Anion exchange protein 2 (AE2)

Anion exchange protein 2 (AE2) is a sodium-independent chloride/bicarbonate exchanger encoded by the SLC4A2 gene, functioning as a transmembrane transporter that mediates electroneutral exchange of Cl^−^ and HCO₃^−^ ions across cellular membranes[1][3][4][6]. AE2 is widely expressed, especially at the basolateral membranes of epithelial cells in gastrointestinal, hepatic, renal, and bone tissues, and plays a major role in regulating intracellular pH and maintaining systemic acid-base homeostasis[1][6][7]. It is essential for physiological processes such as gastric acid secretion, bile formation, and bone resorption (osteoclast function)[4][5][6]. Dysregulation or mutation of AE2 has been implicated in diseases including various cancers, primary biliary cholangitis, osteopetrosis, and renal tubular acidosis[2][4][7]. Although AE2 is a validated transporter and physiological target, there are no currently approved drugs targeting AE2 in clinical use; most pharmacological modulation is restricted to experimental research compounds[5].

Other names

SLC4A2AE2Anion exchanger 2Solute carrier family 4 member 2EPB3L1HKB3MPB3LBND3LNBND3OPTB9Non-erythroid band 3-like proteinErythrocyte membrane protein band 3-like 1Anion exchanger 2 type aAnion exchanger 2 type b1Anion exchanger 2 type b2

Inhibition of the Cl^−^/HCO₃^−^ exchange function by small molecules such as stilbene disulfonate derivatives (primarily used in research) Modulation of expression or function may alter cell pH and ion homeostasis, particularly in tumor biology and biliary tract disease