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.