Fig. 1

Molecular composition of filopodia induced by myosin X expression. a Images of filopodia in HeLa-JW cells co-expressing GFP-myosin X with mCherry fusion constructs of mDia2, VASP, and talin, respectively. b Line scans of the fluorescence intensities through the filopodia indicated by dashed boxes in images in (a). Intensities of the myosin X, mDia2, VASP, and formin were normalized to their maximal values at the filopodia tips. c Visualization of mApple-myosin X (red), myosin II RLC-GFP (green), and actin (mTagBFP-Lifeact, blue) in HeLa-JW cell. d–e Zoomed images of bipolar myosin IIA filaments at the bases of filopodia. d Myosin IIA and myosin X labeled as indicated in (c). e Cos-7 cell expressing mApple-myosin X (red) and myosin IIA-GFP heavy chain (green). Arrows indicate the doublets of fluorescent spots corresponding to heads of myosin II mini-filaments. f–i Images of Cos-7 cells expressing various constructs of myosin X (red) and myosin II (green): f GFP-myosin X, g mApple-myosin X and myosin IIA-GFP heavy chain, h mApple-myosin X and GFP-myosin IIA N93K, i mApple-myosin X and Emerald-myosin IIB heavy chain. Note, that both myosin IIA wild-type- and N93K-containing filaments, but not myosin IIB, can be seen at the bases of filopodia. See also Supplementary Movies 1–5, which correspond to images (c, f–i), respectively. Images were collected using spinning disk confocal microscopy (SDCM) (a, f) and structural illumination microscopy (SIM) (c–e and g–i). Scale bars, 5 μm (a), 2 μm (c–i)