Laboratoire MFP, UMR 5234, CNRS-Université Victor Segalen Bordeaux 2, IFR 66 Pathologies Infectieuses et Cancers, Bordeaux, France.
J Virol. 2012 Jan;86(1):513-26. doi: 10.1128/JVI.05425-11. Epub 2011 Oct 19.
Stable HIV-1 replication requires the DNA repair of the integration locus catalyzed by cellular factors. The human RAD51 (hRAD51) protein plays a major role in homologous recombination (HR) DNA repair and was previously shown to interact with HIV-1 integrase (IN) and inhibit its activity. Here we determined the molecular mechanism of inhibition of IN. Our standard in vitro integration assays performed under various conditions promoting or inhibiting hRAD51 activity demonstrated that the formation of an active hRAD51 nucleofilament is required for optimal inhibition involving an IN-DNA complex dissociation mechanism. Furthermore we show that this inhibition mechanism can be promoted in HIV-1-infected cells by chemical stimulation of the endogenous hRAD51 protein. This hRAD51 stimulation induced both an enhancement of the endogenous DNA repair process and the inhibition of the integration step. Elucidation of this molecular mechanism leading to the restriction of viral proliferation paves the way to a new concept of antiretroviral therapy based on the enhancement of endogenous hRAD51 recombination activity and highlights the functional interaction between HIV-1 IN and hRAD51.
稳定的 HIV-1 复制需要细胞因子催化的整合位点的 DNA 修复。人类 RAD51（hRAD51）蛋白在同源重组（HR）DNA 修复中起主要作用，先前已显示其与 HIV-1 整合酶（IN）相互作用并抑制其活性。在这里，我们确定了抑制 IN 的分子机制。我们在促进或抑制 hRAD51 活性的各种条件下进行的标准体外整合测定表明，形成活性 hRAD51 核丝需要最佳抑制，涉及 IN-DNA 复合物解离机制。此外，我们表明，通过化学刺激内源性 hRAD51 蛋白，这种抑制机制可以在感染 HIV-1 的细胞中得到促进。这种 hRAD51 刺激既增强了内源性 DNA 修复过程，又抑制了整合步骤。阐明导致病毒增殖受限的这种分子机制为基于增强内源性 hRAD51 重组活性的新型抗逆转录病毒治疗铺平了道路，并突出了 HIV-1 IN 和 hRAD51 之间的功能相互作用。
