Mechanism of the Antiviral Activity of BAF Against Poxvirus and HSV-1 Infection

BAF 对抗痘病毒和 HSV-1 感染的抗病毒活性机制

• 批准号: 9413298
• 负责人: MATTHEW S WIEBE
• 金额: $ 36.83万
• 依托单位: UNIVERSITY OF NEBRASKA LINCOLN
• 依托单位国家: 美国
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-02-01 至 2020-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9413298
• 关键词: Address; Adenoviruses; Antiviral Agents; Antiviral Response; Binding; Binding Proteins; Biochemical; Cell Nucleus; Cell physiology; Cells; Communicable Diseases; Complex; Cytoplasm; DNA; DNA Binding; DNA Damage; DNA Repair; DNA Viruses; DNA biosynthesis; DNA-Binding Proteins; DNA-Protein Interaction; Data; Defense Mechanisms; Development; Diagnostic; Ensure; Enzymes; Euchromatin; Future; Genetic; Genetic Transcription; Genome; Goals; Growth; HIV; Herpesviridae; Herpesvirus 1; Host Defense; Host Defense Mechanism; Immune; Impairment; Infection; Investigation; Knowledge; Laboratory Study; Link; Maintenance; Mediating; Mitosis; Mitotic; Modeling; Molecular; Nuclear; Nucleoproteins; Outcome; Pathway interactions; Phosphorylation; Phosphotransferases; Post-Translational Regulation; Poxviridae; Process; Property; Proteins; Regulation; Repression; Research; Role; Signal Pathway; Signal Transduction; Testing; Transcriptional Regulation; Vaccinia; Viral; Viral Physiology; Virus; Virus Diseases; Virus Replication; Work; barrier-to-autointegration factor; base; cell growth regulation; ds-DNA; extrachromosomal DNA; genome integrity; inhibitor/antagonist; innovation; insight; pathogen; protein complex; public health relevance; recruit; response; scaffold; sensor; targeted treatment; tool; transcription factor; viral DNA

 DESCRIPTION (provided by applicant): Much remains to be learned about mechanisms cells utilize to defend against foreign DNA, both in the cytoplasm and nucleus, as well as how these defenses are subverted by viral countermeasures during infection. To address this knowledge gap, our studies of host defenses against foreign DNA focus on the poxvirus vaccinia and HSV1 as model pathogens. Understanding how these viruses accomplish DNA replication and transcription will yield new insights into the defense mechanisms cells use to respond to all foreign DNA. Toward this goal, our studies of vaccinia have led to the discovery that the poxviral B1 kinase is essential for viral DNA replication because it is needed to inactivate the cellular DNA binding protein BAF (barrier to autointegration factor). If it is not inactivated, BAF binds to viral DNA and acts as a defense against vaccinia DNA replication. Recent data from our lab suggests that BAF can act as an HSV1 inhibitor as well, indicating BAF may impair growth of multiple DNA viruses. BAF's antiviral activity likely occurs via its ability to compact and aggregate DNA to which it binds; we postulate that this compaction may contribute to host defense in multiple ways. For example, compaction likely limits the accessibility of the DNA to viral replication proteins via steric hindrance, and facilitates binding of other antiviral protein to the foreign genomes. Further examination of BAF's antiviral activity will yield unique insights int its mechanism of action. Our central hypothesis is that BAF initiates the assembly of DNA:protein complexes in a phosphorylation-regulated manner, providing a scaffold on which intrinsic defense effectors can converge. To test our hypothesis we propose three aims. AIM 1) Determine how phosphorylation and localization both regulate BAF's repression of poxviral DNA replication. These studies will yield insights into how post-translational regulation and localization provide interconnected mechanisms of regulating BAF's host defense activity. AIM 2) Determine how BAF- DNA complexes modulate transcription and DDR signaling to protect genomic integrity. Understanding how BAF and DNA repair machinery coordinate the silencing of foreign DNA, but are eluded by poxviruses, will be a central focus of this aim. AIM 3) Determine the mechanism whereby BAF acts as an antiviral against HSV-1 infection. Our data demonstrate that BAF can impair HSV-1 infection in a manner regulated by localization and/or phosphorylation, thus paralleling how BAF's anti-poxviral activity is modulated. These studies will yield insights into the molecular mechanism of BAF's activity against HSV-1. Throughout the course of these studies, we will compare and contrast how BAF works against both a cytoplasmic and a nuclear DNA virus, which will be an innovative application of these pathogens. As an outcome of this work we will better understand BAF's contribution to these nucleoprotein complexes and how BAF itself is regulated during viral infection. Thus, we will gain insight into cellular mechanisms which overlap in their ability to 1) silence foreign DNA through compaction and 2) protect genome integrity even in the absence of infection.

 描述（由申请人提供）：关于细胞用于防御细胞质和细胞核中的外来 DNA 的机制，以及这些防御在感染过程中如何被病毒对策破坏，还有很多需要了解的内容。宿主针对外来 DNA 的防御研究重点关注痘病毒和 HSV1 作为模型病原体，了解这些病毒如何完成 DNA 复制和转录将为细胞用于应对所有外来 DNA 的防御机制提供新的见解。我们对痘苗病毒的研究发现，痘病毒 B1 激酶对于病毒 DNA 复制至关重要，因为它需要使细胞 DNA 结合蛋白 BAF（自动整合因子屏障）失活，如果不失活，BAF 就会与病毒 DNA 结合。 我们实验室的最新数据表明，BAF 也可以充当 HSV1 抑制剂，这表明 BAF 可能通过其压缩和抑制多种 DNA 病毒的生长而发挥抗病毒活性。聚集与其结合的DNA；我们假设这种压缩可能以多种方式有助于宿主防御，例如，压缩可能通过空间位阻限制DNA与病毒复制蛋白的可及性，并促进其他蛋白的结合。进一步检查 BAF 的抗病毒活性将对其作用机制产生独特的见解，我们的中心假设是 BAF 以磷酸化调节的方式启动 DNA：蛋白质复合物的组装，从而提供了内在的支架。为了检验我们的假设，我们提出了三个目标： 1) 确定磷酸化和定位如何调节 BAF 对痘病毒 DNA 复制的抑制。深入了解翻译后调控和定位如何提供调节 BAF 宿主防御活性的相互关联机制 AIM 2) 确定 BAF-DNA 复合物如何调节转录和 DDR 信号传导以保护基因组完整性。 DNA，但被痘病毒所躲避，将成为这一目标的核心焦点 3) 确定 BAF 作为抗 HSV-1 感染的病毒的机制。证明 BAF 可以通过定位和/或磷酸化调节的方式损害 HSV-1 感染，从而与 BAF 的抗痘病毒活性的调节方式相似，这些研究将深入了解 BAF 抗 HSV-1 活性的分子机制。在这些研究过程中，我们将比较和对比 BAF 如何对抗细胞质和核 DNA 病毒，这将是这些病原体的创新应用。作为这项工作的成果，我们将更好地理解。 BAF 对这些核蛋白复合物的贡献以及 BAF 本身在病毒感染过程中如何受到调节，因此，我们将深入了解其重叠能力的细胞机制：1）通过压缩沉默外源 DNA，2）即使在没有感染的情况下也能保护基因组完整性。 。