Figure 5.

OPN opposes β₂AR signaling via physical interaction with G_αs in H9c2 cardiomyoblasts. Co-immunoprecipitation (co-IP) of OPN with G_αs in native WT H9c2 cells treated with vehicle (Veh) or 10 µM salbutamol (Salb). Representative blots are shown in (A), and the densitometric quantitation of three independent experiments is shown in (B). IB: immunoblotting; IP: immunoprecipitation; IgG: IP with a general IgG antibody (negative control for the OPN IP). No significant difference (at p = 0.05) in the amount of G_αs co-IP’d with OPN was observed between Veh and Salb (n = 3).