Key regulator of striated muscle performance by acting as the major Ca(2+) ATPase responsible for the reuptake of cytosolic Ca(2+) into the sarcoplasmic reticulum. Catalyzes the hydrolysis of ATP coupled with the translocation of calcium from the cytosol to the sarcoplasmic reticulum lumen (PubMed:10914677, PubMed:11438520, PubMed:15189864, PubMed:29081402, PubMed:18075584, PubMed:24270570, PubMed:23996003). Contributes to calcium sequestration involved in muscular excitation/contraction. ATP + Ca(2+)(in) + H2O = ADP + Ca(2+)(out) + H(+) + phosphate Inhibited by sarcolipin (SLN) and myoregulin (MRLN) (PubMed:10551848, PubMed:8428955, PubMed:29081402). Inhibited by phospholamban (PLN) (PubMed:10551848, PubMed:8428955, PubMed:29081402, PubMed:23996003). Reversibly inhibited by phospholamban (PLN) at low calcium concentrations (PubMed:10551848, PubMed:8428955, PubMed:29081402, PubMed:23996003). Dephosphorylated PLN decreases the apparent affinity of the ATPase for calcium (PubMed:10551848, PubMed:8428955). This inhibition is regulated by the phosphorylation of PLN (PubMed:10551848, PubMed:8428955). Enhanced by DWORF; DWORF increases activity by displacing sarcolipin (SLN), phospholamban (PLN) and myoregulin (MRLN) (By similarity). Interacts with sarcolipin (SLN) (PubMed:29081402, PubMed:23455422, PubMed:23455424). Interacts with phospholamban (PLN) (PubMed:8428955, PubMed:10551848, PubMed:29081402, PubMed:23996003). Interacts with myoregulin (MRLN) (By similarity). Interacts with DWORF (By similarity). Interacts VMP1 (By similarity). Skeletal muscle (at protein level) (PubMed:11438520, PubMed:15189864, PubMed:29081402, PubMed:10864315, PubMed:18075584, PubMed:23996003, PubMed:23455422). Skeletal muscle, fast twitch muscle (type II) fibers (PubMed:2936465, PubMed:3029125). Isoform SERCA1A and isoform SERCA1B are predominantly found in adult and neonatal skeletal muscle respectively. Ca(2+) and ATP binding cause major rearrangements of the cytoplasmic and transmembrane domains. According to the E1-E2 model, Ca(2+) binding to the cytosolic domain of the pump in the high-affinity E1 conformation is followed by the ATP-dependent phosphorylation of the active site Asp, giving rise to E1P. A conformational change of the phosphoenzyme gives rise to the low-affinity E2P state that exposes the Ca(2+) ions to the lumenal side and promotes Ca(2+) release. Dephosphorylation of the active site Asp mediates the subsequent return to the E1 conformation. PLN and SLN both have a single transmembrane helix; both occupy a similar binding site on ATP2A1 that is situated between the ATP2A1 transmembrane helices. Belongs to the cation transport ATPase (P-type) (TC 3.A.3) family. Type IIA subfamily.