Figure 5

Ets factors synergize with Nanog and are indispensable for Gata4 to restore the activity of the p455 promoter in differentiated cells. (A, B, C, E, F) cES cells induced to differentiate 48 h with retinoic acid (Diff) were transfected with the p455-Luc vector and with pCi-neo vectors expressing the indicated transcription factors tested in combinations or alone. Equal quantities of each vector were transfected. (D) Co-transfections were performed as in (A) but with unequal quantities of each vector. The proportion of each is indicated as parts of five in the figure in the order indicated on the abscissa. (E) Combinations of transcription factors restoring the promoter activity in differentiated cells were tested on p455-Luc mutated on one or two of the activation sites. (F) Effect of mutations on the activity mediated by each transcription factors transfected alone in differentated cells. All luciferase activities were measured 24 h after transfection and are represented as percentages of the value obtained with p455-Luc in cES cells co-transfected with empty vectors (Not Diff.). Results are the means of at least three independent experiments +/- s.d. In all the figures, t test values are relative to the results obtained in undifferentiated cES cells with p455-Luc: *p < 0.05, **p > 0.05. For (E) only, t test values relatively to the p455-Luc activity in differentiated cells transfected with a given combination of transcription factors have also been calculated and are indicated in the text.