This magnesium-dependent enzyme catalyzes the hydrolysis of ATP coupled with the transport of calcium. Transports calcium ions from the cytosol into the sarcoplasmic/endoplasmic reticulum lumen. Contributes to calcium sequestration involved in muscular excitation/contraction. ATP + Ca(2+)(in) + H2O = ADP + Ca(2+)(out) + H(+) + phosphate Inhibited by sarcolipin (SLN), phospholamban (PLN) and myoregulin (MRLN) (By similarity). Enhanced by DWORF; DWORF increases activity by displacing sarcolipin (SLN), phospholamban (PLN) and myoregulin (MRLN) (By similarity). Interacts with sarcolipin (SLN) (By similarity). Interacts with phospholamban (PLN) (By similarity). Interacts with myoregulin (MRLN). Interacts with DWORF (By similarity). Interacts VMP1 (By similarity). Interacts with TUNAR; the interaction occurs at low levels in low glucose conditions and is increased by high glucose levels (By similarity). Expressed in endothelial tissues. Belongs to the cation transport ATPase (P-type) (TC 3.A.3) family. Type IIA subfamily.