MinE conformational switching confers robustness on self-organized Min protein patterns

Abstract

SignificanceMany fundamental cellular processes are spatially regulated by self-organized protein patterns, which are often based on nucleotide-binding proteins that switch their nucleotide state upon interaction with a second, activating protein. For reliable function, these protein patterns must be robust against parameter changes, although the basis for such robustness is generally elusive. Here we take a combined theoretical and experimental approach to the Escherichia coli Min system, a paradigmatic system for protein self-organization. By mathematical modeling and in vitro reconstitution of mutant proteins, we demonstrate that the robustness of pattern formation is dramatically enhanced by an interlinked functional switching of both proteins, rather than one. Such interlinked functional switching could be a generic means of obtaining robustness in biological pattern-forming systems.

Pattern localization to a domain edge

“…Diffusion in the cytosol is a simple means of protein transport that accounts for many self-organization processes [1]. To analyze how the interplay of diffusive protein transport and protein-protein interactions on a nanometer scale influences the protein patterns on the cellular scale, mass-conserving reaction-diffusion models have proven useful [2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18]. The study of reactiondiffusion systems in general goes back to Turing [19], who showed how patterns can emerge from a homogenous steady state when two reactive components have different diffusivities.…”

Dynamics of theBacillus subtilisMin system

“…Here, on the basis of previous theoretical studies of intracellular protein dynamics [30, 32, 34, 79], we propose a minimal reaction-diffusion system to model Min localization in B. subtilis . Building on the idea of geometry sensing put forward in Ref.…”

“…S1 and Tab. S2 ) and the values for the rate constants were estimated from previous work on protein pattern formation [30, 32, 34, 78]. The action on DivIVA and MinJ is accounted for effectively through space-dependent recruitment and detachment rates of MinD at membrane areas with a negative curvature; for details please refer to the Methods section ( Fig.…”

Lebensfunktionen neu erdacht

“…MinD kann seinerseits auch bei MinE eine Konformationsänderung auslösen, welche diesem Protein eine stärkere Membranaffinität verleiht. Erst vor kurzem konnte Schwilles Arbeitsgruppe nachweisen, dass auch diese Wechselwirkung eine wichtige Rolle bei der Selbstorganisation und Musterbildung des Systems spielt .…”