Kinesin switch in neurites

Before axon specification, seemingly identical neurites are not so alike after all. New research from Catherine Jacobson, Bruce Schnapp, and Gary Banker (Oregon Heath & Science Center, Portland, OR) reveals a hitherto unseen biochemical distinction in neurites of developing neurons.

The distinction was noted while visualizing a constitutive version of the Kinesin-1 motor, which in mature neurons is found only in the axon. Because the plus ends of axonal microtubules point away from the cell body, whereas those in dendrites face both directions, Kinesin-1's plus end–directed activity could explain this specific accumulation. But the new results show that Kinesin-1 is found in a subset of young neurites, often in just one, at a time when the microtubules in all neurites are still similarly oriented.

The accumulation of...