Tug-of-War in Motor Protein Ensembles Revealed with a Programmable DNA Origami Scaffold

Push Me, Release, Pull You In eukaryotic cells, nearly all long-distance transport of cargos is carried out by the microtubule-based motors kinesin and dynein. These opposite-polarity motors move cargos bidirectionally so that they reach their cellular destinations with spatial and temporal specificity. To understand transport by motor ensembles, Derr et al. (p. 662 , published online 11 October; see the Persective by Diehl ) used a DNA scaffold for building an artificial cargo that could be programmed to bind different numbers and types of molecular motors with defined geometry. A cargo with multiple copies of the same motor was transported with minimal interference, suggesting that similar-polarity motors can coordinate without the need for additional cellular factors. However, ensembles of opposite-polarity motors frequently engaged in a sort of “tug of war,” which could only be resolved by releasing one motor from the microtubule track. Thus, within the cell, it is likely that regulation is required for bidirectional transport.