A Modular Design for Synthetic Membraneless Organelles Enables Compositional and Functional Control

Living cells organize a wide variety of processes through compartmentalization into membraneless organelles, known as biomolecular condensates. Given their ubiquitous presence across a wide spectrum of different organisms and cell types, biomolecular condensates are increasingly considered to offer great potential for biotechnological applications. However, native condensates remain difficult to harness for engineering applications, both due to their intertwined mechanisms of assembly and compositional control, and potential disruptions to native cellular processes. Here, we demonstrate a modular framework for the formation of synthetic condensates designed to decouple cluster formation and protein recruitment. Synthetic condensates are built through constitutive oligomerization of intrinsically-disordered regions (IDRs), which drive the formation of condensates whose composition can be independently defined through fused interaction domains. The composition of the proteins driven to partition into the condensate can be quantitatively described using a binding equilibrium model, demonstrating predictive control of how component expression levels and interaction affinity determine the degree of protein recruitment. Finally, the engineered system is utilized to regulate protein interactions and metabolic flux by harnessing the systems compositional tunability.