Molecular Genetics of HSV Reactivation

HSV 再激活的分子遗传学

• 批准号: 7635744
• 负责人: David C. Bloom
• 金额: $ 34.07万
• 依托单位: UNIVERSITY OF FLORIDA
• 依托单位国家: 美国
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-07-01 至 2011-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7635744
• 关键词: Acetylation; Chromatin; Chromatin Modeling; Chromatin Structure; Chromosomes; Complex; Control Locus; DNA Methylation; Data; Deacetylation; Elements; Enhancers; Epigenetic Process; Epinephrine; Exhibits; Eye; Functional RNA; Funding; Genes; Genetic Transcription; Genome; Goals; Grant; Herpesvirus 1; Histone Acetylation; Histone Deacetylase; Histone Deacetylation; Histones; Homologous Gene; Human; Hybrids; Infection; Insulator Elements; Lead; Libraries; Lytic; Malignant Neoplasms; Modeling; Molecular; Molecular Genetics; Morbidity - disease rate; Mus; Neurons; Nucleosomes; Oryctolagus cuniculus; Pathway interactions; Process; Proteins; RNA; Recurrent disease; Regulation; Regulatory Element; Role; Simplexvirus; Site; Spinal Ganglia; Stimulus; Stress; Structure of trigeminal ganglion; Transcriptional Regulation; Virus; Work; Yeasts; base; chromatin immunoprecipitation; chromatin remodeling; developmental disease; histone acetyltransferase; histone methyltransferase; histone modification; latent gene expression; latent infection; lytic gene expression; mortality; mutant; permissiveness; prevent; promoter; reactivation from latency

DESCRIPTION (provided by applicant): The long-term goal of this project is to understand the molecular mechanism that governs the reactivation of Herpes Simplex Virus type 1 (HSV-1) from latency. Work during the previous funding period has focused on the role of the reactivation critical region (rcr) in this process, and whether latent gene expression was regulated in an epigenetic manner. Our key findings were that: 1) the suppression of HSV-1 lytic genes during latency is associated with histone modifications and not DNA methylation; 2) the histones associated with the rcr are maintained in a hyperacetylated state during latency; 3) CTCF-containing chromatin insulator-like elements flank the region of hyperacetylation, preventing the spread of transcriptionally active chromatin to the surrounding lytic genes and 4) following reactivation stimulus rapid deacetylation of the LAT enhancer is followed by a dramatic decrease in LAT abundance and acetylation of the ICP0 promoter. These data suggest that the rcr functions as a regulatory element that controls LAT and ICP0 transcription at the level of chromatin. Specifically, the LAT enhancer portion of the rcr and a chromatin insulator act together as a switch that regulates LAT and ICP0 in a bi-phasic manner. Based on this new data and drawing from chromatin-level regulatory models employed by cellular chromosomes, we have refined our model for the LAT region's role in reactivation. This model views the LAT region as a regulatory locus that controls the transcriptional permissiveness of ICP0 through epigenetic regulation of histone modifications. This regulatory locus consists of at least three components: 1) the LAT enhancer that controls histone modifications, and has the potential to regulate transcription of both the LAT and ICP0; 2) the CTCF-insulator elements which flank the rcr and regulate the extent of the LAT enhancer's influence, and 3) transcription of the LAT RNA itself, which we hypothesize regulates the insulator. This project will seek to prove our overall hypothesis that regulation of these three components governs the ability of HSV-1 to reactivate. HSV-1 is a persistent infection of humans that causes significant morbidity and mortality. Understanding the mechanism of how stress induces reactivation could lead to new therapies to treat and prevent recurrent disease. At a broader level, understanding the mechanism by which HSV regulates transcription via modulation of chromatin structure will increase our understanding of similar processes and pathways in cellular chromosomes, potentially leading to new therapies for developmental disorders and cancer.

描述（由申请人提供）：该项目的长期目标是了解控制潜伏期中单纯疱疹病毒1（HSV-1）的重新激活的分子机制。在上一个资金期间的工作集中在此过程中重新激活临界区域（RCR）的作用，以及是否以表观遗传学方式调节潜在基因表达。我们的主要发现是：1）潜伏期期间HSV-1裂解基因的抑制与组蛋白的修饰有关，而不是DNA甲基化； 2）与RCR相关的组蛋白在潜伏期期间保持高乙酰化状态； 3）含有CTCF的染色质绝缘子样元素侧面是高乙酰化的区域，从而防止了转录活性的染色质向周围的裂解基因传播，4）在重生激励刺激快速脱乙酰基的lat增强剂的快速脱乙酰基化之后，late和乙酰化的ICP0促进剂的lateancy和乙酰化促进症会急剧下降。这些数据表明，RCR是控制染色质水平的LAT和ICP0转录的调节元件。具体而言，RCR的LAT增强剂部分和染色质绝缘子作为一个开关，以双重指示方式调节LAT和ICP0。 基于这些新数据并从细胞染色体采用的染色质级调节模型中绘制，我们为LAT区域在重新激活中的作用而完善了模型。该模型将LAT区域视为一个调节基因座，该基因座通过组蛋白修饰的表观遗传调节来控制ICP0的转录允许性。该调节基因座至少由三个组成部分组成：1）控制组蛋白修饰的LAT增强子，并有可能调节LAT和ICP0的转录； 2）侧翼RCR侧面并调节LAT增强剂影响程度的CTCF绝缘子元件，以及3）LAT RNA本身的转录，我们假设调节绝缘体。该项目将寻求证明我们的整体假设，即对这三个组成部分的调节控制HSV-1重新激活的能力。 HSV-1是人类的持续感染，会引起明显的发病率和死亡率。了解压力如何诱导重新激活的机制可能导致新的疗法治疗和预防复发性疾病。在更广泛的层面上，了解HSV通过调节染色质结构调节转录的机制将增加我们对细胞染色体中相似过程和途径的理解，这有可能导致新的发育障碍和癌症疗法。