MGAT4B

MGAT4B
Identifiers
Aliases	MGAT4B, GNT-IV, GNT-IVB, mannosyl (alpha-1,3-)-glycoprotein beta-1,4-N-acetylglucosaminyltransferase, isozyme B, alpha-1,3-mannosyl-glycoprotein 4-beta-N-acetylglucosaminyltransferase B
External IDs	OMIM: 604561; MGI: 2143974; HomoloGene: 8611; GeneCards: MGAT4B; OMA:MGAT4B - orthologs
Gene location (Human)
Chr.	Chromosome 5 (human)
End	179,806,952 bp
Gene location (Mouse)
Chr.	Chromosome 11 (mouse)
End	50,125,930 bp
RNA expression pattern
	Top expressed in
	mucosa of transverse colon; ; duodenum; ; stromal cell of endometrium; ; rectum; ; right lobe of liver; ; apex of heart; ; right hemisphere of cerebellum; ; left adrenal cortex; ; islet of Langerhans; ; right adrenal gland;
	Top expressed in
	crypt of lieberkuhn of small intestine; ; ankle; ; stroma of bone marrow; ; olfactory epithelium; ; right kidney; ; gastrula; ; yolk sac; ; endothelial cell of lymphatic vessel; ; left colon; ; pyloric antrum;
	More reference expression data
	More reference expression data
Gene ontology
Molecular function	transferase activity; alpha-1,3-mannosylglycoprotein 4-beta-N-acetylglucosaminyltransferase activity; acetylglucosaminyltransferase activity; metal ion binding; glycosyltransferase activity; hexosyltransferase activity;
Cellular component	integral component of membrane; Golgi membrane; Golgi apparatus; membrane; endoplasmic reticulum; endoplasmic reticulum-Golgi intermediate compartment; Golgi stack;
Biological process	protein glycosylation; N-glycan processing; protein N-linked glycosylation; carbohydrate metabolic process;
	Sources:Amigo / QuickGO
Orthologs
	11282
	103534
	ENSG00000284501; ENSG00000161013
	ENSMUSG00000036620
	Q9UQ53
	Q812F8
	NM_054013; NM_014275
	NM_145926
	NP_055090; NP_463459
	NP_666038
	Wikidata
View/Edit Human	View/Edit Mouse

Alpha-1,3-mannosyl-glycoprotein 4-beta-N-acetylglucosaminyltransferase B is an enzyme that in humans is encoded by the MGAT4B gene.

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 A, 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. Therefore, the protein is essential for the production of tri- and tetra-antennary sugar chains. The encoded protein may play a role in regulating the availability of serum glycoproteins, oncogenesis, and differentiation. Its affinities for donors of acceptors are lower than that of MGAT4A so it is suggested that it is not the main contributor in N-glycan biosynthesis.