Figure 2.

Molecular mechanisms of MasR constitutive activity. (A) Effect of deletion of the PDZ- binding motif. Cells were transfected with pcDNA3.1/c-myc-MasR or a plasmid lacking the last 5 amino acids including the PDZ-binding motif. Basal cAMP levels were determined after 30 min incubation with IBMX. 100% corresponds to cAMP levels in cells transfected with the empty vector. Data represent mean ± SEM of three independent experiments. Different letters denote significant difference at p < 0.05. (B) Effect of treatment with pertussis toxin. Basal cAMP levels were determined after 30 min incubation with IBMX in cells treated with PTX 100 ng/mL or vehicle for 1 h. 100% corresponds to cAMP levels in cells transfected with the empty vector and incubated with vehicle. Data represent mean ± SEM of four independent experiments. Different letters denote significant difference at p < 0.05. (C) Effect of Gαi overexpression. Cells were transfected with the indicated amounts of pcDNA3.1/c-myc-MasR and empty vector or 0.3 μg/well of pZN-Gαi₂. Basal cAMP levels were determined after 30 min incubation with IBMX. 100% corresponds to cAMP levels in cells transfected with the empty vector. Data represent mean ± SEM of three independent experiments. Different letters denote significant difference at P < 0.05.