Nuclear transport of single molecules: dwell times at the nuclear pore complex
UMass Chan Affiliations
RNA Therapeutics InstituteDepartment of Biochemistry and Molecular Pharmacology
Document Type
Journal ArticlePublication Date
2005-01-17Keywords
Active Transport, Cell NucleusAntibodies
Binding Sites
Green Fluorescent Proteins
HeLa Cells
Heterogeneous-Nuclear Ribonucleoprotein Group A-B
Humans
Immunohistochemistry
Kinetics
Membrane GlycoproteinsMicroscopy, FluorescenceModels, MolecularMolecular ChaperonesNuclear EnvelopeNuclear Localization SignalsNuclear PoreNuclear Pore Complex ProteinsNucleocytoplasmic Transport ProteinsPregnancy ProteinsProtein BindingRecombinant ProteinsRibonucleoproteinsThymus HormonesTransfectionbeta Karyopherinsran GTP-Binding ProteinBiochemistryBiochemistry, Biophysics, and Structural BiologyCell BiologyMolecular Biology
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Show full item recordAbstract
The mechanism by which macromolecules are selectively translocated through the nuclear pore complex (NPC) is still essentially unresolved. Single molecule methods can provide unique information on topographic properties and kinetic processes of asynchronous supramolecular assemblies with excellent spatial and time resolution. Here, single-molecule far-field fluorescence microscopy was applied to the NPC of permeabilized cells. The nucleoporin Nup358 could be localized at a distance of 70 nm from POM121-GFP along the NPC axis. Binding sites of NTF2, the transport receptor of RanGDP, were observed in cytoplasmic filaments and central framework, but not nucleoplasmic filaments of the NPC. The dwell times of NTF2 and transportin 1 at their NPC binding sites were 5.8 +/- 0.2 and 7.1 +/- 0.2 ms, respectively. Notably, the dwell times of these receptors were reduced upon binding to a specific transport substrate, suggesting that translocation is accelerated for loaded receptor molecules. Together with the known transport rates, our data suggest that nucleocytoplasmic transport occurs via multiple parallel pathways within single NPCs.Source
Kubitscheck U, Grünwald D, Hoekstra A, Rohleder D, Kues T, Siebrasse JP, Peters R. Nuclear transport of single molecules: dwell times at the nuclear pore complex. J Cell Biol. 2005 Jan 17;168(2):233-43. Link to article on publisher's site
DOI
10.1083/jcb.200411005Permanent Link to this Item
http://hdl.handle.net/20.500.14038/26039PubMed ID
15657394Notes
At the time of publication, David Grünwald was not yet affiliated with the University of Massachusetts Medical School.
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Publisher PDF posted as allowed by the publisher's author rights policy at http://www.rupress.org/site/subscriptions/terms.xhtml.
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