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

Hyuk Joon Lee, Hyeongseop Jeong, Jaekyung Hyun, Bumhan Ryu, Kunwoong Park, Hyun Ho Lim, Jejoong Yoo, Jae Sung Woo

Research output: Contribution to journalArticlepeer-review

4 Citations (Scopus)

Abstract

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.

Original languageEnglish
Article numbereaba4996
JournalScience Advances
Volume6
Issue number35
DOIs
Publication statusPublished - 2020 Aug

ASJC Scopus subject areas

  • General

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