Immediate Early Genes of Herpes Simplex Virus

描述（由申请人提供）：单纯疱疹病毒1型（HSV-1）在人类宿主中建立终身感染，其特征是活跃循环上皮细胞和成纤维细胞的生产性感染，以及非循环感觉神经元的非生产性潜伏感染。潜伏感染的特点是胁迫后病毒基因表达和新病毒合成的生产周期重新激活。在多产性感染的早期阶段，病毒即时早期（IE）蛋白共同作用，创造一个促进病毒基因表达的核环境。现有证据表明，细胞周期蛋白依赖性激酶（cdks）、其他细胞激酶和病毒激酶对IE蛋白的磷酸化是IE蛋白功能及时激活的原因。在生产性感染期间，循环细胞中激酶活性的表达，在非循环潜伏感染的神经元中这些活性的缺失，以及它们在应激诱导的再激活后在非循环神经元中的诱导，导致了一种假设，即生产性感染，再激活和IE蛋白的活性与这些cdks和其他激酶的活性相关，而潜伏期与它们的缺失相关。在HSV IE蛋白中，ICP0、ICP22和ppUS1.5已被证明影响cdks及其周期蛋白伴侣，并受其影响。这些蛋白质赋予HSV-1显著的生长优势，并且是有效建立和重新激活潜伏期所必需的。这一提议将验证在非神经元细胞和神经元细胞中表达差异的cdks和其他激酶对ICP0、ICP22和ppUS1.5的磷酸化会影响这些蛋白在生产性感染、潜伏期和再激活期间的功能能力。为此，我们将i)确定ICP0， ICP22和ppUS1.5上磷酸化的位点以及磷酸化这些位点的cdks和其他激酶，ii)测试特定激酶在选定位点磷酸化对ICP0， ICP22和ppUS1.5在细胞培养和生产感染和潜伏期中的功能的影响，iii)检查ICP22和/或ppUSl能力的分子基础。5和磷酸化位点突变体抑制ICP0的功能。在这些研究中获得的信息将为HSV- 1产生性感染和潜伏期的分子机制提供新的见解，并导致干预这种临床重要病毒生命周期的新方法。

DESCRIPTION (provided by applicant): Herpes simplex virus 1 (HSV-1) establishes life-long infections of the human host characterized by productive infection of actively cycling epithelial cells and fibroblasts, and nonproductive latent infections of noncycling sensory neurons. Latent infections are characterized by the reactivation of productive cycle viral gene expression and new virus synthesis following stress. During the early stages of productive infection, viral immediate-early (IE) proteins act together to create a nuclear environment that promotes viral gene expression. Available evidence indicates that the phosphorylation of IE proteins by cyclin dependent kinases (cdks), other cellular kinases and viral kinases is responsible for the timely activation of IE protein functions. The expression of kinase activities in cycling cells during productive infection, the absence of these activities in noncycling latently infected neurons, and their induction in noncycling neurons following stress-induced reactivation, has led to the hypothesis that productive infection, reactivation and the activities of IE proteins are associated with the activities of these cdks and other kinases whereas latency is associated with their absence. Among HSV IE proteins, ICP0, ICP22 and ppUS1.5 have been shown to affect and be affected by cdks and their cyclin partners. These proteins confer a significant growth advantage on HSV-1 and are required for the efficient establishment and reactivation of latency. This proposal will test the hypothesis that the phosphorylation of ICP0, ICP22 and ppUS1.5 by cdks and other kinases expressed differentially in nonneuronal and neuronal cells affects the functional capabilities of these proteins during productive infection, latency and reactivation. For this purpose we will i) identify the sites on ICP0, ICP22 and ppUS1.5 that are phosphorylated and the cdks and other kinases that phosphorylate these sites, ii) test the effects of phosphorylation at selected sites by specific kinases on the functions of ICP0, ICP22 and ppUS1.5 in cell culture and during productive infection and latency and iii) examine the molecular basis for the ability of ICP22 and/or ppUSl.5 and phosphorylation site mutants thereof to inhibit the functions of ICP0. The information obtained in these studies will provide new insight into the molecular mechanism underlying HSV- 1 productive infection and latency and lead to novel approaches to intervening in the life-cycle of this clinically important virus.