Time-resolved cryo-EM of G-protein activation by a GPCR.

Autor: Papasergi-Scott MM; Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA, USA., Pérez-Hernández G; Charité-Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Institute of Medical Physics and Biophysics, Berlin, Germany., Batebi H; Institute of Medical Physics and Biophysics, Faculty of Medicine, Leipzig University, Leipzig, Germany., Gao Y; Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA, USA., Eskici G; Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA, USA., Seven AB; Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA, USA., Panova O; Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA, USA., Hilger D; Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA, USA.; Institute of Pharmaceutical Chemistry, Philipps-University of Marburg, Marburg, Germany., Casiraghi M; Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA, USA.; Dipartimento di Bioscienze, Università degli Studi di Milano, Milan, Italy., He F; Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA, USA., Maul L; Department of Chemistry and Pharmacy, Medicinal Chemistry, Friedrich-Alexander University Erlangen-Nürnberg, Erlangen, Germany., Gmeiner P; Department of Chemistry and Pharmacy, Medicinal Chemistry, Friedrich-Alexander University Erlangen-Nürnberg, Erlangen, Germany., Kobilka BK; Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA, USA., Hildebrand PW; Charité-Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Institute of Medical Physics and Biophysics, Berlin, Germany.; Institute of Medical Physics and Biophysics, Faculty of Medicine, Leipzig University, Leipzig, Germany.; Berlin Institute of Health at Charité-Universitätsmedizin Berlin, Berlin, Germany., Skiniotis G; Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA, USA. yiorgo@stanford.edu.; Department of Structural Biology, Stanford University School of Medicine, Stanford, CA, USA. yiorgo@stanford.edu.
Jazyk: angličtina
Zdroj: Nature [Nature] 2024 May; Vol. 629 (8014), pp. 1182-1191. Date of Electronic Publication: 2024 Mar 13.
DOI: 10.1038/s41586-024-07153-1
Abstrakt: G-protein-coupled receptors (GPCRs) activate heterotrimeric G proteins by stimulating guanine nucleotide exchange in the Gα subunit 1 . To visualize this mechanism, we developed a time-resolved cryo-EM approach that examines the progression of ensembles of pre-steady-state intermediates of a GPCR-G-protein complex. By monitoring the transitions of the stimulatory G s protein in complex with the β 2 -adrenergic receptor at short sequential time points after GTP addition, we identified the conformational trajectory underlying G-protein activation and functional dissociation from the receptor. Twenty structures generated from sequential overlapping particle subsets along this trajectory, compared to control structures, provide a high-resolution description of the order of main events driving G-protein activation in response to GTP binding. Structural changes propagate from the nucleotide-binding pocket and extend through the GTPase domain, enacting alterations to Gα switch regions and the α5 helix that weaken the G-protein-receptor interface. Molecular dynamics simulations with late structures in the cryo-EM trajectory support that enhanced ordering of GTP on closure of the α-helical domain against the nucleotide-bound Ras-homology domain correlates with α5 helix destabilization and eventual dissociation of the G protein from the GPCR. These findings also highlight the potential of time-resolved cryo-EM as a tool for mechanistic dissection of GPCR signalling events.
(© 2024. The Author(s), under exclusive licence to Springer Nature Limited.)
Databáze: MEDLINE
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