Plasma membrane calcium-transporting ATPase 2 (ATP2B2, also known as PMCA2) belongs to the IIB subfamily of P-type ATPases, whose members are plasma membrane Ca2+ ATPases (PMCAs) that catalyse the hydrolysis of ATP coupled with the transport of calcium []. ATP2B2 has very high calmodulin affinity, however, it is only poorly stimulated by calmodulin [].ATP2B2 is expressed in the developing nervous system, adult cerebellar neurons, uterus, liver, and kidney []. Interestingly, it is expressed in the mammary gland, where it has a role in the enrichment of Ca2+ in milk [, ]. It is also expressed in the hair cells of the Corti organ of the inner ear, and acts as a regulator of the dendritic calcium equilibrium controlling Purkinje cell dendritic growth in brains []. In mice, mutations in the ATP2B2 gene cause deafness []and cerebellar ataxia []. In the retina, it regulates the homeostasis of Ca2+ which controls the transmission of visual signals to the synapses []. Therefore, mutations in the ATP2B2 gene also cause defective synaptic signalling within rod cells []. ATP2B2 has also been linked to the progression of breast cancer [].
