Anion exchange protein 1 (AE1)

Anion exchange protein 1 (AE1), also known as Band 3 or SLC4A1, is the most abundant integral membrane protein in human erythrocytes and is also expressed in the alpha-intercalated cells of the kidney's distal tubule (Walsh & Stewart, 2010). It primarily functions as an electroneutral chloride/bicarbonate exchanger, facilitating the transport of carbon dioxide from tissues to the lungs and maintaining systemic acid-base balance (Capper et al., 2022). Beyond its transport role, AE1 serves as a critical structural scaffold, anchoring the erythrocyte cytoskeleton to the plasma membrane through interactions with proteins like ankyrin and protein 4.2, which provides the red blood cell with its characteristic biconcave shape and flexibility (Rivera-Santiago et al., 2017). In the kidney, the kAE1 isoform is essential for urinary acidification, and its dysfunction leads to impaired acid secretion and metabolic acidosis (Walsh & Stewart, 2010). Mutations in the SLC4A1 gene are linked to several clinical conditions, including hereditary spherocytosis, Southeast Asian ovalocytosis, and distal renal tubular acidosis (NCBI SLC4A1, 2024). While not a primary target for many current systemic therapies, AE1 is inhibited by drugs such as dipyridamole and niflumic acid, and its role in gastric cancer progression and malaria susceptibility makes it a subject of ongoing therapeutic research (Capper et al., 2022; NCBI SLC4A1, 2024).

Other names

Band 3 anion transport proteinSLC4A1Solute carrier family 4 member 1Erythrocyte membrane protein band 3CD233Anion exchanger 1

Inhibition of chloride/bicarbonate exchange through substrate channel blocking or allosteric modulation (Capper et al., 2022)