Mechanisms that determine subcellular sites of HIV-1 assembly

决定 HIV-1 组装亚细胞位点的机制

• 批准号: 10362907
• 负责人: Akira Ono
• 金额: $ 68.28万
• 依托单位: UNIVERSITY OF MICHIGAN AT ANN ARBOR
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-07-01 至 2027-06-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10362907
• 关键词: Acquired Immunodeficiency Syndrome; Binding; Cell membrane; Cells; Goals; HIV-1; Instruction; Integral Membrane Protein; Integration Host Factors; Knowledge; Lipids; Mediating; Membrane; Movement; N-terminal; Phospholipids; Process; Production; Property; Research; Site; Structural Protein; T-Lymphocyte; Testing; Transfer RNA; Translations; Viral; Viral Structural Proteins; Virion; Virus; Virus Assembly; cell type; experimental study; extracellular; gag Gene Products; novel; particle; recruit; transmission process; virological synapse

Virus particle assembly of HIV-1, the causative agent of AIDS, takes place at the plasma membrane (PM) in most cell types including natural host T cells. This process is driven by a viral structural protein Gag. The N-terminal matrix (MA) domain of Gag determines Gag localization to and hence virus assembly at the PM. MA mediates membrane binding of Gag via N-terminal myristoyl moiety and a highly basic region (HBR) that binds acidic lipids. Binding of HBR to a PM-specific acidic phospholipid PI(4,5)P2 is critical for PM localization of Gag and efficient virus release. Notably, we and others showed that MA HBR also interacts with tRNAs, which suppress binding of Gag to non-PI(4,5)P2 acidic lipids, suggesting tRNAs as a host factor that regulates MA-membrane interactions. However, structural determinants for the tRNA-MA HBR interaction and its reversal by the interaction with PI(4,5)P2, combination of which regulates PM-specific Gag localization, remain to be examined. Binding of tRNAs to MA HBR is most likely to occur at translation sites due to limited availability of tRNAs outside of the translation machinery. However, little is known about subcellular sites of Gag translation, where Gag begins its movement to the PM. At the PM, Gag multimerization and subsequent accumulation of acidic lipids are likely to promote recruitment of host transmembrane proteins, but their effects on virus spread to uninfected cells remains to be determined in the context of cell-free and cell-to-cell transmission. Our long-term goal is to elucidate mechanisms that determine sites of HIV-1 assembly and to use the knowledge for developing antiviral strategies. Our central hypothesis in this application is that MA HBR interactions with tRNAs, which begin during translation, and with acidic lipids determine subcellular Gag localization and the properties of progeny virions. To test this hypothesis, we plan to: 1) identify structural determinants for interactions of MA HBR with tRNAs and acidic lipids; 2) identify tRNAs that suppress PI(4,5)P2-independent membrane binding but allow PI(4,5)P2-mediated reversal; 3) understand the effects of Gag translation sites on the fate of Gag; and 4) examine the effects of host transmembrane proteins incorporated into virus particles on formation of virological synapse and virus-cell contact. The knowledge gained from experiments outlined in this proposal will likely help us develop antiviral strategies that target mechanisms regulating Gag localization to the PM, thereby inhibiting extracellular virus release and spread. RELEVANCE (See instructions): Proper localization of viral components in cells is critical for efficient production of virus particles and spread from infected to uninfected cells. The goal of the proposed research is to elucidate the mechanisms that direct Gag, a structural protein of HIV-1 that causes AIDS, to the proper sites within virus-expressing cells. Knowledge obtained from proposed studies will help us develop novel antiviral strategies that may either directly suppress assembly and release of HIV-1 particles or inhibit spread of this virus to uninfected host cells

HIV-1（艾滋病的病原体）的病毒颗粒组装发生在质膜 (PM) 上 存在于大多数细胞类型中，包括天然宿主 T 细胞。这个过程是由病毒结构蛋白 Gag 驱动的。这 Gag 的 N 端矩阵 (MA) 结构域决定了 Gag 的定位，从而决定了病毒在 PM 上的组装。 MA 通过 N 端肉豆蔻酰部分和高碱性区域 (HBR) 介导 Gag 的膜结合 结合酸性脂质。 HBR 与 PM 特异性酸性磷脂 PI(4,5)P2 的结合对于 PM 至关重要 Gag 的本地化和高效的病毒释放。值得注意的是，我们和其他人表明 MA HBR 也相互作用 与 tRNA 结合，抑制 Gag 与非 PI(4,5)P2 酸性脂质的结合，表明 tRNA 作为宿主 调节 MA 膜相互作用的因子。然而，tRNA-MA HBR 的结构决定因素 相互作用及其通过与 PI(4,5)P2 相互作用的逆转，其组合调节 PM 特异性 堵嘴的定位，还有待检验。 tRNA 与 MA HBR 的结合最有可能发生在翻译时 由于翻译机器之外的 tRNA 可用性有限。然而，人们对此知之甚少 Gag 翻译的亚细胞位点，Gag 开始向 PM 移动。下午，堵嘴 多聚化和随后酸性脂质的积累可能会促进宿主的招募 跨膜蛋白，但它们对病毒传播到未感染细胞的影响仍有待确定 无细胞和细胞间传播的背景。 我们的长期目标是阐明决定 HIV-1 组装位点的机制并利用 制定抗病毒策略的知识。我们在此应用中的中心假设是 MA HBR 与 tRNA 的相互作用（在翻译过程中开始）以及与酸性脂质的相互作用决定了亚细胞 Gag 子代病毒颗粒的定位和特性。为了检验这个假设，我们计划：1）确定结构 MA HBR 与 tRNA 和酸性脂质相互作用的决定因素； 2) 识别抑制的 tRNA PI(4,5)P2 独立的膜结合，但允许 PI(4,5)P2 介导的逆转； 3）了解效果 Gag 翻译网站对 Gag 命运的看法； 4) 检查宿主跨膜蛋白的影响 在病毒突触形成和病毒与细胞接触时掺入病毒颗粒中。知识点 从本提案中概述的实验中获得的结果可能会帮助我们制定针对目标的抗病毒策略 调节 Gag 定位到 PM 的机制，从而抑制细胞外病毒释放和 传播。 相关性（参见说明）： 病毒成分在细胞中的正确定位对于有效生产病毒颗粒和 从受感染的细胞传播到未受感染的细胞。拟议研究的目标是阐明其机制 将 Gag（一种导致艾滋病的 HIV-1 结构蛋白）引导至病毒表达的适当位点 细胞。从拟议的研究中获得的知识将帮助我们开发新的抗病毒策略，这些策略可能 直接抑制 HIV-1 颗粒的组装和释放，或抑制该病毒向未感染者传播 宿主细胞