Plasma membrane Ca2+ ATPase

The plasma membrane Ca ATPase (PMCA) is a transport protein in the plasma membrane of cells and functions to remove calcium (Ca) from the cell. PMCA function is vital for regulating the amount of Ca within all eukaryotic cells. There is a very large transmembrane electrochemical gradient of Ca driving the entry of the ion into cells, yet it is very important that they maintain low concentrations of Ca for proper cell signalling. Thus, it is necessary for cells to employ ion pumps to remove the Ca. The PMCA and the sodium calcium exchanger (NCX) are together the main regulators of intracellular Ca concentrations. Since it transports Ca into the extracellular space, the PMCA is also an important regulator of the calcium concentration in the extracellular space.