Sodium-hydrogen exchanger 2 (NHE2) (NHE2)

Sodium-hydrogen exchanger 2 (NHE2), encoded by the SLC9A2 gene, is a transmembrane protein that mediates the electroneutral exchange of one extracellular sodium ion for one intracellular proton (UniProt: Q9UBY0). It is primarily localized to the apical membranes of epithelial cells in the gastrointestinal tract, specifically the stomach and colon, and to a lesser extent in the kidney (PubMed: 10564079). NHE2 is essential for the regulation of intracellular pH, cell volume, and the absorption of sodium from the intestinal lumen (NCBI Gene: 6549). In the stomach, it contributes to the maintenance of the gastric mucosal barrier and pH homeostasis (PubMed: 15155274). While NHE2 shares functional similarities with NHE3, its specific role in disease is highlighted by its downregulation in inflammatory bowel disease and its potential involvement in diarrheal states (PubMed: 16339299). Pharmacologically, NHE2 is sensitive to amiloride and its derivatives, though highly selective clinical inhibitors are currently lacking compared to other NHE isoforms (PubChem: CID 2162).

Other names

SLC9A2Sodium/hydrogen exchanger 2NHE-2Solute carrier family 9 member A2

Inhibition of the electroneutral exchange of sodium ions for protons across the plasma membrane, thereby modulating intracellular pH and transepithelial sodium transport (PubMed: 10564079).