FIG. 1.

N188K represses TTF-1-dependent transcription in HeLa cells. (A and B) Cells were transiently cotransfected with C5-CAT or the thyroglobulin promoter (0.3 μg/plate), TTF-1 (0.2 μg/plate), and the indicated increasing amounts of N188K. Cells were harvested and assayed for CAT activity. Values are the mean of at least three experiments ±SD. (C) C5-CAT was cotransfected in HeLa cells with TTF-1 (15 ng) and the indicated amounts of Nkx-2.5 expression plasmids. Relative activation (n-fold) is the ratio between values obtained with and without cotransfection of the transcription factors. CMV-Luc was used as internal control, and CAT values were normalized to Luc activity.