Crystal structures of Ryanodine Receptor reveal dantrolene and azumolene interactions guiding inhibitor development

作者：Hadiatullah Hadiatullah, Lianyun Lin, Zhiyan Wang, Rajamanikandan Sundarraj, Qin Wang, Xinru Lai, Nagomi Kurebayashi, Takuya Kobayashi, Toshiko Yamazawa, Yu Seby Chen, Wenlan Wang, Hongxia Zhao, Yiqing Yin, Takashi Murayama, Filip Van Petegem, Zhiguang Yuchi · 发表于：Nature Communications · 年份：2025 · DOI：10.1038/s41467-025-65096-1 · 被引用次数：3 · 研究领域：Coordination Chemistry and Organometallics、Crystallography and molecular interactions、Ion channel regulation and function

The ryanodine receptor (RyR) is a critical drug target, yet dantrolene (DAN) remains the only FDA-approved inhibitor, limited by hepatotoxicity and unsuitable for chronic use. To guide improved inhibitor development, we determine high-resolution crystal structures of the RyR Repeat12 (R12) domain bound to DAN, its analog azumolene (AZU), and adenine nucleotides (AMP-PCP or ADP). DAN/AZU and nucleotides bind cooperatively to a pseudosymmetric cleft, with key interactions involving Trp880 and Trp994. Binding induces a clamshell-like closure of the R12 domain. Isothermal titration calorimetry (ITC) reveals higher affinity in the presence of nucleotides and lower affinity for RyR2 due to nearby substitutions. Structural comparison with cryo-EM data suggests that DAN/AZU binding allosterically influences RyR gating and functional regulation. Structure-based screening identifies a potent compound targeting the same site but with a distinct binding mode. Our findings highlight the power of domain-focused crystallography in guiding RyR inhibitor discovery and overcoming cryo-EM resolution limitations.