Figure 4: KlpA exhibits opposite directional preference inside and outside the microtubule overlaps.

(a) Schematic diagram of the microtubule-sliding assay showing that KlpA contains context-dependent opposite directional preference. Track and cargo microtubules were fluorescently labelled with Hilyte 647 and TMR, respectively, and polarity-marked with a dim minus end and a bright plus end. (b) Example kymographs of GFP-KlpA motility inside and outside the antiparallel microtubule overlap. Yellow arrow indicates GFP-KlpA accumulation at the microtubule plus end outside the antiparallel microtubule overlap. White arrow indicates minus end-directed movement of GFP-KlpA inside the antiparallel microtubule overlap. (c) Example kymographs of GFP-KlpA motility inside and outside the parallel microtubule overlap. Yellow arrow indicates GFP-KlpA accumulation at the microtubule plus end outside the parallel microtubule overlap. White arrow indicates GFP-KlpA accumulation at the microtubule minus end inside the parallel microtubule overlap. Scale bars, 30 s (vertical) and 5 μm (horizontal).