Membrane tension, myosin force, and actin turnover maintain actin treadmill in the nerve growth cone.

ABSTRACT: A growth cone is a motile structure at the tips of axons that is driven by the actin network and guides axon extension. Low actin adhesion to the substrate creates a stationary actin treadmill that allows leading-edge protrusion when adhesion increases in response to guidance cues. We use experimental measurements in the Aplysia bag growth cone to develop and constrain a simple mechanical model of the actin treadmill. We show that actin retrograde flow is primarily generated by myosin contractile forces, but when myosin is inhibited, leading-edge membrane tension increases and drives the flow. By comparing predictions of the model with previous experimental measurements, we demonstrate that lamellipodial and filopodial filament breaking contribute equally to the resistance to the flow. The

SUBMITTER: Craig EM 

PROVIDER: S-EPMC3318135 | biostudies-literature | 2012 Apr

REPOSITORIES: biostudies-literature