title: High-resolution three-dimensional mapping of mRNA export through the nuclear pore.
abstract: The flow of genetic information is regulated by selective nucleocytoplasmic transport of messenger RNA:protein complexes (mRNPs) through the nuclear pore complexes (NPCs) of eukaryotic cells. However, the three-dimensional (3D) pathway taken by mRNPs as they transit through the NPC, and the kinetics and selectivity of transport, remain obscure. Here we employ single-molecule fluorescence microscopy with an unprecedented spatiotemporal accuracy of 8 nm and 2 ms to provide new insights into the mechanism of nuclear mRNP export in live human cells. We find that mRNPs exiting the nucleus are decelerated and selected at the centre of the NPC, and adopt a fast-slow-fast diffusion pattern during their brief, ~12 ms, interaction with the NPC. A 3D reconstruction of the export route indicates that mRNPs primarily interact with the periphery on the nucleoplasmic side and in the centre of the NPC, without entering the central axial conduit utilized for passive diffusion of small molecules, and eventually dissociate on the cytoplasmic side.
authors.affiliation: Department of Biology, Temple University, Philadelphia, Pennsylvania 19122, USA.
authors.forename: Jiong
authors.initials: J
authors.lastname: Ma
authors.forename: Zhen
authors.initials: Z
authors.lastname: Liu
authors.forename: Nicole
authors.initials: N
authors.lastname: Michelotti
authors.forename: Sethuramasundaram
authors.initials: S
authors.lastname: Pitchiaya
authors.forename: Ram
authors.initials: R
authors.lastname: Veerapaneni
authors.forename: John R
authors.initials: JR
authors.lastname: Androsavich
authors.forename: Nils G
authors.initials: NG
authors.lastname: Walter
authors.forename: Weidong
authors.initials: W
authors.lastname: Yang
mesh_terms: D021581:Active Transport, Cell Nucleus; D002467:Cell Nucleus / Q000378:metabolism; D004058:Diffusion; D006367:HeLa Cells; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods*; D008853:Microscopy; D022022:Nuclear Pore / Q000378:metabolism*; D034443:RNA Transport; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D012261:Ribonucleoproteins / Q000378:metabolism
chemical_list: D012333:RNA, Messenger; D012261:Ribonucleoproteins; C026452:messenger ribonucleoprotein