ⓘ Sodium-calcium exchanger
The sodium-calcium exchanger is an antiporter membrane protein that removes calcium from cells. It uses the energy that is stored in the electrochemical gradient of sodium by allowing Na + to flow down its gradient across the plasma membrane in exchange for the countertransport of calcium ions. A single calcium ion is exported for the import of three sodium ions. The exchanger exists in many different cell types and animal species. The NCX is considered one of the most important cellular mechanisms for removing Ca 2+.
The exchanger is usually found in plasma membranes and mitochondria, and endoplasmic reticulum of excitable cells.