RT Journal Article SR Electronic T1 A Combinatorial MAP Code Dictates Polarized Microtubule Transport JF bioRxiv FD Cold Spring Harbor Laboratory SP 731604 DO 10.1101/731604 A1 Monroy, Brigette Y. A1 Tan, Tracy C. A1 Oclaman, Janah May A1 Han, Jisoo S. A1 Simo, Sergi A1 Nowakowski, Dan W. A1 McKenney, Richard J. A1 Ori-McKenney, Kassandra M. YR 2019 UL http://biorxiv.org/content/early/2019/08/10/731604.abstract AB Many eukaryotic cells distribute their intracellular components through asymmetrically regulated active transport driven by molecular motors along microtubule tracks. While intrinsic and extrinsic regulation of motor activity exists, what governs the overall distribution of activated motor-cargo complexes within cells remains unclear. Here, we utilize in vitro reconstitution of purified motor proteins and non-enzymatic microtubule-associated proteins (MAPs) to demonstrate that these MAPs exhibit distinct influences on the motility of the three main classes of transport motors: kinesin-1, kinesin-3, and cytoplasmic dynein. Further, we dissect how combinations of MAPs affect motors, and reveal how transient interactions between MAPs and motors may promote these effects. From these data, we propose a general “MAP code” that has the capacity to strongly bias directed movement along microtubules and helps elucidate the intricate intracellular sorting observed in highly polarized cells such as neurons.