Serotonin receptors are important targets for established therapeutics and drug development as they are expressed throughout the human body and play key roles in cell signaling. There are 12 serotonergic G protein-coupled receptor members encoded in the human genome, of which the 5-hydroxytryptamine (5-HT)5A receptor (5-HT5AR) is the least understood and lacks selective tool compounds. Here, we report four high-resolution (2.73–2.80 Å) structures of human 5-HT5ARs, including an inactive state structure bound to an antagonist AS2674723 by crystallization and active state structures bound to a partial agonist lisuride and two full agonists, 5-carboxamidotryptamine (5-CT) and methylergometrine, by cryo-EM. Leveraging the new structures, we developed a highly selective and potent antagonist for 5-HT5AR. Collectively, these findings both enhance our understanding of this enigmatic receptor and provide a roadmap for structure-based drug discovery for 5-HT5AR.
Bibliographical noteFunding Information:
This work was supported by US National Institutes of Health grants RO1MH112205 and U24DK1169195 (to B.L.R.) and by R35GM122481 (to B.K.S.). This work also used the NMR spectrometer systems at Mount Sinai, acquired with funding from National Institutes of Health SIG grants 1S10OD025132 and 1S10OD028504 (to J.J.). We gratefully acknowledge M.J. Miley and the UNC macromolecular crystallization core for the use of their equipment for crystal collection and transport along with the UNC Flow Cytometry Core Facility. Both facilities are supported in part by a P30 CA016086 Cancer Center Core Support Grant to the UNC Lineberger Comprehensive Cancer Center. We also thank the staff of GM/CA@APS, which has been funded with federal funds from the National Cancer Institute (ACB-12002) and the National Institute of General Medical Sciences (AGM-12006). This research used resources of the Advanced Photon Source, a US Department of Energy Office of Science User Facility operated for the Department of Energy Office of Science by Argonne National Laboratory under contract no. DE-AC02-06CH11357. We thank J. Peck and J. Strauss of the UNC CryoEM Core Facility for their excellent technical assistance with this project. We are grateful to Schrödinger for the academic grant of FEP+ and multiple other tools in their software suite. The Titan X Pascal used for this research was kindly donated to J.F.F. by Nvidia.
© 2022, The Author(s), under exclusive licence to Springer Nature America, Inc.
All Science Journal Classification (ASJC) codes
- Structural Biology
- Molecular Biology