Activities of HHV-8 vIRF-1 in Virus Biology

HHV-8 vIRF-1 在病毒生物学中的活性

• 批准号: 8508375
• 负责人: John Nicholas
• 金额: $ 40.5万
• 依托单位: JOHNS HOPKINS UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-08-01 至 2014-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8508375
• 关键词: Affinity; Apoptosis; Apoptotic; B lymphoid malignancy; BH3 Domain; Binding; Biological; Biology; Cell Cycle Arrest; Cell Nucleus; Cell Survival; Cells; Cessation of life; Cytoplasm; Data; Development; Dissection; Dissociation; EP300 gene; Endothelial Cells; Family; Future; Generations; Goals; Homologous Gene; Human Herpesvirus 8; IRF1 gene; IRF3 gene; Individual; Infection; Interferons; Investigation; Laboratories; Link; Maps; Mediating; Mitochondria; Molecular; Mutate; Noxae; Nuclear; Nuclear Localization Signal; Nuclear Proteins; Nuclear Translocation; Pathway interactions; Peptides; Play; Production; Protein Binding; Protein Binding Domain; Protein Family; Proteins; Reagent; Refractory; Relative (related person); Reporting; Research; Role; Signal Transduction; Site; Specific qualifier value; Specificity; Stress; Testing; Variant; Viral; Viral Proteins; Virus; Virus Diseases; Virus Inhibitors; Virus Replication; base; biological adaptation to stress; cellular targeting; gain of function; loss of function; lytic replication; member; novel; overexpression; response; tool; transcription factor; viral interferon regulatory factor; viral resistance

DESCRIPTION (provided by applicant): Human herpesvirus 8 (HHV-8) specifies four viral interferon regulatory factor homologues (vIRFs) that function to inhibit cellular IRFs in addition to other components of cellular defense pathways that promote cell cycle arrest and apoptosis in response to virus infection. Cellular proteins targeted for inhibition by vIRF-1 include p53, ATM, GRIM19, Smad transcription factors, and p300/CBP transcriptional co-activators required for IRF-?mediated responses. This laboratory has identified an entirely novel class of interaction, between vIRF-1 and stress-responsive, pro-apoptotic BH3-only proteins (BOPs) Bim and Bid, demonstrated to be inhibited by vIRF-1 binding, and other newly recognized BOP targets. Furthermore, we have identified partial localization of vIRF-1 to mitochondria, suggesting that vIRF-1 can inactivate BOPs directly at their site of action. vIRF-1- induced nuclear translocation of Bim represents a secondary, unique mode of inactivation. vIRF-1:BOP interaction is via the Bid-BH3B-related BOP-binding domain (BBD) of vIRF-1 (residues 170-187) and the BH3 domains of targeted BOPs. Both Bim and Bid are induced by HHV-8 lytic replication and Bim, at least, is a powerful inhibitor of virus production, suggesting that Bim and probably other BOPs need to be controlled effectively by HHV-8 for virus replication to occur. Indeed, vIRF-1 BBD-mediated interactions contribute specifically and significantly to promotion of HHV-8 productive replication and vIRF-1-mediated apoptotic inhibition. However, the precise contributions of each vIRF-1:BOP interaction and the significance of other vIRF-1:protein interactions in virus biology are at present unknown. Furthermore, our newly-identified mitochondrial localization of vIRF-1 has yet to be assessed functionally. This application proposes: identification of the molecular/specificity determinants of BOP/BH3 targeting and inhibition by vIRF-1 (Aim 1); molecular dissection and dissociation of other protein-binding and functional domains of vIRF-1 (Aim 2); establishing the contributions of each vIRF-1:protein interaction and mitochondrial-localized activity of vIRF-1 in the context of HHV-8 infection (Aim 3). The project comprises a comprehensive, yet focused analysis of an HHV-8 protein with a demonstrated positive role in virus replication and which provides a uniquely valuable tool to study the relative importance of multiple (vIRF-1-targeted) cellular defense pathways in virus biology. Information generated from this study could provide the basis for development of novel anti-viral therapies.

描述（由申请人提供）：人疱疹病毒8型（HHV-8）指定了四种病毒干扰素调节因子同源物（vIRF），其功能除了抑制细胞IRF外， 细胞防御途径的其他组分，其促进细胞周期停滞和细胞凋亡以响应病毒感染。vIRF-1抑制的靶细胞蛋白包括p53、ATM、GRIM 19、Smad转录因子和IRF-1所需的p300/CBP转录共激活因子。介导的反应。这个实验室已经发现了一种全新的相互作用， vIRF-1和应激反应性促凋亡BH 3-only蛋白（BOP）Bim和Bid之间的相互作用，其被证明被vIRF-1结合和其他新识别的BOP靶标抑制。此外，我们已经确定了vIRF-1的部分定位到线粒体，这表明vIRF-1可以直接在其作用位点抑制BOP。vIRF-1诱导的Bim核转位代表了一种次要的、独特的失活模式。vIRF-1：BOP相互作用是通过vIRF-1的Bid-BH 3B相关BOP结合结构域（BBD）（残基170-187）和靶向BOP的BH 3结构域。Bim和Bid都是由HHV-8裂解复制诱导的，Bim至少是病毒产生的有力抑制剂，这表明Bim和可能的其他BOP需要由HHV-8有效控制才能发生病毒复制。事实上，vIRF-1 BBD介导的相互作用对促进HHV-8生产性复制和vIRF-1介导的凋亡抑制有特异性和显著性贡献。然而，每个vIRF-1：BOP相互作用的精确贡献和其他vIRF-1：蛋白质相互作用在病毒生物学中的意义目前尚不清楚。此外，我们新发现的vIRF-1的线粒体定位尚未进行功能评估。本申请提出：vIRF-1靶向和抑制BOP/BH 3的分子/特异性决定因素的鉴定（目标1）; vIRF-1的其他蛋白结合和功能结构域的分子解剖和解离（目标2）;确定每种vIRF-1的贡献：HHV-8感染背景下vIRF-1的蛋白相互作用和尿道定位活性（目标3）。该项目包括对HHV-8蛋白进行全面而集中的分析，该蛋白在病毒复制中具有积极作用，并为研究病毒生物学中多种（vIRF-1靶向）细胞防御途径的相对重要性提供了独特的有价值的工具。 从这项研究中产生的信息可以为开发新的抗病毒疗法提供基础。