Neuronal junctophilins recruit specific CaV and RyR isoforms to ER-PM junctions and functionally alter CaV2.1 and CaV2.2

  1. Stefano Perni
  2. Kurt Beam  Is a corresponding author
  1. University of Colorado Anschutz Medical Campus, United States

Abstract

Despite their recognized physiological importance, the molecular architecture of ER-PM junctions induced by neuronal junctophilins (JPH3 and JPH4) is still poorly understood and challenging to address in neurons. This is due to the small size of the junctions and to the multiple isoforms of candidate junctional proteins in different brain areas. Using colocalization of tagged proteins expressed in tsA201 cells, and electrophysiology, we compared the interactions of JPH3 and JPH4 with different calcium channels. We found that JPH3 and JPH4 caused junctional accumulation of all the tested high-voltage-activated CaV isoforms, but not a low-voltage-activated CaV. Also, JPH3 and JPH4 noticeably modify CaV2.1 and CaV2.2 inactivation rate. RyR3 moderately colocalized at junctions with JPH4, whereas RyR1 and RyR2 did not. By contrast, RyR1 and RyR3 strongly colocalized with JPH3, and RyR2 moderately. Likely contributing to this difference, JPH3 binds to cytoplasmic domain constructs of RyR1 and RyR3, but not of RyR2.

Data availability

Raw data for peak current vs voltage, inactivation vs voltage, and Pearson's coefficients have been provided with the uploaded manuscript files.

Article and author information

Author details

  1. Stefano Perni

    Physiology & Biophysics, University of Colorado Anschutz Medical Campus, Aurora, United States
    Competing interests
    No competing interests declared.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0002-0591-4376
  2. Kurt Beam

    Physiology & Biophysics, University of Colorado Anschutz Medical Campus, Aurora, United States
    For correspondence
    kurt.beam@cuanschutz.edu
    Competing interests
    Kurt Beam, Reviewing editor, eLife.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0001-6902-085X

Funding

NIH Office of the Director (R01 AR070298)

  • Kurt Beam

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

Reviewing Editor

  1. Mark T Nelson, University of Vermont, United States

Version history

  1. Received: October 22, 2020
  2. Accepted: March 19, 2021
  3. Accepted Manuscript published: March 26, 2021 (version 1)
  4. Version of Record published: April 14, 2021 (version 2)

Copyright

© 2021, Perni & Beam

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.

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  1. Stefano Perni
  2. Kurt Beam
(2021)
Neuronal junctophilins recruit specific CaV and RyR isoforms to ER-PM junctions and functionally alter CaV2.1 and CaV2.2
eLife 10:e64249.
https://doi.org/10.7554/eLife.64249

Share this article

https://doi.org/10.7554/eLife.64249

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