文献类型：期刊文献

英文题名：Tamsulosin ameliorates bone loss by inhibiting the release of Cl- through wedging into an allosteric site of TMEM16A

作者：Li, Shiliang[1,2,3];Sun, Weijia[4,5];Li, Shuang[2];Zhu, Lili[2];Guo, Shuai[6];He, Jiaqi[2];Li, Yuheng[4];Tian, Chaoquan[2];Zhao, Zhenjiang[2];Yu, Tao[1];Li, Jianwei[4];Zhang, Yiqing[2];Hai, Youlong[7];Wang, Jiawen[2];Zheng, Yongjun[3];Wang, Rui[2];Hu, Xiaoyong[7];Ling, Shukuan[8];Li, Honglin[1,2,9];Li, Yingxian[4]

机构：[1]East China Normal Univ, Innovat Ctr AI & Drug Discovery, Sch Pharm, Shanghai 200062, Peoples R China;[2]East China Univ Sci & Technol, Sch Pharm, Shanghai Key Lab New Drug Design, Shanghai 200237, Peoples R China;[3]Fudan Univ, HuaDong Hosp, Dept Pain Management, Shanghai 200040, Peoples R China;[4]China Astronaut Res & Training Ctr, Natl Key Lab Space Med, Beijing 100094, Peoples R China;[5]Beijing Inst Technol, Sch Med Technol, Beijing 100081, Peoples R China;[6]Hebei Univ, Sch Life Sci, Baoding 071000, Hebei, Peoples R China;[7]Shanghai Jiao Tong Univ, Dept Urol, Shanghai Peoples Hosp 6, Sch Med, Shanghai 200233, Peoples R China;[8]Zhejiang Lab Regenerat Med Vis & Brain Hlth, Oujiang Lab, Wenzhou, Zhejiang, Peoples R China;[9]Lingang Lab, Shanghai 200031, Peoples R China

年份：2025

卷号：122

期号：1

外文期刊名：PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA

收录：;WOS:【SCI-EXPANDED(收录号:WOS:001394502500004)】；

基金：We sincerely thankthe staff atthe Shuimu BioSciences Ltd. fortheir technical support with cryo-EM data collection. This work was supported in part by the National Natural Science Foundation of China (82425104and 82150208to H.L., 82173690 to Shiliang Li, 82192880 and 82192882 to Yingxian Li) ; the National Key Research and Development Program of China (2022YFC3400501, 2022YFC3400504) ; the Postdoctoral Fellowship Program of CPSF (GZC20233414) and China Postdoctoral Science Foundation (2024T171124) to W.S.; Shiliang Li is also sponsored by the Shanghai Rising-Star Program (23QA1402800) .

语种：英文

外文关键词：TMEM16A; Tamsulosin; allosteric site; bone loss

摘要：TMEM16A, a key calcium- activated chloride channel, is crucial for many physiological and pathological processes such as cancer, hypertension, and osteoporosis, etc. However, the regulatory mechanism of TMEM16A is poorly understood, limiting the discovery of effective modulators. Here, we unveil an allosteric gating mechanism by presenting a high- resolution cryo-EM structure of TMEM16A in complex with a channel inhibitor that we identified, Tamsulosin, which is resolved at 2.93 & Aring;. Tamsulosin wedges itself into a pocket within the extracellular domain of TMEM16A, surrounded by alpha 1-alpha 2, alpha 5-alpha 6, and alpha 9-alpha 10 loops. This binding stabilizes a transient preopen conformation of TMEM16A, which is activated by Ca2+ ions while still preserving a closed pore to prevent Cl- permeation. Validation of this binding site through computational, electrophysiological, and functional experiments, along with site- directed mutagenesis, confirmed the pivotal roles of the pocket- lining residues R605 and E624 on alpha 5-alpha 6 loop in modulating Tamsulosin binding and pore activity. Tamsulosin induces significant positional shifts in extracellular loops, particularly the alpha 5-alpha 6 loop, which moves toward the extracellular exit of the pore, leading to noticeable structural rearrangements in pore- lining helices. The hinges induced by P595 in alpha 5 and G711 in alpha 7 introduce flexibility to the transmembrane helices, orienting Y593 to collaborate with I641 in effectively gating the preopening pore. Notably, Tamsulosin demonstrates significant antiosteoporotic effects by inhibiting TMEM16A, suggesting potential for its repurposing in new therapeutic indications. Our study not only enhances our understanding of the gating mechanism of TMEM16A inhibition but also facilitates structure- based drug design targeting TMEM16A.