Figure 1
From: Intra-bundle contractions enable extensile properties of active actin networks
The activity of NMMII leads to the growth of clusters in actin networks bundled by methylcellulose. (a) Illustration of the experimental setup. A polymerization solution containing actin (magenta) in absence or presence of NMMII (cyan) was added to an SLB (blue). Actin was crowded on the fluid surface due to a high concentration of methylcellulose (0.8%). (b) The resulting actin network was imaged by TIRF microscopy. Bundles of actin formed spontaneously due to the presence of methylcellulose. (c) Here, the network was polymerized in the presence of NMMII and clusters formed in a swelling manner. In both cases, time frames at 150 s, 300 s and 600 s after the start of the experiment are shown. Scale bars = 10 µm. (d) Histogram of the pore sizes in both network types in an area of 100 µm. (e) The width of bundles and clusters in both networks type measured at multiple locations throughout the network. While the width of bundles in the absence of NMMII remains almost constant with 250 nm, NMMII-containing clusters grow on overage almost ten times as wide and much more disperse. At least ten locations were evaluated for both network types.
