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)：该项目涉及宿主细胞因子-1(HCF-1)在调节单纯疱疹病毒(HSV)生命周期中的作用。HSV是一种重要的人类病原体，可导致一系列疾病，包括疼痛的皮损、角膜疤痕和危及生命的脑炎。上皮细胞的产生性或裂解性感染是由病毒转录因子VP16启动的，病毒转录因子VP16从病毒粒子释放到细胞质中。在那里，VP16与HCF-1结合，转位到细胞核，共同激活HSV即刻早期(IE)基因。单纯疱疹病毒也在感觉神经元上定植，在那里它可以建立潜伏期，重新出现为局部裂解复制的周期性发作。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的致病因素。HCF-1存在于大多数细胞的细胞核中，是细胞增殖和胞质分裂所必需的转录辅因子。然而，在神经元中，HCF-1是细胞质的，但在DNA损伤剂、毒素或机械压力的反应下移动到细胞核。同样的刺激诱导潜伏的HSV重新进入裂解复制，暗示了HCF-1定位和HSV裂解复制之间的因果关系。这项建议研究了控制HCF-1在细胞核不同区域的定位和功能的机制。我们专注于HPIP和Brd7，这两种细胞蛋白与HCF-1的保守结构域结合。HPIP是一种穿梭因子，将HCF-1从细胞核输出到胞浆。我们的研究表明，HPIP在胞浆和线粒体中都有发现，在目标1中，我们将检查允许HPIP在这些细胞质之间分配的信号，并更准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在新的核仁结构中的掺入。当细胞持续DNA双链断裂时，也会发生类似的变化，我们假设HCF-1和Brd7是对基因组侮辱的反应中的关键角色。目的2研究Brd7和HCF-1启动核仁破裂的分子机制，目的3研究细胞周期、rRNA转录和HSV裂解复制的生理后果。