Cooperativity between the orthosteric and allosteric ligand binding sites of RORγt.

Autor: de Vries RMJM; Laboratory of Chemical Biology, Department of Biomedical Engineering, Technische Universiteit Eindhoven, 5612 AZ Eindhoven, The Netherlands.; Institute for Complex Molecular Systems, Technische Universiteit Eindhoven, 5612 AZ Eindhoven, The Netherlands., Meijer FA; Laboratory of Chemical Biology, Department of Biomedical Engineering, Technische Universiteit Eindhoven, 5612 AZ Eindhoven, The Netherlands.; Institute for Complex Molecular Systems, Technische Universiteit Eindhoven, 5612 AZ Eindhoven, The Netherlands., Doveston RG; Laboratory of Chemical Biology, Department of Biomedical Engineering, Technische Universiteit Eindhoven, 5612 AZ Eindhoven, The Netherlands.; Institute for Complex Molecular Systems, Technische Universiteit Eindhoven, 5612 AZ Eindhoven, The Netherlands.; Leicester Institute of Structural and Chemical Biology, University of Leicester, LE1 7RH Leicester, United Kingdom.; School of Chemistry, University of Leicester, LE1 7RH Leicester, United Kingdom., Leijten-van de Gevel IA; Laboratory of Chemical Biology, Department of Biomedical Engineering, Technische Universiteit Eindhoven, 5612 AZ Eindhoven, The Netherlands.; Institute for Complex Molecular Systems, Technische Universiteit Eindhoven, 5612 AZ Eindhoven, The Netherlands., Brunsveld L; Laboratory of Chemical Biology, Department of Biomedical Engineering, Technische Universiteit Eindhoven, 5612 AZ Eindhoven, The Netherlands; l.brunsveld@tue.nl.; Institute for Complex Molecular Systems, Technische Universiteit Eindhoven, 5612 AZ Eindhoven, The Netherlands.
Jazyk: angličtina
Zdroj: Proceedings of the National Academy of Sciences of the United States of America [Proc Natl Acad Sci U S A] 2021 Feb 09; Vol. 118 (6).
DOI: 10.1073/pnas.2021287118
Abstrakt: Cooperative ligand binding is an important phenomenon in biological systems where ligand binding influences the binding of another ligand at an alternative site of the protein via an intramolecular network of interactions. The underlying mechanisms behind cooperative binding remain poorly understood, primarily due to the lack of structural data of these ternary complexes. Using time-resolved fluorescence resonance energy transfer (TR-FRET) studies, we show that cooperative ligand binding occurs for RORγt, a nuclear receptor associated with the pathogenesis of autoimmune diseases. To provide the crucial structural insights, we solved 12 crystal structures of RORγt simultaneously bound to various orthosteric and allosteric ligands. The presence of the orthosteric ligand induces a clamping motion of the allosteric pocket via helices 4 to 5. Additional molecular dynamics simulations revealed the unusual mechanism behind this clamping motion, with Ala355 shifting between helix 4 and 5. The orthosteric RORγt agonists regulate the conformation of Ala355, thereby stabilizing the conformation of the allosteric pocket and cooperatively enhancing the affinity of the allosteric inverse agonists.
Competing Interests: Competing interest statement: L.B. is scientific cofounder of Ambagon Therapeutics, a 14-3-3 drug discovery company. F.A.M., R.G.D., and L.B. are coinventors of patent WO2020149740: Substituted heterocyclic compounds and their use as retinoid-related orphan receptor (ROR) gamma-t inhibitors.
(Copyright © 2021 the Author(s). Published by PNAS.)
Databáze: MEDLINE