title: Mathematical model with spatially uniform regulation explains long-range bidirectional transport of early endosomes in fungal hyphae.
abstract: In many cellular contexts, cargo is transported bidirectionally along microtubule bundles by dynein and kinesin-family motors. Upstream factors influence how individual cargoes are locally regulated, as well as how long-range transport is regulated at the whole-cell scale. Although the details of local, single-cargo bidirectional switching have been extensively studied, it remains to be elucidated how this results in cell-scale spatial organization. Here we develop a mathematical model of early endosome transport in Ustilago maydis. We demonstrate that spatiotemporally uniform regulation, with constant transition rates, results in cargo dynamics that is consistent with experimental data, including data from motor mutants. We find that microtubule arrays can be symmetric in plus-end distribution but asymmetric in binding-site distribution in a manner that affects cargo dynamics and that cargo can travel past microtubule ends in microtubule bundles. Our model makes several testable predictions, including secondary features of dynein and cargo distributions.
authors.affiliation: Department of Mathematics, University of British Columbia, Vancouver, BC V6T1Z2, Canada.
authors.forename: Jia
authors.initials: J
authors.lastname: Gou
authors.affiliation: Department of Mathematics, University of British Columbia, Vancouver, BC V6T1Z2, Canada.
authors.forename: Leah
authors.initials: L
authors.lastname: Edelstein-Keshet
authors.affiliation: Department of Mathematics, Department of Physics and Astronomy, and Center for Complex Biological Systems, University of California, Irvine, Irvine, CA 92617 jun.allard@uci.edu.
authors.forename: Jun
authors.initials: J
authors.lastname: Allard
mesh_terms: D001692:Biological Transport; D004398:Dyneins / Q000378:metabolism*; D011992:Endosomes / Q000378:metabolism*; D005656:Fungal Proteins / Q000378:metabolism*; D025301:Hyphae / Q000378:metabolism*; D016547:Kinesins / Q000378:metabolism*; D008870:Microtubules / Q000378:metabolism*; D008954:Models, Biological; D014588:Ustilago / Q000378:metabolism
chemical_list: D005656:Fungal Proteins; D004398:Dyneins; D016547:Kinesins