LOCALIZATION OF A BAND 3-RELATED PROTEIN IN THE MITOCHONDRIA-RICH CELLS OF AMPHIBIAN SKIN EPITHELIUM

Based on immunoblotting procedure, the isolated epithelium of amphibia n skin was found to contain a 180 kDa protein which cross-reacts with a polyclonal antiserum raised against human erythrocyte Band 3. Immuno peroxidase and immunofluorescence staining techniques indicated that t he Band 3-related protein was localized in the mitochondria-rich cells (MRC) of this epithelium, with characteristic apical labelling patter n. Our findings show that the putative apical anion exchanger of the M RC is immunologically related to the band 3 multigenic family, which c atalyzes Cl--HCO3- transmembranous exchange. It thus suggests a molecu lar basis for the role played by these cells in the transepithelial Cl - pathway and acid-base regulation.