Accumulation of 10-kilobase DNA replication intermediates in cells treated with 3-aminobenzamide.
During eukaryotic DNA synthesis there is formation of, in addition to Okazaki fragments, discrete 10-kilobase (kb) DNA replication intermediates. We have investigated the ligation of 10-kb DNA replication intermediates to high molecular weight DNA, using the drug 3-aminobenzamide, an inhibitor of poly(ADP-ribose) synthetase. In human melanoma cells treated with this inhibitor, there is an accumulation of 10-kb DNA. In contrast, in cells treated with aphidicolin, which inhibits DNA polymerase alpha, there is continued ligation of 10-kb DNA to high molecular weight DNA. Furthermore, using sequential treatment with aphidicolin and 3-aminobenzamide, one can observe the conversion of radiolabeled Okazaki fragments into 10-kb intermediates. The 10-kb DNA pieces are, however, not ligated to high molecular weight DNA in the presence of 3-aminobenzamide. Our results imply that functioning poly(ADP-ribose) synthetase is necessary for the ligation process.
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D016590:Aphidicolin; D001549:Benzamides / Q000494:pharmacology*; D002460:Cell Line; D004261:DNA Replication / Q000187:drug effects*; D004277:DNA, Single-Stranded / Q000378:metabolism; D004224:Diterpenes / Q000494:pharmacology; D006801:Humans; D007399:Interphase / Q000187:drug effects; D008545:Melanoma / Q000201:enzymology; D008970:Molecular Weight; D009244:NAD+ Nucleosidase / Q000037:antagonists & inhibitors*; D009694:Nucleic Acid Precursors / Q000378:metabolism*; D000067856:Poly(ADP-ribose) Polymerase Inhibitors
D001549:Benzamides; D004277:DNA, Single-Stranded; D004224:Diterpenes; D009694:Nucleic Acid Precursors; D000067856:Poly(ADP-ribose) Polymerase Inhibitors; D016590:Aphidicolin; C025160:3-aminobenzamide; D009244:NAD+ Nucleosidase