FIGURE 6.

PKA signaling modulates the phosphorylation status of human PXR in vivo. CV-1 cells were transduced with an adenovirus expressing FLAG-tagged human PXR. Cells were treated with 10 μm rifampicin, 1 mm 8-Br-cAMP, and 1 mm 8-Br-cGMP for 24 h. The PXR protein was immunoprecipitated using anti-hPXR antibody and subjected to Western blot analysis using anti-phosphothreonine 14B3 antibody (top). The blot was stripped and reprobed with anti-FLAG monoclonal antibody to ensure equal loading (bottom). PPase, protein phosphatase; veh, vehicle.