Movie 3.

Actin filament cross-linking by recombinant human septin octamers-9_i1. Time-lapse sequence (Δt interval of 0.5 s) at the surface of a PLL-PEG passivated glass coverslip showing cross-linked actin filaments (at 1 μM) in the presence of SEPT2-msfGFP human septin octamer-9_i1 at 0.3 μM (20% GFP-septins). G-actin was polymerized in the presence of Alexa Fluor 568-phalloidin. The actin channel is shown. Spinning disk fluorescence images, using an inverted grayscale, are displayed at 5 frames per second. A still image from this time lapse sequence is shown in Fig. 4C.