May participate in the axonal transport system and influences the acetylcholine flow in motor neurons (PubMed:1347782, PubMed:8398155). Probably by regulating neuronal transmission downstream of lin-3 and receptor lin-23 and phospholipase plc-3 and upstream of innexin unc-7 and egl-4/PKG in ALA neurons, involved in the decrease in pharyngeal pumping during the quiescent state that precedes each larval molt (PubMed:17891142). Motor neurons and a limited number of neurons constituting nerve ganglia. Abundant at the early larval stage, decreased amounts seen at the fourth larval and the adult stages. Belongs to the STXBP/unc-18/SEC1 family.