Fig. 3

M2[45–62] reduces cell membrane tension, and FBP17 plays an important role in M2[45–62]-driven lamellipodium formation. a Measurement of the tether force in COS-1 cells. The tether force of identical cells was measured after treatment with phosphate buffered saline (PBS) or M2[45–62] (20 µm). The mean ± standard deviation were derived from data pooled from three independent experiments. In total, 28 cells (no peptide = PBS treatment) and 26 cells (M2[45–62] treatment) were analyzed. ***P < 0.001, Student’s t test. b Time-lapse images of COS-1 cells co-expressing GFP–FBP17 and Lifeact-mCherry after addition of M2[45–62] (20 µm). Arrowheads indicate lamellipodia. Scale bar, 20 µm. c Quantification of the lamellipodia formed after treatment with control (Ctr) siRNA or FBP17 siRNA. The mean ± standard error were derived from ~ 250 cells pooled from three independent experiments. *P < 0.05, Student’s t test. d Confocal laser scanning microscopy images of F-actin (stained with rhodamine–phalloidin) in control (Ctr) siRNA or FBP17 siRNA-treated COS-1 cells. Cells were treated with M2[45–62] for 15 min. Scale bar, 30 µm