Movie 4

Polymerizing and branching actin filaments sliding along glass-anchored Myo1b (corresponding to Fig. 3).
Polymerized and branched actin filaments in the absence of myosin or sliding on Myo1b at high density (8000 μm^-2). Scale bar, 5 μm. Time in s. Wide field movies corresponding to time-lapse images shown in Fig. 3B. White arrow points to a mother filament. The appearance over time of new actin filaments on the right side of the movie likely results from the high affinity of these filaments for the surface coated with Myo1b.