Surface topology assisted alignment of Min protein waves

Abstract

a b s t r a c t Self-organization of proteins into large-scale structures is of pivotal importance for the organization of cells. The Min protein system of the bacterium Escherichia coli is a prime example of how pattern formation occurs via reaction-diffusion. We have previously demonstrated how Min protein patterns are influenced by compartment geometry. Here we probe the influence of membrane surface topology, as an additional regulatory element. Using microstructured membrane-clad soft polymer substrates, Min protein patterns can be aligned. We demonstrate that Min pattern alignment starts early during pattern formation and show that macroscopic millimeter-sized areas of protein patterns of well-defined orientation can be generated.

Mapping out Min protein patterns in fully confined fluidic chambers

“…Previously, Min proteins were reconstituted in vitro (Loose et al, 2008; Ivanov and Mizuuchi, 2010; Loose et al, 2011a; Schweizer et al, 2012; Martos et al, 2013; Vecchiarelli et al, 2014; Zieske et al, 2014; Martos et al, 2015; Vecchiarelli et al, 2016), and Min oscillations were observed in fabricated microchambers (Zieske and Schwille, 2013, 2014). In the latter case, the microchambers had a half-open configuration (i.e., with a top surface not coated with SLB) with a limited width (∼10 µm), a height of 10 µm, and varying lengths leading to a range of aspect ratios (1.2–24).…”

“…For example, when rectangular patches of flat surface SLB were separated one from the other with gold barriers that were much larger than the characteristic size of the Min dynamics in vitro (∼100 μm), Min waves propagated in a direction that depended on the aspect ratio of the patch (Schweizer et al, 2012). Similarly, Min waves can be oriented within an SLB if parallel grooves are molded into the surface (Zieske et al, 2014). However, the geometry-selection rules that were found in these in vitro experiments do not correspond to the ones that were observed in vivo (Wu et al, 2015).…”

Large-scale modulation of reconstituted Min protein patterns and gradients by defined mutations in MinE’s membrane targeting sequence

“…coli but are scaled to the roughly ten times larger spatial dimensions of Min patterns in vitro [20, 21]. It has been characterized extensively how the geometry of the surrounding boundaries modulates Min protein dynamics [21–26]. Likewise, several studies investigated physical and biochemical influences on reconstituted Min protein patterns [27–30].…”

Protein Patterns and Oscillations on Lipid Monolayers and in Microdroplets

“…Previously, we have reconstituted the pole‐to‐pole oscillations of the Min proteins, as well as their ability to spatially direct FtsZ‐mts (FtsZ fused to a membrane‐targeting sequence)16 to the middle of a microfabricated compartment 12, 17. However, although the cell membrane of E. col i is a closed compartment, Min oscillations have thus far only been successfully reconstituted in volumes not fully enclosed by membranes, but open at least at one site 12, 18, 19. Moreover, although membrane‐attached FtsZ rings have been observed in vesicles16, 20, 21 and FtsZ bundles have been characterized in the lumen of droplets,22 we are just beginning to understand how systems parameters, such as compartment geometry, influence FtsZ ring structure and dynamics.…”