Fig. 2: Assembly of distinct actin cortex architectures within liposomes.

a Schematic of the Arp2/3-nucleated branched F-actin cortex activated via His-VCA ([Arp2/3] = 25 nM). b A snapshot showing the surface of the Arp2/3 cortex liposome before 405 nm illumination. The nematic order parameter, \(S=\langle \cos 2\theta \rangle\), is calculated from the director field (black dashes). c Snapshots showing the actin and membrane before and post 405 nm illumination. Membrane curvature is color-coded at 2 min. d Schematic of the mDia1-nucleated linear F-actin cortex ([mDia1] = 25 nM). e A snapshot showing the surface of the mDia1 cortex liposome and nematic order parameter. f Snapshots showing the actin and membrane before and post 405 nm illumination. Membrane curvature is color-coded at 2 min. g Schematic of the mixed F-actin architecture cortex at [mDia1]:[Arp2/3] = 1:1 ([mDia1] = 25 nM; [Arp2/3] = 25 nM). h A snapshot showing the surface of the mixed cortex liposome and nematic order parameter. i Snapshots showing the actin and membrane before and post 405 nm illumination. White arrows indicate local deformations. Membrane curvature is color-coded at 2 min. j Boxplot showing the mean order parameter (n = 8 liposomes and N = 5 independent experiments in Arp2/3; n = 9 and N = 3 in mDia1; n = 11 and N = 2 in Mixed). Membrane strain (k) and actin polarity (l) over time (n = 33 and N = 6 in Arp2/3; n = 24 and N = 5 in mDia1; n = 26 and N = 2 in Mixed). Maximum membrane strain (m) and maximum actin polarity (n) extracted from (k) and (l) (n = 33 and N = 6 in Arp2/3; n = 24 and N = 5 in mDia1; n = 26 and N = 2 in Mixed). Curves are mean ± SD. *, **, and *** represents p < 0.05, p < 0.01, and p < 0.001, respectively. n.s. not significant. Scale bars, 10 μm.