Figure 4.

c-Fos activates and physically interacts with CDS. A, top row, neurons were co-transfected at 24 h of culture to express c-Fos-CFP (first panel) and CDS-YFP (second panel) and examined by confocal microscopy at 48 h. FRET images were obtained by the sensitized emission method and pseudocolored using ImageJ software (third panel). The bottom row shows a negative control with cells co-transfected with the CFP empty vector and CDS-YFP. The scale goes from no FRET (black) to maximum FRET (yellow). Scale bar, 30 μm. B, the graphic shows the quantification of the mean efficiencies ± S.D. (error bars) for the donor/acceptor pairs shown in the images, with one-way ANOVA and Tukey's post-test. ***, p < 0.001; n = 25 cells for each condition. The results of one of three independent experiments are shown. C, evaluation of CDS activity through measurement of the incorporation of [³H]CTP into CDP-DAG in neuron homogenates in the presence of c-Fos (+ c-Fos). Elution buffer was used as a control (– c-Fos). Results are the mean of three independent experiments performed in triplicate. The results are expressed as the mean ± S.D., with Student's t test analysis. *, p < 0.05.