Beta-1,4-galactosyltransferase 4 (B4GALT4)

Beta-1,4-galactosyltransferase 4 (B4GALT4) is an enzyme encoded by the B4GALT4 gene, belonging to the glycosyltransferase family 7 (GT7), and is categorized as a type II membrane-bound glycoprotein localized mainly to the Golgi apparatus[1][2][3]. It catalyzes the transfer of galactose from UDP-galactose to terminal N-acetylglucosamine, glucose, or xylose residues in a beta-1,4 linkage, playing a specific role in the biosynthesis of glycoproteins, glycolipids (notably neolacto-series glycosphingolipids), and keratan sulfate[1][2][3]. The enzyme is crucial for forming N- and O-linked keratan sulfate proteoglycans and participates in the construction and elongation of mono- and disulfated disaccharide units in keratan sulfate, working cooperatively with other glycosyltransferases and sulfotransferases[2]. Loss or dysfunction of B4GALT4 leads to profound reduction in keratan sulfate synthesis and is associated with congenital disorders of glycosylation and spondylodysplastic Ehlers-Danlos syndrome types[1][2]. B4GALT4 is additionally characterized by essential N-glycosylation sites that determine its Golgi localization, stability, and enzymatic activity[1].

Other names

B4GALT4Beta-1,4-GalTase 4Beta4Gal-T4beta4Gal-T4beta-N-acetylglucosaminyl-glycolipid beta-1,4-galactosyltransferaselactotriaosylceramide beta-1,4-galactosyltransferaseN-acetyllactosamine synthaseNal synthaseUDP-Gal:beta-GlcNAc beta-1,4-galactosyltransferase 4UDP-galactose:beta-N-acetylglucosamine beta-1,4-galactosyltransferase 4UNQ552/PRO1109