Nuclear transport of single molecules: dwell times at the nuclear pore complex
Siebrasse, Jan Peter
UMass Chan AffiliationsRNA Therapeutics Institute
Department of Biochemistry and Molecular Pharmacology
Document TypeJournal Article
KeywordsActive Transport, Cell Nucleus
Green Fluorescent Proteins
Heterogeneous-Nuclear Ribonucleoprotein Group A-B
Nuclear Localization Signals
Nuclear Pore Complex Proteins
Nucleocytoplasmic Transport Proteins
ran GTP-Binding Protein
Biochemistry, Biophysics, and Structural Biology
MetadataShow full item record
AbstractThe 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.
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
Permanent Link to this Itemhttp://hdl.handle.net/20.500.14038/26039
At the time of publication, David Grünwald was not yet affiliated with the University of Massachusetts Medical School.
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