Glycosyltransferase that catalyzes 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 (, ). Prefers complex-type N-glycans over hybrid-types . Has lower affinities for donors or acceptors than MGAT4A, suggesting that, under physiological conditions, it is not the main contributor in N-glycan biosynthesis .
Subcellular locations: Golgi apparatus membrane
A processed soluble form also exists.
Widely expressed. Strongly overexpressed in pancreatic cancer.