title: The N-terminal domain of the mammalian nucleoporin p62 interacts with other nucleoporins of the FXFG family during interphase.
abstract: Nuclear pore complexes (NPCs) provide the only sites for macromolecular transport between nucleus and cytoplasm. The nucleoporin p62, a component of higher eukaryotic NPCs, is located at the central gated channel and involved in nuclear trafficking of various cargos. p62 is organized into an N-terminal segment that contains FXFG repeats and binds the soluble transport factor NTF2, whereas the C-terminal portion associates with other nucleoporins and importin-beta1. We have now identified new components that interact specifically with the p62 N-terminal domain. Using the p62 N-terminal segment as bait, we affinity-purified nucleoporins Nup358, Nup214 and Nup153 from crude cell extracts. In ligand binding assays, the N-terminal p62 segment associated with Nup358 and p62, suggesting their direct binding to the p62 N-terminal portion. Furthermore, p62 was isolated in complex with Nup358, Nup214 and Nup153 from growing HeLa cells, indicating that the interactions Nup358/p62, Nup214/p62 and p62/Nup153 also occur in vivo. The formation of Nup358/p62 and p62/Nup153 complexes was restricted to interphase cells, whereas Nup214/p62 binding was detected in interphase as well as during mitosis. Our results support a model of complex interactions between FXFG containing nucleoporins, and we propose that some of these interactions may contribute to the movement of cargo across the NPC.
authors.affiliation: Department of Physiology, McGill University, 3655 Promenade Sir William Osler, Montreal, Canada PQ H3G 1Y6. ursula.stochaj@mcgill.ca
authors.forename: Ursula
authors.initials: U
authors.lastname: Stochaj
authors.forename: Piotr
authors.initials: P
authors.lastname: Bański
authors.forename: Mohamed
authors.initials: M
authors.lastname: Kodiha
authors.forename: Neola
authors.initials: N
authors.lastname: Matusiewicz
mesh_terms: D000117:Acetylglucosamine / Q000378:metabolism; D006367:HeLa Cells; D006801:Humans; D007399:Interphase; D008024:Ligands; D008562:Membrane Glycoproteins / Q000737:chemistry* / Q000378:metabolism*; D008938:Mitosis; D008954:Models, Biological; D028861:Nuclear Pore Complex Proteins / Q000145:classification* / Q000378:metabolism*; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D021381:Protein Transport; D011993:Recombinant Fusion Proteins / Q000378:metabolism
chemical_list: D008024:Ligands; D008562:Membrane Glycoproteins; D028861:Nuclear Pore Complex Proteins; D011993:Recombinant Fusion Proteins; C049312:nuclear pore protein p62; D000117:Acetylglucosamine