title: Bleomycin-induced DNA repair synthesis in permeable human fibroblasts: mediation of long-patch and short-patch repair by distinct DNA polymerases.
abstract: Treatment of permeable human fibroblasts with bleomycin elicits DNA repair synthesis that is only partially sensitive to aphidicolin, an inhibitor of mammalian DNA polymerases alpha and delta. Inhibition of long-patch repair synthesis by omission of the three unlabeled deoxyribonucleoside triphosphates (dNTPs) selectively eliminates the aphidicolin-sensitive component. The majority of this residual aphidicolin-resistant repair synthesis is contained in ligated patches as revealed by resistance to exonuclease III. Determination of repair patch length by bromodeoxyuridine-induced density shift under conditions where essentially all of the repair synthesis is sensitive or resistant to aphidicolin yielded values of approximately 20 and 4 nucleotides per patch, respectively. On the basis of these data and the relative sensitivity of bleomycin-induced repair synthesis to N2-(p-n-butylphenyl)-2'-deoxyguanosine 5'-triphosphate (BuPdGTP), 2',3'-dideoxythymidine 5'-triphosphate (ddTTP), and N-ethylmaleimide (NEM), long-patch repair is attributed to DNA polymerase delta and short-patch repair to DNA polymerase beta.
authors: Department of Pediatrics, St. Louis Children's Hospital, Washington University School of Medicine, Missouri 63110.
authors: J A
authors: JA
authors: DiGiuseppe
authors: S L
authors: SL
authors: Dresler
mesh_terms: D016590:Aphidicolin; D001761:Bleomycin / Q000494:pharmacology*; D001973:Bromodeoxyuridine / Q000494:pharmacology; D002463:Cell Membrane Permeability; D002478:Cells, Cultured; D004247:DNA / Q000096:biosynthesis*; D004249:DNA Damage; D004256:DNA Polymerase I / Q000378:metabolism*; D004257:DNA Polymerase II / Q000037:antagonists & inhibitors; D004258:DNA Polymerase III / Q000378:metabolism*; D004260:DNA Repair / Q000187:drug effects; D004259:DNA-Directed DNA Polymerase / Q000378:metabolism*; D004224:Diterpenes / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D005092:Exonucleases / Q000378:metabolism; D005347:Fibroblasts; D006801:Humans; D013997:Time Factors
chemical_list: D004224:Diterpenes; D001761:Bleomycin; D016590:Aphidicolin; D004247:DNA; D004256:DNA Polymerase I; D004257:DNA Polymerase II; D004258:DNA Polymerase III; D004259:DNA-Directed DNA Polymerase; D005092:Exonucleases; D001973:Bromodeoxyuridine