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. Regulates neurotrophin release from granule cells leading to regulate cell differentiation and survival during cerebellar development. May specifically mediate the Ca(2+)-dependent exocytosis of large dense-core vesicles (DCVs) and other dense-core vesicles (By similarity). Homodimer (By similarity). Interacts with the dopamine receptor DRD2. Membrane-associated to vesicles. Strongly enriched in synaptic fractions. Probably localizes to different vesicles compared to CADPS. Enriched on vesicular structures in the parallel fiber terminal of granule cells that are distinct from synaptic vesicles. Widely expressed. Expressed in all adult and fetal tissues examined, with the strongest expression in kidney and pancreas. In brain, it is expressed at high levels in cerebellum, to a lesser degree in cerebral cortex, occipital pole, and frontal and temporal lobes. Only weakly expressed in medulla, spinal cord and putamen. The PH domain is essential for regulated exocytosis and binds phospholipids. Contaminating sequence. Potential poly-A sequence. Chimera.