Specificity of anion exchange mediated by mouse Slc26a6.

摘要: Abstract Recently, CFEX, the mouse orthologue of human SLC26A6, was localized to brush border membrane proximal tubule cells and demonstrated mediate Cl−-formate exchange when expressed in Xenopus oocytes. The purpose present study examine whether Slc26a6 can one or more additional anion processes observed take place across apical cells. Influx [14C]formate into Slc26a6-expressing oocytes inhibited by sulfate, oxalate, p-aminohippurate (PAH), indicating affinity for these anions. Measurements uptake [14C]oxalate, [14C]PAH, [35S]sulfate indicated that transport oxalate sulfate but not PAH. Studies effect external anions on [14C]oxalate efflux Slc26a6-mediated Cl−-oxalate, oxalate-formate, oxalate-oxalate, oxalate-sulfate exchange. Two-electrode voltage clamp measurements Cl−-oxalate is electrogenic. Intracellular pH recordings Cl−-HCO exchange, Cl−-OH− detected. presence 100 μm rate 60%. We conclude has HCO addition Cl− formate function multiple modes involving pairs In high concentrations as found renal tubular fluid urine, may largely an electrogenic exchanger.