FIGURE 4.

Formation of GRK3‐Gβγ complexes is partially independent of CB1R C‐tail phosphorylation. The association of GRK3‐Gβγ complexes in the mutant receptors that interact with partner proteins is enhanced in SGIP1 presence. HEK293 were transiently co‐transfected with CB1R, GRK3‐Rluc8, Gγ‐YFP, Gβ, and empty vector/SGIP1‐mCherry (1:1:2:1:2 ratio). Twenty‐four hours after transfection, cells were stimulated by 1 μM WIN. (a) Kinetic profile of GRK3 recruitment to Gγ in CB1R in the presence and absence of SGIP1. (b) Kinetic profile of GRK3 recruitment to Gγ in CB1R, CB1R_2A, and CB1R_2A + SGIP1. (c) Kinetic profile of GRK3 recruitment to Gγ driven by CB1R and CB1R_6A in presence/absence of SGIP1. (d) Kinetic profile of GRK3 recruitment to Gγ driven by CB1R and CB1R_8A in presence/absence of SGIP1. Data represent the mean ± SEM of three experiments of independent cell preparations performed in three technical replicates. *p ≤ 0.05 (full statistical analysis is disclosed in Table S2 and Table S3)