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Cryo-EM analysis of PIP(2) regulation in mammalian GIRK channels
G-protein-gated inward rectifier potassium (GIRK) channels are regulated by G proteins and PIP(2). Here, using cryo-EM single particle analysis we describe the equilibrium ensemble of structures of neuronal GIRK2 as a function of the C8-PIP(2) concentration. We find that PIP(2) shifts the equilibriu...
Autores principales: | , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
eLife Sciences Publications, Ltd
2020
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7556866/ https://www.ncbi.nlm.nih.gov/pubmed/32844743 http://dx.doi.org/10.7554/eLife.60552 |
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author | Niu, Yiming Tao, Xiao Touhara, Kouki K MacKinnon, Roderick |
author_facet | Niu, Yiming Tao, Xiao Touhara, Kouki K MacKinnon, Roderick |
author_sort | Niu, Yiming |
collection | PubMed |
description | G-protein-gated inward rectifier potassium (GIRK) channels are regulated by G proteins and PIP(2). Here, using cryo-EM single particle analysis we describe the equilibrium ensemble of structures of neuronal GIRK2 as a function of the C8-PIP(2) concentration. We find that PIP(2) shifts the equilibrium between two distinguishable structures of neuronal GIRK (GIRK2), extended and docked, towards the docked form. In the docked form the cytoplasmic domain, to which G(βγ) binds, becomes accessible to the cytoplasmic membrane surface where G(βγ) resides. Furthermore, PIP(2) binding reshapes the G(βγ) binding surface on the cytoplasmic domain, preparing it to receive G(βγ). We find that cardiac GIRK (GIRK1/4) can also exist in both extended and docked conformations. These findings lead us to conclude that PIP(2) influences GIRK channels in a structurally similar manner to Kir2.2 channels. In Kir2.2 channels, the PIP(2)-induced conformational changes open the pore. In GIRK channels, they prepare the channel for activation by G(βγ). |
format | Online Article Text |
id | pubmed-7556866 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2020 |
publisher | eLife Sciences Publications, Ltd |
record_format | MEDLINE/PubMed |
spelling | pubmed-75568662020-10-16 Cryo-EM analysis of PIP(2) regulation in mammalian GIRK channels Niu, Yiming Tao, Xiao Touhara, Kouki K MacKinnon, Roderick eLife Structural Biology and Molecular Biophysics G-protein-gated inward rectifier potassium (GIRK) channels are regulated by G proteins and PIP(2). Here, using cryo-EM single particle analysis we describe the equilibrium ensemble of structures of neuronal GIRK2 as a function of the C8-PIP(2) concentration. We find that PIP(2) shifts the equilibrium between two distinguishable structures of neuronal GIRK (GIRK2), extended and docked, towards the docked form. In the docked form the cytoplasmic domain, to which G(βγ) binds, becomes accessible to the cytoplasmic membrane surface where G(βγ) resides. Furthermore, PIP(2) binding reshapes the G(βγ) binding surface on the cytoplasmic domain, preparing it to receive G(βγ). We find that cardiac GIRK (GIRK1/4) can also exist in both extended and docked conformations. These findings lead us to conclude that PIP(2) influences GIRK channels in a structurally similar manner to Kir2.2 channels. In Kir2.2 channels, the PIP(2)-induced conformational changes open the pore. In GIRK channels, they prepare the channel for activation by G(βγ). eLife Sciences Publications, Ltd 2020-08-26 /pmc/articles/PMC7556866/ /pubmed/32844743 http://dx.doi.org/10.7554/eLife.60552 Text en © 2020, Niu et al http://creativecommons.org/licenses/by/4.0/ http://creativecommons.org/licenses/by/4.0/This article is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/) , which permits unrestricted use and redistribution provided that the original author and source are credited. |
spellingShingle | Structural Biology and Molecular Biophysics Niu, Yiming Tao, Xiao Touhara, Kouki K MacKinnon, Roderick Cryo-EM analysis of PIP(2) regulation in mammalian GIRK channels |
title | Cryo-EM analysis of PIP(2) regulation in mammalian GIRK channels |
title_full | Cryo-EM analysis of PIP(2) regulation in mammalian GIRK channels |
title_fullStr | Cryo-EM analysis of PIP(2) regulation in mammalian GIRK channels |
title_full_unstemmed | Cryo-EM analysis of PIP(2) regulation in mammalian GIRK channels |
title_short | Cryo-EM analysis of PIP(2) regulation in mammalian GIRK channels |
title_sort | cryo-em analysis of pip(2) regulation in mammalian girk channels |
topic | Structural Biology and Molecular Biophysics |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7556866/ https://www.ncbi.nlm.nih.gov/pubmed/32844743 http://dx.doi.org/10.7554/eLife.60552 |
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