Bioluminescence resonance energy transfer (BRET) to detect the interactions between kappa opioid receptor and non visual arrestins.

Bioluminescence resonance energy transfer (BRET) is a very sensitive technique employed to study protein-protein interactions, including G-protein-coupled receptors (GPCRs) hetero- and homo-dimerization. Recently, BRET has also been used to investigate the interaction between GPCRs (e.g., beta2 adrenergic receptor, muscarinic M2 receptor, dopaminergic D2 receptor) and non-visual arrestins. Here a BRET protocol is described to investigate interactions between the kappa opioid receptor (KOR) and non visual arrestins (arrestin-2 and arrestin-3) in HEK-293 cells, both under basal conditions and after exposure to KOR ligands.