Glycosyltransferase family 18 (IPR026116)

Short name: GlyclTrfase_18

Overlapping homologous superfamilies


Family relationships



The glycosyltransferase family 18 consists of alpha-1,6-mannosylglycoprotein 6-beta-N-acetylglucosaminyltransferases. This enzyme catalyses the addition of N-acetylglucosamine in beta 1-6 linkage to the alpha-linked mannose of biantennary N-linked oligosaccharides. It is one of the most important enzymes involved in the regulation of the biosynthesis of glycoprotein oligosaccharides.

In humans, two homologues have been described, Gnt-V(A) and Gnt-VB (GnT-IX). Gnt-VB is predominantly expressed in brain and catalyses the transfer of N-acetylglucosamine (GlcNAc) to the beta 1-6 linkage of the mannose residue of GlcNAcbeta1,2-Manalpha on both the alpha1,3- and alpha1,6-linked mannose arms in the core structure of N-glycan. Gnt-VB could be responsible for the synthesis of a unique oligosaccharide structure in the brain. It plays an active role in modulating integrin and laminin-dependent adhesion and migration of neuronal cells via its activity in the O-mannosyl glycan pathway [PMID: 14623122, PMID: 12941944, PMID: 14617637, PMID: 16857188, PMID: 16606368].

Caenorhabditis elegans has only one homologue [PMID: 11937505].

GO terms

Biological Process

GO:0006487 protein N-linked glycosylation

Molecular Function

GO:0030144 alpha-1,6-mannosylglycoprotein 6-beta-N-acetylglucosaminyltransferase activity

Cellular Component

No terms assigned in this category.

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.