Nucleotide-dependent Dynamics and Material Properties of a Model Biomolecular Condensate

Biomolecular condensates are biochemical organizing centers within cells made up of complex mixtures of protein and RNA. The dynamics and material states of these bodies are often central to their function, controlling condensate formation and dissolution, how condensates interact with other cellular structures, and the mobility of their constituents. Identifying specific biomolecular players capable of controlling material state and uncovering fundamental principles surrounding dynamics within biomolecular condensates is crucial to our understanding of their regulation in biological systems. This information will also be key to understanding how these bodies may be leveraged for bioengineering and biomedical purposes. By studying DEAD-box helicases, a family of proteins commonly found in eukaryotic condensates, we are uncovering how nucleotide-dependent protein-RNA interactions structure biomolecular condensates at the microscopic scale, coupling measurements of biomolecular mobility to their consequences for condensate material properties. We identify two distinct modes for nucleotide-dependent regulation of condensate material state and demonstrate tunable dynamics dependent on nucleotide concentration.