title: Organization of perinuclear actin in live tobacco cells observed by PALM with optical sectioning.
abstract: Actin performs a wide variety of different tasks. This functional diversity may be accomplished either by the formation of different isotypes or by suitable protein decoration that regulates structure and dynamics of actin filaments. To probe for such a potential differential decoration, the actin-binding peptide Lifeact was fused to different photoactivatable fluorescent proteins. These fusions were stably expressed in Nicotiana tabacum L. cv. Bright Yellow 2 cells to follow dynamic reorganization of the actin cytoskeleton during the cell cycle. The Lifeact-monomeric variant of IrisFP fusion protein was observed to indiscriminately label both, central and cortical, actin filaments, whereas the tetrameric Lifeact-photoswitchable red fluorescent protein fusion construct selectively labeled only a specific perinuclear sub-population of actin. By using photoactivated localization microscopy, we acquired super-resolution images with optical sectioning to obtain a 3D model of perinuclear actin. This novel approach revealed that the perinuclear actin basket wraps around the nuclear envelope in a lamellar fashion and repartitions toward the leading edge of the migrating nucleus. Based on these data, we suggest that actin that forms the perinuclear basket differs from other actin assemblies by a reduced decoration with actin binding proteins, which is consistent with the differential decoration model.
authors: Botanical Institute, Molecular Cell Biology, Karlsruhe Institute of Technology (KIT), Kaiserstraße 2, D-76131 Karlsruhe, Germany.
authors: Steffen
authors: S
authors: Durst
authors: Institute of Applied Physics and Center for Functional Nanostructures (CFN), Karlsruhe Institute of Technology (KIT), Wolfgang-Gaede-Straße 1, D-76131 Karlsruhe, Germany.
authors: Per Niklas
authors: PN
authors: Hedde
authors: Botanical Institute, Molecular Cell Biology, Karlsruhe Institute of Technology (KIT), Kaiserstraße 2, D-76131 Karlsruhe, Germany.
authors: Linda
authors: L
authors: Brochhausen
authors: Botanical Institute, Molecular Cell Biology, Karlsruhe Institute of Technology (KIT), Kaiserstraße 2, D-76131 Karlsruhe, Germany.
authors: Peter
authors: P
authors: Nick
authors: Institute of Applied Physics and Center for Functional Nanostructures (CFN), Karlsruhe Institute of Technology (KIT), Wolfgang-Gaede-Straße 1, D-76131 Karlsruhe, Germany; Department of Physics, University of Illinois at Urbana-Champaign, Urbana, IL, USA.
authors: Gerd Ulrich
authors: GU
authors: Nienhaus
authors: Botanical Institute, Molecular Cell Biology, Karlsruhe Institute of Technology (KIT), Kaiserstraße 2, D-76131 Karlsruhe, Germany. Electronic address: Jan.Maisch@kit.edu.
authors: Jan
authors: J
authors: Maisch
mesh_terms: D008841:Actin Cytoskeleton / Q000378:metabolism*; D000199:Actins / Q000378:metabolism*; D002467:Cell Nucleus / Q000378:metabolism; D049408:Luminescent Agents; D008164:Luminescent Proteins; D008856:Microscopy, Fluorescence; D008938:Mitosis; D014026:Nicotiana; D000097573:Red Fluorescent Protein
chemical_list: D000199:Actins; D049408:Luminescent Agents; D008164:Luminescent Proteins; D000097573:Red Fluorescent Protein
keywords: ABP; AFs; Actin filaments; BY-2; Lifeact; Nicotiana tabacum L. cv. Bright Yellow 2 cell culture; Nuclear migration; PALM; Photoactivatable fluorescent proteins; Photoactivated localization microscopy; actin filaments; actin-binding protein; mIrisFP; monomeric variant of IrisFP; pa-FP; photoactivatable fluorescent protein; photoactivated localization microscopy; photoswitchable red fluorescent protein; psRFP