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Updated: Jan 10, 2026
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G Protein-selective GPCR Conformations Measured Using FRET Sensors in a Live Cell Suspension Fluorometer Assay
Published on: September 10, 2016
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BRET-based G Protein Biosensors for Measuring G Protein-Coupled Receptor Activity in Live Cells.
Adeline Cœugnet1, Hannes Schihada2, Estelle Rascol1
1CNRS, Bordeaux INP, CBMN, UMR, University of Bordeaux.
Journal of Visualized Experiments : Jove
|November 24, 2025
Summary
G protein-coupled receptors (GPCRs) are key in cell signaling. New G-CASE biosensors use bioluminescence resonance energy transfer (BRET) for sensitive, real-time GPCR activity monitoring, aiding drug discovery.
Area of Science:
- Cellular signaling and molecular biology.
- Receptor pharmacology and drug discovery.
Background:
- G protein-coupled receptors (GPCRs) are crucial transmembrane receptors mediating cellular responses.
- GPCR activation involves heterotrimeric G protein dissociation, a key signaling event.
- Existing methods for studying GPCR activation have limitations.
Purpose of the Study:
- To introduce and validate G protein-based tricistronic activity sensors (G-CASE biosensors) for real-time GPCR activity monitoring.
- To demonstrate the utility of G-CASE biosensors in live-cell assays using BRET.
- To assess the activation of specific GPCRs, including β2-adrenergic receptor (β2-AR) and cannabinoid type 1 receptor (CB1R).
Main Methods:
- Utilized bioluminescence resonance energy transfer (BRET)-based G-CASE biosensors.
- Performed live-cell assays in 96-well plates.
- Transfected HEK 293T cells with β2-AR and used CB1R stably expressing cells to test Gs and Gi3 G-CASE biosensors.
Main Results:
- Demonstrated the robustness of Gs and Gi3 G-CASE biosensors in HEK 293T cells.
- Successfully monitored GPCR activity in real-time via G protein activation.
- Confirmed the sensitivity and non-invasive nature of BRET-based G-CASE biosensors.
Conclusions:
- G-CASE biosensors provide a sensitive and efficient method for studying GPCR activity.
- This approach facilitates pharmacological studies and high-throughput screening of GPCR ligands.
- The findings support the discovery of novel therapeutic compounds by elucidating biased signaling pathways.
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