Conformation- and activation-based BRET sensors differentially report on GPCR–G protein coupling

• DOI: 10.1126/scisignal.adi4747
• Publication Date: 2024-06-18T18:05:43Z
• Authors: Shane C. Wright; Charlotte Avet; Supriya A. Gaitonde; Itziar Muneta-Arrate; Christian Le Gouill; Mireille Hogue; Billy Breton; Stefania Koutsilieri; Rebeca Diez Alarcia; Madeleine Héroux; Volker M. Lauschke; Michel Bouvier
• Keywords: Functional selectivity

G protein–coupled receptors (GPCRs) regulate cellular signaling processes by coupling to diverse combinations of heterotrimeric proteins composed Gα, Gβ, and Gγ subunits. Biosensors based on bioluminescence resonance energy transfer (BRET) have advanced our understanding GPCR functional selectivity. Some BRET biosensors monitor ligand-induced conformational changes in the receptor or proteins, whereas others recruitment downstream effectors sites protein activation. Here, we compared ability conformation-and activation-based assess various class A B GPCRs specific Gα cultured cells. These included serotonin 5-HT 2A 7 receptors, GLP-1 (GLP-1R), M 3 muscarinic receptor. We observed different profiles between two types sensors, highlighting how data interpretation could be affected nature biosensor. also found that identity Gβγ subunits used assay differentially influence selectivity a toward subtypes, emphasizing importance receptor-Gβγ pairing determining specificity. Last, addition epitope tags affect stoichiometry yield artifactual findings. results highlight need for careful sensor selection experimental design when probing GPCR–G coupling.