Regulation of HSV Gene Expression by HCF

HCF 对 HSV 基因表达的调节

• 批准号: 7097516
• 负责人: ANGUS WILSON
• 金额: $ 33.87万
• 依托单位: NEW YORK UNIVERSITY SCHOOL OF MEDICINE
• 依托单位国家: 美国
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-03-01 至 2010-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7097516
• 关键词: Alphaherpesvirinae; chimeric proteins; gene expression; genetic regulation; laboratory mouse; neurons; protein localization; tissue /cell culture; transcription factor; transfection; virus genetics; virus protein

DESCRIPTION (provided by applicant): This project addresses the role of host cell factor-1 (HCF-1) in regulating the herpes simplex virus (HSV) life cycle. HSV is an important human pathogen responsible for a spectrum of diseases including painful lesions, corneal scarring and life-threatening encephalitis. Productive or lytic infection in epithelial cells is initiated by the viral transcription factor VP16, which is released from the virion into the cytosol. There VP16 binds HCF- 1, translocates to the nucleus and together activates the HSV immediate-early (IE) genes. HSV also colonizes sensory neurons where it can establish latency, re-emerging as periodic episodes of localized lytic replication. In spite of extensive analyses, the molecular roadblocks preventing lytic replication in latent neurons remain elusive. Insufficient IE gene expression is likely to be an important contributing factor. HCF-1 is found in the nucleus of most cells, acting as an essential transcriptional cofactor for cell proliferation and cytokinesis. In neurons, however, HCF-1 is cytoplasmic but moves to the nucleus in response to DNA-damaging agents, toxins or mechanical stress. The same stimuli induce latent HSV to re-enter lytic replication, implying a causal relationship between HCF-1 localization and HSV lytic replication. This proposal investigates mechanisms that control localization and function of HCF-1 in different regions of the nucleus. We focus on HPIP and Brd7, two cellular proteins that bind to conserved domains of HCF-1. HPIP is a shuttle factor that exports HCF-1 from the nucleus to the cytosol. Our studies show that HPIP is found in both cytosol and mitochondrial and in Aim 1 we will examine the signals that allow HPIP to partition between these cytoplasmic compartments and more precisely define the localization within mitochondria. Brd7 is a chromatin-binding bromodomain protein and ectopic expression causes major changes in nucleolar structure, leading to stabilization of the stress-sensor p53 and incorporation of HCF-1 in novel nucleolar structures. Similar alterations occur when cells sustain DNA double-strand breaks and we hypothesize that HCF-1 and Brd7 are key players in the response to genomic insults. Aim 2 investigates the molecular mechanisms by which Brd7 and HCF-1 initiate nucleolar breakdown and Aim 3 addresses the physiological consequences with regard to cell cycle, rRNA transcription and HSV lytic replication.

描述（由申请人提供）：本项目研究宿主细胞因子-1 （HCF-1）在调节单纯疱疹病毒（HSV）生命周期中的作用。单纯疱疹病毒是一种重要的人类病原体，可导致一系列疾病，包括疼痛性病变、角膜瘢痕和危及生命的脑炎。上皮细胞的产生性或溶解性感染是由病毒转录因子VP16启动的，VP16从病毒粒子释放到细胞质中。VP16与HCF- 1结合，易位到细胞核，共同激活HSV即早（IE）基因。HSV也定植在感觉神经元上，在那里它可以建立潜伏期，以周期性的局部裂解复制的形式重新出现。尽管进行了广泛的分析，但阻止潜伏神经元裂解复制的分子障碍仍然难以捉摸。IE基因表达不足可能是一个重要因素。HCF-1存在于大多数细胞的细胞核中，是细胞增殖和细胞质分裂的重要转录辅助因子。然而，在神经元中，HCF-1是细胞质的，但在dna损伤剂、毒素或机械应力的作用下会移动到细胞核。同样的刺激诱导潜伏的HSV重新进入溶性复制，这意味着HCF-1定位与HSV溶性复制之间存在因果关系。本研究探讨了HCF-1在细胞核不同区域的定位和功能控制机制。我们重点研究了HPIP和Brd7这两种结合HCF-1保守结构域的细胞蛋白。HPIP是一种将HCF-1从细胞核输出到细胞质的穿梭因子。我们的研究表明，HPIP存在于细胞质和线粒体中，在Aim 1中，我们将检查允许HPIP在这些细胞质区室之间划分的信号，并更精确地定义线粒体内的定位。Brd7是一种染色质结合的溴结构域蛋白，异位表达引起核仁结构的重大变化，导致应力传感器p53的稳定和HCF-1在新型核仁结构中的掺入。当细胞维持DNA双链断裂时也会发生类似的改变，我们假设HCF-1和Brd7是对基因组损伤反应的关键参与者。目的2研究Brd7和HCF-1启动核核分解的分子机制，目的3研究细胞周期、rRNA转录和HSV裂解复制的生理后果。