title: Transient and stable complementation of ultraviolet repair in xeroderma pigmentosum cells by the denV gene of bacteriophage T4.
abstract: In this paper we report both transient and stable complementation of pyrimidine dimer repair in xeroderma pigmentosum cells by the denV gene of bacteriophage T4, coding for endonuclease V, a dimer-specific DNA glycosylase. Cotransfection with pRSVdenV in SV40-transformed XP12RO(M1) cells (complementation group A) restored transient expression of an indicator plasmid (pRSVcat) bearing a UV-inactivated chloramphenicol acetyltransferase (cat) gene. In addition, XP12RO(M1) clones stably transformed by pRSVdenV-SVgpt expressed transient chloramphenicol acetyltransferase activity when transfected with UV-inactivated pRSVcat plasmid. These clones also showed partial restoration of colony forming ability and excision repair synthesis after UV irradiation. Immunofluorescence, using an endonuclease V polyclonal antibody, showed the presence of the phage glycosylase in stably transformed xeroderma pigmentosum cells. The cotransfection assay affords a rapid, sensitive procedure to screen for functional cloned DNA repair genes and to test mutant cells for the deficiency of specific steps in DNA repair, such as incision.
mesh_terms: D002478:Cells, Cultured; D004260:DNA Repair; D043224:Deoxyribonuclease (Pyrimidine Dimer); D004706:Endodeoxyribonucleases / Q000235:genetics*; D005814:Genes, Viral; D005816:Genetic Complementation Test; D006801:Humans; D014162:Transfection; D014466:Ultraviolet Rays; D014983:Xeroderma Pigmentosum / Q000235:genetics*
chemical_list: D004706:Endodeoxyribonucleases; D043224:Deoxyribonuclease (Pyrimidine Dimer)