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. Uses ATP as an energy source to transport cytosolic Ca(2+) ions across the plasma membrane to the extracellular compartment (By similarity). Has fast activation and Ca(2+) clearance rate suited to control fast neuronal Ca(2+) dynamics. 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 (By similarity). 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 (By similarity). In non-excitable cells, regulates Ca(2+) signaling through spatial control of Ca(2+) ions extrusion and 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 (By similarity). ATP + Ca(2+)(in) + H2O = ADP + Ca(2+)(out) + H(+) + phosphate Interacts with PDZD11. There is a combination of two alternatively spliced domains at N-terminal site A (W, X, Y and Z) and at C-terminal site C (A, B and C). So far the splice sites have only been studied independently. Experimental confirmation may be lacking for some isoforms. Isoforms containing segment B are found in brain, uterus, liver and kidney and in low levels in other tissues. Isoforms containing segment W are found in kidney, uterus, and pancreas. Isoforms containing segment Y are found in pancreas and in low levels in brain and heart. Isoforms containing segment Z are found in brain and heart and isoforms containing segment X are found in low levels in brain. Isoforms containing segment A are found in low levels in heart and small intestine while isoforms containing segment C are found in testis and in low levels in other tissues. Belongs to the cation transport ATPase (P-type) (TC 3.A.3) family. Type IIB subfamily.