Figure 5.
Confocal microscopy analysis of crowding-induced FtsZ assembly in ZipA-SLBs. (A) Confocal fluorescence images showing FtsZ networks formed on ZipA-SLBs in the presence of 0, 50, 130, and 180 g/L of Ficoll70. (B) 3D reconstruction of confocal fluorescence images showing Ficoll-induced FtsZ bundles on ZipA-SLBs. The image was taken at 190 g/L Ficoll70. These dense and dynamic 3D networks localize in solution and are connected to the bilayer by some fibers. Frame size: 45 μm × 45 μm (4.4 nm per pixel). (C) Half-time turnover (τ1/2) of FtsZ subunits on the membrane depending on the Ficoll concentration, as determined by FRAP (●) and image correlation (○). Ficoll70 significantly retards the subunit exchange within the polymer. The dashed line is an arbitrary curve drawn to guide the eye. The data shown correspond to the mean values of at least three independent measurements plotted with the corresponding standard error. To see this figure in color, go online.