Microtubule networks and virus trafficking

描述(申请人提供)：进入细胞后，许多不同的病毒利用它们宿主的细胞骨架运输网络到达它们的亚细胞复制站点，而NW病毒的后代利用这些相同的网络返回细胞表面并传播。病毒经常沿着细胞外围的肌动蛋白移动，然后过渡到宿主微管(MT)网络，该网络介导细胞内的长距离运输。MT是一种高度动态的微管蛋白(半衰期为5分钟)的杂聚体，从核周MT组织中心(MTOC)向细胞表面辐射。MT的亚群对各种环境和发育信号的反应变得稳定(半衰期1小时)，并被认为在细胞极化和运动等事件中作为囊泡运输的专门网络。MT的动态和稳定由许多高度专门化的调节因子控制，包括肌动蛋白-MT交联因子和MT+端结合蛋白(+TIPS)，其在MT端的积累由MT+端跟踪蛋白EB1促进。货物在这些MT网络上的运动涉及到马达蛋白；通常，动力蛋白负责负端运输，而动蛋白则直接进行正端运输。然而，我们对MTS、它们的调节器和马达在感染期间病毒颗粒运动中的作用的了解严重有限。该计划项目资助(PPG)集中了细胞骨架调节、马达和基于MT的运动性、细胞信号和不同病毒感染方面的专业知识，以在各种系统中解决这些基本问题的机械细节。作为一个整体，到目前为止，我们的相互作用已经确定，RNA和DNA病毒都会引起不同的MT修饰，需要一系列专门的MT调节因子才能有效感染，包括肌动蛋白-MT交联物、+TIPS和EB1，以及识别用于病毒粒子运输到细胞核的特定宿主马达。在这篇PPG中，我们的目标是确定MT亚群、发动机和入侵病毒粒子之间这些高度动态相互作用背后的机制细节，包括使用最先进的双色成像来实时分析这些事件。这种综合和互动的方法不仅通过利用其他成员的优势极大地增强了每个单独项目的潜力，而且还将我们的累积专业知识集中在解决这一项目小组总体目标的关键方面--“微管网络和病毒贩运”。这种有效的小组方法有可能发现在病毒感染过程中MT功能和调节的基本新见解，这在更广泛的生物学背景下可能是重要的，并可能导致新的治疗方法的发展。

DESCRIPTION (provided by applicant): Upon entry into cells, many diverse viruses exploit their hosts' cytoskeletal transport networks to reach their sub-cellular site of replication, and nw viral progeny use these same networks to return to the cell surface and spread. Viruses frequently move along actin at the cell periphery before transitioning onto host microtubule (MT) networks that mediate long-range intracellular transport. MTs are highly dynamic heteropolymers of ¿/¿ tubulin (half-lives <5 min), which radiate from the perinuclear MT Organization Center (MTOC) towards the cell surface. Subsets of MTs become stabilized (half-life >1h) in response to various environmental and developmental signals, and are thought to act as specialized networks for vesicle transport during events such as cell polarization and motility. MT dynamics and stabilization are controlled by a number of highly specialized regulators, including actin-MT crosslinking factors and MT plus-end binding proteins (+TIPs), whose accumulation at MT ends is facilitated by the MT plus-end tracking protein, EB1. Movement of cargos on these MT networks involves motor proteins; generally, dynein directs minus-end and kinesins direct plus-end transport. However, our understanding of the role of MTs, their regulators and motors in the movement of viral particles during infection is severely limited. This Program Project Grant (PPG) nucleates expertise in cytoskeletal regulation, motors and MT-based motility, cell signaling and infection by diverse viruses to address these fundamental questions in mechanistic detail in a variety of systems. As a group, our interactions to date have established that both RNA and DNA viruses cause distinct MT modifications and require a range of specialized MT regulatory factors for efficient infection, including actin-MT crosslinkers, +TIPs and EB1, as well as identifying specific host motors used for virion traffickin to the nucleus. In this PPG we aim to determine the mechanistic details underlying these highly dynamic interactions between MT subsets, motors and invading virions, including the use of state-of-the-art dual-color imaging to analyze these events in real time. This integrated and interactive approach not only greatly enhances each individual project's potential by leveraging the strengths of other members, but also serves to focus our cumulative expertise on addressing key aspects of the Overall Aims of this PPG, "Microtubule Networks and Virus Trafficking". This efficient group approach has the potential to uncover fundamental new insights in MT function and regulation during viral infection that will likely be important in broaer biological contexts and may lead to the development of novel therapeutic approaches.