The<unk>  (often denoted Na+/Ca2+<unk> , NCX, or<unk> protein) is an antiporter membrane protein which removes<unk>  from cells.  It uses the energy that is stored in the electrochemical gradient of<unk>  (Na+) by allowing Na+ to flow down its gradient across the plasma membrane in<unk> for the countertransport of<unk>  ions (Ca2+).  The NCX removes a single<unk>  ion in<unk> for the import of three<unk>  ions.  The<unk>  exists in many different cell types and animal species.  The NCX is considered one of the most important cellular mechanisms for removing Ca2+.
The<unk>  is usually found in the plasma membranes and the mitochondria and endoplasmic reticulum of excitable cells.
Sodium calcium exchanger
Calcium channel
Sodium channel
Magnesium transporters
Chloride channel
Voltage-dependent calcium channel
Cyclic nucleotide-gated ion channel
Tandem pore domain potassium channel