Engineering Light-Responsive Contractile Actomyosin Networks with DNA Nanotechnology.

Area of Science:

• Synthetic biology
• Biophysics
• Cellular engineering

Background:

• Bottom-up engineering of synthetic cells requires precise external control.
• Minimal actomyosin networks are key components but lack light-triggered contraction.
• Previous efforts have not demonstrated light-induced symmetry breaking in these networks.

Purpose of the Study:

• To engineer light-activated directional contractility in minimal synthetic actomyosin networks.
• To achieve symmetry breaking within cell-sized compartments using external stimuli.
• To demonstrate a method for controlling active multi-component systems in synthetic biology.

Main Methods:

• Co-encapsulation of actin filaments, heavy-meromyosin-coated beads, and caged ATP into water-in-oil droplets.
• Light-induced release of ATP to generate myosin-driven force and network contraction.
• Utilizing DNA nanotechnology to link actin filaments to the compartment periphery for symmetry breaking.

Main Results:

• Demonstrated light-activated directional contractility of the actomyosin network.
• Achieved symmetry breaking, leading to actin filament contraction to one side and formation of actin asters.
• Quantified the dynamics of the contraction process.

Conclusions:

• An engineering approach combining biological and artificial elements can control complex active systems.
• This method enriches the complexity of synthetic cellular systems.
• Light-triggered contractility offers precise manipulation for bottom-up synthetic cell design.