Mechanical boundary conditions for motor protein dictate geometric pattern and dynamics of actin gel contraction

The actomyosin network, consisting of actin filaments and myosin motors, is essential for cell dynamic behaviors. The sliding motion of actin filaments propelled by myosin motors is converted into contraction of the cytoskeleton network, leading to cell deformation. Here, we demonstrated that active gels exhibited varied contraction geometries such as local radial patterns and global network contraction depending on the motor mobility condition at the boundary. Under two motor conditions (immobile and mobile), both experimental and computational methods were utilized to characterize the contraction dynamics at varied network connectivities. We revealed that the effect of network connectivity on the contraction dynamics depends on the motor mobility condition. Our computational models simulate the cellular functions such as cell division and muscle contraction, providing insights into disease development related to motor mobility conditions. Our study helps to explain the dynamics of active materials under varied mechanical environments.