FIG. 8.

dTGIFa and TGF-β signaling. (A) L17 cells were transfected with either a control or a dTGIFa expression vector together with a reporter with eight copies of the SBE driving luciferase (SBE-luc). Cells were either treated with TGF-β for 18 h or left untreated and then assayed for luciferase activity, which is presented as mean ± standard deviation of triplicate transfections. Fold activation by TGF-β is shown. (B) COS-1 cells were cotransfected with an expression vector encoding Smad3 together with either a Flag-dTGIFa or control vector. Proteins were immunoprecipitated (IP) on Flag agarose and Western blotted (WB) for the presence of Smad3. Lysates were analyzed for protein expression by direct Western blotting (shown below). Coprecipitating Smad3 is indicated with an arrowhead.