Engineering Light‐Responsive Contractile Actomyosin Networks with DNA Nanotechnology

Abstract

External control and precise manipulation is key for the bottom‐up engineering of complex synthetic cells. Minimal actomyosin networks have been reconstituted into synthetic cells; however, their light‐triggered symmetry breaking contraction has not yet been demonstrated. Here, light‐activated directional contractility of a minimal synthetic actomyosin network inside microfluidic cell‐sized compartments is engineered. Actin filaments, heavy‐meromyosin‐coated beads, and caged ATP are co‐encapsulated into water‐in‐oil droplets. ATP is released upon illumination, leading to a myosin‐generated force which results in a motion of the beads along the filaments and hence a contraction of the network. Symmetry breaking is achieved using DNA nanotechnology to establish a link between the network and the compartment periphery. It is demonstrated that the DNA‐linked actin filaments contract to one side of the compartment forming actin asters and quantify the dynamics of this process. This work exemplifies that an engineering approach to bottom‐up synthetic biology, combining biological and artificial elements, can circumvent challenges related to active multi‐component systems and thereby greatly enrich the complexity of synthetic cellular systems.

Autonomous Directional Motion of Actin‐Containing Cell‐Sized Droplets

“…[ 28,29 ] Availability of MC in the actin polymerization buffer leads to a strong bundling of actin fibers due to the depletion effect, as can be observed in Figure 4C. [ 30 ] As expected, under these conditions, we observed a rotational motility of the droplets also in the presence of 0.54 m m Krytox (for 90% of the droplets) and even in the presence of 1.04 m m Krytox (for 72% of the droplets) (Figure 4D).…”

Building a community to engineer synthetic cells and organelles from the bottom-up

“…Such droplet-based approaches have also been adopted for lipid membrane engineering ( Lussier et al, 2021 ; Steinkühler et al, 2020 ). Similarly, DNA nanotechnology has allowed to combine programmable molecular architectures with extrinsically controlled functions ( Bazrafshan et al, 2020 ; Jahnke et al, 2020 ). In a combinatorial approach, integration of DNA nano-architectures with synthetic cells has synergized top-down and bottom-up strategies ( Jahnke et al, 2021 ).…”

Building a community to engineer synthetic cells and organelles from the bottom-up

“…Droplet-based microfluidic approaches have also been adopted for lipid membrane engineering 37,48 . Similarly, DNA nanotechnology has allowed to combine programmable molecular architectures with extrinsically controlled functions 49,50 . In a combinatorial approach, integration of DNA nano-architectures with synthetic cells has synergized top-down and bottom-up strategies 51 .…”