<p>Remodeling parameters.</p>

Directional motion emerged at intermediate turnover rates, at which tension in the network accumulated through several turnover cycles before eventually exceeding the adhesion removal threshold locally at the edge, mirroring our recent experimental findings on the correlation of the traction force with protrusion-retraction transitions in the cell. At high turnover rates, forces were unable to build up to sufficiently high levels, while at low turnover rates, anchors hindered motion.

These results demonstrate how directed motion can emerge as an intrinsic property of a simple mechanical network, independently of external cues or complex signaling networks. Given the concordance between this model and recent experimental findings, we suggest that polarization by contraction-adhesion dynamics could be a fundamental emergent behavior of actin-myosin networks.</p></div>