Figure 2: KlpA moves processively towards the plus end on single microtubules.
From: The mitotic kinesin-14 KlpA contains a context-dependent directionality switch
(a) Schematic diagram of the in vitro KlpA motility assay. Microtubules were fluorescently labelled with Hilyte 647, and polarity-marked with a dim minus end and a bright plus end. (b) Example kymograph showing GFP-KlpA molecules (green), at relatively high protein input levels, form a plus end-directed flux and accumulate there on a surface-immobilized polarity-marked microtubule (red). Yellow arrow indicates GFP-KlpA accumulation at the microtubule plus end, and white arrow indicates minus end-directed movement of a GFP-KlpA aggregate. (c) Example kymographs showing that individual GFP-KlpA molecules (green) move towards the plus end on single polarity-marked microtubules (red) in a processive manner. (d) Velocity histogram of individual GFP-KlpA molecules on single microtubules. Red line indicates a Gaussian fit to the velocity histogram. (e) Run-length histogram of individual GFP-KlpA molecules on single microtubules. Red line indicates a single exponential fit to the run-length histogram. Scale bars, 1 min (vertical) and 5 μm (horizontal).
