| abstract |
sarco/endoplasmic reticulum Ca(2+)-ATPase (SERCA), similar to mammalian ATP2A1-3/SERCA1-3. SERCA is a transmembrane (Ca2+)-ATPase and a major regulator of Ca(2+) homeostasis and contractility in cardiac and skeletal muscle. It re-sequesters cytoplasmic Ca(2+) to the sarco/endoplasmic reticulum store, thereby also terminating Ca(2+)-induced signaling such as in muscle contraction. Three genes (ATP2A1-3/SERCA1-3) encode SERCA pumps in mammals, further isoforms exist due to alternative splicing of transcripts. The activity of SERCA is regulated by two small membrane proteins called phospholamban and sarcolipin. This subfamily belongs to the P-type ATPases, a large family of integral membrane transporters that are of critical importance in all kingdoms of life. They generate and maintain (electro-) chemical gradients across cellular membranes, by translocating cations, heavy metals and lipids, and are distinguished from other main classes of transport ATPases (F- , V- , and ABC- type) by the formation of a phosphorylated (P-) intermediate state in the catalytic cycle. |