p53 modulation of TFIIH-associated nucleotide excision repair activity

p53 has pleiotropic functions including control of genomic plasticity and integrity. Here we report that p53 can bind to several transcription factor IIH−associated factors, including transcription−repair factors, XPD (Rad3) and XPB, as well as CSB involved in strand−specific DNA repair, via its C−terminal domain. We also found that wild−type, but not Arg273His mutant p53 inhibits XPD (Rad3) and XPB DNA helicase activities. Moreover, repair of UV−induced dimers is slower in Li−Fraumeni syndrome cells (heterozygote p53 mutant) than in normal human cells. Our findings indicate that p53 may play a direct role in modulating nucleotide excision repair pathways