Remodeling of the nuclear membrane during herpesvirus assembly

我们对细胞增殖和执行特定生物功能的基本过程的了解，大部分来自于对病毒-宿主细胞相互作用的研究。这一事实在一定程度上是由于病毒有能力将关键的细胞过程从其预期的细胞功能转向构建数千个由相对较少成分组成的新病毒颗粒。这些病毒成分通常大量产生，这使得它们影响的细胞过程比在未感染细胞中研究这些过程更容易研究。这种应用侧重于正常细胞中发生的细胞过程，但也涉及疱疹病毒的组装，疱疹病毒是感染从软体动物到人类等动物的一大群病毒。我们使用2型单纯疱疹病毒作为模型系统，然而正在研究的过程与该组中的所有病毒相关。疱疹病毒组装的初始阶段发生在细胞核中，在那里病毒DNA被复制并包装成一种叫做衣壳的蛋白质外壳。含有dna的衣壳必须离开细胞核进入细胞质，在那里进行病毒组装的最后步骤。这一过程被称为核出口，需要许多病毒和细胞蛋白的活动，包括两种关键的病毒蛋白UL31和UL34。我们已经发现UL31和UL34蛋白具有驱动核膜结构显著重组的能力。我们假设这种核膜重组是核出口所必需的。有趣的是，UL31和UL34促进的核膜重组与许多正常细胞类型中被称为核质网的一种鲜为人知的结构非常相似。本提案所描述的实验将：1)利用最先进的成像技术描述核膜重组的特征。2)研究UL31和UL34驱动核膜重组的机制。3)确定核膜重组对HSV-2组装的意义。预计我们的研究结果将有助于深入了解大蛋白复合物跨膜运输的规则，核膜的增殖和重塑以及核质网的组装和功能。这些发现对于研究细胞生物学和正常细胞功能的许多方面的研究人员来说都是重要的，因为它们促进了我们对基本细胞过程的理解。此外，上述研究的表现将为HQP提供先进成像和前沿分子遗传学技术方面的实践培训，这将为这些个人进入学术、工业或生物技术职业领域提供强大的竞争优势。

Much of what we understand about the fundamental processes that enable cells to proliferate and to perform specific biological functions has come from the study of virus-host cell interactions. This fact is, in part, due to the ability of viruses to redirect key cellular processes away from their intended cellular functions towards building thousands of new virus particles comprised of relatively few components. These viral components are often produced in abundance, making the cellular processes that they influence easier to study than if one was investigating these processes in non-infected cells.This application focuses on cellular processes that take place in normal cells but are also involved in the assembly of herpesviruses, a large group of viruses that infect animals ranging from mollusks to man. We use herpes simplex virus type 2 as a model system, however the processes under investigation are relevant to all viruses in this group. The initial stages of herpesvirus assembly take place in the cell nucleus where virus DNA is replicated and packaged into a protein shell called a capsid. DNA-containing capsids must exit the nucleus into the cell cytoplasm where final steps in virus assembly take place. This process is referred to as nuclear egress and requires the activities of numerous viral and cellular proteins including two key virus proteins called UL31 and UL34. We have discovered that the UL31 and UL34 proteins have the capacity to drive a remarkable reorganization of nuclear membrane structure. We hypothesize that this nuclear membrane reorganization is required for nuclear egress. Intriguingly, the nuclear membrane reorganization promoted by UL31 and UL34 closely resembles a poorly understood structure found in many normal cell types called the nucleoplasmic reticulum. The experiments described in this proposal will:1) Describe the features of nuclear membrane reorganization using state-of-the-art imaging technologies.2) Address the mechanisms by which UL31 and UL34 drive nuclear membrane reorganization.3) Determine the significance of nuclear membrane reorganization on HSV-2 assembly.It is anticipated that our findings will provide insight into the rules governing the trafficking of large protein complexes across membranes, the proliferation and remodeling of nuclear membranes and insights into the assembly and function of the nucleoplasmic reticulum. These findings will be important to researchers studying many aspects of cell biology and normal cell function by advancing our understanding of fundamental cellular processes. Furthermore, the performance of the studies described will provide HQP with hands on training in advanced imaging and leading edge molecular genetics techniques that will offer a powerful competitive edge to these individuals when they enter the academic, industrial, or biotechnology career sectors.