Members of the superfamilies of molecular motors, kinesins, dyneins and myosins, are the machines that drive many forms of crucial intracellular transport. The three motor families coordinate their actions with dynamic (and highly regulated) cytoskeletal filaments to control cell growth, define cell shape, deliver and polarize intracellular cargoes, traffic endosomal membranes, and participate in signaling cascades. Many critical cellular processes involve the regulated switching of cargo organelles from one type of cytoskeletal filament to another, but the requisite coordination and competition among multiple motors are not understood. This integrated program project will study the interactions, structure, regulation, and biophysical mechanisms of the molecular motors in growing and functioning cells. The cytoskeletal tracks for intracellular motility, actin and microtubules, the actin-based motors, myosin I, myosin V, and the microtubule-based motors, cytoplasmic dynein and kinesin, will be studied intensively using a battery of state-of-the-art approaches that open exciting research opportunities. Single-molecule fluorescence polarization, nanometer-resolved fluorophore localization, infrared optical traps, rapid biochemical reaction kinetics, genetic manipulations, and novel forms of electron microscopy, correlated with hyper-resolution light microscopy in the same regions, will be applied in collaborative studies to understand the mechanisms of individual molecular motors and their mutual interactions. These approaches yield high temporal and spatial resolution that enables us to dissect mechanisms in assays of increasing molecular complexity that model aspects of the intracellular environment. Particular biological systems, selected for facility of study as well as relevance to broader mechanisms of intracellular motility are endocytosis and vesicle trafficking in neurons and insulin-stimulated fusion of glucose transporter vesicles with the surface membrane in adipocytes. There are close synergies and practical links between all of the sections and cores in this program. We anticipate that the proposed work will take us significantly further toward our goal of understanding motility in the normal and pathological function of cells.

Public Health Relevance

Fundamental research into mechanisms of intracellular motility relate to diseases and developmental deficits including sub-types of Charcot-Marie-Tooth disease, lissencephaly, motor neuron degeneration, Alzheimer's, Huntington's, Amyotrophic Lateral Sclerosis, Kartagener's, and polycystic kidney diseases. Thus the cytoskeleton and molecular motors are increasingly relevant as diagnostic and therapeutic targets.

National Institute of Health (NIH)
National Institute of General Medical Sciences (NIGMS)
Research Program Projects (P01)
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Special Emphasis Panel (ZRG1-CB-P (40))
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Deatherage, James F
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University of Pennsylvania
Schools of Medicine
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McIntosh, Betsy B; Pyrpassopoulos, Serapion; Holzbaur, Erika L F et al. (2018) Opposing Kinesin and Myosin-I Motors Drive Membrane Deformation and Tubulation along Engineered Cytoskeletal Networks. Curr Biol 28:236-248.e5
Moore, Andrew S; Holzbaur, Erika L F (2018) Mitochondrial-cytoskeletal interactions: dynamic associations that facilitate network function and remodeling. Curr Opin Physiol 3:94-100
Woody, Michael S; Capitanio, Marco; Ostap, E Michael et al. (2018) Electro-optic deflectors deliver advantages over acousto-optical deflectors in a high resolution, ultra-fast force-clamp optical trap. Opt Express 26:11181-11193
Lee, In-Gyun; Olenick, Mara A; Boczkowska, Malgorzata et al. (2018) A conserved interaction of the dynein light intermediate chain with dynein-dynactin effectors necessary for processivity. Nat Commun 9:986
Lippert, Lisa G; Dadosh, Tali; Hadden, Jodi A et al. (2017) Angular measurements of the dynein ring reveal a stepping mechanism dependent on a flexible stalk. Proc Natl Acad Sci U S A 114:E4564-E4573
Pyrpassopoulos, Serapion; Shuman, Henry; Ostap, E Michael (2017) Adhesion force and attachment lifetime of the KIF16B-PX domain interaction with lipid membranes. Mol Biol Cell 28:3315-3322
Lewis, John H; Jamiolkowski, Ryan M; Woody, Michael S et al. (2017) Deconvolution of Camera Instrument Response Functions. Biophys J 112:1214-1220
Greenberg, Michael J; Shuman, Henry; Ostap, E Michael (2017) Measuring the Kinetic and Mechanical Properties of Non-processive Myosins Using Optical Tweezers. Methods Mol Biol 1486:483-509
Hendricks, Adam G; Goldman, Yale E (2017) Measuring Molecular Forces Using Calibrated Optical Tweezers in Living Cells. Methods Mol Biol 1486:537-552
Kast, David J; Dominguez, Roberto (2017) The Cytoskeleton-Autophagy Connection. Curr Biol 27:R318-R326

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