CAREER: Establishing the mechanistic role of differential phosphorylation in regulating viral life-cycle processes

在它们的生命周期中，病毒必须执行许多过程才能成功地劫持宿主细胞。本项目研究了两种不同病毒对这些过程的调控。更详细地了解这一调节过程将使研究人员能够利用它来控制病毒，既抑制病毒感染，又将病毒结构重新用于生物技术。为了确保病毒在保持小基因组的同时拥有完成这些过程所需的工具，一些病毒编码具有多种功能的蛋白质结构域。例如，内在无序蛋白（IDP）结构域通过改变形状来执行不同的功能。该项目研究了使IDP结构域在功能形状之间切换的关键机制，这是用磷酸盐修饰蛋白质，这一过程称为磷酸化。该项目还将吸引许多服务不足的人群，并通过不同类型的外展活动激励他们更多地了解病毒以及如何使用计算机来研究病毒。​磷酸化已被认为是病毒衣壳功能的关键调节因子，但这一现象的分子决定因素尚未阐明。例如，乙型肝炎病毒（HBV，一种感染肝组织的人类病毒）和溴代花叶病毒（BMV，一种感染谷类作物的植物病毒）衣壳都含有经过差异化可逆磷酸化的多功能IDPs。据推测，可变的磷酸化模式控制着IDPs的构象组合。然而，由于内在的无序性，IDPs的原子结构尚未得到解决，阻碍了结构-功能关系的表征。该项目将使用原子模型和分子动力学模拟来确定磷酸化模式在调节基因组包装的特定RNA识别中的作用，细胞内运输信号显示的机制和时间，以及浸润宿主细胞器（即HBV的细胞核和BMV的内质网）所需的相互作用。通过从构象、动力学和结合相互作用方面对磷酸盐对病毒IDPs的影响进行编目，我们可以开始建立病毒利用磷酸化调控规则进行基因组封装和宿主细胞操作。该项目由生物科学理事会分子和细胞生物科学部的分子生物物理学计划和促进竞争性研究的既定计划（EPSCoR）共同资助。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Over the course of their life cycles, viruses must execute a number of processes to successfully hijack a host cell. This project investigates the regulation of these processes in two different viruses. Understanding of this regulation process in greater detail will allow researchers to use it to exert control over viruses, both to inhibit viral infection and to re-purpose viral structures for biotechnology. To ensure that viruses have the tools necessary for these processes while still maintaining a small genome, some viruses encode protein domains that have multiple functions. Intrinsically disordered protein (IDP) domains, for example, change shape to perform different functions. This project investigates a key mechanism enabling IDP domains to switch between functional shapes, which is modification of the protein with phosphate, a process called phosphorylation. The project will also engage multiple under-served populations and motivate them to learn more about viruses and how computers are used to study them through different types of outreach activities. Researchers will develop software to enable students who are blind to participate in computational biophysical chemistry, update undergraduate courses with hands-on computational biophysics modules to improve interdisciplinary training of biochemists, and leverage crochet to engage students, adults, and non-scientists alike in learning about virus structure and research.Phosphorylation has been implicated as a key regulator of capsid function in viruses, but the molecular determinants of this phenomena have not been elucidated. For example, hepatitis B virus (HBV, a human virus that infects liver tissue) and Brome mosaic virus (BMV, a plant virus that infects cereal crops) capsids both contain multi-functional IDPs that undergo differential, reversible phosphorylation. It is hypothesized that variable phosphorylation patterns control the conformational ensembles of the IDPs. However, owing to intrinsic disorder, atomistic structures of the IDPs have not been resolved, impeding characterization of structure-function relationships. This project will use atomistic modeling and molecular dynamics simulations to establish the role of phosphorylation patterns in regulating specific RNA recognition for genome packaging, the mechanism and timing of intracellular trafficking signal display, and interactions required for the infiltration of host organelles, namely the nucleus for HBV and the endoplasmic reticulum for BMV. By cataloging the effects of phosphates on viral IDPs in terms of conformation, dynamics, and binding interactions, we can begin to establish the rules of phospho-regulation as utilized by viruses for genome encapsidation and host cell manipulation. This project is jointly funded by the Molecular Biophysics Program of the Molecular and Cellular Biosciences Division in the Biological Sciences Directorate and the Established Program to Stimulate Competitive Research (EPSCoR).This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.