The N-terminal domain of the mammalian nucleoporin p62 interacts with other nucleoporins of the FXFG family during interphase.
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.
Stochaj
Ursula
U
Department of Physiology, McGill University, 3655 Promenade Sir William Osler, Montreal, Canada PQ H3G 1Y6. ursula.stochaj@mcgill.ca
Bański
Piotr
P
Kodiha
Mohamed
M
Matusiewicz
Neola
N
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
D008024:Ligands; D008562:Membrane Glycoproteins; D028861:Nuclear Pore Complex Proteins; D011993:Recombinant Fusion Proteins; C049312:nuclear pore protein p62; D000117:Acetylglucosamine