Candidate Genes Diabetic Retinopathy

UDP-Gal:betaGlcNAc beta 1,4- galactosyltransferase, polypeptide 2

Official Symbol
B4GALT2
Alternative Names
Beta-1,4-galactosyltransferase 2
Beta-4-GalT2
OTTHUMP00000010008
OTTHUMP00000010009
beta-1,4-GalTase 2
UDP-Gal:beta-GlcNAc beta-1,4-galactosyltransferase 2
UDP-Gal:betaGlcNAc beta 1,4- galactosyltransferase 2
UDP-Gal:betaGlcNAc beta 1,4-galactosyltransferase, polypeptide 2
beta-N-acetylglucosaminyl-glycolipid beta-1,4-galactosyltransferase 2
UDP-galactose:beta-N-acetylglucosamine beta-1,4-galactosyltransferase 2
Description
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. The enzyme encoded by this gene synthesizes N-acetyllactosamine in glycolipids and glycoproteins. Its substrate specificity is affected by alpha-lactalbumin but it is not expressed in lactating mammary tissue. Three transcript variants encoding two different isoforms have been found for this gene.
Location
1p34-p33
Map
Chr 17
Start: 44,444,615 bp from pter
End: 44,456,840 bp from pter
Size: 12,226 bases
Orientation: plus strand
Exons and Introns
7 exons and 15 distinct gt-ag introns.
Nucleotide Sequence
Aminoacid Sequence
Variation
rs730915 G/A
Motif
Pfam: Galactosyl_T_2
Ec No.
2.4.1.22
Catalytic Activity
UDP-galactose + D-glucose = UDP + lactose.
UDP-galactose + N-acetyl-beta-D-glucosaminylglycopeptide = UDP + beta-D-galactosyl-(1->4)-N-acetyl-beta-D-glucosaminylglycopeptide.
UDP-galactose + N-acetyl-D-glucosamine = UDP + N-acetyllactosamine
Cofactor
Manganese
Biophysico chemical Properties
Kinetic parameters:
KM=71 ÁM for GlcNAc-B-S-pNP
Pathway

Galactose metabolism

GAL PATH1

Pathway

N-Glycan biosynthesis

N-GLYCONE

Pathway

Glycosaminoglycan biosynthesis - keratan sulphate

KARTYN

Pathway

Glycosphingolipid biosynthesis - lacto and neolacto series

LACTO-ADIPOK

Interactors
Protein interactors
alpha lactalbumin
Post Translational Modification
Disulfide bond Glycosylation
Molecular Weight
41972 da
Molecular Class
Enzyme: Galactosyltransferase
Molecular Function
Galactosyltransferase activity Responsible for the synthesis of complex-type N-linked oligosaccharides in many glycoproteins as well as the carbohydrate moieties of glycolipids. Can produce lactose
3D Structure