Expression of different PIF1 splicing variants. (A) Western blot showing the abundance of different PIF1 isoforms in cells transfected with the empty pCDNA plasmid or pCDNA bearing the vPIF1 or tPIF1 splicing variants. (B) Percentage of survival to different doses of camptothecin (CPT) in cells overexpressing the tPIF1 or vPIF1 isoforms relative to the DMSO treated control, as indicated. Cells transfected with the empty pCDNA vector were used as a control. The average and standard deviations of three independent experiments are shown. (C) Percentage of cells positive for RPA foci upon exposure to 10 Gy of ionizing radiation. Cells expressed the indicated PIF1 variants. An empty pCDNA vector was used as a control. The average and standard deviations of three independent experiments are shown. No statistically significant differences were found using an ANOVA test. (D) Same as A, but for BRCA1 foci. (E) Cell cycle analysis of cells transfected with the indicated plasmids. The percentage of cells in each cell cycle phase was analyzed as described in the Materials and Methods section. The average and standard deviation of three independent experiments is shown.
