The function of MGAT2 (alpha-1,6-mannosyl-glycoprotein 2-beta-N-acetylglucosaminyltransferase, ENSG00000168282) is as follows. Plays an essential role in protein N-glycosylation. Catalyzes the transfer of N-acetylglucosamine (GlcNAc) onto the free terminal mannose moiety in the core structure of the nascent N-linked glycan chain, giving rise to the second branch in complex glycans. {ECO:0000269|PubMed:11228641, ECO:0000269|PubMed:29666272, ECO:0000269|PubMed:36280670, ECO:0000269|PubMed:8808595}.