|Name:||solute carrier family 4 (anion exchanger), member 1, adaptor protein|
|Old Name:||solute carrier family 4 (anion exchanger), member 1, adapter protein|
|PubMed (9422766):|| Chen J, Vijayakumar S, Li X, Al-Awqati Q. Kanadaptin is a protein that interacts with the kidney but not the erythroidform of band 3.J Biol Chem. 1998 Jan 9;273(2):1038-43. PMID: 9422766 [PubMed - indexed for MEDLINE]|
Although epithelial membrane proteins are separately targeted to apical or basolateral domains, some are apically located in one cell type but are basolateral in others. More dramatically, the anion exchanger of a clonal cell line of intercalated cells derived from the kidney can be retargeted from the apical to basolateral domain. This Cl:HCO3 exchanger, kAE1, is an alternately spliced form of the erythroid anion exchanger (AE1, band 3), but unlike band 3 it does not bind ankyrin. Here we identify a new protein (kanadaptin) that binds to the cytoplasmic domain of kAE1 in vitro and in vivo but not to the erythroid AE1 or to ankyrin. No significant homologous proteins have been reported so far. Kanadaptin is widely expressed in epithelial (kidney, lung, and liver) and non-epithelial cells (brain and skeletal and cardiac muscle). In kidney, we found by immunocytochemistry that kanadaptin was only expressed in the collecting tubule. In the intercalated cells of this segment, it colocalized with kAE1 in cytoplasmic vesicles but not when the exchanger was in the basolateral membrane. These results raised the possibility that this protein is involved in the targeting of kAE1 vesicles to their final destination.