Figure 1.

Inhibition of retinoic acid-induced transcription by Ski in QT6 cells. QT6 cells were transiently transfected with estrogen response element (ERE)–TK–luciferase or DR5–TK–luciferase by using 0 μg or 5 μg of v-Ski or c-Ski expression plasmids as indicated. Cells were treated or mock-treated with 1 μM of all-trans-retinoic acid (Sigma) for 30 h as indicated. Extracts were prepared at 48 h posttransfection. The luciferase activity is shown as the relative light units that were obtained from each sample and has been normalized for transfection efficiency as described. Relative light units are an average of the values obtained from three independent transfections. Error bars represent the SD from the mean.