B4GALT3

This gene is one of seven beta-1,4-galactosyltransferase (beta4GalT) genes. They encode type II membrane-bound glycoproteins that appear to have exclusive specificity for the donor substrate UDP-galactose; all transfer galactose in a beta1,4 linkage to similar acceptor sugars: GlcNAc, Glc, and Xyl. Each beta4GalT has a distinct function in the biosynthesis of different glycoconjugates and saccharide structures. As type II membrane proteins, they have an N-terminal hydrophobic signal sequence that directs the protein to the Golgi apparatus and which then remains uncleaved to function as a transmembrane anchor. By sequence similarity, the beta4GalTs form four groups: beta4GalT1 and beta4GalT2, beta4GalT3 and beta4GalT4, beta4GalT5 and beta4GalT6, and beta4GalT7. This gene encodes an enzyme that may be mainly involved in the synthesis of the first N-acetyllactosamine unit of poly-N-acetyllactosamine chains. Multiple alternatively spliced transcript variants encoding the same protein have been found for this gene. [provided by RefSeq, Dec 2010]

Full Name

Beta-1,4-Galactosyltransferase 3

Function

Responsible for the synthesis of complex-type N-linked oligosaccharides in many glycoproteins as well as the carbohydrate moieties of glycolipids.

Biological Process

Carbohydrate metabolic process Source: InterPro
Galactosylceramide biosynthetic process Source: BHF-UCL
Glycosylation Source: GO_Central
Keratan sulfate biosynthetic process Source: Reactome
Protein glycosylation Source: UniProtKB-UniPathway

Cellular Location

Golgi stack membrane. Trans cisternae of Golgi stack.

Topology

Cytoplasmic: 1-10 aa
Helical: 11-31 aa
Lumenal: 32-393 aa