Evidence that the retroviral DNA integration process triggers an ATR-dependent DNA damage response

Abstract

Caffeine is an efficient inhibitor of cellular DNA repair, likely through its effects on ATM (ataxia telangiectasia mutated) and ATR (ATM and Rad3-related) kinases. Here, we show that caffeine treatment causes a dose-dependent reduction in the total amount of HIV-1 and avian sarcoma virus retroviral vector DNA that is joined to host DNA in the population of infected cells and also in the number of transduced cells. These changes were observed at caffeine concentrations that had little or no effect on overall cell growth, synthesis, and nuclear import of the viral DNA, or the activities of the viral integrase in vitro. Substantial reductions in the amount of host-viral-joined DNA in the infected population, and in the number of transductants, were also observed in the presence of a dominant-negative form of the ATR protein, ATRkd. After infection, a significant fraction of these cells undergoes cell death. In contrast, retroviral transduction is not impeded in ATM-deficient cells, and addition of caffeine leads to the same reduction that was observed in ATM-proficient cells. These results suggest that activity of the ATR kinase, but not the ATM kinase, is required for successful completion of the viral DNA integration process and͞or survival of transduced cells. Components of the cellular DNA damage repair response may represent potential targets for antiretroviral drug development.

Retroviral DNA integration and the DNA damage response

“…46 The transduction efficiency of two retroviral vectors (HIV-1 and ASV) was found to be decreased in the presence of concentrations of caffeine that had little or no effect on early steps in infection that precede integration. The amount of viral DNA physically joined to host DNA was also reduced in the presence of caffeine.…”

HIV-1 Vpr induces ATM-dependent cellular signal with enhanced homologous recombination

“…The induction of a cellular response similar to DNAdamage-sensing signals has been shown during human immunodeficiency virus type-1 (HIV-1) infection (Daniel et al, 1999(Daniel et al, , 2003(Daniel et al, , 2004Lau et al, 2004). The synthesis of linear HIV-1 DNA in the cytoplasm by reverse transcription and the integration process of HIV-1 DNA into the host genome are thought to be possible triggers for the DNA-damage signals (Lau et al, 2004(Lau et al, , 2005.…”

Human Immunodeficiency Virus Type 1 (HIV-1) Integrase: Resistance to Diketo Acid Integrase Inhibitors Impairs HIV-1 Replication and Integration and Confers Cross-Resistance to l -Chicoric Acid

“…Next, IN catalyzes strand transfer, a concerted cleavage-ligation reaction in which the free hydroxyl at each 3Ј end of the LTR undergoes nucleophilic attack on both strands of the host chromosome. Finally, the resulting gaps in the DNA are repaired, a step likely mediated by host DNA double-stranded break repair enzymes (16,17,68). This yields the fully integrated provirus flanked by 5-bp direct repeats (63,64).…”