The sodium-calcium exchanger (often denoted Na+/Ca2+ exchanger, exchange protein, or NCX) is an antiportermembrane protein that removes calcium from cells. It uses the energy that is stored in the electrochemical gradient of sodium (Na+) by allowing Na+ to flow down its gradient across the plasma membrane in exchange for the countertransport of calcium ions (Ca2+). A single calcium ion is exported for the import of three sodium ions.[1] The exchanger exists in many different cell types and animal species.[2] The NCX is considered one of the most important cellular mechanisms for removing Ca2+.[2]
The exchanger is usually found in the plasma membranes and the mitochondria and endoplasmic reticulum of excitable cells.[3][4]
^Yu SP, Choi DW (Jun 1997). "Na(+)-Ca2+ exchange currents in cortical neurons: concomitant forward and reverse operation and effect of glutamate". The European Journal of Neuroscience. 9 (6): 1273–81. doi:10.1111/j.1460-9568.1997.tb01482.x. PMID9215711. S2CID23146698.