Fig. 1. A. Sequence of disordered RGG domain of Laf-1. B. Coarse-grain simulations identifies hydrophobic motif 21-28 that self-associates for condensation. C. Re-design of charge partitioning tunes phase behavior. D-F. Photocleavable RGG construct undergoes soluble to condensed transition upon 405 nm illum. G-H. Expression and optically induced condensation construct (D) in a model single cell system.