1
|
Zilberg G, Parpounas AK, Warren AL, Fiorillo B, Provasi D, Filizola M, Wacker D. Structural insights into the unexpected agonism of tetracyclic antidepressants at serotonin receptors 5-HT 1eR and 5-HT 1FR. Sci Adv 2024; 10:eadk4855. [PMID: 38630816 PMCID: PMC11023502 DOI: 10.1126/sciadv.adk4855] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/05/2023] [Accepted: 03/15/2024] [Indexed: 04/19/2024]
Abstract
Serotonin [5-hydroxytryptamine (5-HT)] acts via 13 different receptors in humans. Of these receptor subtypes, all but 5-HT1eR have confirmed roles in native tissue and are validated drug targets. Despite 5-HT1eR's therapeutic potential and plausible druggability, the mechanisms of its activation remain elusive. To illuminate 5-HT1eR's pharmacology in relation to the highly homologous 5-HT1FR, we screened a library of aminergic receptor ligands at both receptors and observe 5-HT1eR/5-HT1FR 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-HT1eR 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-HT1eR and 5-HT1FR contribute to the agonist activity of these antidepressants.
Collapse
Affiliation(s)
- Gregory Zilberg
- Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Alexandra K. Parpounas
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Audrey L. Warren
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Bianca Fiorillo
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Davide Provasi
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Marta Filizola
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Daniel Wacker
- Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| |
Collapse
|
2
|
Yang R, Ko YH, Li F, Lokareddy RK, Hou CFD, Kim C, Klein S, Antolínez S, Marín JF, Pérez-Segura C, Jarrold MF, Zlotnick A, Hadden-Perilla JA, Cingolani G. Structural basis for nuclear import of hepatitis B virus (HBV) nucleocapsid core. Sci Adv 2024; 10:eadi7606. [PMID: 38198557 PMCID: PMC10780889 DOI: 10.1126/sciadv.adi7606] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2023] [Accepted: 12/08/2023] [Indexed: 01/12/2024]
Abstract
Nuclear import of the hepatitis B virus (HBV) nucleocapsid is essential for replication that occurs in the nucleus. The ~360-angstrom HBV capsid translocates to the nuclear pore complex (NPC) as an intact particle, hijacking human importins in a reaction stimulated by host kinases. This paper describes the mechanisms of HBV capsid recognition by importins. We found that importin α1 binds a nuclear localization signal (NLS) at the far end of the HBV coat protein Cp183 carboxyl-terminal domain (CTD). This NLS is exposed to the capsid surface through a pore at the icosahedral quasi-sixfold vertex. Phosphorylation at serine-155, serine-162, and serine-170 promotes CTD compaction but does not affect the affinity for importin α1. The binding of 30 importin α1/β1 augments HBV capsid diameter to ~620 angstroms, close to the maximum size trafficable through the NPC. We propose that phosphorylation favors CTD externalization and prompts its compaction at the capsid surface, exposing the NLS to importins.
Collapse
Affiliation(s)
- Ruoyu Yang
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, 1020 Locust Street, Philadelphia, PA 19107, USA
| | - Ying-Hui Ko
- Department of Biochemistry and Molecular Genetics, The University of Alabama at Birmingham, 1825 University Blvd, Birmingham, AL 35294, USA
| | - Fenglin Li
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, 1020 Locust Street, Philadelphia, PA 19107, USA
| | - Ravi K. Lokareddy
- Department of Biochemistry and Molecular Genetics, The University of Alabama at Birmingham, 1825 University Blvd, Birmingham, AL 35294, USA
| | - Chun-Feng David Hou
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, 1020 Locust Street, Philadelphia, PA 19107, USA
| | - Christine Kim
- Department of Molecular and Cellular Biochemistry, Indiana University, Bloomington, Indiana, IN 47405, USA
| | - Shelby Klein
- Department of Chemistry, Indiana University, Bloomington, Indiana, IN 47405, USA
| | - Santiago Antolínez
- Department of Chemistry and Biochemistry, University of Delaware, Newark, DE 19716, USA
| | - Juan F. Marín
- Department of Chemistry and Biochemistry, University of Delaware, Newark, DE 19716, USA
| | - Carolina Pérez-Segura
- Department of Chemistry and Biochemistry, University of Delaware, Newark, DE 19716, USA
| | - Martin F. Jarrold
- Department of Chemistry, Indiana University, Bloomington, Indiana, IN 47405, USA
| | - Adam Zlotnick
- Department of Molecular and Cellular Biochemistry, Indiana University, Bloomington, Indiana, IN 47405, USA
| | | | - Gino Cingolani
- Department of Biochemistry and Molecular Genetics, The University of Alabama at Birmingham, 1825 University Blvd, Birmingham, AL 35294, USA
| |
Collapse
|