QUICK SEARCH:   [advanced] Author: Keyword(s):
Home     Help     Feedback     Subscriptions     Archive     Search     Table of Contents

Help viewing high resolution images Return to article

Fig. 4. The PCNA-binding domain of p21 inhibits GFP-pol foci formation after UV irradiation. (A) U2OS cells transfected with GFP-pol and the indicated p21 plasmids were UV irradiated (20 J/m²) when indicated. Six hours later, cells were fixed and the sub-nuclear distribution of pol and p21 determined by confocal microscopy. In control samples, pol foci detected after UV irradiation were of two types: larger and fewer (EV, left-hand panel), or much smaller and greater in number (EV, right-hand panel). When 6Mycp21 (CDK–) was present, pol did not reorganize into foci structures after UV irradiation, neither in cells with pan-nuclear [6Mycp21 (CDK–) left-hand panel] or focal [6Mycp21 (CDK–) right-hand panel] p21 distribution. See merged panels in supplementary material Fig. S5. (B) The percentage of cells with GFP-pol foci before and after 6 hours of UV irradiation (20 J/m²) was determined. In all cases, at least 200 transfected nuclei were counted. Values are the average and error bars are the standard deviation between equivalent samples in three independent experiments. The significance of the differences between the non-irradiated (NI) and UV samples was assessed by Student's t-test for each p21 variant (^***P<0.001; ^**P<0.01). Further statistical analysis was performed using one-way ANOVA with Tukey-Kramer post-test (Table 1). (C) The percentage of cells with GFP-pol foci was determined at different time points after UV irradiation (20 J/m²). In all cases at least 200 transfected nuclei/sample were counted. Values are the average and error bars are the standard deviation between equivalent samples in two independent experiments.

Return to article