Changes in VRK1 RNA level upon serum withdrawal or readdition to the culture.

<p>(A). Quantification of the VRK1 gene expression in WS1 fibroblasts at different time points upon serum withdrawal (top) and serum readdition to the cell culture (bottom) which was previously serum-deprived for five days. These experiments were independently performed three times. (B). Regulation of the human proximal promoter of human VRK1 by serum. WS1 cells were transfected with plasmid pGL2-B-VRK1(−1028+52). The luciferase activity was determined under different experimental conditions. Control activity is that of cells in the continuous presence of serum. The result is the mean of three experiments.