Biophysical and structural analysis of the herpesviral nuclear budding machinery

项目概要/摘要 疱疹病毒是双链DNA包膜病毒，是最复杂的感染性病毒之一， 动物这项建议的重点是核出口，这是核武器组装和释放过程中的一个关键的保守步骤。 子代病毒体，在此期间，核衣壳从细胞核转移到细胞质中， 成熟为感染性病毒体。病毒核出口复合物（NEC）是这一过程中的关键参与者。使用 在体外模型系统中，我们以前发现NEC是一个完整的，病毒编码的膜 在核膜上运行的出芽机。然而，理解核武器的一个主要障碍是， 出口是缺乏知识的NEC如何产生膜曲率，导致萌芽。的 这项研究的长期目标是阐明疱疹病毒核出口的详细机制， 获得这个不寻常的过程的基本知识，并确定和表征新的目标， 抗病毒治疗设计。这一建议是由中心假设驱动的，基于大量的 初步数据表明，NEC/膜相互作用和NEC寡聚成涂层是主要的 使负膜曲率形成和出芽的驱动力。本提案的目的 系统地剖析了单纯疱疹病毒（HSV）中NEC的出芽机制， 必需的蛋白质/蛋白质和蛋白质/膜相互作用和出芽中间体， 多学科方法，其中包括冷冻电子显微镜的尖端方法， 电子自旋共振这项工作的科学前提是，全面剖析 NEC介导的负膜曲率的形成对于解开不寻常的 疱疹病毒核出口的机制和发展策略，以阻止它。除了病毒，这项研究将 扩展我们对膜变形机制的有限的机械理解。的 该提案是创新的，因为它调查了一个不寻常的机制，由原始假设指导， 采用新颖的方法。这项建议意义重大，因为它旨在推进我们的机械化 了解病毒复制周期中的一个重要步骤，目的是确定新的靶点， 治疗干预，因为它提供了一个机会，发展模型的负曲率 目前，这是一个黑匣子。

PROJECT SUMMARY/ABSTRACT Herpesviruses are double-stranded-DNA enveloped viruses that are among the most complex viruses infecting animals. This proposal focuses on nuclear egress, a critical, conserved step in the assembly and release of progeny virions during which nucleocapsids are translocated from the nucleus into the cytoplasm where they mature into infectious virions. The viral nuclear egress complex (NEC) is the key player in this process. Using in vitro model systems, we previously discovered that the NEC is a complete, virally encoded membrane budding machine that operates at the nuclear envelope. However, a major barrier to understanding nuclear egress is the lack of knowledge of how the NEC generates membrane curvature that results in budding. The long-term goal of this research is to elucidate the detailed mechanism of herpesvirus nuclear egress, both to gain a fundamental knowledge of this unusual process and to identify and characterize novel targets for antiviral therapeutic design. This proposal is driven by the central hypothesis, based on substantial preliminary data, that both NEC/membrane interactions and NEC oligomerization into a coat are the major driving forces that enable negative membrane curvature formation and budding. The objective of this proposal is to systematically dissect the NEC budding mechanism in Herpes Simples virus (HSV) by characterizing essential protein/protein and protein/membrane interactions and budding intermediates by employing a multidisciplinary approach, which includes the cutting-edge approaches of cryoelectron microscopy and electron spin resonance. The scientific premise of the proposed work is that a comprehensive dissection of the NEC-mediated formation of negative membrane curvature is essential for unraveling the unusual mechanism of herpesviral nuclear egress and developing strategies to block it. Beyond viruses, this study will expand our limited mechanistic understanding of the mechanisms of membrane deformation in general. The proposal is innovative because it investigates an unusual mechanism, is guided by an original hypothesis, and employs novel approaches. The proposal is significant because it aims to advance our mechanistic understanding of an essential step in viral replication cycle with the goal of identifying new targets for therapeutic interventions and because it provides an opportunity to develop models of negative curvature formation, currently a black box.