Neuronal extracellular proteases facilitate cell migration, axonal growth, and pathfinding

The release of extracellular proteases by the axonal growth cone has been proposed to facilitate its movement by digesting cell-cell and cell-matrix contacts in the path of the advancing growth cone. The serine protease plasminogen activator (PA) has been shown to be secreted and focally concentrated at axonal growth cones of cultured mammalian neurons. Thus, PAs are well-placed to play an active role in growth cone movement and axonal pathfinding in development and regeneration. We discuss recent findings that suggest that the biological action of these proteases is more complex than originally thought.