title: Cryo-electron tomography provides novel insights into nuclear pore architecture: implications for nucleocytoplasmic transport.
abstract: To go beyond the current structural consensus model of the nuclear pore complex (NPC), we performed cryo-electron tomography of fully native NPCs from Xenopus oocyte nuclear envelopes (NEs). The cytoplasmic face of the NPC revealed distinct anchoring sites for the cytoplasmic filaments, whereas the nuclear face was topped with a massive distal ring positioned above the central pore with indications of the anchoring sites for the nuclear basket filaments and putative intranuclear filaments. The rather "spongy" central framework of the NPC was perforated by an elaborate channel and void system, and at the membrane pore interface it exhibited distinct "handles" protruding into the lumen of the NE. The most variable structural moiety of the NPC was a rather tenuous central plug partially obstructing the central pore. Its mobile character was documented by time-lapse atomic force microscopy. Taken together, the new insights we gained into NPC structure support the notion that the NPC acts as a constrained diffusion pore for molecules and particles without retention signal and as an affinity gate for signal-bearing cargoes.
authors.affiliation: Biozentrum, ME Müller Institute for Structural Biology, University of Basel CH-4056, Basel, Switzerland.
authors.forename: Daniel
authors.initials: D
authors.lastname: Stoffler
authors.forename: Bernhard
authors.initials: B
authors.lastname: Feja
authors.forename: Birthe
authors.initials: B
authors.lastname: Fahrenkrog
authors.forename: Jochen
authors.initials: J
authors.lastname: Walz
authors.forename: Dieter
authors.initials: D
authors.lastname: Typke
authors.forename: Ueli
authors.initials: U
authors.lastname: Aebi
mesh_terms: D021581:Active Transport, Cell Nucleus; D000818:Animals; D002467:Cell Nucleus / Q000737:chemistry / Q000648:ultrastructure*; D020285:Cryoelectron Microscopy; D003593:Cytoplasm / Q000648:ultrastructure; D005260:Female; D007053:Ice; D021621:Imaging, Three-Dimensional; D018625:Microscopy, Atomic Force; D008954:Models, Biological; D022022:Nuclear Pore / Q000648:ultrastructure*; D009865:Oocytes / Q000648:ultrastructure; D014054:Tomography / Q000379:methods*; D014982:Xenopus laevis
chemical_list: D007053:Ice