Mapping out Min protein patterns in fully confined fluidic chambers

Abstract

The bacterial Min protein system provides a major model system for studying reaction-diffusion processes in biology. Here we present the first in vitro study of the Min system in fully confined three-dimensional chambers that are lithography-defined, lipid-bilayer coated and isolated through pressure valves. We identify three typical dynamical behaviors that occur dependent on the geometrical chamber parameters: pole-to-pole oscillations, spiral rotations, and traveling waves. We establish the geometrical selection rules and show that, surprisingly, Min-protein spiral rotations govern the larger part of the geometrical phase diagram. Confinement as well as an elevated temperature reduce the characteristic wavelength of the Min patterns, although even for confined chambers with a bacterial-level viscosity, the patterns retain a ~5 times larger wavelength than in vivo. Our results provide an essential experimental base for modeling of intracellular Min gradients in bacterial cell division as well as, more generally, for understanding pattern formation in reaction-diffusion systems.DOI: http://dx.doi.org/10.7554/eLife.19271.001

A cell length‐dependent transition in MinD‐dynamics promotes a switch in division‐site placement and preservation of proliferating elongated Vibrio parahaemolyticus swarmer cells

“…Thus, the maximum MinD‐wavelength, and consequently the cell length at which a transition in MinD dynamics occur, are very similar between the Min‐systems of E. coli and V. parahaemolyticus , suggesting it is a cell length‐dependent intrinsic property of the Min‐system that triggers the transition in localization dynamics. This is further supported by in vitro reconstitution experiments of Min‐dynamics in fabricated microchambers, where Min‐dynamics has been observed to switch from a pole‐to‐pole oscillation to symmetric double oscillations or traveling waves correlated with chamber length (Schweizer et al, ; Zieske and Schwille, ; Zieske and Schwille, ; Caspi and Dekker, ). A function for such multi‐node standing wave oscillation of the Min‐system, however, has never been reported before.…”

“…The prospective outcome is that free FtsZ molecules exist in a concentration sufficient for Z-ring formation at midcell and LD-sites when directed to these locations by the Min-system. In E. coli (Bernhardt and de Boer, 2005;Cho et al, 2011;Tonthat et al, 2013) and V. cholerae (Galli et al, 2016), SlmA prevents Z-ring formation when bound to specific DNA sequences. It is likely that SlmA similarly in V. parahaemolyticus needs to be DNA bound in order to perform its role in preventing formation of division-deficient FtsZ clusters.…”

“…Furthermore, in many bacteria another system referred to as nucleoid occlusion (NO) inhibits division at sites within the cell occupied by the nucleoid (Ortiz et al, 2015). In E. coli the NO effector protein is SlmA (Bernhardt and de Boer, 2005), a DNA-binding protein that blocks FtsZ-ring formation when bound to specific DNA sequences (Cho et al, 2011;Tonthat et al, 2013).…”

Division plane placement in pleomorphic archaea is dynamically coupled to cell shape

“…In vitro, MinD and MinE can spontaneously form spatiotemporal patterns on a lipid bilayer when supplied with ATP (Loose et al, 2008). In artificial membrane-lined chambers, Min patterning displays rich dynamics that are determined by the geometry of the confining chamber (Zieske and Schwille, 2014;Caspi and Dekker, 2016;Kretschmer and Schwille, 2016).…”

In long bacterial cells, the Min system can act off‐center

“…Therefore, the maximum Min wavelength and cell‐length at which a transition to multi‐node dynamics occur are very similar between E. coli and V. parahaemolyticus . Similar length‐dependent transitions in Min oscillation have also been reconstituted in rod‐shaped compartments covered with membranes (Zieske and Schwille, ; Caspi and Dekker, ). Together the findings show that it is a cell length‐dependent intrinsic property of the Min system that triggers the transition in localization dynamics.…”