title: Switching of membrane organelles between cytoskeletal transport systems is determined by regulation of the microtubule-based transport.
abstract: Intracellular transport of membrane organelles occurs along microtubules (MTs) and actin filaments (AFs). Although transport along each type of the cytoskeletal tracks is well characterized, the switching between the two types of transport is poorly understood because it cannot be observed directly in living cells. To gain insight into the regulation of the switching of membrane organelles between the two major transport systems, we developed a novel approach that combines live cell imaging with computational modeling. Using this approach, we measured the parameters that determine how fast membrane organelles switch back and forth between MTs and AFs (the switching rate constants) and compared these parameters during different signaling states. We show that regulation involves a major change in a single parameter: the transferring rate from AFs onto MTs. This result suggests that MT transport is the defining factor whose regulation determines the choice of the cytoskeletal tracks during the transport of membrane organelles.
authors.affiliation: Center for Cell Analysis and Modeling, University of Connecticut Health Center, Farmington, CT 06032, USA.
authors.forename: Boris M
authors.initials: BM
authors.lastname: Slepchenko
authors.forename: Irina
authors.initials: I
authors.lastname: Semenova
authors.forename: Ilya
authors.initials: I
authors.lastname: Zaliapin
authors.forename: Vladimir
authors.initials: V
authors.lastname: Rodionov
mesh_terms: D008841:Actin Cytoskeleton / Q000187:drug effects / Q000378:metabolism / Q000502:physiology*; D000465:Algorithms; D000818:Animals; D001692:Biological Transport / Q000187:drug effects / Q000502:physiology; D002110:Caffeine / Q000494:pharmacology; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism; D019295:Computational Biology / Q000379:methods; D003599:Cytoskeleton / Q000187:drug effects / Q000378:metabolism / Q000502:physiology*; D004058:Diffusion; D004837:Epinephrine / Q000494:pharmacology; D005399:Fishes / Q000502:physiology; D008547:Melanophores / Q000187:drug effects / Q000378:metabolism; D008870:Microtubules / Q000187:drug effects / Q000502:physiology*; D008954:Models, Biological; D015388:Organelles / Q000187:drug effects / Q000502:physiology*; D010860:Pigments, Biological / Q000378:metabolism / Q000502:physiology; D013997:Time Factors
chemical_list: D010860:Pigments, Biological; D002110:Caffeine; D004837:Epinephrine