Figure 4. Neither DNA binding nor transcriptional activation are required for enhancement of DNA damage. A.

: Site-specific (S306P) and non-specific (S306P/V358A) DNA binding mutant of LT sensitize cells to UV. Uninduced (UN) MEFs or MEFs inducibly expressing wild type (WT) and S306P T or S306P,V358A T were untreated or exposed to UV light (40 J/m²). Morphology of uninduced cells (UN) and cells expressing OBD is shown 16 h after exposure to UV light (40 J/m²). B: Top Panel: CASP calculated tail moments (TM) from analysis of comet assays from uninduced MEFs, wild type (WT) or S306P,V358A (S/V) expressing cells that were untreated or treated with UV (40 J/m²). Data are shown for a representative experiment, where at least 100 comets were quantitated for each cell line. Bottom Panel: CASP calculated tail moment (TM) from analysis of comet assays from uninduced MEFs, wild type (WT) or S306P expressing cells that were untreated or treated with UV (40 J/m²). Data are shown for a representative experiment, where at least 100 comets were quantitated for each cell line. C: NIH 3T3 cells maintained under growing conditions (10% CS) were cotransfected with Gal4TK-Luc reporter and Gal4-CREB (CREB) and WT OBD or mutant P402R/G403D (PGRD). Cells were harvested 48 hours post-transfection and assayed for luciferase activity. Assays were done as previously described (30). D: CASP calculated tail moment (TM) from analysis of comet assays from uninduced MEFs, wild type (WT) or PGRD LT expressing cells that were untreated or treated with UV (40 J/m²) and immediately analyzed for comets. Data are shown for a representative experiment, where at least 100 comets were quantitated for each cell line.