Atomic force microscopy imaging reveals the formation of ASIC/ENaC cross-clade ion channels

Biochem Biophys Res Commun. 2015 Aug 14;464(1):38-44. doi: 10.1016/j.bbrc.2015.05.091. Epub 2015 May 29.

Abstract

ASIC and ENaC are co-expressed in various cell types, and there is evidence for a close association between them. Here, we used atomic force microscopy (AFM) to determine whether ASIC1a and ENaC subunits are able to form cross-clade hybrid ion channels. ASIC1a and ENaC could be co-isolated from detergent extracts of tsA 201 cells co-expressing the two subunits. Isolated proteins were incubated with antibodies against ENaC and Fab fragments against ASIC1a. AFM imaging revealed proteins that were decorated by both an antibody and a Fab fragment with an angle of ∼120° between them, indicating the formation of ASIC1a/ENaC heterotrimers.

Keywords: Acid-sensing ion channel (ASIC); Atomic force microscopy; Channel assembly; Epithelial Na(+) channel (ENaC).

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acid Sensing Ion Channels / chemistry*
  • Acid Sensing Ion Channels / genetics
  • Acid Sensing Ion Channels / metabolism
  • Animals
  • Antibodies / chemistry
  • CHO Cells
  • Cell Line, Transformed
  • Cricetulus
  • Epithelial Sodium Channels / chemistry*
  • Epithelial Sodium Channels / genetics
  • Epithelial Sodium Channels / metabolism
  • Epitopes / chemistry*
  • Epitopes / metabolism
  • Gene Expression
  • HEK293 Cells
  • Humans
  • Hydrogen-Ion Concentration
  • Microscopy, Atomic Force
  • Patch-Clamp Techniques
  • Protein Multimerization
  • Proto-Oncogene Proteins c-myc / genetics
  • Proto-Oncogene Proteins c-myc / metabolism
  • Recombinant Fusion Proteins / chemistry*
  • Recombinant Fusion Proteins / genetics
  • Recombinant Fusion Proteins / metabolism

Substances

  • ASIC1 protein, human
  • Acid Sensing Ion Channels
  • Antibodies
  • Epithelial Sodium Channels
  • Epitopes
  • MYC protein, human
  • Proto-Oncogene Proteins c-myc
  • Recombinant Fusion Proteins
  • SCNN1A protein, human
  • SCNN1B protein, human
  • SCNN1G protein, human