Lack of Charge Interaction in the Ion Binding Site Determines Anion Selectivity in the Sodium Bicarbonate Cotransporter NBCe1.

ABSTRACT: The Na/HCO₃ cotransporter NBCe1 is a member of SLC4A transporters that move HCO₃^- across cell membranes and regulate intracellular pH or transepithelial HCO₃ transport. NBCe1 is highly selective to HCO₃^- and does not transport other anions; the molecular mechanism of anion selectivity is presently unclear. We previously reported that replacing Asp⁵⁵⁵ with a Glu (D555E) in NBCe1 induces increased selectivity to other anions, including Cl^-. This finding is unexpected because all SLC4A transporters contain either Asp or Glu at the corresponding position and maintain a high selectivity to HCO₃^-. In this study, we tested whether the Cl^- transport in D555E is mediated by an in

SUBMITTER: Lee S 

PROVIDER: S-EPMC8745181 | biostudies-literature | 2022 Jan

REPOSITORIES: biostudies-literature