Figure 6.

PELP1-mediated growth factor signaling cross-talk with the ER requires a functional PKA pathway. A. MCF-7 cells were transfected with ERE-luciferase reporter along with pcDNA vector or pcDNA-PELP1 expression vector. After 48 h, cells were stimulated with EGF (100 ng/mL), tamoxifen (10⁻⁸ mol/L) in the presence or absence of forskolin for 12 h, and then luciferase activity was measured. B. MCF-7 cells expressing GFP-PELP1-WT or GFP-PELP1-MT (S350, S415, S613A) were treated with EGF (100 ng/mL) for indicated periods of time, chromatin was prepared and immunoprecipitated with anti-GFP monoclonal antibody to precipitate GFP-PELP1, and chromatin immunoprecipitation analysis was done using primers specific for pS2. C. Ishikawa cells were transfected with ERE-luciferase reporter with the pcDNA vector or the pcDNA-PELP1 expression vector. After 48 h, cells were stimulated with tamoxifen (10⁻⁸ mol/L) in the presence or absence of H89 or forskolin for 12 h, and then luciferase activity was measured. D. Ishikawa cells were transfected with ERE-luciferase reporter with or without the GFP vector, GFP-PELP1-WT, or GFP-PELP1-MT (S350, S415, S613A). After 48 h, cells were stimulated with tamoxifen (10⁻⁸ mol/L) for 12 h, and then luciferase activity was measured. *, P < 0.05; **, P < 0.001. Columns, means from three independent experiments done in triplicate wells; bars, SE.