Fig. 2: Direct interactions between stabilized microtubules and vimentin IFs.
From: Vimentin intermediate filaments stabilize dynamic microtubules by direct interactions
a Schematic of the setup for the OT experiments for interaction measurements in microfluidic flow channels. Four streptavidin-coated beads were captured by OTs (I.). We used one bead pair (beads 3 and 4) to attach a vimentin IF (II., red), and the other bead pair (beads 1 and 2) to attach a microtubule (III., green-cyan). We brought the IF and the microtubule into contact in a crossed configuration (IV.). Next, we moved the IF perpendicularly to the microtubule to study the IF-microtubule interactions while we took confocal fluorescence images (starting position marked in yellow in (a) and (b)). b Typical confocal fluorescence images of an IF-microtubule interaction which broke while the IF was moved vertically and c a strong IF-microtubule interaction for which the microtubule broke off the bead. d Typical experimental force increase F1y on bead 1 in the y-direction once a bond forms. Breaking of the force causes a force jump of ΔF1y. e Typical confocal fluorescence images of a breaking IF-microtubule interaction at a 45∘ angle between them while the IF was moved vertically. f Typical confocal fluorescence images of a breaking IF-microtubule interaction in perpendicular configuration while the IF was moved horizontally. Scale bars: 5 μm. Measurements were conducted on at least three different days. Source data are provided as a Source Data file.
