Fig. 4.

PMA and PA-Rac1 together give rise to complex coalescence of membrane protrusions. a Montage of PA-Rac1 ruffle coalescence in RPE1 cells treated with PMA (100 nM); figure runs from left to right, top to bottom (Additional file 8: Movie S8). Scale bar = 15 μm. b Insert from Fig. 3a. Marked by the white rectangle, montage of PA-Rac1 ruffle formation with optogenetic stimulation. Arrows indicate ruffle formation. Scale bar = 4 μm. c Insert from Fig. 3a. Indicated by red arrows, montage of ruffle contraction post Rac1 stimulation. Scale bar = 5 μm. d Insert from Fig. 3a. Marked by magenta arrows; montage of ruffle closing, indicated by magenta arrows. Scale bar = 5 μm. e Insert from Fig. 3a, marked by the green arrows; montage of ruffle collapses following Rac1 inactivation, indicated by green arrows. Scale bar = 5 μm. f Insert from Fig. 3a. Marked by black square; montage of ruffle buckling. The segmented ruffles are represented by yellow surface. Scale bar = 3 μm. g Montage of Rac1 ruffle collapse leading to cup-closure as a surface rendered volume. Scale bar = 4 μm