HIV-1 Preintegration Trafficking and Nuclear Localization

项目总结 NIH在其生命周期内的这项长期拨款在核内机制方面取得了开创性的发现 艾滋病毒-1贩运和核本地化。在之前的资金周期中，我们确定了核孔复合体 核孔蛋白153与病毒衣壳蛋白相互作用影响传入病毒的转位 复制复合体进入细胞核和人类基因组中病毒DNA整合的位置。我们也 首次鉴定了细胞交替多聚腺苷酸化蛋白裂解和多腺苷酸化特异性因子6 (CPSF6)作为病毒衣壳的直接结合伙伴，并揭示了这种相互作用在 病毒逆转录入活性染色质的整合。在最近的资金周期中，我们的工作 已经阐明衣壳与CPSF6的相互作用是病毒复制复合体进入核的关键 结构，在那里它们与被称为核斑点的核细胞器结构共存。vbl.使用 新的生物信息学工具，我们的工作还揭示了HIV-1整合到 我们基因组中与核斑点物理相关的区域。这样，我们最新的研究 阐明了最有利于和最吸引HIV-1的核结构结构的粒度 染色体上的整合部位。展望未来，我们将确定这一点的几个未知方面 基本的病毒-宿主相互作用，包括CPSF6在HIV-1核内作用的机制基础 靶向以及错误靶向的功能后果，其中HIV-1已知 不同寻常地整合到异色板层--近端序列向外延伸到 核结构。我们将进一步调查我们所拥有的其他宿主因素的参与 被标记为在生化行为上与CPSF6相似，因为它们在核内贩运HIV-1到 首选的整合地点。我们还将调查这些病毒宿主的功能后果 单核细胞类型的相互作用，其中HIV-1复制复合体可以由细胞固有的感觉到 用于中和感染过程的机械。这项基础科学研究的翻译相关性是 通过衣壳蛋白抑制剂的作用机制，如来那帕韦，这是晚期的 阶段性临床试验，已知可抑制HIV-1衣壳与Nup153和CPSF6的相互作用 蛋白，并在细胞内诱导HIV-1整合重定向。我们提议的全部工作将解决 在HIV-1感染期间发生的病毒-宿主相互作用的基本方面，以保护病毒免受感知 在先天免疫细胞中，将整合导航到首选的基因组DNA位置，以及 错误地整合了病毒功能，并从延迟中重新激活。

PROJECT SUMMARY This longstanding NIH grant over its lifetime has made seminal discoveries on the mechanisms of intranuclear HIV-1 trafficking and nuclear localization. In prior funding cycles, we determined that the nuclear pore complex protein nucleoporin 153 interacted with the viral protein capsid to affect the translocation of incoming viral replication complexes into the cell nucleus and sites of viral DNA integration in the human genome. We also first identified the cellular alternate polyadenylation protein cleavage and polyadenylation specificity factor 6 (CPSF6) as a direct binding partner of the viral capsid and revealed an important role for this interaction in integration of the viral reverse transcript into active chromatin. Over the most recent funding cycle, our work has clarified that the capsid-CPSF6 interaction is critical for viral replication complexes to travel into the nuclear structure, where they colocalize with nuclear organelle structures that are known as nuclear speckles. Using novel bioinformatic tools, our work moreover revealed the significant preference for HIV-1 to integrate into regions of our genome that physically associate with nuclear speckles. In this way, our most recent research has clarified the granularity of nuclear architectural structure that most favors and most attracts HIV-1 to its chromosomal sites of integration. Moving forward, we will determine several unknown aspects of this fundamental virus-host interaction, including the mechanistic basis of CPSF6 action in HIV-1 intranuclear targeting as well as the functional consequences of mistargeting, wherein HIV-1 is known to uncharacteristically integrate into heterochromatic lamina-proximal sequences out towards the periphery of the nuclear structure. We furthermore will investigate the participations of other host factors that we have earmarked as behaving biochemically similar to CPSF6 for their roles in HIV-1 trafficking in the nucleus to preferred sites of integration. We will also investigate the functional consequences of these virus-host interactions in monocytic cell types, wherein HIV-1 replication complexes can be sensed by cellular innate machinery to counteract the infection process. The translational relevance of this basic scientific research is highlighted through the mechanism of action of capsid protein inhibitors such as lenacapavir, which are in late stage clinical trials and are known to inhibit the interaction of the HIV-1 capsid with Nup153 and CPSF6 proteins in vitro, and to induce HIV-1 integration retargeting in cells. Our proposed work in total will address fundamental aspects of virus-host interactions that occur during HIV-1 infection to shield the virus from sensing in innate immune cells, navigate integration to preferred genomic DNA sites, as well as the consequences of misguided integration on virus function and reactivation from latency.