TorsinA and Nuclear Envelope Function in HSV Infection

描述(申请人提供)：疱疹病毒的核出口是病毒复制过程中必不可少的和保守的过程。在过去的十年里，对这一过程所需的病毒蛋白进行了鉴定和功能鉴定。细胞鉴定的研究进展 参与核出口的因素一直较慢。细胞因子的鉴定 从两个角度来看，参与核出口具有重要意义。一方面，识别关键因素可能会产生抗病毒治疗的靶点。另一方面，对这些因子功能的表征肯定会让我们深入了解它们在未受感染的细胞中的正常功能。这是人类疾病生物学中的一个重要问题，因为许多有趣的遗传性疾病是由编码核膜及其下层蛋白质的基因突变引起的。这些疾病包括肌肉营养不良、心脏、骨骼和结缔组织疾病以及扭转肌张力障碍。在任何情况下，突变蛋白与疾病发病机制之间的关系都不是完全清楚的。在此，我们拟探讨TorsinA基因产物在HSV感染中的作用。编码torsinA的基因突变会导致一种名为早发性扭转肌张力障碍的神经肌肉疾病，其发病机制尚不清楚。我们已经发现了扭蛋白A和1型单纯疱疹病毒之间功能相互作用的初步证据，以及扭蛋白A在核膜融合调节中的作用的证据。为了追求两个特定的目标，我们建议充分描述扭力A和单纯疱疹病毒之间的相互作用。目的1.单纯疱疹病毒1型感染中TorsinA功能的表型特征。我们将使用TorsinA过表达和敲除/敲除的互补方法来检验以下假设：有效的HSV感染需要正常的Torsin表达，以及有效的HSV核出口需要Torsin A。目的2.明确TorsinA在单纯疱疹病毒感染中的作用机制。TorsinA的功能被认为是通过与其他蛋白质的相互作用和对其活性的调节来实现的。我们的初步数据表明，Torsin A可能通过调节先前已发现的细胞蛋白的活性或通过直接调节核膜或初级病毒粒子被膜中的HV糖蛋白的功能来调节HSV核出口。我们将结合遗传和生物化学的方法来检验这两种假说。 公共卫生相关性：病毒与宿主细胞因子的相互作用提供了有关病毒复制的关键步骤和细胞因子功能的信息。这项研究将阐明TorsinA蛋白在疱疹病毒感染细胞中的功能，TorsinA蛋白是人类神经疾病的罪魁祸首。

DESCRIPTION (provided by applicant): Nuclear egress of herpesviruses is an essential and conserved process in virus replication. Over the past decade, viral proteins required for this process have been identified and functionally characterized. Progress in identification of cellular factors that participate in nuclear egress has been slower. Identification of cellular factors that participate in nuclear egress is highly significant from two points of view. On one hand, identification of essential factors might yield targets for antiviral therapy. On the other, characterization of the function of these factors will certainly provide insight into their normal functions in the uninfected cell. This is an important problem in human disease biology because many interesting inherited diseases are caused by mutations in genes that encode proteins of the nuclear envelope and its underlying lamina. These diseases include muscular dystrophies, cardiac, and bone and connective tissue disorders and torsion dystonias. In no case is the relationship between the mutant protein and disease pathogenesis completely clear. Here, we propose to explore the function of the torsinA gene product in HSV infection. Mutation of the gene encoding torsinA results in a neuromuscular disease called early-onset torsion dystonia, and the mechanism of disease is unclear. We have found preliminary evidence for a functional interaction between torsinA and herpes simplex type 1, and evidence specifically for a role for torsinA in regulation of membrane fusion at the nuclear envelope. We propose to fully characterize the interaction between torsinA and HSV pursuing two specific aims. Aim 1. Phenotypic characterization of the function of TorsinA in HSV-1 infection. We will use complementary approaches of TorsinA over-expression and knock-down/knock-out to test the hypothesis that normal Torsin expression is required for efficient HSV infection and to test the hypothesis that Torsin A is specifically required for efficient nuclear egress of HSV. Aim 2. Identification of the mechanism of TorsinA function in HSV infection. TorsinA function is thought to be mediated by interaction with, and regulation of, the activity of other proteins. Our preliminary data suggest that Torsin A might regulate HSV nuclear egress either by regulating the activity of previously identified cellular proteins or by directly regulating the function of HV glycoproteins in the nuclear envelope or the primary virion envelope. We will test both of these hypotheses using a combination of genetic and biochemical approaches. PUBLIC HEALTH RELEVANCE: The interaction of viruses with host cell factors provides information both about critical steps in virus replication and about the function of the cellular factors. This study will clarify the function of the torsinA protein, which is responsible for a human neurological disease, in herpesvirus-infected cells.