Fig. 2.
Myosin X motors move on filopodia and around the lamella edge of permeabilized Drosophila S2 cells. (A) Multiple extracted S2 cells displaying filopodia, lamella edge (purple dotted line) and a cell edge (yellow dotted line). The actin cytoskeleton is visible with TMR-phalloidin. (Scale bar, 10 μm.) (B) Trajectory map (white arrows) of all moving MX motors throughout these cells. (C) MX motors that make runs on filopodia (red circles) and around the lamella edge (magenta) move at various velocities (Fig. S6) on this bundled actin. (D–F) Orientation angle measurements for all moving MX motors. Motors moving on filopodia (D) have a center angle of 100–180°, indicating that motors start at the base of filopodia and run out, toward the cell periphery. Center angles determined for motors moving on the lamella (E) indicated that these motors move circumferentially at an angle of 55–120°. All other motors moving throughout the cells revealed an uncorrelated center angle measurement (F), indicating that these motors move in all directions. (G) Some MX motors switch tracks (white) while making a run. These track switching events do not occur on the filopodia (red lines), the lamellar edge (purple dotted line), or at the cell edge (yellow dotted line).