HIV Gag Precursor Protein Interactions

描述（由申请人提供）：尽管在艾滋病诊断和治疗方面取得了很大进展，但艾滋病流行的持续破坏要求继续努力了解艾滋病毒复制的各个方面，并开发新的抑制方法。为了实现这些目标，我们试图确定HIV-1结构蛋白（Gag）的活性，以便设计干扰这些功能的抗病毒药物。Gag蛋白是有吸引力的靶标，因为它们在生命周期中发挥多种作用。这些蛋白最初被合成为N-末端豆蔻酰化前体（PrGag）蛋白，其利用其N-末端基质（MA）结构域靶向递送至质膜（PM）病毒组装位点。有证据表明，MA优先结合信号磷脂磷脂酰肌醇4，5二磷酸（PI[4，5]P2），HIV-1病毒膜富含脂筏成分，如胆固醇、鞘磷脂和神经酰胺。MA还显示介导HIV-1包膜（Env）糖蛋白复合物掺入病毒颗粒，并与Env的跨膜（TM，gp 41）部分的胞质尾区（CT）相互作用。逆转录病毒基质蛋白也已知结合核酸，并且我们最近发现MA上的RNA和PI（4，5）P2结合位点重叠，支持了一种新的模型，其中RNA结合保护MA在PrGag递送至PM之前不与不适当的细胞膜缔合。利用我们以前的研究和初步结果作为基础，我们提出了新的方法来剖析基质蛋白膜，核酸和包膜蛋白结合的机制，并表征其抑制方法。我们的研究结果将有助于阐明艾滋病毒组装机制如何运作，并将导致开发以Gag为靶点的抗病毒药物，并了解它们是如何工作的。为了实现这些目标，我们的具体目标如下：1。HIV-1基质蛋白的核酸结合活性的表征。2. HIV-1 MA膜结合特性的测定。3. HIV-1基质-包膜蛋白相互作用的阐明。

DESCRIPTION (provided by applicant): Despite great advances in AIDS diagnosis and treatment, the continuing devastation of the AIDS epidemic demands continuing efforts to understand all aspects of HIV replication, and to develop new methods for its inhibition. In pursuit of these goals, we have sought to define the activities of the HIV-1 structural (Gag) proteins so as to design antivirals that interfere with these functions. The Gag proteins are attractive targets since they perform multiple roles during the life cycle. The proteins initially are synthesized as N-terminally myristylated precursor (PrGag) proteins that employ their N-terminal matrix (MA) domains to target delivery to plasma membrane (PM) virus assembly sites. Evidence indicates that MA preferentially binds to the signaling phospholipid phosphatidylinositol 4,5 bisphosphate (PI[4,5]P2), and that HIV-1 virus membranes are enriched for lipid raft constituents such as cholesterol, sphingomyelin, and ceramide. MA also has been shown to mediate the incorporation of the HIV-1 envelope (Env) glycoprotein complex into virus particles, and interacts with the cytoplasmic tail (CT) of the transmembrane (TM, gp41) portion of Env. Retrovirus matrix proteins also have been known to bind nucleic acids, and we recently discovered that the RNA and PI(4,5)P2 binding sites on MA overlap, supporting a new model in which RNA binding protects MA from association with inappropriate cellular membranes prior to PrGag delivery to the PM. Using our previous studies and preliminary results as a foundation, we propose novel approaches to dissect the mechanisms of matrix protein membrane, nucleic acid, and envelope protein binding, and to characterize methods for their inhibition. Our results will help elucidate how the HIV assembly machinery operates; and will lead to the development of Gag-targeted antivirals, and an understanding of how they work. To achieve these ends, our specific aims are as follows: 1. Characterization of the nucleic acid binding activity of the HIV-1 matrix protein. 2. Determination of membrane binding properties of HIV-1 MA. 3. Elucidation of HIV-1 matrix-envelope protein interactions.