Fig. 2
From: Myosin IIA and formin dependent mechanosensitivity of filopodia adhesion
Effects of myosin IIA on lifetime of myosin X-induced filopodia. a A region of Cos-7 cell with myosin X positive filopodia either associated or non-associated with myosin IIA filaments. The cell expressed mApple-myosin X (red), myosin IIA-GFP heavy chain (green), and mTagBFP-Lifeact (blue). Dashed boxes outline filopodia associated (1) and nonassociated (2) with myosin IIA filaments. See also Supplementary Movie 6. b, c High magnification of frames showing filopodium 1 (b) and 2 (c) boxed in (a) at different time points. The purple 1.5 μm diameter circles at the left-most frames illustrate how the presence of myosin IIA filaments at the filopodia bases was assessed (see Methods). Images were collected using SIM. Scale bars 2 μm. d Lifetime values of filopodia associated and nonassociated with myosin IIA filaments. Pooled data showing 102 filopodia from 3 cells (including the cell shown in (a)). Each bar corresponded to individual filopodium; the bars labeled by one, two, or three black dots represent filopodia taken from first (shown in (a) and (b)), second and third cell, respectively. The bars are arranged in ascending order according to filopodia lifetime. The filopodia, which survived longer than the observation period of 240 s, are shown as bars with the uniform maximal height (240 s). Color code: filopodia nonassociated with myosin IIA filaments—cyan, filopodia associated with myosin IIA filaments part time—yellow, filopodia associated with myosin IIA filaments during entire period of observations—magenta. e Dynamics of survival fractions of the filopodia cohorts in Cos-7 cells transfected with the indicated constructs. Number of assessed filopodia (n) and cells for each type of transfection were: myo X (n = 72, 3 cells), myoX, myoIIA (n = 86, 3 cells), myoX ΔFERM (n = 104, 3 cells), myoX ΔFERM, myoIIA (n = 100, 3 cells, myoX, myoIIB (n = 93, 3 cells) and myoX, myoIIA N93K (n = 104, 4 cells). f Average lifetimes of filopodia (mean ± s.d.) calculated by fitting graphs shown in (e) to exponential decay function
