Predicted to enable protein transmembrane transporter activity and syntaxin binding activity. Involved in Golgi organization; positive regulation of interleukin-1 production; and positive regulation of protein secretion. Acts upstream of or within negative regulation of aspartic-type endopeptidase activity involved in amyloid precursor protein catabolic process; regulated exocytosis; and vesicle targeting, to, from or within Golgi. Located in zymogen granule membrane. Part of gamma-secretase complex. Is expressed in several structures, including alimentary system; eye; genitourinary system; hemolymphoid system gland; and nervous system. Orthologous to human TMED10 (transmembrane p24 trafficking protein 10). [provided by Alliance of Genome Resources, Apr 2022]