DNA sequences for: Synthetic control of actin polymerization and symmetry breaking in active protocells

Non-linear biomolecular interactions on membranes drive membrane
remodeling crucial for biological processes including chemotaxis,
cytokinesis, and endocytosis. The complexity of biomolecular interactions,
their redundancy, and the importance of spatiotemporal context in membrane
organization impede understanding of the physical principles governing
membrane mechanics. Developing a minimal in vitro system that mimics
molecular signaling and mem- brane remodeling while maintaining
physiological fidelity poses a significant challenge. Inspired by
chemotaxis, we reconstructed chemically regulated actin polymerization
inside vesicles, guiding membrane self-organization. An external,
undirected chemical input induced directed actin polymerization and
membrane deformation uncorrelated with upstream biochemical cues,
suggesting symmetry breaking. A biophysical model incorporating actin
dynamics and membrane mechanics proposes that uneven actin distributions
cause non-linear membrane deformations, consistent with experimental
findings. This protocellular system illuminates the interplay between
actin dynamics and membrane shape during symmetry breaking, offering
insights into chemotaxis and other cell biological processes.