title: Inhibition of SV40 DNA replication by benzo[a]pyrene diol epoxide adducts: two recovery modes.
abstract: Anti-benzo[a]pyrene diol epoxide (BPDE) adducts produced in vitro in SV40 initially inhibit SV40 DNA replication in vivo, in cells unexposed to BPDE. A single adduct in a replicon is probably sufficient to block DNA replication. The recovery process appears to begin immediately after infection. The rate of recovery of replicative capacity is inversely related to the initial adduct number. Holding the infected cells temporarily under conditions that prevent viral DNA replication results subsequently in increased recovery, proportional to the holding time. The mechanism of recovery appears to be constitutive and prereplicative. In addition, there is a second mode of recovery which is induced by pretreatment of the host cells with BPDE before infection. The effect of pretreatment is similar to that of extending the holding time before replication: the first molecules begin to replicate earlier but the subsequent rate of recovery is unchanged. The induced mechanism may be either a limited stoichiometric repair process or a slow replicative bypass.
mesh_terms: D000818:Animals; D001580:Benzopyrenes / Q000494:pharmacology*; D002460:Cell Line; D002522:Chlorocebus aethiops; D004260:DNA Repair; D004261:DNA Replication / Q000187:drug effects*; D004279:DNA, Viral / Q000096:biosynthesis; D007668:Kidney; D012093:Replicon / Q000187:drug effects; D013539:Simian virus 40 / Q000187:drug effects / Q000502:physiology*; D014779:Virus Replication / Q000187:drug effects*
chemical_list: D001580:Benzopyrenes; D004279:DNA, Viral; C039385:7,8-dihydroxy-9,10-epoxy-8-methyl-7,8,9,10-tetrahydrobenzo(a)pyrene