Modulation of Retroviral Uncoating by Cellular Factors

 描述(申请人提供)：在之前的资助期间，我们在对HIV-1去涂层和逆转录的理解方面取得了重大进展，发表了36篇手稿，其中19篇是资深最后作者。我们的突出发现是，细胞蛋白质和药物破坏了HIV-1核心的稳定，从而加速了脱壳，防止了逆转录的发生，并扰乱了感染。总体而言，我们的发现导致我们提出了一个模型，在该模型中，HIV-1核心是一个“容器”，确保在揭开涂层之前完成逆转录。诸如trim5HIV-1或小分子抑制剂α74和Bi2等破坏HIV-1核心稳定的药物可以防止反转录的发生。然而，稳定HIV-1核心的蛋白质和药物也可以破坏感染。为了了解稳定HIV-1核心阻止HIV-1感染的机制，我们将利用最近发现的人类MXB蛋白。MXB是一种干扰素-α诱导蛋白，在逆转录后整合之前阻止艾滋病毒-1感染。基因实验表明，衣壳是MXB阻断HIV-1感染能力的病毒决定因素；我们的初步结果表明，MXB与HIV-1核心结合，并在感染期间稳定HIV-1核心。MXB是已知的第一种天然表达的稳定HIV-1核心的蛋白质，使MXB成为了解核心稳定如何导致阻断HIV-1感染的理想候选者。这一应用将检验MXB与HIV-1核心结合并在其表面形成更高级结构，从而防止脱膜的假设。以下目的将用于验证这一假说：1)检测MXB与衣壳的结合在限制中的作用，2)检测MXB与HIV-1核心结合能力中的寡聚和高阶自结合的作用，3)检测限制b MXB的亚细胞定位，以及4)检测磷酸化在MXB阻断HIV-1感染的能力中的作用。通过这一提议获得的知识将有助于理解HIV-1的基本揭膜过程和MXB阻止感染的机制。这里所获得的知识是开发针对HIV-1的新疗法的潜在基础。

 DESCRIPTION (provided by applicant): During the previous funding period we made major advances in our understanding of HIV-1 uncoating and reverse transcription, publishing 36 manuscripts, including 19 with senior last authorship. Our salient finding was that cellular proteins and drugs that destabilize the HIV-1 core, thereby accelerating uncoating, prevent the occurrence of reverse transcription and disrupt infection. Overall our findings lead us to propose a model in which the HIV-1 core is a "container" that ensures the completion of reverse transcription before uncoating. Agents such as TRIM5α or the small molecule inhibitors PF74 and Bi2, which destabilize the HIV-1 core, prevent the occurrence of reverse transcription. Proteins and drugs that stabilize the HIV-1 core, however, also disrupt infection. To understand the mechanism by which stabilization of the HIV-1 core blocks HIV-1 infection, we are going to take advantage of the recently discovered human MxB protein. MxB is an interferon-α-inducible protein that blocks HIV-1 infection after reverse transcription but prior to integration. Genetic experiments suggested that capsid is the viral determinant for the ability of MxB to block HIV-1 infection; In agreement, our preliminary results indicated that MxB binds to the HIV-1 core and stabilizes the HIV-1 core during infection. MxB is the first naturally expressed protein known to stabilize the HIV-1 core, making MxB an ideal candidate to understand how core stabilization leads to a block on HIV-1 infection. This application will test the hypothesis that MxB binds to the HIV-1 core and forms higher order structures on its surface, thereby preventing uncoating. The following aims will be used to test this hypothesis: 1) Examine the role of MxB binding to capsid on restriction, 2) Examine the role of oligomerization and higher-order self-association in the ability of MxB to bind the HIV-1 core, 3) Examine the subcellular localization of restriction b MxB, and 4) Examine the role of phosphorylation in the ability of MxB to block HIV-1 infection. The knowledge gain by this proposal will be instrumental for understanding the basic uncoating process of HIV-1 and the mechanism by which MxB blocks infection. The knowledge gain here is the potential basis for the development of novel treatments against HIV-1.