ATPase, Ca++ Transporting, Ubiquitous (ATP2A3)

ATP2A3 encodes one of the SERCA Ca(2+)-ATPases, which are intracellular pumps located in the sarcoplasmic or endoplasmic reticula of cells. SERCA3 expression was originaly described as non-muscular, but was recently observed in cardiomyocyte. This enzyme catalyzes the hydrolysis of ATP coupled with the translocation of calcium from the cytosol to the sarcoplasmic reticulum lumen, and is involved in calcium sequestration associated with muscular excitation and contraction. Alternative splicing results in 6 transcript variants encoding different isoforms named SERCA3a to SERCA3f. The deduced 109,237-Da protein contains 999 amino acids and is 94% similar to rat SERCA3. SERCA3 was expressed at relatively constant levels at all stages of fetal heart development examined and in adult heart and placenta.