MGAT4A

This gene encodes a key glycosyltransferase that regulates the formation of tri- and multiantennary branching structures in the Golgi apparatus. The encoded protein, in addition to the related isoenzyme B, catalyzes the transfer of N-acetylglucosamine (GlcNAc) from UDP-GlcNAc in a beta-1,4 linkage to the Man-alpha-1,3-Man-beta-1,4-GlcNAc arm of R-Man-alpha-1,6(GlcNAc-beta-1,2-Man-alpha-1,3)Man-beta-1,4-GlcNAc-beta-1,4-GlcNAc-beta-1-Asn. The encoded protein may play a role in regulating the availability of serum glycoproteins, oncogenesis, and differentiation. [provided by RefSeq]

Full Name

mannosyl (alpha-1,3-)-glycoprotein beta-1,4-N-acetylglucosaminyltransferase, isozyme A

Function

Glycosyltransferase that catalyze the transfer of GlcNAc from UDP-GlcNAc to the GlcNAcbeta1-2Manalpha1-3 arm of the core structure of N-linked glycans through a beta1-4 linkage and participates in the production of tri- and tetra-antennary N-linked sugar chains (PubMed:17006639).

Involved in glucose transport by mediating SLC2A2/GLUT2 glycosylation, thereby controlling cell-surface expression of SLC2A2 in pancreatic beta cells (By similarity).

Biological Process

Glyoxylate metabolic process Source: UniProtKB
N-glycan processing Source: UniProtKB
Positive regulation of protein glycosylation in Golgi Source: UniProtKB
Protein N-linked glycosylation Source: GO_Central
Viral protein processing Source: Reactome

Cellular Location

Alpha-1,3-mannosyl-glycoprotein 4-beta-N-acetylglucosaminyltransferase A:
Golgi apparatus
Golgi apparatus membrane
Alpha-1,3-mannosyl-glycoprotein 4-beta-N-acetylglucosaminyltransferase A soluble form:
Secreted

Topology

Cytoplasmic: 1-4
Helical: 5-27
Lumenal: 28-535

PTM

N-glycosylated.