Fig. 7: PomY condensates enrich FtsZ.
a Schematic of the experimental setup. b Representative high-resolution images and fluorescence intensity line plots (lower panels, smoothed) of 4 µM PomY-mCh in the presence of 4% PEG8000 and either no client protein (bleedthrough control), EGFP, Strep-A488 or A488-FtsZ. Note that Strep-A488 and A488-FtsZ are labeled with on average 19 and 0.5 molecules per protein, respectively. Therefore, brightness and contrast settings for the 488 channel were individually adjusted to enable the display of all images. Fluorescence intensity inside the condensates (ICd) and of the background (IBg) is indicated in the schematics on the right and in the line plots. The line plots are from scans across two condensates as shown in the overlay images and are normalized to the highest intensity value. Scale bars, 5 µm. c Quantification of the enrichment of EGFP, Strep-A488 and A488-FtsZ in PomY-mCh condensates from confocal z-stacks. For normalization, the respective enrichment of the bleedthrough control was subtracted from each value. The average enrichment of the bleedthrough control was close to an equal partitioning of 1 (1.7 ± 0.5). d The presence of A488-FtsZ, EGFP or Strep-A488 does not alter the extent of PomY phase separation. Quantification of the separation factor of PomY-mCh in the presence of 4% PEG8000 alone and in the presence of A488-FtsZ, EGFP or Strep-A488. e FtsZ-A488 fluorescence in the condensates is more variable than that of EGFP or Strep-A488. Quantification of the CV of the client protein fluorescence in PomY-mCh condensates. c–e Data from five independent experiments as indicated with colors with in total n = 20 analyzed images per condition in which on average n = 553 ± 139 condensates were identified per analyzed image. Error bars, mean ± STDEV.
