Impaired regulation of tumor suppressor p53 caused by mutations in the xeroderma pigmentosum DDB2 gene: mutual regulatory interactions between p48(DDB2) and p53.
Tumor suppressor p53 controls cell cycle progression and apoptosis following DNA damage, thus minimizing carcinogenesis. Mutations in the human DDB2 gene generate the E subgroup of xeroderma pigmentosum (XP-E). We report here that XP-E strains are defective in UV irradiation-induced apoptosis due to severely reduced basal and UV-induced p53 levels. These defects are restored by infection with a p53 cDNA expression construct or with a DDB2 expression construct if and only if it contains intron 4, which includes a nonmutated p53 consensus-binding site. We propose that both before and after UV irradiation, DDB2 directly regulates p53 levels, while DDB2 expression is itself regulated by p53.
Itoh
Toshiki
T
Division of Biochemistry and Molecular Biology, Department of Molecular and Cell Biology, University of California, Berkeley, California 94720-3202, USA.
O'Shea
Cristin
C
Linn
Stuart
S
D017209:Apoptosis / Q000502:physiology; D002460:Cell Line; D004247:DNA / Q000378:metabolism / Q000528:radiation effects; D004249:DNA Damage; D004268:DNA-Binding Proteins / Q000235:genetics* / Q000378:metabolism; D005786:Gene Expression Regulation; D016147:Genes, Tumor Suppressor; D006801:Humans; D007438:Introns; D009154:Mutation; D010641:Phenotype; D015398:Signal Transduction / Q000502:physiology; D016159:Tumor Suppressor Protein p53 / Q000235:genetics / Q000378:metabolism*; D014466:Ultraviolet Rays; D014983:Xeroderma Pigmentosum
C117669:DDB2 protein, human; D004268:DNA-Binding Proteins; D016159:Tumor Suppressor Protein p53; D004247:DNA