This gene encodes a member of the glycosyltransferase 2 family. The encoded protein participates in glucosylation of the oligomannose core in N-linked glycosylation of proteins. The addition of glucose residues to the oligomannose core is necessary to ensure substrate recognition, and therefore, effectual transfer of the oligomannose core to the nascent glycoproteins. Multiple transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Nov 2008].