Which of the following membrane proteins is involved in the 'Chloride-Shift' for CO₂ transport in RBCs?
Physiological transport of carbon dioxide from tissues to lungs uses chloride shift mechanism. CO2 diffusing into erythrocytes hydrated by zinc metalloenzyme carbonic anhydrase II to carbonic acid rapidly dissociating into bicarbonate and proton; proton buffered by deoxygenated hemoglobin promoting Bohr effect increasing oxygen release. Accumulating bicarbonate exported down gradient via anion exchanger Band 3 also termed AE1 SLC4A1 comprising fourteen transmembrane helices functioning as electroneutral one to one Cl- HCO3- antiporter exchanging extracellular chloride inward for intracellular
Ref: Alberts et al., Molecular Biology of the Cell, 6th ed., Chapter 11, Anion Exchanger Band 3 and CO2 Transport.
