Figure 3. The recruitment of POI into protein compartment.
A. Illustration of PhASE#1 system design. CIB1 and CRY2 could bind to each other under 488 nm light. B, C. Induction of PhASE#1 system by light of different intensity. With intense 488 nm laser irradiation for 8 seconds, the protein compartments could enrich POI up to 15-fold compared to cytosol concentration. GFP signal was not shown since its capture also need 488 nm laser but note that the compartment formed by phase module had formed before the induction process. The merged image was captured after the end of stimulation process. More confirmations of the co-localization of two modules after light were shown in Supplementary Figure 4 (B). With laser irradiation of lower intensity for 3 seconds, the protein compartments enriched POI at about 2-fold. After 10 to 15 minutes, the system fully reversed to previous state and was ready for the second round of induction (data not shown) and the third round of induction (1:08:19). With the same set of parameters, this system could be induced to almost the same enrichment fold as the first round. Since the bacteria were actively dividing, the intensity profile of the last time point was not precisely overlapped with that of former time points (C). D. Illustration of PhASE#2 system design. SIM and SUMO are utilized for compartment formation. E. Induction of PhASE#2 system by light. With intense laser irradiation for 8 seconds, the protein compartments could enrich POI for more than 10-fold. Scale bar, 1 μm.