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Insights into the molecular mechanisms underlying the inhibition of acid-sensing ion channel 3 gating by stomatin

Stomatin (STOM) is a monotopic integral membrane protein found in all classes of life that has been shown to regulate members of the acid-sensing ion channel (ASIC) family. However, the mechanism by which STOM alters ASIC function is not known. Using chimeric channels, we combined patch-clamp electr...

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Autores principales: Klipp, Robert C., Cullinan, Megan M., Bankston, John R.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Rockefeller University Press 2020
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7054857/
https://www.ncbi.nlm.nih.gov/pubmed/32012213
http://dx.doi.org/10.1085/jgp.201912471
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author Klipp, Robert C.
Cullinan, Megan M.
Bankston, John R.
author_facet Klipp, Robert C.
Cullinan, Megan M.
Bankston, John R.
author_sort Klipp, Robert C.
collection PubMed
description Stomatin (STOM) is a monotopic integral membrane protein found in all classes of life that has been shown to regulate members of the acid-sensing ion channel (ASIC) family. However, the mechanism by which STOM alters ASIC function is not known. Using chimeric channels, we combined patch-clamp electrophysiology and FRET to search for regions of ASIC3 critical for binding to and regulation by STOM. With this approach, we found that regulation requires two distinct sites on ASIC3: the distal C-terminus and the first transmembrane domain (TM1). The C-terminal site is critical for formation of the STOM–ASIC3 complex, while TM1 is required only for the regulatory effect. We then looked at the mechanism of STOM-dependent regulation of ASIC3 and found that STOM does not alter surface expression of ASIC3 or shift the pH dependence of channel activation. However, a point mutation (Q269G) that prevents channel desensitization also prevents STOM regulation, suggesting that STOM may alter ASIC3 currents by stabilizing the desensitized state of the channel. Based on these findings, we propose a model whereby STOM is anchored to the channel via a site on the distal C-terminus and stabilizes the desensitized state of the channel via an interaction with TM1.
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spelling pubmed-70548572020-09-02 Insights into the molecular mechanisms underlying the inhibition of acid-sensing ion channel 3 gating by stomatin Klipp, Robert C. Cullinan, Megan M. Bankston, John R. J Gen Physiol Article Stomatin (STOM) is a monotopic integral membrane protein found in all classes of life that has been shown to regulate members of the acid-sensing ion channel (ASIC) family. However, the mechanism by which STOM alters ASIC function is not known. Using chimeric channels, we combined patch-clamp electrophysiology and FRET to search for regions of ASIC3 critical for binding to and regulation by STOM. With this approach, we found that regulation requires two distinct sites on ASIC3: the distal C-terminus and the first transmembrane domain (TM1). The C-terminal site is critical for formation of the STOM–ASIC3 complex, while TM1 is required only for the regulatory effect. We then looked at the mechanism of STOM-dependent regulation of ASIC3 and found that STOM does not alter surface expression of ASIC3 or shift the pH dependence of channel activation. However, a point mutation (Q269G) that prevents channel desensitization also prevents STOM regulation, suggesting that STOM may alter ASIC3 currents by stabilizing the desensitized state of the channel. Based on these findings, we propose a model whereby STOM is anchored to the channel via a site on the distal C-terminus and stabilizes the desensitized state of the channel via an interaction with TM1. Rockefeller University Press 2020-02-03 /pmc/articles/PMC7054857/ /pubmed/32012213 http://dx.doi.org/10.1085/jgp.201912471 Text en © 2020 Klipp et al. http://www.rupress.org/terms/https://creativecommons.org/licenses/by-nc-sa/4.0/This article is distributed under the terms of an Attribution–Noncommercial–Share Alike–No Mirror Sites license for the first six months after the publication date (see http://www.rupress.org/terms/). After six months it is available under a Creative Commons License (Attribution–Noncommercial–Share Alike 4.0 International license, as described at https://creativecommons.org/licenses/by-nc-sa/4.0/).
spellingShingle Article
Klipp, Robert C.
Cullinan, Megan M.
Bankston, John R.
Insights into the molecular mechanisms underlying the inhibition of acid-sensing ion channel 3 gating by stomatin
title Insights into the molecular mechanisms underlying the inhibition of acid-sensing ion channel 3 gating by stomatin
title_full Insights into the molecular mechanisms underlying the inhibition of acid-sensing ion channel 3 gating by stomatin
title_fullStr Insights into the molecular mechanisms underlying the inhibition of acid-sensing ion channel 3 gating by stomatin
title_full_unstemmed Insights into the molecular mechanisms underlying the inhibition of acid-sensing ion channel 3 gating by stomatin
title_short Insights into the molecular mechanisms underlying the inhibition of acid-sensing ion channel 3 gating by stomatin
title_sort insights into the molecular mechanisms underlying the inhibition of acid-sensing ion channel 3 gating by stomatin
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7054857/
https://www.ncbi.nlm.nih.gov/pubmed/32012213
http://dx.doi.org/10.1085/jgp.201912471
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