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

University Of Delaware, Newark DE

Investigators

Abstract

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 and motivate the public 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 to learn 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.