{"id":3237,"date":"2025-08-01T15:11:34","date_gmt":"2025-08-01T19:11:34","guid":{"rendered":"https:\/\/www.med.unc.edu\/pharm\/miaolab\/?p=3237"},"modified":"2025-08-01T15:11:34","modified_gmt":"2025-08-01T19:11:34","slug":"new-paper-on-cryo-em-reveals-an-extrahelical-allosteric-binding-site-at-the-m5-machr","status":"publish","type":"post","link":"https:\/\/www.med.unc.edu\/pharm\/miaolab\/2025\/08\/new-paper-on-cryo-em-reveals-an-extrahelical-allosteric-binding-site-at-the-m5-machr\/","title":{"rendered":"New paper on “Cryo-EM reveals an extrahelical allosteric binding site at the M5 mAChR”"},"content":{"rendered":"

Congratulations to Jinan and Keya for a new paper just published in Nature Communications<\/em> on “Cryo-EM reveals an extrahelical allosteric binding site at the M5 mAChR<\/a><\/strong>“! Thanks to Profs. David Thal, Celine Valant and Arthur Christopoulos at Monash University and other team members for the wonderful collaboration!<\/p>\n

Abstract<\/h2>\n
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The M5<\/sub>\u00a0muscarinic acetylcholine receptor (M5<\/sub>\u00a0mAChR) represents a promising therapeutic target for neurological disorders. However, the high conservation of its orthosteric binding site poses significant challenges for drug development. While selective positive allosteric modulators (PAMs) offer a potential solution, a structural understanding of the M5<\/sub>\u00a0mAChR and its allosteric binding sites remains limited. Here, we present a 2.8\u2009\u00c5 cryo-electron microscopy structure of the M5<\/sub>\u00a0mAChR complexed with heterotrimeric Gq<\/sub>\u00a0protein and the agonist iperoxo, completing the active-state structural characterization of the mAChR family. To identify the binding site of M5<\/sub>-selective PAMs, we implement an integrated approach combining mutagenesis, pharmacological assays, structural biology, and molecular dynamics simulations. Our mutagenesis studies reveal that selective M5<\/sub>\u00a0PAMs bind outside previously characterized M5<\/sub>\u00a0mAChR allosteric sites. Subsequently, we obtain a 2.1\u2009\u00c5 structure of M5<\/sub>\u00a0mAChR co-bound with acetylcholine and the selective PAM VU6007678, revealing an allosteric pocket at the extrahelical interface between transmembrane domains 3 and 4 that is confirmed through mutagenesis and simulations. These findings demonstrate the diverse mechanisms of allosteric regulation in mAChRs and highlight the value of integrating pharmacological and structural approaches to identify allosteric binding sites.<\/p>\n<\/div>\n","protected":false},"excerpt":{"rendered":"

Congratulations to Jinan and Keya for a new paper just published in Nature Communications on “Cryo-EM reveals an extrahelical allosteric binding site at the M5 mAChR“! Thanks to Profs. David Thal, Celine Valant and Arthur Christopoulos at Monash University and other team members for the wonderful collaboration! Abstract The M5\u00a0muscarinic acetylcholine receptor (M5\u00a0mAChR) represents a … Read more<\/a><\/p>\n","protected":false},"author":115433,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"layout":"","cellInformation":"","apiCallInformation":"","footnotes":"","_links_to":"","_links_to_target":""},"categories":[1],"tags":[],"class_list":["post-3237","post","type-post","status-publish","format-standard","hentry","category-news","odd"],"acf":[],"featured_image":false,"featured_image_medium":false,"featured_image_medium_large":false,"featured_image_large":false,"featured_image_thumbnail":false,"featured_image_alt":false,"category_details":[{"name":"News","link":"https:\/\/www.med.unc.edu\/pharm\/miaolab\/category\/news\/"}],"tag_details":[],"_links_to":[],"_links_to_target":[],"_links":{"self":[{"href":"https:\/\/www.med.unc.edu\/pharm\/miaolab\/wp-json\/wp\/v2\/posts\/3237","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.med.unc.edu\/pharm\/miaolab\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.med.unc.edu\/pharm\/miaolab\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.med.unc.edu\/pharm\/miaolab\/wp-json\/wp\/v2\/users\/115433"}],"replies":[{"embeddable":true,"href":"https:\/\/www.med.unc.edu\/pharm\/miaolab\/wp-json\/wp\/v2\/comments?post=3237"}],"version-history":[{"count":1,"href":"https:\/\/www.med.unc.edu\/pharm\/miaolab\/wp-json\/wp\/v2\/posts\/3237\/revisions"}],"predecessor-version":[{"id":3239,"href":"https:\/\/www.med.unc.edu\/pharm\/miaolab\/wp-json\/wp\/v2\/posts\/3237\/revisions\/3239"}],"wp:attachment":[{"href":"https:\/\/www.med.unc.edu\/pharm\/miaolab\/wp-json\/wp\/v2\/media?parent=3237"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.med.unc.edu\/pharm\/miaolab\/wp-json\/wp\/v2\/categories?post=3237"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.med.unc.edu\/pharm\/miaolab\/wp-json\/wp\/v2\/tags?post=3237"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}