Figure 1.

Interaction of G protein-coupled receptor (GPCR)-kinase (GRK)-5 but not GRK2 with the mineralocorticoid receptor (MR) in cardiac myocytes and the role of β-adrenergic receptors (ARs): (A) Immunoblotting for GRK2 and GRK5 in MR immunoprecipitates from H9c2 cardiomyocyte extracts prepared after 15-min-long treatments with vehicle (dimethylsulfoxide—DMSO, Veh), 100 nM G1, 100 nM aldosterone (Ald), 10 µM isoproterenol (Iso), or 10 µM formoterol (For). Blots for MR are also shown to confirm equal amounts of receptor immunoprecipitated. IP: immunoprecipitation; IB: Immunoblotting; IgG: Negative control for the co-IP (general rabbit IgG was used in the IP instead of an anti-MR antibody). Representative blots are shown in (A) and the relative densitometric quantitation of five independent experiments done in duplicate is shown in (B). * p < 0.05, vs. any other treatment; n = 5.