Actin- and microtubule-dependent organelle motors: interrelationships between the two motility systems.

Membranous organelles move on both actin filaments and microtubules. Evidence for the presence of myosin and microtubule-based motors on the same organelle has raised the question of the interrelationship between the two motility systems. Functional studies of unconventional myosins are beginning to provide insights into this question and the important roles these motors play in membrane trafficking and organelle movement.