Figure 4.

Agonist-specific formation of GRK/Gβγ complexes. Cos-7 cells transfected with either GRK2 (A) or GRK3 (B) were starved overnight in serum-free medium prior to exposure to lysophosphatidic acid (LPA; 10 μM), isoproterenol (ISO; 10 μM), or the thrombin receptor agonist SFLLRN (100 μM). GRK2 or GRK3/Gβγ complex formation was assessed by coimmunoprecipitation. The data represent mean ± SEM values from four independent experiments and are expressed as fold increase over unstimulated (control) cells. (Inset) Immunoblot of a representative experiment.