The Molecular Mechanisms Contributing to the Specific Localization of HIV-1 Gag to the Plasma Membrane

HIV-1 Gag 特异性定位于质膜的分子机制

• 批准号: 9754564
• 负责人: Christopher Aaron Sumner
• 金额: $ 3.67万
• 依托单位: UNIVERSITY OF MICHIGAN AT ANN ARBOR
• 依托单位国家: 美国
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-08-01 至 2020-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9754564
• 关键词: Antiviral Agents; Binding; Biological Assay; Blood Coagulation Factor VII; Capsid; Cell membrane; Cells; Ensure; Genetic Transcription; Goals; HIV; HIV-1; Higher Order Chromatin Structure; Imagery; Liposomes; Location; Mediating; Mediator of activation protein; Membrane; Methods; Modeling; Modification; Molecular; Movement; Nucleocapsid; Optimum Populations; Outcome Study; Phase; Phospholipids; Play; Population; Process; Publishing; RNA; RNA Binding; Resistance development; Role; Site; Surface; Testing; Transfer RNA; Translations; Viral; Viral Structural Proteins; Virion; Virus; Virus Assembly; Work; crosslinking and immunoprecipitation sequencing; improved; in vitro testing; molecular modeling; particle; recruit; trafficking; unilamellar vesicle

Project Summary/Abstract HIV-1 Gag is a viral structural protein that mediates virus particle assembly at the plasma membrane of infected cells. Gag trafficking to this site is a result of its interaction with the plasma membrane specific phospholipid PI(4,5)P2. After membrane binding, Gag multimerizes into higher order structures through the capsid and nucleocapsid domains, which then drives the budding of new virus particles from the surface of the host cell. Although the MA domain is capable of binding any acidic phospholipid, RNA binding to MA inhibits the association of Gag with non-PI(4,5)P2-containing membranes. Cellular tRNA has been shown to be the major RNA species that binds to the MA domain of Gag. Notably, however, our published and preliminary results revealed that some tRNAs are incapable of inhibiting Gag-membrane binding, whereas other tRNA species inhibit Gag association with membranes even when they contain PI(4,5)P2. Once Gag localizes to the plasma membrane, it is not known whether the presence of PI(4,5)P2 is sufficient for the stable binding of Gag or whether Gag multimerization also contributes to this stable association. Additionally, although we observed differences in the abilities to bind the MA domain and to inhibit membrane binding of Gag among different tRNA subsets, the molecular features of tRNA that are important for the optimal inhibition of Gag membrane binding are still unclear. Defining the molecular interactions that contribute to the stable membrane binding of Gag and binding of tRNA to the MA domain are essential for understanding the processes that occur within infected cells to drive the specific localization of Gag to the plasma membrane. Our central hypothesis is that optimally inhibitory tRNA species become bound to the MA domain of Gag at the site of translation, ensuring that Gag targets specifically to the plasma membrane where PI(4,5)P2 and the multimerization of Gag promote stable membrane binding. In order to test our hypothesis, we aim to identify the molecular interactions that contribute to the binding and retention of Gag on the membrane (Aim 1) and to determine how and when optimally inhibitory tRNA species become associated with the MA domain of Gag (Aim 2). The completion of this work will clarify the model for the molecular factors that are important for the trafficking of Gag to the plasma membrane and its retention at this location.

项目概要/摘要 HIV-1 Gag 是一种病毒结构蛋白，可介导病毒颗粒在 受感染细胞的质膜。对该网站的言论贩运是其互动的结果 具有质膜特异性磷脂 PI(4,5)P2。膜结合后， Gag 通过衣壳和核衣壳多聚成更高阶的结构 域，然后驱动新病毒颗粒从表面萌芽 宿主细胞。尽管 MA 结构域能够结合任何酸性磷脂，但 RNA 与 MA 结合可抑制 Gag 与不含 PI(4,5)P2 的膜的结合。 细胞 tRNA 已被证明是与 MA 结合的主要 RNA 种类 加格的领域。然而值得注意的是，我们公布的初步结果表明 一些 tRNA 无法抑制 Gag 膜结合，而其他 tRNA 即使它们含有 PI(4,5)P2，物种也会抑制 Gag 与膜的结合。 一旦 Gag 定位于质膜，尚不清楚是否存在 PI(4,5)P2 足以稳定结合 Gag 或是否也发生 Gag 多聚化 为这种稳定的关联做出了贡献。此外，尽管我们观察到差异 结合 MA 结构域和抑制 Gag 膜结合的能力 不同的 tRNA 子集，tRNA 的分子特征对于最佳结果很重要 Gag 膜结合的抑制作用仍不清楚。定义分子相互作用 有助于 Gag 的稳定膜结合以及 tRNA 与 MA 的结合 域对于理解受感染细胞内发生的过程至关重要 驱动 Gag 特定定位到质膜。我们的中心假设是 最佳抑制性 tRNA 种类与 Gag 的 MA 结构域结合 翻译位点，确保 Gag 专门针对质膜 PI(4,5)P2 和 Gag 的多聚化促进稳定的膜结合。为了 检验我们的假设，我们的目标是确定有助于 Gag 在膜上的结合和保留（目标 1）并确定如何以及何时 最佳抑制性 tRNA 种类与 Gag 的 MA 结构域相关（目的 2）。这项工作的完成将阐明分子因素的模型 对于 Gag 向质膜的运输及其在质膜上的保留很重要 地点。