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Cryo-EM structure of human Cx31.3/GJC3 connexin hemichannel

Connexin family proteins assemble into hexameric channels called hemichannels/connexons, which function as transmembrane channels or dock together to form gap junction intercellular channels (GJIChs). We determined the cryo–electron microscopy structures of human connexin 31.3 (Cx31.3)/GJC3 hemichan...

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Autores principales: Lee, Hyuk-Joon, Jeong, Hyeongseop, Hyun, Jaekyung, Ryu, Bumhan, Park, Kunwoong, Lim, Hyun-Ho, Yoo, Jejoong, Woo, Jae-Sung
Formato: Online Artículo Texto
Lenguaje:English
Publicado: American Association for the Advancement of Science 2020
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7455182/
https://www.ncbi.nlm.nih.gov/pubmed/32923625
http://dx.doi.org/10.1126/sciadv.aba4996
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author Lee, Hyuk-Joon
Jeong, Hyeongseop
Hyun, Jaekyung
Ryu, Bumhan
Park, Kunwoong
Lim, Hyun-Ho
Yoo, Jejoong
Woo, Jae-Sung
author_facet Lee, Hyuk-Joon
Jeong, Hyeongseop
Hyun, Jaekyung
Ryu, Bumhan
Park, Kunwoong
Lim, Hyun-Ho
Yoo, Jejoong
Woo, Jae-Sung
author_sort Lee, Hyuk-Joon
collection PubMed
description Connexin family proteins assemble into hexameric channels called hemichannels/connexons, which function as transmembrane channels or dock together to form gap junction intercellular channels (GJIChs). We determined the cryo–electron microscopy structures of human connexin 31.3 (Cx31.3)/GJC3 hemichannels in the presence and absence of calcium ions and with a hearing-loss mutation R15G at 2.3-, 2.5-, and 2.6-Å resolutions, respectively. Compared with available structures of GJICh in open conformation, Cx31.3 hemichannel shows substantial structural changes of highly conserved regions in the connexin family, including opening of calcium ion–binding tunnels, reorganization of salt-bridge networks, exposure of lipid-binding sites, and collocation of amino-terminal helices at the cytoplasmic entrance. We also found that the hemichannel has a pore with a diameter of ~8 Å and selectively transports chloride ions. Our study provides structural insights into the permeant selectivity of Cx31.3 hemichannel.
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spelling pubmed-74551822020-09-11 Cryo-EM structure of human Cx31.3/GJC3 connexin hemichannel Lee, Hyuk-Joon Jeong, Hyeongseop Hyun, Jaekyung Ryu, Bumhan Park, Kunwoong Lim, Hyun-Ho Yoo, Jejoong Woo, Jae-Sung Sci Adv Research Articles Connexin family proteins assemble into hexameric channels called hemichannels/connexons, which function as transmembrane channels or dock together to form gap junction intercellular channels (GJIChs). We determined the cryo–electron microscopy structures of human connexin 31.3 (Cx31.3)/GJC3 hemichannels in the presence and absence of calcium ions and with a hearing-loss mutation R15G at 2.3-, 2.5-, and 2.6-Å resolutions, respectively. Compared with available structures of GJICh in open conformation, Cx31.3 hemichannel shows substantial structural changes of highly conserved regions in the connexin family, including opening of calcium ion–binding tunnels, reorganization of salt-bridge networks, exposure of lipid-binding sites, and collocation of amino-terminal helices at the cytoplasmic entrance. We also found that the hemichannel has a pore with a diameter of ~8 Å and selectively transports chloride ions. Our study provides structural insights into the permeant selectivity of Cx31.3 hemichannel. American Association for the Advancement of Science 2020-08-28 /pmc/articles/PMC7455182/ /pubmed/32923625 http://dx.doi.org/10.1126/sciadv.aba4996 Text en Copyright © 2020 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works. Distributed under a Creative Commons Attribution License 4.0 (CC BY). https://creativecommons.org/licenses/by/4.0/ https://creativecommons.org/licenses/by/4.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution license (https://creativecommons.org/licenses/by/4.0/) , which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
spellingShingle Research Articles
Lee, Hyuk-Joon
Jeong, Hyeongseop
Hyun, Jaekyung
Ryu, Bumhan
Park, Kunwoong
Lim, Hyun-Ho
Yoo, Jejoong
Woo, Jae-Sung
Cryo-EM structure of human Cx31.3/GJC3 connexin hemichannel
title Cryo-EM structure of human Cx31.3/GJC3 connexin hemichannel
title_full Cryo-EM structure of human Cx31.3/GJC3 connexin hemichannel
title_fullStr Cryo-EM structure of human Cx31.3/GJC3 connexin hemichannel
title_full_unstemmed Cryo-EM structure of human Cx31.3/GJC3 connexin hemichannel
title_short Cryo-EM structure of human Cx31.3/GJC3 connexin hemichannel
title_sort cryo-em structure of human cx31.3/gjc3 connexin hemichannel
topic Research Articles
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7455182/
https://www.ncbi.nlm.nih.gov/pubmed/32923625
http://dx.doi.org/10.1126/sciadv.aba4996
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