Ca+2-dependent secretion activator 2 (Ca+2-dependent activator protein for secretion 2, CAPS-2, CADPS2, CAPS2, KIAA1591)

Function: 1) Ca⁺²-binding protein 2) role in exocytosis of vesicles filled with neurotransmitters & neuropeptides 3) probably acts upstream of fusion in the biogenesis or maintenance of mature secretory vesicles 4) regulates neurotrophin release from granule cells, thus role in cell differentiation & survival during cerebellar development 5) may specifically mediate the Ca⁺²-dependent exocytosis of large dense-core vesicles & other dense-core vesicles 6) interacts with the dopamine receptor DRD2 7) isoform 2 is phosphorylated upon DNA damage, probably by ATM or ATR Structure: - homodimer - contains 1 C2 domain - contains 1 MHD1 domain (MUNC13 homology domain 1 domain) - contains 1 PH domain with role in regulation of exocytosis, binds phospholipids Compartment: - cytoplasmic vesicle membrane - 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 Alternative splicing: named isoforms=3 Expression: - widely expressed - expressed in all adult & fetal tissues examined - strongest expression in kidney & pancreas - in CNS, expressed in cerebellum > cerebral cortex, occipital pole, frontal & temporal lobes > medulla, spinal cord, putamen

Properties

SIZE: MW = 148 kD entity length = 1296 aa COMPARTMENT: cytoplasm MOTIF: C2 domain {367-447} MOTIF: binding site FOR-BINDING-OF: phospholipid Ca+2-binding site PH domain {487-590} DRD2 interaction {755-1074} MOTIF: MHD1 {885-1056}

Database Correlations

UniProt Q86UW7 PFAM correlations

References

UniProt :accession Q86UW7