ABSTRACT
A high affinity for Ultraviolet (UV)-damaged DNA, and the absence of specific binding in at least some repair-deficient xeroderma pigmentosum (XP) E patients, suggest a role for the UV-Damage-specific DNA binding protein (UV-DDB) in DNA repair. The presence of UV-DDB proteins was determined by incubating UV-irradiated oligonucleotide 3/4 with nuclear extracts, and examining the appearance of specific protein-DNA complexes after resolution of the reaction mixtures on nondenaturing polyacrylamide gels. The effect of viral transformation on UV-DDB protein induction by UV is intriguing. The assay permits the study of species, tissue, and developmental expression of DDB proteins when extracts from cells of different genotypes and/or phenotypes are tested. The lack of induction of UV-DDB protein in some primary XP cell lines also can be interpreted as an inability of these XP cells to recover after UV irradiation.
