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巨大进展，但艾滋病流行病的持续破坏要求继续努力了解艾滋病毒复制的各个方面，并开发新的方法来抑制它。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端豆芽状前体（PrGag）蛋白，利用它们的n端基质（MA）结构域靶向传递到质膜（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），并且HIV-1病毒膜富含脂质筏成分，如胆固醇、鞘磷脂和神经酰胺。MA也被证明介导HIV-1包膜（Env）糖蛋白复合物进入病毒颗粒，并与Env跨膜（TM, gp41）部分的细胞质尾部（CT）相互作用。逆转录病毒基质蛋白也已知与核酸结合，我们最近发现MA上的RNA和PI(4,5)P2结合位点重叠，支持一种新的模型，即RNA结合保护MA在PrGag递送到PM之前不与不合适的细胞膜结合。利用我们之前的研究和初步结果为基础，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，并表征它们的抑制方法。我们的研究结果将有助于阐明HIV组装机制是如何运作的；并将导致针对gag的抗病毒药物的开发，以及对它们如何起作用的理解。为达到这些目的，我们的具体目标如下：HIV-1基质蛋白核酸结合活性的表征。2. hiv - 1ma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.