Figure 1.

Agonist-dependent association of GRK2 with the plasma membrane is inhibited by the GRK2 carboxyl terminus (GRK2ct). Cos-7 cells transiently overexpressing GRK2 (CN, ISO) or GRK2 and the GRK2ct (GRK2ct/ISO) were incubated either in medium alone (CN) or medium containing 10 μM isoproterenol (ISO) for 5 min. Cells were harvested and plasma membranes were subjected to Western blot analysis using an anti-GRK2 monoclonal antibody. The intensity of the immunoreactive band corresponding to GRK2 was measured by laser densitometry. Data represent the mean ± SEM. of three independent experiments expressed as fold increase over basal. The basal value represents that amount of membrane-associated GRK2 observed in the absence of agonist (ISO) treatment.