Electroneutral sodium- and bicarbonate-dependent cotransporter with a Na(+):HCO3(-) 1:1 stoichiometry. Regulates intracellular pH and may play a role in bicarbonate salvage in secretory epithelia. May also have an associated sodium channel activity. Transporter activity is regulated by CA2/carbonic anhydrase 2, cAMP and PKA. Insensitive to stilbene derivatives. PubMed:10347222 states it is inhibited by 5-(N-ethyl-N-isopropyl)-amiloride (EIPA). Interacts with CFTR through SLC9A3R1/EBP50. Interacts with USH1C. Forms a complex with ATP6V1B1 and SLC9A3R1/EBP50. Interacts in a pH dependent-manner with CA2/carbonic anhydrase 2. Also described at the apical cell membrane. Localizes to the stereocilia of cochlear outer hair cells and to the lateral membrane of cochlear inner hair cells (By similarity). Highly expressed in testis and spleen. Also expressed in retina, colon, small intestine, ovary, thymus, prostate, muscle, heart and kidney. Isoform 1 is expressed in skeletal muscle and heart muscle. The PDZ-binding motif mediates interaction with the CFTR, SLC9A3R1/EBP50 complex and probably with USH1C. Belongs to the anion exchanger (TC 2.A.31) family.