title: Microtubule-dependent transport and dynamics of vimentin intermediate filaments.
abstract: We studied two aspects of vimentin intermediate filament dynamics-transport of filaments and subunit exchange. We observed transport of long filaments in the periphery of cells using live-cell structured illumination microscopy. We studied filament transport elsewhere in cells using a photoconvertible-vimentin probe and total internal reflection microscopy. We found that filaments were rapidly transported along linear tracks in both anterograde and retrograde directions. Filament transport was microtubule dependent but independent of microtubule polymerization and/or an interaction with the plus end-binding protein APC. We also studied subunit exchange in filaments by long-term imaging after photoconversion. We found that converted vimentin remained in small clusters along the length of filaments rather than redistributing uniformly throughout the network, even in cells that divided after photoconversion. These data show that vimentin filaments do not depolymerize into individual subunits; they recompose by severing and reannealing. Together these results show that vimentin filaments are very dynamic and that their transport is required for network maintenance.
authors.affiliation: Department of Cell and Molecular Biology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611.
authors.forename: Caroline
authors.initials: C
authors.lastname: Hookway
authors.affiliation: Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390.
authors.forename: Liya
authors.initials: L
authors.lastname: Ding
authors.affiliation: National High Magnetic Field Laboratory and Department of Biological Science, Florida State University, Tallahassee, FL 32310.
authors.forename: Michael W
authors.initials: MW
authors.lastname: Davidson
authors.affiliation: Department of Cell and Molecular Biology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611.
authors.forename: Joshua Z
authors.initials: JZ
authors.lastname: Rappoport
authors.affiliation: Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390.
authors.forename: Gaudenz
authors.initials: G
authors.lastname: Danuser
authors.affiliation: Department of Cell and Molecular Biology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611 vgelfand@northwestern.edu.
authors.forename: Vladimir I
authors.initials: VI
authors.lastname: Gelfand
mesh_terms: D057809:HEK293 Cells; D056572:Histone Deacetylase Inhibitors / Q000494:pharmacology; D006801:Humans; D007382:Intermediate Filaments / Q000378:metabolism*; D008870:Microtubules / Q000502:physiology*; D055503:Protein Multimerization; D021381:Protein Transport; D014746:Vimentin / Q000378:metabolism*
chemical_list: D056572:Histone Deacetylase Inhibitors; D014746:Vimentin