Elucidating Roles of Biomolecular Condensates in Replication and Assembly of RNA Viruses

There is a need for new drugs to combat viruses that threaten our health. Most existing antivirals inhibit virus attachment/entry or target critical enzymes, and new antiviral targets are needed to develop novel treatments and counter antiviral resistance. One key process in the life cycle of many viruses is the formation of dynamic organelles called viral factories. There is increasing evidence that some viral factories form via liquid-liquid phase separation (LLPS), including SARS-CoV-2, influenza, and measles virus. These compartments concentrate viral replication enzymes and sequester replication intermediates from the immune sensors. Targeting the physicochemical process of phase separation is an emerging paradigm that may underlie the discovery of novel, broad-spectrum antivirals, but this can only be realised by first understanding how viral factories form. This research project will focus on dissecting the physicochemical properties of these viral condensates to understand how their dynamic conformations and posttranslational modifications that affect charge mediate assembly of viral factories, and in doing so, identify targets for future therapeutic intervention. To quantitatively describe the formation of these condensates, we will examine the observed phase transitions of binary and tertiary mixtures of recombinantly produced viral proteins, as well as viral RNAs in vitro using the recently developed high-throughput microfluidics platform PhaseScan. These findings will lead us to define a new model of viral replicative condensate formation that addresses protein-specific attributes (posttranslational modifications, conformation), and their highly selective RNA composition (partitioning of cognate viral transcripts and exclusion of non-viral RNAs). The insights gained from these approaches will underlie the search for compounds that could serve as drug templates for prospective therapies for RNA viruses and improve our fundamental understanding of the synergistic interactions of viral proteins that spontaneously form complex condensates that are involved in viral replication.

This project will provide an excellent research environment that will foster the future development of the PhD candidate through extensive multi-disciplinary training in
i) microfluidics;
ii) protein biochemistry;
iii) biophysics of condensates;
iv) machine learning approaches required for bespoke data analyses.

This project will provide a unique training environment required for training next-generation biochemists interested in exploring biomolecular condensates and their roles in viral replication and assembly, with an ultimate goal of identifying new druggable antiviral targets.