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Mutation of a conserved glutamine residue does not abolish desensitization of acid-sensing ion channel 1
Desensitization is a common feature of ligand-gated ion channels, although the molecular cause varies widely between channel types. Mutations that greatly reduce or nearly abolish desensitization have been described for many ligand-gated ion channels, including glutamate, GABA, glycine, and nicotini...
Autores principales: | , , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
Rockefeller University Press
2021
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8167889/ https://www.ncbi.nlm.nih.gov/pubmed/34061161 http://dx.doi.org/10.1085/jgp.202012855 |
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author | Rook, Matthew L. Miaro, Megan Couch, Tyler Kneisley, Dana L. Musgaard, Maria MacLean, David M. |
author_facet | Rook, Matthew L. Miaro, Megan Couch, Tyler Kneisley, Dana L. Musgaard, Maria MacLean, David M. |
author_sort | Rook, Matthew L. |
collection | PubMed |
description | Desensitization is a common feature of ligand-gated ion channels, although the molecular cause varies widely between channel types. Mutations that greatly reduce or nearly abolish desensitization have been described for many ligand-gated ion channels, including glutamate, GABA, glycine, and nicotinic receptors, but not for acid-sensing ion channels (ASICs) until recently. Mutating Gln276 to a glycine (Q276G) in human ASIC1a was reported to mostly abolish desensitization at both the macroscopic and the single channel levels, potentially providing a valuable tool for subsequent studies. However, we find that in both human and chicken ASIC1, the effect of Q276G is modest. In chicken ASIC1, the equivalent Q277G slightly reduces desensitization when using pH 6.5 as a stimulus but desensitizes, essentially like wild-type, when using more acidic pH values. In addition, steady-state desensitization is intact, albeit right-shifted, and recovery from desensitization is accelerated. Molecular dynamics simulations indicate that the Gln277 side chain participates in a hydrogen bond network that might stabilize the desensitized conformation. Consistent with this, destabilizing this network with the Q277N or Q277L mutations largely mimics the Q277G phenotype. In human ASIC1a, the Q276G mutation also reduces desensitization, but not to the extent reported previously. Interestingly, the kinetic consequences of Q276G depend on the human variant used. In the common G212 variant, Q276G slows desensitization, while in the rare D212 variant desensitization accelerates. Our data reveal that while the Q/G mutation does not abolish or substantially impair desensitization as previously reported, it does point to unexpected differences between chicken and human ASICs and the need for careful scrutiny before using this mutation in future studies. |
format | Online Article Text |
id | pubmed-8167889 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2021 |
publisher | Rockefeller University Press |
record_format | MEDLINE/PubMed |
spelling | pubmed-81678892022-02-02 Mutation of a conserved glutamine residue does not abolish desensitization of acid-sensing ion channel 1 Rook, Matthew L. Miaro, Megan Couch, Tyler Kneisley, Dana L. Musgaard, Maria MacLean, David M. J Gen Physiol Communication Desensitization is a common feature of ligand-gated ion channels, although the molecular cause varies widely between channel types. Mutations that greatly reduce or nearly abolish desensitization have been described for many ligand-gated ion channels, including glutamate, GABA, glycine, and nicotinic receptors, but not for acid-sensing ion channels (ASICs) until recently. Mutating Gln276 to a glycine (Q276G) in human ASIC1a was reported to mostly abolish desensitization at both the macroscopic and the single channel levels, potentially providing a valuable tool for subsequent studies. However, we find that in both human and chicken ASIC1, the effect of Q276G is modest. In chicken ASIC1, the equivalent Q277G slightly reduces desensitization when using pH 6.5 as a stimulus but desensitizes, essentially like wild-type, when using more acidic pH values. In addition, steady-state desensitization is intact, albeit right-shifted, and recovery from desensitization is accelerated. Molecular dynamics simulations indicate that the Gln277 side chain participates in a hydrogen bond network that might stabilize the desensitized conformation. Consistent with this, destabilizing this network with the Q277N or Q277L mutations largely mimics the Q277G phenotype. In human ASIC1a, the Q276G mutation also reduces desensitization, but not to the extent reported previously. Interestingly, the kinetic consequences of Q276G depend on the human variant used. In the common G212 variant, Q276G slows desensitization, while in the rare D212 variant desensitization accelerates. Our data reveal that while the Q/G mutation does not abolish or substantially impair desensitization as previously reported, it does point to unexpected differences between chicken and human ASICs and the need for careful scrutiny before using this mutation in future studies. Rockefeller University Press 2021-06-01 /pmc/articles/PMC8167889/ /pubmed/34061161 http://dx.doi.org/10.1085/jgp.202012855 Text en © 2021 Rook 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 | Communication Rook, Matthew L. Miaro, Megan Couch, Tyler Kneisley, Dana L. Musgaard, Maria MacLean, David M. Mutation of a conserved glutamine residue does not abolish desensitization of acid-sensing ion channel 1 |
title | Mutation of a conserved glutamine residue does not abolish desensitization of acid-sensing ion channel 1 |
title_full | Mutation of a conserved glutamine residue does not abolish desensitization of acid-sensing ion channel 1 |
title_fullStr | Mutation of a conserved glutamine residue does not abolish desensitization of acid-sensing ion channel 1 |
title_full_unstemmed | Mutation of a conserved glutamine residue does not abolish desensitization of acid-sensing ion channel 1 |
title_short | Mutation of a conserved glutamine residue does not abolish desensitization of acid-sensing ion channel 1 |
title_sort | mutation of a conserved glutamine residue does not abolish desensitization of acid-sensing ion channel 1 |
topic | Communication |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8167889/ https://www.ncbi.nlm.nih.gov/pubmed/34061161 http://dx.doi.org/10.1085/jgp.202012855 |
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