Microtubule networks and virus trafficking

描述（由申请人提供）：在进入细胞后，许多不同的病毒利用其宿主的细胞骨架运输网络到达其亚细胞复制位点，并且新的病毒后代使用这些相同的网络返回细胞表面并传播。病毒在进入介导远距离细胞内转运的宿主微管（MT）网络之前，经常沿着细胞周围的肌动蛋白移动。MT是微管蛋白的高动态异聚物（半衰期<5分钟），从核周MT组织中心（MTOC）向细胞表面辐射。MTs的亚群在各种环境和发育信号的响应下变得稳定（半衰期bbbb1小时），并且被认为在细胞极化和运动等事件中充当囊泡运输的专门网络。MT动力学和稳定性由许多高度专业化的调节因子控制，包括肌动蛋白-MT交联因子和MT +端结合蛋白（+TIPs），其在MT末端的积累是由MT +端跟踪蛋白EB1促进的。这些MT网络上的货物运动涉及运动蛋白；一般来说，动力蛋白指导负端运输，而运动蛋白指导正端运输。然而，我们对MTs、它们的调节因子和马达在感染期间病毒颗粒运动中的作用的理解严重有限。该计划项目资助（PPG）在细胞骨架调节，马达和基于mt的运动，细胞信号传导和不同病毒感染方面提供专业知识，以解决各种系统中机械细节的这些基本问题。作为一个群体，我们迄今为止的相互作用已经确定，RNA和DNA病毒都会引起不同的MT修饰，并且需要一系列专门的MT调节因子来进行有效感染，包括肌动蛋白-MT交联剂，+TIPs和EB1，以及识别用于将病毒粒子运输到细胞核的特定宿主马达。在这个PPG中，我们的目标是确定MT子集，马达和入侵病毒粒子之间这些高度动态相互作用的机制细节，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大大提高了每个单独项目的潜力，而且还有助于将我们积累的专业知识集中于解决PPG总体目标“微管网络和病毒贩运”的关键方面。这种有效的群体方法有可能揭示病毒感染期间MT功能和调节的基本新见解，这可能在更广泛的生物学背景下很重要，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.