Characterization of the L683P mutation of SLC26A9 in Xenopus oocytes

► In the present study, we characterized a STAS-domain amino acid mutation of SLC26A9 having a significant impact on ion transport. ► This mutation was found to reduce Cl− transport through SLC26A9 as well as the positive interaction exerted by SLC26A9 on CFTR ion transport activity. ► This study strengthens the role of the STAS domain in channel function as accounted for its interaction or stabilization of CFTR. ► SLC26A9 mutations in the STAS domain may be associated with some “cystic fibrosis-like” patient phenotypes that do not imply a CFTR gene defect.