Fig. 4: A fine-tuning of the mixed F-actin architecture facilitates membrane deformation.

a Schematic of the mixed F-actin cortex with increasing mDia1 concentration. b Snapshots of the surface of the liposome and the mid-plane of the actin cortex at post-illumination (after 2 min) for different mDia1 to Arp2/3 ratio. Boxplots showing maximum membrane strain (c) and maximum actin polarity (d) at varied mDia1 to Arp2/3 ratio (n = 33 liposomes and N = 2 independent experiments in [mDia1]/[Arp2/3] = 0; n = 28 and N = 2 in 1/25; n = 26 and N = 2 in 1/5; n = 41 and N = 2 in 1/2; n = 32 and N = 3 in 1; n = 23 and N = 2 in 5; n = 36 and N = 2 in 25). e Schematic of the mDia1-nucleated linear F-actin cortex with increasing mDia1 concentration. f Snapshots of the surface of the liposome and the mid-plane of the actin cortex at post-illumination (after 2 min) for different mDia1 concentrations. Maximum membrane strain (g) and maximum actin polarity (h) at varied mDia1 concentration (n = 31 and N = 2 in [mDia1] = 25 nM; n = 36 and N = 2 in 125 nM; n = 49 and N = 2 in 625 nM). i Schematic of the Arp2/3-nucleated branched F-actin cortex at three times higher Arp2/3 concentration than the control condition in (a) with increasing mDia1 concentration. j Snapshots of the surface of the liposome and the mid-plane of the actin cortex at post-illumination (after 2 min) for different mDia1 concentrations. Maximum membrane strain (k) and maximum actin polarity (l) at varied mDia1 concentration (n = 31 and N = 3 in [mDia1] = 0 nM; n = 22 and N = 2 in 25 nM; n = 29 and N = 3 in 125 nM). *, **, *** represent p < 0.05, p < 0.01, and p < 0.001, respectively. n.s. not significant. Scale bars, 10 μm.