Viral disruption of host transcriptome integrity

病毒破坏宿主转录组完整性

• 批准号: 10666992
• 负责人: ANGUS WILSON
• 金额: $ 32.88万
• 依托单位: NEW YORK UNIVERSITY SCHOOL OF MEDICINE
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-02-01 至 2028-01-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10666992
• 关键词: Adenosine; Antibodies; Antiviral Response; Biogenesis; Biological Process; Catalysis; Cell Fractionation; Cells; Chemicals; Chromatin; Co-Immunoprecipitations; Code; Complex; Coupled; Coupling; Cytoplasm; DNA Polymerase II; Elements; Ensure; Environment; Epigenetic Process; Excision; Exons; Frequencies; Gene Expression; Genes; Genetic Transcription; Goals; Herpes Simplex Infections; Herpesvirus 1; Infection; Knowledge; Location; Mass Spectrum Analysis; Measures; Mediating; Messenger RNA; Methylation; Methyltransferase; Modification; Molecular; Mutagenesis; Nuclear; Nuclear RNA; Nucleic Acids; Pathway interactions; Pattern; Peptide Signal Sequences; Poly A; Poly(A) Tail; Polyadenylation; Polyadenylation Pathway; Positioning Attribute; Predisposition; Productivity; Protein Biosynthesis; RNA; RNA Polymerase II; RNA Precursors; RNA Processing; RNA Splicing; RNA-Binding Proteins; Recording of previous events; Reproduction; Resources; Role; Sedimentation process; Signal Transduction; Site; Small Interfering RNA; Structure; Testing; Transcript; Translations; Untranslated RNA; Untranslated Regions; Viral; Viral Genes; Viral Proteins; Viral Regulatory Proteins; Virus; Virus Diseases; Virus Replication; Work; base; inhibitor; innovation; insight; mRNA Stability; novel therapeutic intervention; premature; prevent; promoter; protein complex; recruit; transcription termination; transcriptome; transcriptome sequencing; viral RNA

Most viral infections invoke major changes in host gene expression as part of a broader strategy to create an optimal environment for viral replication. By suppressing host protein synthesis, viruses repurpose the biosynthetic resources of the host cell to maximize the accumulation of viral proteins or nucleic acids and thus ultimately boost the yield of new infectious progeny. Herpes simplex virus type 1 (HSV-1) provides a prime example of this important ‘host shutoff’ phenomenon. HSV-1 infection is accompanied by widescale disruption of host mRNA biogenesis through dysregulation of transcription by RNA polymerase II coupled with changes in mRNA stability, splicing, 3’-end formation, and transcription termination. Although multiple studies have implicated the essential viral regulatory protein ICP27 in aspects of shutoff by HSV-1, the exact mechanisms and their relative contributions remain to be elucidated. Recently, we demonstrated that HSV-1 infection induces widespread changes in the subcellular localization of host nuclear factors required for the installation, removal and recognition of internal RNA modifications including methylation at the N6-position of adenosine (m6A). This results in global reductions in the internal base modifications present on both host and viral RNAs. Importantly, we identified the essential viral regulatory protein ICP27 as both necessary and sufficient for this striking effect. Internal RNA modifications such as m6A influence many aspects of mRNA and lncRNA biogenesis including recognition of hardwired splicing and cleavage/polyadenylation signals, and m6A also regulates the export, stability and translation of mature mRNAs. We observed that viral gene expression is sensitive to loss of m6A at the beginning of the infection cycle but is less impacted at later times, coincident with reduced RNA modification frequency. Drawing these observations together we propose that the poorly understood ability of ICP27 to broadly disrupt host gene expression is mediated, at least in part, by its ability to redefine the epigenetic landscape of the host transcriptome. To understand this better, we will more fully characterize the impact of ICP27 expression on the host machinery responsible for RNA chemical modification and for 3’-end processing and transcription termination. Recent studies reveal a mechanistic linkage between the sites of m6A placement and use of nearby polyadenylation and signals and we hypothesize that this is exploited by ICP27 to bring about a widescale disruption of transcription termination (DoTT) that preferentially impacts the host transcriptome in HSV-1 infected cells. To understand why 3’-end formation of HSV-1 mRNAs is largely insensitive to ICP27- mediated DoTT, we will profile m6A installation across the viral transcriptome to determine the impact of m6A on cleavage and polyadenylation site usage within viral transcription units.

大多数病毒感染引起宿主基因表达的重大变化，作为创造病毒复制最佳环境的更广泛策略的一部分。通过抑制宿主蛋白质合成，病毒重新利用宿主细胞的生物合成资源，以最大限度地积累病毒蛋白质或核酸，从而最终提高新的感染性后代的产量。单纯疱疹病毒1型（HSV-1）提供了这种重要的“宿主关闭”现象的一个主要例子。HSV-1感染伴随着通过RNA聚合酶II的转录失调以及mRNA稳定性、剪接、3 '端形成和转录终止的变化而引起的宿主mRNA生物发生的大规模破坏。虽然多项研究表明，HSV-1阻断病毒的关键病毒调节蛋白ICP 27，但其确切机制及其相对贡献仍有待阐明。最近，我们证明，HSV-1感染诱导广泛的变化，在亚细胞定位的宿主核因子所需的安装，删除和识别内部RNA修饰，包括甲基化在N6-位置的腺苷（m6 A）。这导致宿主和病毒RNA上存在的内部碱基修饰的整体减少。重要的是，我们确定了必需的病毒调节蛋白ICP 27对于这种惊人的效果是必要的和足够的。内部RNA修饰如m6 A影响mRNA和lncRNA生物发生的许多方面，包括硬连线剪接和切割/多聚腺苷酸化信号的识别，并且m6 A还调节成熟mRNA的输出、稳定性和翻译。我们观察到，病毒基因表达在感染周期开始时对m6 A的丢失敏感，但在后期受影响较小，与RNA修饰频率降低一致。将这些观察结果汇总在一起，我们提出，ICP 27广泛破坏宿主基因表达的能力知之甚少，至少部分是由其重新定义宿主转录组的表观遗传景观的能力介导的。为了更好地理解这一点，我们将更全面地表征ICP 27表达对负责RNA化学修饰和3 '端加工和转录终止的宿主机制的影响。最近的研究揭示了m6 A放置位点与附近多聚腺苷酸化和信号的使用之间的机制联系，我们假设这被ICP 27利用来引起转录终止的大规模破坏（DoTT），其优先影响HSV-1感染细胞中的宿主转录组。为了理解为什么HSV-1 mRNA的3 '端形成对ICP 27介导的DoTT很大程度上不敏感，我们将分析m6 A在病毒转录组中的安装，以确定m6 A对病毒转录单位内切割和多聚腺苷酸化位点使用的影响。