Chloride-bicarbonate anion exchanger AE2

The chloride-bicarbonate anion exchanger AE2 is a membrane protein that mediates the electroneutral exchange of chloride (Cl^−) and bicarbonate (HCO₃^−) ions across the plasma membrane. This process is essential for maintaining ionic homeostasis, pH regulation, and fluid secretion in various epithelial tissues. It is highly expressed in the small intestine, colon, stomach, pancreas, and salivary glands, localized mainly to the basolateral membranes of epithelial cells. AE2 facilitates the exchange of Cl^− and HCO₃^− ions, which helps regulate intracellular pH. Its deficiency or dysfunction can lead to impaired bicarbonate secretion, increasing the risk for mucosal injury/inflammation, and has been implicated in digestive cancers, secretory diarrheas, and disorders involving abnormal fluid/electrolyte transport such as cystic fibrosis-related pathologies.

Other names

SLC4A2

Electroneutral exchange of chloride and bicarbonate ions across the cell membrane.