Calcium-binding protein involved in exocytosis of vesicles filled with neurotransmitters and neuropeptides. Probably acts upstream of fusion in the biogenesis or maintenance of mature secretory vesicles. May specifically mediate the Ca(2+)-dependent exocytosis of large dense-core vesicles (DCVs) and other dense-core vesicles. Specifically required to activate the neuronal G-alpha pathway. Functions with G-alpha proteins from the same motor neurons to regulate locomotion. Involved in regulating entry into quiescence triggered by satiety. 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. Plays a role in octopamine signaling and specifically, the octopamine inhibition of aversion responses in olfactory sensory neurons. Probably by controlling the secretion of FLP neuropeptides, regulates the turning step of male mating behavior. Membrane-associated to vesicles. Strongly enriched in synaptic fractions. The PH domain is essential for regulated exocytosis and binds phospholipids.