Figure EV1. Comparing the VCA motifs from different NPFs in their ability to destabilize linear filaments nucleated by SPIN90‐Arp2/3 (left) or Arp2/3‐mediated branches (right).

The dissociation rates of Arp2/3‐nucleated filaments exposed to nearly saturating amounts (3 μM) of VCA from different NPFs were measured, as in Fig 2. The histogram represents the average koff of three independent measurements (black dots) and the error bars represent the standard deviation. The dissociation rate of SPIN90‐Arp2/3‐nucleated filaments is 0.037 ± 0.003, 0.022 ± 0.002, and 0.011 ± 0.001 s⁻¹, for N‐WASP, WASH, and WASP, respectively. The dissociation rate of Arp2/3‐mediated actin branches is 0.012 ± 0.003, 0.016 ± 0.005, and 0.007 ± 0.003 s⁻¹, for N‐WASP, WASH, and WASP, respectively. The P‐values were determined with an unpaired t‐test.