Axon Outgrowth: Motor Protein Moonlights in Microtubule Sliding

Neurons develop from small, spherical precursors into the largest, most asymmetric of all metazoan cells by extending thin axonal processes over enormous distances. Although the forces for this extension have been unclear, recent work shows that the initial axonal extension may involve an unexpected mechanism: sliding of microtubules, driven by a motor protein previously thought to be deployed only in organelle transport.