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.