Figure 3.

ERG protein binds to Smad3 and phospho-Smad3 protein in PNT1A cells. (a), ERG interacts with exogenous Smad3 proteins. PNT1A cells were transiently co-transfected with expression plasmids Smad3 and ERG or parental empty expression vector. Total cell extracts were prepared and subjected to immunoprecipitation (IP) using antibody against Flag (anti-Flag-M2-affinity gel). Immunoprecipitates were subjected to western blot analysis using anti-ERG antibody. (b), ERG protein binds to endogenous Smad3 and phospho-Smad3 protein. PNT1A cells were transiently transfected with expression plasmid ERG2 or parental empty expression vector. Cells were treated with TGF-β for 2hours before harvest. Total cell extracts were prepared and subjected to immunoprecipitation (IP) using normal mouse IgG and antibody against anti-Smad3. Immunoprecipitates were subjected to western blot analysis using anti-p-Smad3, anti-Smad3, and anti-ERG antibody.