode different isoforms have been described.

Full Name

Beta-1,3-N-Acetylgalactosaminyltransferase 2

Function

Beta-1,3-N-acetylgalactosaminyltransferase that synthesizes a unique carbohydrate structure, GalNAc-beta-1-3GlcNAc, on N- and O-glycans. Has no galactose nor galactosaminyl transferase activity toward any acceptor substrate. Involved in alpha-dystroglycan (DAG1) glycosylation: acts coordinately with GTDC2/POMGnT2 to synthesize a GalNAc-beta3-GlcNAc-beta-terminus at the 4-position of protein O-mannose in the biosynthesis of the phosphorylated O-mannosyl trisaccharide (N-acetylgalactosamine-beta-3-N-acetylglucosamine-beta-4-(phosphate-6-)mannose), a carbohydrate structure present in alpha-dystroglycan, which is required for binding laminin G-like domain-containing extracellular proteins with high affinity.

Biological Process

Protein glycosylation Source: UniProtKB
Protein O-linked glycosylation Source: UniProtKB

Cellular Location

Endoplasmic reticulum; Golgi apparatus membrane

Involvement in disease

Muscular dystrophy-dystroglycanopathy congenital with brain and eye anomalies A11 (MDDGA11): An autosomal recessive disorder characterized by congenital muscular dystrophy associated with cobblestone lissencephaly and other brain anomalies, eye malformations, profound mental retardation, 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.

Topology

Cytoplasmic: 1-6 aa
Helical: 7-23 aa
Lumenal: 24-500 aa

PTM

N-glycosylated.