title: Poly (ADP-ribose) is not involved in the rejoining of DNA breaks accumulated to high levels in u.v.-irradiated HeLa cells.
abstract: U.v. damage to the DNA of HeLa cells induces the polymerisation of ADP-ribose, but only if repair synthesis is inhibited so that incomplete repair sites (i.e., DNA breaks) accumulate to abnormally high levels. 3-Aminobenzamide greatly reduces the ADP-ribose polymerisation response. However, 3-aminobenzamide does not reduce the rate of rejoining of the accumulated breaks when the inhibition of repair synthesis is reversed. Therefore, rejoining of these DNA breaks (in contrast to the rejoining of other kinds of break) appears not to depend on activation of polynucleotide ligase by ADP-ribosylation.
mesh_terms: D000477:Alkylating Agents / Q000494:pharmacology; D001549:Benzamides / Q000494:pharmacology; D003561:Cytarabine / Q000494:pharmacology; D004260:DNA Repair; D004261:DNA Replication / Q000187:drug effects / Q000528:radiation effects; D004273:DNA, Neoplasm / Q000528:radiation effects*; D006367:HeLa Cells / Q000187:drug effects / Q000378:metabolism / Q000528:radiation effects; D006801:Humans; D006918:Hydroxyurea / Q000494:pharmacology; D007700:Kinetics; D009243:NAD / Q000378:metabolism / Q000528:radiation effects; D009702:Nucleoside Diphosphate Sugars / Q000378:metabolism*; D011064:Poly Adenosine Diphosphate Ribose / Q000378:metabolism*; D013463:Sulfuric Acid Esters / Q000494:pharmacology; D014466:Ultraviolet Rays
chemical_list: D000477:Alkylating Agents; D001549:Benzamides; D004273:DNA, Neoplasm; D009702:Nucleoside Diphosphate Sugars; D013463:Sulfuric Acid Esters; D003561:Cytarabine; D009243:NAD; D011064:Poly Adenosine Diphosphate Ribose; C025160:3-aminobenzamide; C007482:dimethyl sulfate; D006918:Hydroxyurea