Solute carrier family 4 member (SLC4) bicarbonate transporter (SLC4)

The SLC4 family of bicarbonate transporters consists of a group of membrane proteins responsible for transporting bicarbonate (HCO₃⁻), carbonate (CO₃²⁻), and related anions, often in exchange for chloride (Cl⁻) or co-transported with sodium (Na⁺), across cell membranes[1][2][4]. The family includes both electroneutral and electrogenic transporters, grouped as anion exchangers (e.g., AE1/SLC4A1, which mediate Cl⁻/HCO₃⁻ exchange) and sodium-coupled bicarbonate cotransporters (e.g., NBCe1/SLC4A4)[2][5]. SLC4 proteins are crucial for the regulation of intracellular and extracellular pH, carbon dioxide transport, renal acid-base balance, and transepithelial absorption and secretion in many tissues[2][4]. Dysfunctional or mutated SLC4 family members are implicated in a variety of human diseases, especially those involving the kidney, blood, heart, and nervous system[2][5]. SLC4 family members are validated therapeutic targets for conditions related to acid-base and electrolyte imbalance and are the focus of ongoing pharmacological research[4].

Other names

Bicarbonate transporterSLC4 HCO₃⁻ transporterAnion exchanger (includes AE1, AE2, AE3)Sodium bicarbonate cotransporter (NBCe1, NBCe2, etc.)SLC4A1–SLC4A11 (gene/protein names)Anion exchange proteinCl⁻/HCO₃⁻ exchanger

Inhibition of anion exchange (DIDS/SITS: block Cl⁻/HCO₃⁻ exchange); Modulation of sodium and bicarbonate co-transport (NBC inhibitors); Indirect modulation of acid-base transport (via carbonic anhydrase inhibition)