title: FG-rich repeats of nuclear pore proteins form a three-dimensional meshwork with hydrogel-like properties.
abstract: Nuclear pore complexes permit rapid passage of cargoes bound to nuclear transport receptors, but otherwise suppress nucleocytoplasmic fluxes of inert macromolecules >/=30 kilodaltons. To explain this selectivity, a sieve structure of the permeability barrier has been proposed that is created through reversible cross-linking between Phe and Gly (FG)-rich nucleoporin repeats. According to this model, nuclear transport receptors overcome the size limit of the sieve and catalyze their own nuclear pore-passage by a competitive disruption of adjacent inter-repeat contacts, which transiently opens adjoining meshes. Here, we found that phenylalanine-mediated inter-repeat interactions indeed cross-link FG-repeat domains into elastic and reversible hydrogels. Furthermore, we obtained evidence that such hydrogel formation is required for viability in yeast.
authors.affiliation: Zentrum für Molekulare Biologie der Universität Heidelberg (ZMBH), INF 282, D-69120 Heidelberg, Germany.
authors.forename: Steffen
authors.initials: S
authors.lastname: Frey
authors.forename: Ralf P
authors.initials: RP
authors.lastname: Richter
authors.forename: Dirk
authors.initials: D
authors.lastname: Görlich
mesh_terms: D021581:Active Transport, Cell Nucleus; D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D001704:Biopolymers; D002135:Calcium-Binding Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D036681:Fluorescence Recovery After Photobleaching; D006367:HeLa Cells; D006801:Humans; D020100:Hydrogels; D006863:Hydrogen-Ion Concentration; D057927:Hydrophobic and Hydrophilic Interactions; D008954:Models, Biological; D008969:Molecular Sequence Data; D009154:Mutation; D022022:Nuclear Pore / Q000737:chemistry / Q000378:metabolism*; D028861:Nuclear Pore Complex Proteins / Q000737:chemistry* / Q000378:metabolism*; D009687:Nuclear Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D029543:Nucleocytoplasmic Transport Proteins / Q000378:metabolism*; D010539:Permeability; D010649:Phenylalanine / Q000737:chemistry; D017434:Protein Structure, Tertiary; D020449:Repetitive Sequences, Amino Acid; D012441:Saccharomyces cerevisiae / Q000737:chemistry / Q000502:physiology; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*
chemical_list: D001704:Biopolymers; D002135:Calcium-Binding Proteins; D020100:Hydrogels; C062748:NSP1 protein, S cerevisiae; D028861:Nuclear Pore Complex Proteins; D009687:Nuclear Proteins; D029543:Nucleocytoplasmic Transport Proteins; D029701:Saccharomyces cerevisiae Proteins; D010649:Phenylalanine