title: How molecular motors work in the crowded environment of living cells: coexistence and efficiency of normal and anomalous transport.
abstract: Recent experiments reveal both passive subdiffusion of various nanoparticles and anomalous active transport of such particles by molecular motors in the molecularly crowded environment of living biological cells. Passive and active microrheology reveals that the origin of this anomalous dynamics is due to the viscoelasticity of the intracellular fluid. How do molecular motors perform in such a highly viscous, dissipative environment? Can we explain the observed co-existence of the anomalous transport of relatively large particles of 100 to 500 nm in size by kinesin motors with the normal transport of smaller particles by the same molecular motors? What is the efficiency of molecular motors in the anomalous transport regime? Here we answer these seemingly conflicting questions and consistently explain experimental findings in a generalization of the well-known continuous diffusion model for molecular motors with two conformational states in which viscoelastic effects are included.
authors.affiliation: Institute for Physics and Astronomy, University of Potsdam, Potsdam-Golm, Germany.
authors.forename: Igor
authors.initials: I
authors.lastname: Goychuk
authors.affiliation: Institute for Physics and Astronomy, University of Potsdam, Potsdam-Golm, Germany; Institute of Applied Physics, National Academy of Sciences of Ukraine, Sumy, Ukraine.
authors.forename: Vasyl O
authors.initials: VO
authors.lastname: Kharchenko
authors.affiliation: Institute for Physics and Astronomy, University of Potsdam, Potsdam-Golm, Germany; Department of Physics, Tampere University of Technology, Tampere, Finland.
authors.forename: Ralf
authors.initials: R
authors.lastname: Metzler
mesh_terms: D001692:Biological Transport; D003600:Cytosol / Q000378:metabolism; D004058:Diffusion; D011992:Endosomes / Q000737:chemistry / Q000378:metabolism*; D057446:Hydrodynamics; D016547:Kinesins / Q000737:chemistry / Q000378:metabolism*; D008962:Models, Theoretical; D020409:Molecular Motor Proteins / Q000737:chemistry / Q000378:metabolism*; D012212:Rheology; D013816:Thermodynamics; D014783:Viscosity
chemical_list: D020409:Molecular Motor Proteins; D016547:Kinesins