Inositol Polyphosphates and HIV-1 Maturation

肌醇多磷酸盐和 HIV-1 成熟

基本信息

批准号：
9927308
负责人：
Christopher R Aiken
金额：
$ 25.5万
依托单位：
VANDERBILT UNIVERSITY MEDICAL CENTER
依托单位国家：
美国
项目类别：
财政年份：
2020
资助国家：
美国
起止时间：
2020-02-25 至 2022-01-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9927308
关键词：
Acquired Immunodeficiency Syndrome Alpha Particles Antiviral Agents Binding Binding Proteins Biological Assay Capsid Cells Cleaved cell Complex Cone Dependence Development Dissociation Drug Targeting Drug resistance Engineering Enzymes Foundations HIV HIV-1 In Vitro Infection Inositol Laboratories Lead Ligands Methods Modeling Molecular Morphology Mutation Peptide Hydrolases Persons Pharmaceutical Preparations Pharmacotherapy Phytic Acid Polyphosphates Process Production Property Proteins Recombinant Proteins Replication-Associated Process Research Retroviridae Role SP1 gene Site Structural Protein Structure Testing Therapeutic Viral Virion Virus Replication base drug development gag Gene Products gel electrophoresis improved mutant novel novel virus particle predictive modeling self assembly stoichiometry virus host interaction

项目摘要

Project Summary/Abstract Replication of HIV-1, the causative agent of Acquired Immune Deficiency Syndrome (AIDS), involves the assembly of immature particles composed of the Gag polyprotein and subsequent maturation of these particles by proteolytic cleavage. Although HIV-1 infection can be effectively controlled through the judicious administration of antiviral drugs, therapy is not curative, and drug resistance is a constant concern. Axiomatically, HIV-1 depends on interactions with host cell molecules at every stage of its replication cycle. Although many of these virus-host interactions occur between proteins, the host cell metabolite inositol hexakisphosphate (IP6) has recently emerged as a key host molecule involved in HIV-1 replication. IP6 appears to bind to the Gag polyprotein in infected cells, thus stabilizing the Gag hexameric lattice and promoting virion assembly. Remarkably, IP6 also binds to the cleaved viral CA protein in vitro and promotes CA self-assembly into cone- like structures that are morphologically similar to native HIV-1 capsids. Based on these observations, a model has been proposed in which IP6 is released upon cleavage of the Gag lattice by the viral protease during HIV-1 maturation. Release of IP6 permits its binding to assembling CA hexamers, thus stabilizing the mature capsid lattice. In this project, we will validate key predictions of this model. Employing novel and sensitive assays to quantify the levels of IP5 and IP6 associated with purified subviral complexes, we will identify the specific cleavages in the Gag polyprotein required for dissociation of these ligands from the immature Gag lattice. Second, we will identify the molecular determinants of IP6 binding to the mature capsid lattice, including testing the role of Arg18 in CA that has been shown to form ionic interactions with IP6 in vitro. Finally, we will quantify the levels of IP6 present in particles of diverse retroviruses as a first step in understanding the range of retroviruses that utilize IP6 in their replication cycles. IP6 is the first non-nucleotide host cell metabolite on which HIV-1 replication has been shown to depend. Defining the mechanism of IP6 action in HIV-1 maturation is essential to understand how HIV-1 exploits this novel virus-host interaction. Ultimately, the project may lead to the development of new antiviral drugs, thus expanding the available therapeutic options for the long-term management of HIV-1 infection.

项目概要/摘要 HIV-1（获得性免疫缺陷综合症（艾滋病）的病原体）的复制涉及由 Gag 多蛋白组成的未成熟颗粒的组装以及这些颗粒随后的成熟通过蛋白水解裂解。尽管通过明智的措施可以有效控制 HIV-1 感染服用抗病毒药物后，治疗并不能治愈，而且耐药性始终是一个令人担忧的问题。公理地讲， HIV-1 在其复制周期的每个阶段都依赖于与宿主细胞分子的相互作用。虽然很多这些病毒-宿主相互作用发生在蛋白质、宿主细胞代谢物肌醇六磷酸 (IP6) 之间最近出现作为参与 HIV-1 复制的关键宿主分子。 IP6 似乎与 Gag 绑定感染细胞中的多蛋白，从而稳定 Gag 六聚体晶格并促进病毒粒子组装。值得注意的是，IP6 还在体外与切割的病毒 CA 蛋白结合，并促进 CA 自组装成圆锥体。其结构在形态上与天然 HIV-1 衣壳相似。根据这些观察，建立了一个模型有人提出，在 HIV-1 期间，病毒蛋白酶裂解 Gag 晶格后释放 IP6 成熟。 IP6 的释放使其能够与组装的 CA 六聚体结合，从而稳定成熟的衣壳格子。在这个项目中，我们将验证该模型的关键预测。采用新颖且灵敏的检测方法量化与纯化的亚病毒复合物相关的 IP5 和 IP6 的水平，我们将确定具体的 Gag 多蛋白中的裂解需要这些配体从未成熟的 Gag 晶格上解离。其次，我们将确定 IP6 与成熟衣壳晶格结合的分子决定因素，包括测试 Arg18 在 CA 中的作用已被证明在体外与 IP6 形成离子相互作用。最后，我们将量化不同逆转录病毒颗粒中 IP6 的水平是了解逆转录病毒范围的第一步在其复制周期中利用 IP6 的逆转录病毒。 IP6是第一个非核苷酸宿主细胞代谢物 HIV-1 复制已被证明具有依赖性。定义 IP6 在 HIV-1 成熟中的作用机制是对于了解 HIV-1 如何利用这种新型病毒与宿主相互作用至关重要。最终，该项目可能会导致开发新的抗病毒药物，从而扩大长期可用的治疗选择 HIV-1 感染的管理。