Abstract

Acid-sensing ion channels (ASICs) are trimeric cation-selective channels activated by decreases in extracellular pH. The intracellular N and C terminal tails of ASIC1 influence channel gating, trafficking, and signaling in ischemic cell death. Despite several x-ray and cryo-EM structures of the extracellular and transmembrane segments of ASIC1, these important intracellular tails remain unresolved. Here we describe the coarse topography of the chicken ASIC1 intracellular domains determined by FRET, measured using either fluorescent lifetime imaging or patch clamp fluorometry. We find the C terminal tail projects into the cytosol by approximately 35 Å and that the N and C tail from the same subunits are closer than adjacent subunits. Using pH-insensitive fluorescent proteins, we fail to detect any relative movement between the N and C tails upon extracellular acidification but do observe axial motions of the membrane proximal segments towards the plasma membrane. Taken together, our study furnishes a coarse topographic map of the ASIC intracellular domains while providing directionality and context to intracellular conformational changes induced by extracellular acidification.

Data availability

All analyzed results contributing to this study are included in the manuscript and supporting files. Source data files have been provided for all figures containing data.

Article and author information

Author details

  1. Tyler Couch

    Department of Pharmacology and Physiology, University of Rochester, Rochester, United States
    Competing interests
    The authors declare that no competing interests exist.
  2. Kyle Berger

    Department of Pharmacology and Physiology, University of Rochester, Rochester, United States
    Competing interests
    The authors declare that no competing interests exist.
  3. Dana L Kneisley

    Department of Pharmacology and Physiology, University of Rochester, Rochester, United States
    Competing interests
    The authors declare that no competing interests exist.
  4. Tyler W McCullock

    Department of Pharmacology and Physiology, University of Rochester, Rochester, United States
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0003-1628-1102
  5. Paul Kammermeier

    Department of Pharmacology and Physiology, University of Rochester, Rochester, United States
    Competing interests
    The authors declare that no competing interests exist.
  6. David M Maclean

    Department of Pharmacology and Physiology, University of Rochester, Rochester, United States
    For correspondence
    David_MacLean@urmc.rochester.edu
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0001-8294-6075

Funding

National Institute of General Medical Sciences (R35GM137951)

  • David M Maclean

National Science Foundation

  • Tyler Couch

The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.

Copyright

© 2021, Couch et al.

This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.

Metrics

  • 1,256
    views
  • 179
    downloads
  • 14
    citations

Views, downloads and citations are aggregated across all versions of this paper published by eLife.

Citations by DOI

Download links

A two-part list of links to download the article, or parts of the article, in various formats.

Downloads (link to download the article as PDF)

Open citations (links to open the citations from this article in various online reference manager services)

Cite this article (links to download the citations from this article in formats compatible with various reference manager tools)

  1. Tyler Couch
  2. Kyle Berger
  3. Dana L Kneisley
  4. Tyler W McCullock
  5. Paul Kammermeier
  6. David M Maclean
(2021)
Topography and motion of the acid-sensing ion channel intracellular domains
eLife 10:e68955.
https://doi.org/10.7554/eLife.68955

Share this article

https://doi.org/10.7554/eLife.68955