Fig. 6

Formin inhibitor SMIFH2 promotes intrafilopodial centripetal movement. a Filopodium of HeLa-JW cell is shown before SMIFH2 treatment (top panel), 15 min following the addition of 20 μM SMIFH2 (middle panel) and 15 min after subsequent addition of 30 μM Y-27632 (bottom panel). Myosin X patches are shown in the left images (see also Supplementary Movies 17, 18, and 21), and kymographs representing the movement of the patches along the boxed filopodium—in the images on the right. Note that treatment with SMIFH2 resulted in formation of numerous myosin X patches moving from the tip to the base of filopodium. Addition of ROCK inhibitor Y-27632 stopped this movement. Images for analysis were obtained with SDCM. Scale bars, 5 μm. b Graph displaying the myosin X patches velocities in filopodia of control cells (left, gray dots), of cells treated with SMIFH2 for 15 min (middle, purple dots), and in SMIFH2-treated cells 15 min following the addition of Y-27632 (right, green dots). Each dot corresponds to individual myosin X patch; numbers of analyzed patches (n) and cells, as well as significance of the differences (p values) are indicated. The p values were calculated using unpaired two-tailed t test with Welch’s correction