Inhibits calcium-dependent inactivation of L-type calcium channel and shifts voltage dependence of activation to more depolarized membrane potentials (PubMed:18586882). Involved in the transmission of light signals (PubMed:18586882). May positively regulate neurotransmitter vesicle endocytosis and exocytosis in a salt-dependent manner (PubMed:22039235). May play a role in the extension and network organization of neurites (PubMed:22039235). Interacts with CACNA1C (via C-terminal CDB motif) in a calcium-dependent manner (PubMed:18586882). Interacts with STXBP1 (By similarity). Interacts with MYO6 (By similarity). Expressed in inner and outer plexiform layers of the retina, and retinal bipolar cells (at protein level) (PubMed:17947313, PubMed:18586882, PubMed:22039235). Expressed in the inner hair cells (IHC) of the cochlea (PubMed:17947313, PubMed:18586882). No morphologic changes, but 50% reduction of the sensitivity of retinal ganglion cell light responses.