Nucleoporin domain topology is linked to the transport status of the nuclear pore complex.
Nuclear pore complexes (NPCs) facilitate macromolecular exchange between the nucleus and cytoplasm of eukaryotic cells. The vertebrate NPC is composed of approximately 30 different proteins (nucleoporins), of which around one third contain phenylalanine-glycine (FG)-repeat domains that are thought to mediate the main interaction between the NPC and soluble transport receptors. We have recently shown that the FG-repeat domain of Nup153 is flexible within the NPC, although this nucleoporin is anchored to the nuclear side of the NPC. By using domain-specific antibodies, we have now mapped the domain topology of Nup214 in Xenopus oocytes and in human somatic cells by immuno-EM. We have found that whereas Nup214 is anchored to the cytoplasmic side of the NPC via its N-terminal and central domain, its FG-repeat domain appears flexible, residing on both sides of the NPC. Moreover, the spatial distribution of the FG-repeat domains of both Nup153 and Nup214 shifts in a transport-dependent manner, suggesting that the location of FG-repeat domains within the NPC correlates with cargo/receptor interactions and that they concomitantly move with cargo through the central pore of the NPC.
Paulillo
Sara M
SM
M.E. Müller Institute for Structural Biology, Biozentrum, University of Basel, Klingelbergstr. 70, 4056 Basel, Switzerland.
Phillips
Erica M
EM
Köser
Joachim
J
Sauder
Ursula
U
Ullman
Katharine S
KS
Powers
Maureen A
MA
Fahrenkrog
Birthe
B
D000818:Animals; D000918:Antibody Specificity; D001693:Biological Transport, Active; D005260:Female; D018922:HL-60 Cells; D006367:HeLa Cells; D006801:Humans; D066298:In Vitro Techniques; D016253:Microscopy, Immunoelectron; D008958:Models, Molecular; D022022:Nuclear Pore / Q000378:metabolism* / Q000648:ultrastructure; D028861:Nuclear Pore Complex Proteins / Q000737:chemistry* / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D009865:Oocytes / Q000378:metabolism; D017434:Protein Structure, Tertiary; D011817:Rabbits; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D020449:Repetitive Sequences, Amino Acid; D014982:Xenopus laevis
C085914:NUP214 protein, human; D028861:Nuclear Pore Complex Proteins; D011994:Recombinant Proteins