Localization of amiloride-sensitive sodium channels in A6 cells by atomic force microscopy

Academic Article

Abstract

  • Atomic force microscopy (AFM) was used for high-resolution imaging of the apical distribution of epithelial Na+ channels in A6 renal epithelial cells. A6 cells grown on coverslips were labeled with antibodies generated against an amiloride-sensitive epithelial Na+ channel complex purified from bovine renal medulla that had been conjugated to 8-nm colloidal gold particles before preparation for AFM. AFM revealed that there was a marked increase in the height of the microvilli in cells labeled with the anti- epithelial Na+ channel antibodies compared with unlabeled cells or cells labeled with rabbit nonimmune immunoglobulin G conjugated to colloidal gold particles. We interpret this apparent increase in microvillar height to be due to anti-epithelial Na+ channel antibody binding to the apical microvilli. These data demonstrate that epithelial Na+ channels are restricted to the apical microvilli in Na+ -transporting renal epithelial cells. Furthermore, they demonstrate the applicability of using AFM for high- resolution imaging of the cell surface distribution of epithelial ion channels.
  • Authors

    Digital Object Identifier (doi)

    Author List

  • Smith PR; Bradford AL; Schneider S; Benos DJ; Geibel JP
  • Volume

  • 272
  • Issue

  • 4 41-4