Figure 4.
Response of repair-defective UV5 cells to UV irradiation following transfection with various XPD constructs. (A and B) UV survival of AA8 (filled cirlces), UV5 (solid line, no symbols) and 24 h transfected UV5 cells (A) or UV5 stable transformants (B) expressing EGFP-XPD (open circles), XPD–EGFP (squares), untagged XPD (triangles) or XPDΔ557–696–EGFP chimera (dashed line, no symbols). Each survival curve represents the means of at least three independent experiments with standard errors (SEM) always <10%. (C) DNA repair synthesis following irradiation with a UV dose of 20 J/m2 in AA8, UV5 and UV5 cells stably transfected with pEGFP-XPD or pXPD-EGFP plasmid. The frequency distributions of nuclei with different grain numbers are shown. Arrows indicate the mean values of UDS ± SEM.