B3GAT3

The protein encoded by this gene is a member of the glucuronyltransferase gene family, enzymes that exhibit strict acceptor specificity, recognizing nonreducing terminal sugars and their anomeric linkages. This gene product catalyzes the formation of the glycosaminoglycan-protein linkage by way of a glucuronyl transfer reaction in the final step of the biosynthesis of the linkage region of proteoglycans. [provided by RefSeq]

Full Name

beta-1,3-glucuronyltransferase 3 (glucuronosyltransferase I)

Function

Glycosaminoglycans biosynthesis (PubMed:25893793).
Involved in forming the linkage tetrasaccharide present in heparan sulfate and chondroitin sulfate. Transfers a glucuronic acid moiety from the uridine diphosphate-glucuronic acid (UDP-GlcUA) to the common linkage region trisaccharide Gal-beta-1,3-Gal-beta-1,4-Xyl covalently bound to a Ser residue at the glycosaminylglycan attachment site of proteoglycans. Can also play a role in the biosynthesis of l2/HNK-1 carbohydrate epitope on glycoproteins. Shows strict specificity for Gal-beta-1,3-Gal-beta-1,4-Xyl, exhibiting negligible incorporation into other galactoside substrates including Galbeta1-3Gal beta1-O-benzyl, Galbeta1-4GlcNAc and Galbeta1-4Glc. Stimulates 2-phosphoxylose phosphatase activity of PXYLP1 in presence of uridine diphosphate-glucuronic acid (UDP-GlcUA) during completion of linkage region formation (PubMed:24425863).

Biological Process

Carbohydrate metabolic process Source: GO_Central
Chondroitin sulfate proteoglycan biosynthetic process Source: MGI
Dermatan sulfate proteoglycan biosynthetic process Source: MGI
Glycosaminoglycan biosynthetic process Source: UniProtKB
Glycosaminoglycan metabolic process Source: Reactome
Heparan sulfate proteoglycan biosynthetic process Source: MGI
Positive regulation of catalytic activity Source: UniProtKB
Positive regulation of intracellular protein transport Source: UniProtKB
Protein glycosylation Source: UniProtKB-UniPathway

Cellular Location

Golgi apparatus membrane; Cis-Golgi network

Involvement in disease

Multiple joint dislocations, short stature, and craniofacial dysmorphism with or without congenital heart defects (JDSCD): An autosomal recessive disease characterized by dysmorphic facies, bilateral dislocations of the elbows, hips, and knees, clubfeet, and short stature, as well as cardiovascular defects.

Topology

Cytoplasmic: 1-7 aa
Helical: 8-28 aa
Lumenal: 29-335 aa

PTM

N-glycosylated.