LFNG belongs to evolutionarily conserved glycosyltransferases that act in the Notch signaling pathway to define boundaries during embryonic development. While their genomic structure is distinct from other glycosyltransferases, fringe proteins have a fucose-specific beta-1,3-N-acetylglucosaminyltransferase activity that leads to elongation of O-linked fucose residues on Notch, which alters Notch signaling. This protein is predicted to be a single-pass type II Golgi membrane protein but it may also be secreted and proteolytically processed like the related proteins in mouse and Drosophila (PMID: 9187150).Synonyms: 3-N-acetylglucosaminyltransferase lunatic fringe, Beta-1, EC=2.4.1.222, LFNG, O-fucosylpeptide 3-beta-N-acetylglucosaminyltransferase