ATPase, Ca++ Transporting, Cardiac Muscle, Fast Twitch 1 (ATP2A1)

ATP2A1 encodes one of the SERCA Ca(2+)-ATPases, which are intracellular pumps located in the sarcoplasmic or endoplasmic reticula of muscle cells. 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 muscular excitation and contraction. Mutations in this gene cause some autosomal recessive forms of Brody disease, characterized by increasing impairment of muscular relaxation during exercise. Alternative splicing results in two transcript variants encoding different isoforms.

In cotransfection experiments, S1T proteins consistently reduced the higher steady state Ca(2+) level in ER following SERCA1 or SERCA2B overexpression.