Download MendeleyStructural insights into the unexpected agonism of tetracyclic antidepressants at serotonin receptors 5-HT 1e R and 5-HT 1F R.
Zilberg, G., Parpounas, A.K., Warren, A.L., Fiorillo, B., Provasi, D., Filizola, M., Wacker, D.(2024) Sci Adv 10: eadk4855-eadk4855
- PubMed: 38630816
- DOI: https://doi.org/10.1126/sciadv.adk4855
- Primary Citation of Related Structures:
8UGY, 8UH3 - PubMed Abstract:
Serotonin [5-hydroxytryptamine (5-HT)] acts via 13 different receptors in humans. Of these receptor subtypes, all but 5-HT 1e R have confirmed roles in native tissue and are validated drug targets. Despite 5-HT 1e R's therapeutic potential and plausible druggability, the mechanisms of its activation remain elusive. To illuminate 5-HT 1e R's pharmacology in relation to the highly homologous 5-HT 1F R, we screened a library of aminergic receptor ligands at both receptors and observe 5-HT 1e R/5-HT 1F R agonism by multicyclic drugs described as pan-antagonists at 5-HT receptors. Potent agonism by tetracyclic antidepressants mianserin, setiptiline, and mirtazapine suggests a mechanism for their clinically observed antimigraine properties. Using cryo-EM and mutagenesis studies, we uncover and characterize unique agonist-like binding poses of mianserin and setiptiline at 5-HT 1e R distinct from similar drug scaffolds in inactive-state 5-HTR structures. Together with computational studies, our data suggest that these binding poses alongside receptor-specific allosteric coupling in 5-HT 1e R and 5-HT 1F R contribute to the agonist activity of these antidepressants.
Organizational Affiliation:
Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA.
