{"id":3172,"date":"2025-12-11T09:30:14","date_gmt":"2025-12-11T00:30:14","guid":{"rendered":"https:\/\/pf-form.kek.jp\/sbrc\/?p=3172"},"modified":"2025-12-18T12:24:56","modified_gmt":"2025-12-18T03:24:56","slug":"seminar31","status":"publish","type":"post","link":"https:\/\/pf-form.kek.jp\/sbrc\/seminar31\/","title":{"rendered":"SBRC International Cryo-EM Seminar No.31"},"content":{"rendered":"\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\">\n<h2 class=\"wp-block-heading\">\u201cFrom Plaques to Pores: In Situ Architecture and Isoform-Specific Gating of Human Gap Junction Channels\u201d<\/h2>\n<\/blockquote>\n\n\n\n<p> _<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Date and Time<\/h2>\n\n\n\n<p style=\"font-size:25px\">4:00 PM &#8211; 5:30 PM Thursday, January 22<sup>nd<\/sup>, 2026<\/p>\n\n\n\n<p><\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Location<\/h2>\n\n\n\n<p style=\"font-size:25px\">Hybrid\uff08CryoEM building and Zoom\uff09<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\" \/>\n\n\n\n<h2 class=\"wp-block-heading\" style=\"font-size:30px\">Speaker<\/h2>\n\n\n\n<figure class=\"wp-block-image size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"320\" height=\"320\" src=\"http:\/\/pf-form.kek.jp\/sbrc\/wp-content\/uploads\/sites\/39\/2025\/12\/Juha-Huiskonen.jpeg\" alt=\"\" class=\"wp-image-3173\" srcset=\"https:\/\/pf-form.kek.jp\/sbrc\/wp-content\/uploads\/sites\/39\/2025\/12\/Juha-Huiskonen.jpeg 320w, https:\/\/pf-form.kek.jp\/sbrc\/wp-content\/uploads\/sites\/39\/2025\/12\/Juha-Huiskonen-300x300.jpeg 300w, https:\/\/pf-form.kek.jp\/sbrc\/wp-content\/uploads\/sites\/39\/2025\/12\/Juha-Huiskonen-150x150.jpeg 150w\" sizes=\"auto, (max-width: 320px) 100vw, 320px\" \/><\/figure>\n\n\n\n<h2 class=\"wp-block-heading\" style=\"font-size:28px\">Juha Huiskonen<\/h2>\n\n\n\n<p>Professor of Structural Biology, University of Helsinki<br>Director of the Institute of Biotechnology (HiLIFE \u2013 Helsinki Institute of Life Science)<br>Member of the Molecular and Integrative Biosciences Research Programme<br>Head of the Laboratory of Structural Biology at the Institute of Biotechnology<\/p>\n\n\n\n<hr class=\"wp-block-separator has-css-opacity is-style-dots\" \/>\n\n\n\n<h2 class=\"wp-block-heading\">Abstract<\/h2>\n\n\n\n<p>Gap junction channels formed by connexins underpin electrical and biochemical coupling across tissues, yet the structural principles that govern their assembly and gating remain only partially defined. I will present two complementary structural studies that bridge native-membrane organization with atomic-level mechanisms of channel function. Our&nbsp;in situ cryo-ET structure of human Cx43&nbsp;gap junction plaques at 14 \u00c5 reveals how the extensive C-terminal domain mediates lateral channel interactions critical for plaque formation. Supported by molecular simulations, we identify lipid and cholesterol densities between channels, resolving long-standing questions about the molecular determinants of gap junction lattice organization. In parallel,&nbsp;cryo-EM structures of human Cx45&nbsp;in apo and Ca\u00b2\u207a-bound forms at near-atomic resolution describe a compact and uniquely shaped pore, distinct N-terminal conformations, and C-terminal\u2013intracellular loop interactions that define an isoform-specific gating mechanism. Ca\u00b2\u207a binding stabilizes a new conformation of E41 without inducing global motion, highlighting a subtle regulatory mechanism consistent with a semi-closed state.<br>Together, these findings contribute to an integrated view of connexin biology, revealing how structural diversity across isoforms and spatial organization within plaques contribute to tissue-specific modes of intercellular communication.<\/p>\n\n\n\n<p><\/p>\n\n\n\n<hr class=\"wp-block-separator has-css-opacity is-style-dots\" \/>\n\n\n\n<h2 class=\"wp-block-heading has-text-align-center has-white-color has-cyan-bluish-gray-background-color has-text-color has-background\"><a href=\"https:\/\/pf-form.kek.jp\/sbrc\/registration_for_internationalseminar\/\" data-type=\"link\" data-id=\"https:\/\/pf-form.kek.jp\/sbrc\/registration_for_international_seminar\/\" target=\"_blank\" rel=\"noreferrer noopener\">Click here to apply<\/a><\/h2>\n","protected":false},"excerpt":{"rendered":"<p>\u201cFrom Plaques to Pores: In Situ Architecture and Isoform-Specific Gating of Human Gap Junction Channels\u201d _ Dat [&hellip;]<\/p>\n","protected":false},"author":26,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[3],"tags":[],"class_list":["post-3172","post","type-post","status-publish","format-standard","hentry","category-kek-cryoem"],"_links":{"self":[{"href":"https:\/\/pf-form.kek.jp\/sbrc\/wp-json\/wp\/v2\/posts\/3172","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/pf-form.kek.jp\/sbrc\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/pf-form.kek.jp\/sbrc\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/pf-form.kek.jp\/sbrc\/wp-json\/wp\/v2\/users\/26"}],"replies":[{"embeddable":true,"href":"https:\/\/pf-form.kek.jp\/sbrc\/wp-json\/wp\/v2\/comments?post=3172"}],"version-history":[{"count":5,"href":"https:\/\/pf-form.kek.jp\/sbrc\/wp-json\/wp\/v2\/posts\/3172\/revisions"}],"predecessor-version":[{"id":3282,"href":"https:\/\/pf-form.kek.jp\/sbrc\/wp-json\/wp\/v2\/posts\/3172\/revisions\/3282"}],"wp:attachment":[{"href":"https:\/\/pf-form.kek.jp\/sbrc\/wp-json\/wp\/v2\/media?parent=3172"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/pf-form.kek.jp\/sbrc\/wp-json\/wp\/v2\/categories?post=3172"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/pf-form.kek.jp\/sbrc\/wp-json\/wp\/v2\/tags?post=3172"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}