Absence of UV-induced non-homologous recombination in repair-deficient CHO cell lines transfected with ERCC genes.
The nucleotide excision repair pathway removes a broad spectrum of DNA lesions, including UV-induced damage. To ascertain whether the repair of the latter has a causative role in the enhancement of non-homologous recombination, Chinese hamster CHO cell lines proficient and deficient in the ability to repair UV-induced damage were transfected with a plasmid containing the bacterial neoR gene. Following UV-treatment an enhancement of non-homologous recombination above the spontaneous level was observed in repair-proficient cells, whereas no increase was observed in repair-deficient cell lines. Hence, the latter were transfected with the corresponding excision repair cross complementing human genes and the resulting repair-proficient transfectants were tested for UV-induced non-homologous recombination. In both untreated and UV-treated transfectants, the frequencies of the event were not significantly different. Cumulatively, the results suggest that non-homologous recombination induced by UV-irradiation is not restored by the correction of the excision repair defect.
Rainaldi
G
G
Istituto di Mutagenesi e Differenziamento, CNR, Pisa, Italy.
Capecchi
B
B
Piras
A
A
Vatteroni
L
L
D000818:Animals; D016466:CHO Cells / Q000528:radiation effects; D006224:Cricetinae; D004265:DNA Helicases; D004260:DNA Repair / Q000235:genetics*; D004268:DNA-Binding Proteins / Q000235:genetics*; D004307:Dose-Response Relationship, Radiation; D004720:Endonucleases; D006801:Humans; D011506:Proteins / Q000235:genetics*; D011995:Recombination, Genetic; D014157:Transcription Factors; D014162:Transfection; D014466:Ultraviolet Rays / Q000009:adverse effects; D051759:Xeroderma Pigmentosum Group D Protein
D004268:DNA-Binding Proteins; D011506:Proteins; D014157:Transcription Factors; C072022:XPBC-ERCC-3 protein; C071447:ERCC1 protein, human; D004720:Endonucleases; D004265:DNA Helicases; D051759:Xeroderma Pigmentosum Group D Protein; C497292:ERCC2 protein, human