Vesicular soluble NSF attachment protein receptor (v-SNARE) mediating vesicle docking and fusion to a specific acceptor cellular compartment. Functions in endoplasmic reticulum to Golgi transport; as part of a SNARE complex composed of GOSR1, GOSR2 and STX5. Functions in early/recycling endosome to TGN transport; as part of a SNARE complex composed of BET1L, GOSR1 and STX5. Has a S-palmitoyl transferase activity. Probably cycles through vesicles between Golgi and endosomes. Maternally inherited. Detected in oocytes and eggs. Expression declines during early development and is not detected in neurula, tailbud and tadpole embryos. The longin domain regulates palmitoylation and membrane targeting. Palmitoylated; catalyzes its own palmitoylation. Palmitoylation is required for Golgi targeting. Farnesylation is required for Golgi targeting. Belongs to the synaptobrevin family.