Table 1.

Four principal modes of transport performed by hAE1, its mutants and tAE1.

function	protein responsible
Cl−–${\text{HCO}}_3^{-}$ exchange only	wt hAE1
cation channel only	S731P, H734R, D705Y, L687P, SAO
Cl−–${\text{HCO}}_3^{-}$ exchange+anion channel	tAE1
Cl−–${\text{HCO}}_3^{-}$ exchange+cation channel	R760Q, dRTA mutants