Nuclear Trafficking of the Retroviral Gag Protein

逆转录病毒 Gag 蛋白的核运输

• 批准号: 8072188
• 负责人: Leslie J Parent
• 金额: $ 25.02万
• 依托单位: PENNSYLVANIA STATE UNIV HERSHEY MED CTR
• 依托单位国家: 美国
• 财政年份: 1998
• 资助国家: 美国
• 起止时间: 1998-07-01 至 2013-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8072188
• 关键词: Address; Animals; Antiviral Agents; Antiviral Therapy; Biochemical; Biological; Biological Models; Borna disease virus; Bypass; Cancer Etiology; Cell Communication; Cell Nucleolus; Cell Nucleus; Cell membrane; Cell physiology; Cells; Centrosome; Collection; Complex; Coronavirus nucleocapsid protein; Cytoplasm; Cytoplasmic Granules; Development; Drosophila genus; Event; Funding; Gagging; Genome; Genomics; Glycine decarboxylase; Goals; Grant; HIV; Image; Immunologic Deficiency Syndromes; Importins; Influenza; Integration Host Factors; Intracellular Transport; Kinetics; Knowledge; Laboratories; Life; Life Cycle Stages; Light; Link; Mediating; Membrane; Methods; Modeling; Molecular; Movement; Murine leukemia virus; NP protein; Nuclear; Nuclear Envelope; Nuclear Export; Nuclear Import; Nucleolar Proteins; Pathway interactions; Play; Process; Property; Proteins; Proteomics; RNA; RNA-Protein Interaction; Research; Research Project Grants; Retrotransposon; Retroviral Vector; Retroviridae; Ribonucleoproteins; Role; Rous sarcoma virus; Signal Transduction; Spumavirus; Staging; Stress; Structural Protein; System; Testing; Transmembrane Transport; Viral; Viral Genome; Viral Structural Proteins; Virion; Virus; Virus Assembly; Virus Replication; design; gag Gene Products; gene therapy; imaging modality; inhibitor/antagonist; innovation; insight; interdisciplinary approach; interest; mutant; novel; nucleocytoplasmic transport; particle; pathogen; programs; protein transport; public health relevance; research study; tool; trafficking; transportin SR; viral RNA; yeast genetics

DESCRIPTION (provided by applicant): Retroviruses interact intimately with their hosts, usurping cellular pathways to complete their life cycles. Identification of novel host factors that contribute to virus replication will enhance our understanding of retrovirus-cell interactions and may provide new targets for antiviral therapy. Host factors are known to play a major role in the late stages of virus particle formation and budding, but the early steps of assembly have remained understudied largely because distinct molecular events have been difficult to identify. Recently, we discovered an early step in Rous sarcoma virus (RSV) assembly: nucleocytoplasmic shuttling of the Gag protein, the viral factor that directs the assembly process. This nuclear trafficking event is crucial for the formation of infectious virus particles, and mutants that bypass the nuclear compartment incorporate reduced amounts of viral genomic RNA. We hypothesize that RSV genome recognition and selection, one of the earliest steps in particle assembly, occurs within the nucleus. This idea challenges the current dogma that retroviruses package their genomes in the cytoplasm; thus this research project has the potential to be paradigm-shifting. Our specific aims are centered on this novel hypothesis and address mechanistic aspects of nuclear shuttling of RSV Gag. We have a well-defined model system and an informative collection of Gag mutants with altered nuclear transport properties to use as tools. In Aim1, we will dissect the nuclear import pathway, define the roles of specific importins, and use inhibitors of entry to investigate the biological role of Gag nuclear trafficking in virus replication. Aim 2 focuses on intranuclear interactions between Gag proteins, Gag-RNA complexes, nucleolar factors, and subnuclear bodies. In Aim 3, we will utilize innovative imaging methods to visualize the movement of Gag-RNA complexes within the nucleus and from the nuclear envelope to the plasma membrane, identifying additional host factors involved in Gag- RNA trafficking. We will also be looking for evidence that Gag nuclear shuttling influences basic cellular processes, as many viruses have recently been shown to compromise nuclear export, activities of import factors, and localization of essential nuclear/nucleolar proteins. Through this focused experimental plan, we hope to shed light on fundamental aspects of retrovirus assembly, genome packaging, and nuclear events engaged in the interplay between retroviral pathogens and their host cells. PUBLIC HEALTH RELEVANCE: Retroviruses cause cancer and immunodeficiency syndromes in people and animals. This application focuses on defining the intracellular trafficking of the retroviral Gag protein, the major structural protein of retroviruses. Results of this research may enhance our understanding of how retroviruses interact with the cells they infect, potentially leading to new antiviral targets and enhanced retroviral vectors for gene therapy.

描述（由申请人提供）：逆转录病毒与其宿主密切相互作用，篡夺细胞途径来完成其生命周期。鉴定有助于病毒复制的新宿主因子将增强我们对逆转录病毒与细胞相互作用的理解，并可能为抗病毒治疗提供新靶点。众所周知，宿主因素在病毒颗粒形成和出芽的后期阶段发挥着重要作用，但组装的早期步骤仍然没有得到充分研究，很大程度上是因为很难识别不同的分子事件。最近，我们发现了劳斯肉瘤病毒 (RSV) 组装的早期步骤：Gag 蛋白的核质穿梭，Gag 蛋白是指导组装过程的病毒因子。这种核运输事件对于感染性病毒颗粒的形成至关重要，绕过核区室的突变体掺入的病毒基因组 RNA 数量减少。我们假设 RSV 基因组识别和选择（颗粒组装的最早步骤之一）发生在细胞核内。这个想法挑战了当前逆转录病毒将基因组包装在细胞质中的教条。因此，这个研究项目有可能改变范式。我们的具体目标集中在这一新颖的假设上，并解决 RSV Gag 核穿梭的机制问题。我们有一个明确的模型系统和一个信息丰富的 Gag 突变体集合，这些突变体具有改变的核运输特性，可以用作工具。在 Aim1 中，我们将剖析核输入途径，定义特定输入蛋白的作用，并使用进入抑制剂来研究 Gag 核运输在病毒复制中的生物学作用。目标 2 重点关注 Gag 蛋白、Gag-RNA 复合物、核仁因子和亚核体之间的核内相互作用。在目标 3 中，我们将利用创新的成像方法来可视化 Gag-RNA 复合物在细胞核内以及从核膜到质膜的运动，从而识别参与 Gag-RNA 运输的其他宿主因子。我们还将寻找 Gag 核穿梭影响基本细胞过程的证据，因为最近已证明许多病毒会损害核输出、输入因子的活动以及必需的核/核仁蛋白的定位。通过这个重点实验计划，我们希望阐明逆转录病毒组装、基因组包装以及参与逆转录病毒病原体与其宿主细胞之间相互作用的核事件的基本方面。 公共卫生相关性：逆转录病毒会导致人和动物癌症和免疫缺陷综合症。本申请重点关注逆转录病毒 Gag 蛋白（逆转录病毒的主要结构蛋白）的细胞内运输。这项研究的结果可能会增强我们对逆转录病毒如何与其感染的细胞相互作用的理解，从而可能导致新的抗病毒靶标和增强的用于基因治疗的逆转录病毒载体。