Herpes simplex virus-mediated regulation of host gene expression

项目概要： 单纯疱疹病毒1（HSV-1）是一种高度传染性的病原体， 从疼痛的皮肤损伤到角膜炎和脑炎。基因 HSV-1的表达程序在过去的几年中已经被广泛研究， 几十年然而，尽管进行了大量的努力，但仍不清楚HSV-1如何 抑制宿主基因表达以允许有效的病毒复制。遗传学研究 研究表明，ICP 27，由一个必需的立即早期基因编码， 在抑制宿主mRNA生物合成中起重要作用。根据体外试验，早期 研究表明ICP 27阻断宿主基因的转录和剪接。 通过对HSV-1感染后宿主基因表达的高通量分析， ICP 27过度表达，然而，最近的研究发现， 转录或剪接，但只有少数基因的剪接变化。 有趣的是，这些研究发现， 在HSV-1感染的细胞中存在缺陷，并且这种抑制对宿主基因是特异性的。 尽管这些最近的研究为HSV-1诱导的宿主 关闭，HSV-1介导的转录阻断的分子机制 终止仍然是完全未知，不清楚这样一个块是否 这是病毒有效复制所必需的。我们的目标是解决这些重要问题， 这个提议。在我们的初步研究中，我们发现ICP 27特异性地与 必需mRNA 3 ′加工因子CPSF和ICP 27阻断mRNA 3 ′ 处理.由于mRNA 3'加工是转录终止所必需的，我们将 检验ICP 27通过阻断mRNA抑制宿主转录终止的假设 通过CPSF的3'加工，以及ICP 27介导的宿主mRNA加工的破坏 对HSV复制很重要。

Project summary: Herpes simplex virus 1 (HSV-1) is a highly contagious pathogen that causes a number of diseases ranging from painful skin lesions to keratitis and encephalitis. The gene expression program of HSV-1 has been extensively studied for the past several decades. Despite the intensive effort, however, it remains unclear how HSV-1 suppresses host gene expression to allow efficient viral replication. Genetic studies have demonstrated that ICP27, encoded by an essential immediate early gene, plays an essential role in the inhibition of host mRNA biogenesis. Based on in vitro assays, earlier studies have suggested that ICP27 blocks transcription and splicing of host genes. Through high throughput analyses of host gene expression following HSV-1 infection or ICP27 overexpression, however, recent studies detected no global inhibition of either transcription or splicing, but only splicing changes in a small number of genes. Interestingly, these studies found that there was widespread transcription termination defect in HSV-1-infected cells and that this inhibition was specific to host genes. Although these recent studies provided important insight into HSV-1-induced host shutoff, the molecular mechanisms underlying HSV-1-mediated block of transcription termination remain completely unknown and it is unclear whether such a block is required for efficient viral replication. We aim to address these important questions in this proposal. In our preliminary studies, we found that ICP27 specifically interacts with the essential mRNA 3' processing factor CPSF and that ICP27 blocks mRNA 3' processing. Since mRNA 3' processing is required for transcription termination, we will test the hypothesis that ICP27 inhibits host transcription termination by blocking mRNA 3' processing via CPSF, and that ICP27-mediated disruption of host mRNA processing is important for HSV replication.