Figure 1. Characterization of stable cell lines expressing PPM1A under the regulation of a Tet-regulated promoter.

PC6-3 cells expressing wt PPM1A were incubated for ( A ) 48 hours with increasing concentrations of Tet, or ( B ) for 0, 4, 8, 24, and 48 hours with 250 ng/ml Tet. PPM1A expression was detected using western blot analysis and specific anti-PPM1A antibodies. p38 served as a loading control. The results shown in ( A ) and ( B ) are of representative experiments out of three. ( C ) Extracts from the experiment discussed in ( B ) were assayed for phosphatase activity. The graph shows the average activity of 4 samples from each time point ± standard deviation from one of 3 independent experiments performed. * P-value<0.002.