Modular Domains of Host Proteins Regulate Filovirus Maturation

宿主蛋白的模块化结构域调节丝状病毒成熟

• 批准号: 9517218
• 负责人: RONALD N HARTY
• 金额: $ 24.64万
• 依托单位: UNIVERSITY OF PENNSYLVANIA
• 依托单位国家: 美国
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-01-15 至 2019-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9517218
• 关键词: Affect; Antiviral Agents; Autophagocytosis; BAG3 gene; Binding; Binding Proteins; Biological; Categories; Cell Survival; Cell membrane; Cells; Data; Defense Mechanisms; Disease Progression; Ebola virus; Ensure; Excision; Filament; Filoviridae Infections; Filovirus; Frankfurt-Marburg Syndrome Virus; Funding Mechanisms; Genetic Engineering; Goals; Homo; Host Defense; Host Defense Mechanism; Innate Immune Response; Laboratories; Mammalian Cell; Mediating; Molecular Chaperones; N-terminal; Pathway interactions; Play; Process; Proteins; Publishing; Role; Site; Stress; Testing; Therapeutic Agents; Time; Ubiquitination; Vaccines; Vesicular stomatitis Indiana virus; Viral; Viral Proteins; Virion; Virus; Virus Assembly; Virus-like particle; base; imaging approach; innovation; insight; mutant; new therapeutic target; novel; novel therapeutic intervention; pathogen; prevent; proteostasis; recombinant virus; recruit; transmission process

The ultimate goal of this proposal is to elucidate the novel antiviral mechanism of host BAG3; a newly discovered filovirus VP40 interacting protein that inhibits viral egress. Filoviruses (Ebola [EBOV] and Marburg [MARV]) are Category A, high-priority pathogens, for which there are no commercially available vaccines or therapeutic agents. Thus, exploratory and innovative approaches are warranted to better understand viral-host interactions that both promote and inhibit the transmission of these deadly viruses. Our laboratory focuses on the mechanisms by which filoviruses interact with and recruit host proteins to regulate the budding process. Here, we identified an unanticipated interaction between filovirus VP40 and the host protein BAG3. BAG3 is a stress-regulated, co-chaperone protein whose function is to ensure cell survival and protein homeostasis via Chaperone-Assisted Selective Autophagy (CASA). While BAG3 has been shown to positively influence entry and replication for some viruses, we found that the interaction of the PPxY motif of both EBOV and MARV VP40 with the single N-terminal WW-domain of BAG3 leads to an unexpected decrease in egress of both EBOV and MARV VP40 virus-like particles (VLPs), as well as VSV recombinant viruses that serve as functional EBOV surrogates, as they are genetically engineered to express either EBOV VP40 WT or mutant L-domains in place of the L-domain of VSV M. We hypothesize that BAG3 expression is induced following filovirus infection, and that BAG3 targets VP40 for removal and/or sequestration from the site of budding at the plasma membrane. We will use a rigorous multifaceted approach to interrogate the mechanisms by which BAG3 disrupts virus particle egress, thus providing new insight into the potential role of CASA as a novel and specific host defense strategy to counteract the ability of VP40 to promote efficient egress and spread of virus particles.

该提案的最终目标是阐明宿主BAG 3的新的抗病毒机制; 发现丝状病毒VP 40相互作用蛋白，抑制病毒外出。丝状病毒（埃博拉病毒[EBOV]和 马尔堡[MARV]）是A类高优先级病原体，目前尚无市售产品 疫苗或治疗剂。因此，有必要采取探索性和创新性办法， 了解促进和抑制这些致命病毒传播的病毒-宿主相互作用。 我们的实验室专注于丝状病毒与宿主蛋白相互作用并招募宿主蛋白的机制， 调节萌芽过程。在这里，我们确定了丝状病毒VP 40和 宿主蛋白BAG 3。BAG 3是一种应激调节的共分子伴侣蛋白，其功能是确保细胞凋亡。 通过伴侣辅助的选择性自噬（CASA）的存活和蛋白质稳态。虽然BAG 3 被证明对某些病毒的进入和复制有积极影响，我们发现， EBOV和MARV VP 40的PPxY基序与BAG 3的单个N-末端WW-结构域导致了一个 EBOV和MARV VP 40病毒样颗粒（VLP）以及VSV的排出意外减少 作为功能性EBOV替代物的重组病毒，因为它们被基因工程化， 表达EBOV VP 40 WT或突变体L-结构域代替VSV M的L-结构域。我们假设 在丝状病毒感染后诱导BAG 3表达，并且BAG 3靶向VP 40以去除 和/或从质膜上的出芽位点隔离。我们将使用严格的多方面 研究BAG 3破坏病毒颗粒外出的机制的方法，从而提供了新的 深入了解CASA作为一种新型和特异性宿主防御策略的潜在作用，以抵消 的VP 40，以促进有效的出口和病毒颗粒的传播。