Keratinocytes contribute to normal cold and heat sensation
- Medical College of Wisconsin, United States
Abstract
The molecular bases of heteromeric assembly and link between Na+ self-inhibition and protease-sensitivity in epithelial sodium channels (ENaCs) are not fully understood. Previously, we demonstrated that ENaC subunits – α, β, and γ – assemble in a counterclockwise configuration when viewed from outside the cell with the protease-sensitive GRIP domains in the periphery (Noreng et al., 2018). Here we describe the structure of ENaC resolved by cryo-electron microscopy at 3 Å. We find that a combination of precise domain arrangement and complementary hydrogen bonding network defines the subunit arrangement. Furthermore, we determined that the α subunit has a primary functional module consisting of the finger and GRIP domains. The module is bifurcated by the α2 helix dividing two distinct regulatory sites: Na+ and the inhibitory peptide. Removal of the inhibitory peptide perturbs the Na+ site via the α2 helix highlighting the critical role of the α2 helix in regulating ENaC function.
Data availability
All data generated or analyzed during this study are included in the manuscript and supporting files.
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Author details
Funding
National Institutes of Health (NS040538)
- Cheryl L Stucky
National Institutes of Health (NS070711)
- Cheryl L Stucky
National Institutes of Health (NS108278)
- Cheryl L Stucky
National Institutes of Health (NS106789)
- Katelyn E Sadler
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Ethics
Animal experimentation: All protocols were in accordance with National Institutes of Health guidelines and were approved by the Institutional Animal Care and Use Committee at the Medical College of Wisconsin (Milwaukee, WI; protocol #383).
Copyright
© 2020, Sadler 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.
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Keratinocytes contribute to normal cold and heat sensation
eLife 9:e58625.
https://doi.org/10.7554/eLife.58625
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