FIGURE 2.

Assembly of myosin-X on the membrane when the protrusion was initiated. A, time courses of TIRF images during assembly of myosin-X in cells overexpressing M10-FULL. Scale bars are 1 μm. Yellow broken line shows the cell membrane. Yellow arrowheads indicate the protrusion site of the membrane. B and C, typical graphs of fluorescence intensities at the protrusion site with M10-FULL (B) and M10-ΔFERM (C). The fluorescence intensity was obtained by integrating the value of 5 × 5 pixels square, and then subtracting the background intensity estimated from the intensity of the boundary of the square. The photobleaching rate under the conditions used was determined by measuring the intensity of GFP fixed on the glass surface. The time constants were corrected with the photobleaching rate. Data were fitted to a single exponential curve (f(x) = I·exp{ − (x − x₀)/τ}). The plots were normalized using the parameter of “I.” Values in panels indicate “τ,” which represents time constants. D and E, histograms of the time constants for M10-FULL (D) and M10-ΔFERM (E). The mean time constants were 9.8 ± 5.8 s (n = 60 in 11 cells) and 11.3 ± 8.2 s (n = 74 in 12 cells) for M10-FULL and M10-ΔFERM, respectively (p = 0.16 by paired t test).