The drosophila protein fringe (FNG) is a glucosaminyltransferase that controls the response of the Notch receptor to specific ligands [1]. FNG is localised to the Golgi apparatus [1] (not secreted as previously thought). Modification of Notch occurs through glycosylation by FNG. The xenopus homologue, lunatic fringe, has been implicated in a variety of functions.

1: The Notch signalling regulator Fringe acts in the Golgi apparatus and requires the glycosyltransferase signature motif DXD. Munro S, Freeman M; Curr Biol 2000;10:813-820. PMID:10899003