Designing multiphase biomolecular condensates by coevolution of protein mixtures

Control of biomolecular condensates may hold considerable therapeutic potential. Intracellular condensates are highly multi-component systems in which complex phase behaviour can ensue, including the formation of architectures comprising multiple immiscible condensed phases. Conceivable avenues for manipulating condensates to bypass pathologies thus extend beyond merely controlling their stability and material properties, and relying solely on physical intuition to manipulate them is difficult because of the complexity of their composition. We address this challenge by developing an efficient computational approach to design pairs of protein sequences that result in well-separated multilayered condensates. Our method couples a genetic algorithm to a residue-resolution coarse-grained protein model. We demonstrate that we can design protein partners to form multiphase condensates containing naturally occurring proteins, such as the low-complexity domain of hnRNPA1 and its mutants, and show how homo- and heterotypic interactions must differ between proteins to result in multiphasicity.