De novo engineering of intracellular condensates using artificial disordered proteins

Abstract

Phase separation of intrinsically disordered proteins (IDPs) is a remarkable feature of living cells to dynamically control intracellular partitioning. Despite the numerous new IDPs that have been identified, progress towards rational engineering in cells has been limited. To address this limitation, we systematically scanned the sequence space of native IDPs and designed artificial IDPs (A-IDPs) with different molecular weights and aromatic content, which exhibit variable condensate saturation concentrations and temperature cloud points in vitro and in cells. We created A-IDP puncta using these simple principles, which are capable of sequestering an enzyme and whose catalytic efficiency can be manipulated by the molecular weight of the A-IDP. These results provide a robust engineered platform for creating puncta with new, phase-separation-mediated control of biological function in living cells.

Artificial intrinsically disordered proteins (A-IDPs) have now been shown to form exclusionary, intracellular droplets that can be designed using simple principles that are based on the aromatic/aliphatic ratio and molecular weight. Droplets that sequester an enzyme and modulate enzyme efficiency on the basis of the molecular weight of the A-IDPs were also engineered using A-IDPs as a minimal condensate scaffold.