Laboratory of Viral Pathogenesis, Institute for Virus Research, Kyoto University, 53 Shogoin-kawahara-cho, Sakyo-ku, Kyoto 606-8507, Japan.
Microbes Infect. 2011 Apr;13(4):339-49. doi: 10.1016/j.micinf.2010.12.002. Epub 2010 Dec 15.
Integration, an indispensable step for retrovirus replication, is executed by integrase (IN), which is expressed as a part of a Gag-Pol precursor. Although mechanistic detail of the IN-catalyzed integration reaction is well defined, numerous evidence have demonstrated that IN is involved in multiple steps of retrovirus replication other than integration. In this study, Huwe1, a HECT-type E3 ubiquitin ligase, was identified as a new cellular interactor of human immunodeficiency virus type 1 (HIV-1) IN. The interaction was mediated through the catalytic core domain of IN and a wide-range region of Huwe1. Interestingly, although depletion of Huwe1 in target cells did not affect the early phase of HIV-1 infection in a human T cell line, we found that infectivity of HIV-1 released from the Huwe1 knockdown cells was significantly augmented more than that of virus produced from control cells. The increase in infectivity occurred in proviral DNA synthesis. Further analysis revealed that Huwe1 interacted with HIV-1 Gag-Pol precursor protein through an IN domain. Our results suggest that Huwe1 in HIV-1 producer cells has a negative impact on early post-entry events during the next round of virus infection via association with an IN region of Gag-Pol.
整合是逆转录病毒复制所必需的步骤，由整合酶（IN）执行，它作为 Gag-Pol 前体的一部分表达。尽管 IN 催化的整合反应的机制细节已经很好地定义，但大量证据表明，IN 除了整合之外，还参与逆转录病毒复制的多个步骤。在这项研究中，Huwe1，一种 HECT 型 E3 泛素连接酶，被鉴定为人类免疫缺陷病毒 1（HIV-1）IN 的新细胞相互作用蛋白。这种相互作用是通过 IN 的催化核心结构域和 Huwe1 的广泛区域介导的。有趣的是，尽管在靶细胞中耗尽 Huwe1 并不影响人 T 细胞系中 HIV-1 的早期感染阶段，但我们发现 Huwe1 敲低细胞释放的 HIV-1 的感染性显著增强，超过了来自对照细胞的病毒。感染性的增加发生在前病毒 DNA 合成中。进一步的分析表明，Huwe1 通过 IN 结构域与 HIV-1 Gag-Pol 前体蛋白相互作用。我们的结果表明，HIV-1 产生细胞中的 Huwe1 通过与 Gag-Pol 的 IN 区域结合，对下一轮病毒感染的进入后早期事件产生负面影响。
