Defining the regulation of double-strand DNA break repair by HIV Vpr

项目摘要/摘要 艾滋病毒是人类健康的主要障碍，特别是在发展中国家。我们已经取得了长足的进步 在了解艾滋病毒的基本分子生物学方面取得了进展和成功 抗逆转录病毒疗法。然而，尽管有这些知识，艾滋病毒生物学的许多方面仍然是我们所做的 我不明白。如果我们要真正治愈个人的艾滋病毒，我们必须首先充分了解分子 病毒复制机制，以开发新的治疗方法，利用这一生命周期中的关键步骤。 尽管经过几十年的研究，HIV生物学的一个这样的方面仍然是一个谜，那就是辅助基因 VPR。Vpr在进化上是保守的，在体内致病中起重要作用，但在病毒中的作用尚不明确。 已定义复制。VPR相关表型的一个新特性是DNA的结合 损害反应(DDR)。DDR是一个信号级联，对确保宿主基因组的保真度至关重要 在存在基因毒性压力的情况下。越来越多的证据强调了激活和 不同的DNA和RNA病毒对宿主DDR的抑制。然而，VPR究竟是如何以及为什么参与的 解甲返乡的情况尚不清楚。 我们最近开始通过识别VPR既激活又抑制VPR来弥合这一知识差距 在多个步骤中执行DDR。具体地说，我们发现VPR抑制了细胞修复双重- 链DNA通过同源重组(HR)和非同源末端连接(NHEJ)断裂。基于我们的 初步数据，我们假设抑制双链DNA断裂修复是原发肿瘤的中心 VPR的功能。此外，我们认为表达vpr的细胞不能修复受损的dna。 代表了一种通过合成致死性基因毒剂选择性地耗尽艾滋病毒细胞的简便方法 诱导低水平的额外DNA损伤。我们将结合分子、蛋白质组和进化 直接检验我们的假设的方法。我们提议的研究的成功将确定VPR的主要角色， 它将阐明DDR如何调节艾滋病毒复制，并将提供一种治疗艾滋病毒个体的新方法 清除受感染的细胞。

PROJECT SUMMARY / ABSTRACT HIV presents a major obstacle to human health, particularly in developing nations. Large strides have been made in understanding the basic molecular biology of HIV, which have led to advances in the development and success of antiretroviral therapies. Yet despite this knowledge, there are still many aspects of HIV biology which we do not understand. If we are to ever truly cure individuals of HIV, we must first fully understand the molecular mechanisms of viral replication to develop novel therapies that take advantage of essential steps in this lifecycle. One such aspect of HIV biology that has remained a mystery despite decades of research is the accessory gene Vpr. Vpr is evolutionarily conserved and important for pathogenesis in vivo, yet no clear role for Vpr in viral replication has been defined. An emerging property of Vpr-associated phenotypes is engagement of the DNA damage response (DDR). The DDR is a signaling cascade that is vital to ensuring the fidelity of the host genome in the presence of genotoxic stress. Growing evidence has emphasized the importance of both activation and repression of the host DDR by diverse DNA and RNA viruses. However, precisely how and why Vpr engages the DDR is unclear. We have recently begun to bridge this gap in knowledge by identifying that Vpr both activates and represses the DDR at multiple steps. Specifically, we have found that Vpr represses the ability of the cell to repair double- strand DNA breaks via homologous recombination (HR) and non-homologous end joining (NHEJ). Based on our preliminary data, we hypothesize that repression of double-strand DNA break repair is central to the primary function of Vpr. Moreover, we propose that the inability of Vpr-expressing cells to repair damaged DNA represents a tractable means to selectively deplete HIV+ cells via synthetic lethality with genotoxic agents that induce low levels of additional DNA damage. We will take a combined molecular, proteomic, and evolutionary approach to directly test our hypotheses. Success of our proposed research will define the primary role of Vpr, it will elucidate how the DDR regulates HIV replication, and it will provide a novel means to treat HIV+ individuals and clear infected cells.