Sodium/Hydrogen Exchanger 5 (NHE5)

The sodium/hydrogen exchangers are plasma membrane proteins that mediate the exchange of extracellular Na+ for intracellular H+. The previous four forms can be classified as either sensitive or insensitive to inhibition by amiloride. Further, their expression patterns differ. NHE1 is transcribed in all tissues tested and functions in the regulation of intracellular pH and cell volume, NHE2 is highly expressed in the kidney and gastrointestinal tract and may play a role in Na+ ion absorption, and NHE4 is expressed mainly in the stomach. A microsatellite marker near SLC9A5 showed strong linkage to the marker D16S421, and multipoint linkage analysis placed SLC9A5 between S16S421 and D16S512. The authors proposed that SLC9A5 may be the predicted amiloride-insensitive sodium/hydrogen exchanger of the brain.