Fig. 7.

M3-R increases the amount of cAMP produced upon activation of ORs. (A) Dose-response curves of nonanedioic acid for the production of cAMP were performed in HEK 293T cells that were cotransfected with plasmids encoding OR-S6 alone, OR-S6 and the M3-R, OR-S6 and RTP1S, or OR-S6, RTP1S, and the M3-R. There was a substantial increase in the concentration of cAMP produced in cells expressing OR-S6, the M3-R, and RTP1S relative to that in cells expressing OR-S6 and either in comparison to cotransfection with either alone (purple curve versus orange and blue, respectively). Data were obtained from triplicate samples, and the experiment was replicated four times. (B) cAMP production is further increased upon costimulation of cells with the nonspecific M3-R agonist carbachol. Dose-response curves of nonanedioic acid for the production of cAMP were performed in HEK 293T cells that were co-transfected with plasmids encoding OR-S6, RTP1S, or the M3-R. Co-stimulation of cells with carbachol (100 nM) further stimulated the production of cAMP in cells cotransfected with plasmids encoding the M3-R and RTP1S. Data were obtained from triplicate samples and the experiment was repeated twice.