FIGURE 5.
Exogenous CBP induces Gαs-luc activity, whereas endogenous CBP is recruited to the −837 to −618 region of the native Gαs promoter. Primary myometrial cultures were transfected with 200 ng of Gαs-luc and 200, 400, or 500 ng of CBP. Cells were harvested after 24 h, and luciferase activity was quantitated. All experiments were performed three times in triplicate. Data were compared using one-way analysis of variance and analyzed further using Tukey's multiple comparison test, and results are expressed as the mean ± S.E. (error bars); p < 0.05 was considered statistically significant. CBP strongly induced Gαs expression at all doses (A; p = 0.001). Using the ChIP assay on cultures of primary myometrial myocytes, it was shown that endogenous CBP also occupied the endogenous Gαs promoter (B, upper panel). CBP occupancy of the CXCL9 promoter served as the positive control (B, lower panel). I, input; IP, immunoprecipitate.