title: A saturated FG-repeat hydrogel can reproduce the permeability properties of nuclear pore complexes.
abstract: The permeability barrier of nuclear pore complexes (NPCs) controls the exchange between nucleus and cytoplasm. It suppresses the flux of inert macromolecules > or = 30 kDa but allows rapid passage of even very large cargoes, provided these are bound to appropriate nuclear transport receptors. We show here that a saturated hydrogel formed by a single nucleoporin FG-repeat domain is sufficient to reproduce the permeability properties of NPCs. Importin beta and related nuclear transport receptors entered such hydrogel >1000x faster than a similarly sized inert macromolecule. The FG-hydrogel even reproduced import signal-dependent and importin-mediated cargo influx, allowing importin beta to accelerate the gel entry of a large cognate cargo more than 20,000-fold. Intragel diffusion of the importin beta-cargo complex occurred rapidly enough to traverse an NPC within approximately 12 ms. We extend the "selective phase model" to explain these effects.
authors: Max-Planck-Institut für Biophysikalische Chemie, Am Fassberg 11, D-37077 Göttingen, Germany.
authors: Steffen
authors: S
authors: Frey
authors: Dirk
authors: D
authors: Görlich
mesh_terms: D002135:Calcium-Binding Proteins / Q000378:metabolism; D005998:Glycine / Q000737:chemistry; D006801:Humans; D020100:Hydrogels / Q000737:chemistry*; D008954:Models, Biological; D028861:Nuclear Pore Complex Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D009687:Nuclear Proteins / Q000378:metabolism; D029543:Nucleocytoplasmic Transport Proteins / Q000378:metabolism; D010539:Permeability; D010649:Phenylalanine / Q000737:chemistry; D011257:Pregnancy Proteins / Q000378:metabolism; D017434:Protein Structure, Tertiary; D020449:Repetitive Sequences, Amino Acid; D015203:Reproducibility of Results; D029701:Saccharomyces cerevisiae Proteins / Q000378:metabolism
chemical_list: D002135:Calcium-Binding Proteins; D020100:Hydrogels; C062748:NSP1 protein, S cerevisiae; C499531:NTF2 protein, S cerevisiae; C038965:NUTF2 protein, human; D028861:Nuclear Pore Complex Proteins; D009687:Nuclear Proteins; D029543:Nucleocytoplasmic Transport Proteins; D011257:Pregnancy Proteins; D029701:Saccharomyces cerevisiae Proteins; D010649:Phenylalanine; D005998:Glycine