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

Papasergi-Scott MM, Pérez-Hernández G, Batebi H, Gao Y, Eskici G, Seven AB, Panova O, Hilger D, Casiraghi M, He F, Maul L, Gmeiner P, Kobilka BK, Hildebrand PW, Skiniotis G (2024)

Publication Type: Journal article

Publication year: 2024

Journal

Nature Nature Research

DOI: 10.1038/s41586-024-07153-1

Abstract

G-protein-coupled receptors (GPCRs) activate heterotrimeric G proteins by stimulating guanine nucleotide exchange in the Gα subunit1. 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 Gs protein in complex with the β2-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.

Authors with CRIS profile

Luis Maul Lehrstuhl für Pharmazeutische Chemie Peter Gmeiner Lehrstuhl für Pharmazeutische Chemie

Additional Organisation(s)

FAU Forschungszentrum Neue Wirkstoffe (FAU NeW)

Involved external institutions

Stanford University US United States (USA) (US) Universität Leipzig DE Germany (DE) Charité - Universitätsmedizin Berlin DE Germany (DE)

How to cite

APA:

Papasergi-Scott, M.M., Pérez-Hernández, G., Batebi, H., Gao, Y., Eskici, G., Seven, A.B.,... Skiniotis, G. (2024). Time-resolved cryo-EM of G-protein activation by a GPCR. Nature. https://doi.org/10.1038/s41586-024-07153-1

MLA:

Papasergi-Scott, Makaía M., et al. "Time-resolved cryo-EM of G-protein activation by a GPCR." Nature (2024).

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