ATP-driven Ca(2+) ion pump involved in the maintenance of basal intracellular Ca(2+) levels in specialized cells of cerebellar circuit and vestibular and cochlear systems (PubMed:17234811, PubMed:9668038). Uses ATP as an energy source to transport cytosolic Ca(2+) ions across the plasma membrane to the extracellular compartment. Has fast activation and Ca(2+) clearance rate suited to control fast neuronal Ca(2+) dynamics (PubMed:17409239, PubMed:20083513). At parallel fiber to Purkinje neuron synapse, mediates presynaptic Ca(2+) efflux in response to climbing fiber-induced Ca(2+) rise. Provides for fast return of Ca(2+) concentrations back to their resting levels, ultimately contributing to long-term depression induction and motor learning (PubMed:17409239, PubMed:20083513). Plays an essential role in hearing and balance. In cochlear hair cells, shuttles Ca(2+) ions from stereocilia to the endolymph and dissipates Ca(2+) transients generated by the opening of the mechanoelectrical transduction channels. Regulates Ca(2+) levels in the vestibular system, where it contributes to the formation of otoconia (PubMed:9668038) (By similarity). Regulates Ca(2+) signaling through dissipation of Ca(2+) transients generated by store-operated channels (By similarity). In lactating mammary gland, allows for the high content of Ca(2+) ions in the milk (PubMed:15302868). ATP + Ca(2+)(in) + H2O = ADP + Ca(2+)(out) + H(+) + phosphate Interacts with PDZD11. Expressed in the retina, with strongest levels in the inner plexiform layer, weaker levels in the outer plexiform layer, and very low levels in the proximal inner nuclear layer (PubMed:12209837). Specifically expressed in the following retinal cell types: rod bipolar cells, horizontal cells, amacrine cells and ganglion cells (PubMed:12209837). Also found in the cochlea (stereocilia and outer wall of hair cells) (at protein level) (PubMed:9697703). Strongly expressed in brain cortex and cerebellum. Found at low levels in heart, liver, lung and testis during late gestation (PubMed:9697703, PubMed:20083513). Expressed in lactating mammary gland (at protein level). Defects in Atp2b2 are associated with early onset profound hearing loss and severe vestibular dysfunction. Mutant mice, born at the expected Mendelian rate, show balance impairment and hearing loss. They develop severe ataxia before 2 weeks of age associated with the absence of otoconia in the vestibular inner ear. Belongs to the cation transport ATPase (P-type) (TC 3.A.3) family. Type IIB subfamily.