Fig. 1: Effect of a change of a bulk height on Min-pattern formation. | Nature Communications

Fig. 1: Effect of a change of a bulk height on Min-pattern formation.

From: Bulk-surface coupling identifies the mechanistic connection between Min-protein patterns in vivo and in vitro

Fig. 1: Effect of a change of a bulk height on Min-pattern formation.

A General concept of the experimental setup. MinD and MinE proteins were reconstituted in laterally large and flat microchambers of different heights. All inner walls of microchambers were covered with supported lipid bilayers made of DOPC:DOPG:TFCL (66 : 32.99 : 0.01 mol%) mimicking the E. coli membrane composition. Min proteins cycle between bulk and the membrane upon which they self-organize into dynamic spatial protein-density patterns. B Min-protein interaction scheme. MinD monomers (light-green hexagons) bind ATP resulting in dimerization and cooperative accumulation on membrane (dark-green hexagons). Next, MinE dimers bind to MinD, activating its ATPase activity, detachment from the membrane, and diffusion to the bulk where ADP is exchanged to ATP, and the cycle repeats. C Influence of the bulk height on Min-pattern formation. Snapshots show overlays of MinD channel (green) and MinE channel (red) imaged on the membrane 30 min after injection. Kymographs below were generated along the dashed magenta lines. In each microchamber, the concentrations of the reconstituted proteins are 1 μM MinE and 1 μM MinD (corresponding to a 1:1 E:D ratio). The gray shaded area marks the range of bulk heights where different patterns are observed in repeated experiments (multistability), cf. Fig. 3. D Snapshots and kymographs from numerical simulations of the reaction-diffusion model describing the skeleton Min-model in a three-dimensional box geometry with a membrane on top and bottom surfaces and reflective boundaries at the sides (see Supplementary Methods 1 and 3 for details). The colors are an overlay of MinD density (green) and MinE density (red) on the top membrane. Parameters (from left to right): H = 2 μm, E:D = 0.8; H = 6 μm, E:D = 0.75; H = 14 μm, E:D = 0.75; H = 20 μm, E:D = 0.725; H = 40 μm, E:D = 0.625. Lateral system dimensions: 200 × 200 μm. The remaining, fixed model-parameters are given in Supplementary Table 1. (White scale bars in C and D: 50 μm).

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