May play a role in normal synaptic function, probably through regulation of Ca(2+) influx and neurotransmitter release in photoreceptor synaptic terminals and in auditory transmission. Modulator of CACNA1F, shifting the activation range to more hyperpolarized voltages (By similarity). Interacts with CACNA1F and CACNA1D (via IQ domain) in a calcium independent manner. Interacts (via N-terminus) with UNC119. Found in rod spherules and cone pedicles of the presynapses from both types of photoreceptors. Expressed in the retina. Phosphorylated. Phosphorylation levels change with the light conditions and regulate the activity (By similarity).