Find in Library
Search millions of books, articles, and more
Indexed Open Access Databases
K<sup>+</sup>-Driven Cl<sup>−</sup>/HCO<sub>3</sub><sup>−</sup> Exchange Mediated by Slc4a8 and Slc4a10
oleh: Gaspar Peña-Münzenmayer, Alvin T. George, Nuria Llontop, Yuliet Mazola, Natalia Apablaza, Carlos Spichiger, Sebastián Brauchi, José Sarmiento, Leandro Zúñiga, Wendy González, Marcelo A. Catalán
Format: | Article |
---|---|
Diterbitkan: | MDPI AG 2024-04-01 |
Deskripsi
Slc4a genes encode various types of transporters, including Na<sup>+</sup>-HCO<sub>3</sub><sup>−</sup> cotransporters, Cl<sup>−</sup>/HCO<sub>3</sub><sup>−</sup> exchangers, or Na<sup>+</sup>-driven Cl<sup>−</sup>/HCO<sub>3</sub><sup>−</sup> exchangers. Previous research has revealed that Slc4a9 (Ae4) functions as a Cl<sup>−</sup>/HCO<sub>3</sub><sup>−</sup> exchanger, which can be driven by either Na<sup>+</sup> or K<sup>+</sup>, prompting investigation into whether other Slc4a members facilitate cation-dependent anion transport. In the present study, we show that either Na<sup>+</sup> or K<sup>+</sup> drive Cl<sup>−</sup>/HCO<sub>3</sub><sup>−</sup> exchanger activity in cells overexpressing Slc4a8 or Slc4a10. Further characterization of cation-driven Cl<sup>−</sup>/HCO<sub>3</sub><sup>−</sup> exchange demonstrated that Slc4a8 and Slc4a10 also mediate Cl<sup>−</sup> and HCO<sub>3</sub><sup>−</sup>-dependent K<sup>+</sup> transport. Full-atom molecular dynamics simulation on the recently solved structure of Slc4a8 supports the coordination of K<sup>+</sup> at the Na<sup>+</sup> binding site in S1. Sequence analysis shows that the critical residues coordinating monovalent cations are conserved among mouse Slc4a8 and Slc4a10 proteins. Together, our results suggest that Slc4a8 and Slc4a10 might transport K<sup>+</sup> in the same direction as HCO<sub>3</sub><sup>−</sup> ions in a similar fashion to that described for Na<sup>+</sup> transport in the rat Slc4a8 structure.