Figure 2
From: Intra-bundle contractions enable extensile properties of active actin networks
NMMII introduces a novel network phenotype on actin networks anchored to supported lipid bilayers by Ena/VASP. (a) A graphical representation of the employed VASP construct is shown to highlight the relevant domains. The N-terminal EVH1 domain is functionalized with a 6xHis-Tag to enable association of VASP with the Ni-NTA lipids. GAB and FAB mark the localization of the G-actin and F-actin binding domains of VASP. Tetra represents the tetramerization domain. (b) Illustration of the experimental setup. VASP (orange) added to the supported lipid bilayer (blue) in an initial step allows binding to the fraction of 2.5% Ni-NTA functionalized lipids (red). A polymerization solution containing actin (magenta) with or without NMMII (cyan) was added. Here, VASP was able to anchor and bundle elongating filaments. NMMII was introduced to study the effect of the motor within the bundled network. (c) Actin network polymerized on VASP-functionalized lipid bilayers imaged by TIRF microscopy. (d) Here, the network was polymerized in the presence of NMMII. Both images were taken 20 min after the start of the polymerization reaction. Scale bars = 5 µm. e Histogram of the pore sizes in both network types in an area of 100 µm2. In the presence of NMMII, the network displays larger pores and less smaller pores in the range of < 0.1 to 2 µm2 compared to the network phenotype without NMMII.
