Ca2ATPáz

Ca2ATPáz is a generic term referring to any enzyme that hydrolyzes adenosine triphosphate (ATP) to release energy for the active transport of calcium ions (Ca2+) across a biological membrane. These enzymes are a type of P-type ATPase, characterized by their transient phosphorylation during the catalytic cycle. The primary function of Ca2ATPáz is to maintain steep electrochemical gradients of calcium ions across cellular membranes, which is crucial for a wide array of cellular processes.

There are several distinct types of Ca2ATPáz, each with specific cellular localizations and roles. The sarco/endoplasmic reticulum Ca2+-ATPase (SERCA) pumps calcium from the cytoplasm into the sarcoplasmic reticulum (SR) of muscle cells or the endoplasmic reticulum (ER) of non-muscle cells. This action is vital for muscle contraction and relaxation, as well as for calcium signaling pathways in all eukaryotic cells. Another important type is the plasma membrane Ca2+-ATPase (PMCA), which extrudes calcium from the cell across the plasma membrane, contributing to the low resting cytoplasmic calcium concentration. Dysregulation or mutations in Ca2ATPáz activity are implicated in various diseases, including certain heart conditions and neurodegenerative disorders, highlighting their critical physiological importance.