Nup98 FG Domains From Diverse Species Spontaneously Phase-Separate Into Particles With Nuclear Pore-Like Permselectivity

Elife. 2015 Jan 6;4:e04251. doi: 10.7554/eLife.04251.

Abstract

Nuclear pore complexes (NPCs) conduct massive transport mediated by shuttling nuclear transport receptors (NTRs), while keeping nuclear and cytoplasmic contents separated. The NPC barrier in Xenopus relies primarily on the intrinsically disordered FG domain of Nup98. We now observed that Nup98 FG domains of mammals, lancelets, insects, nematodes, fungi, plants, amoebas, ciliates, and excavates spontaneously and rapidly phase-separate from dilute (submicromolar) aqueous solutions into characteristic 'FG particles'. This required neither sophisticated experimental conditions nor auxiliary eukaryotic factors. Instead, it occurred already during FG domain expression in bacteria. All Nup98 FG phases rejected inert macromolecules and yet allowed far larger NTR cargo complexes to rapidly enter. They even recapitulated the observations that large cargo-domains counteract NPC passage of NTR⋅cargo complexes, while cargo shielding and increased NTR⋅cargo surface-ratios override this inhibition. Their exquisite NPC-typical sorting selectivity and strong intrinsic assembly propensity suggest that Nup98 FG phases can form in authentic NPCs and indeed account for the permeability properties of the pore.

Keywords: C. elegans; D. melanogaster; Nup100; Nup116; S. cerevisiae; Tetrahymena; arabidopsis; biochemistry; cell biology; human; importin; nucleocytoplasmic transport; nucleoporin.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Cell Survival / drug effects
  • Conserved Sequence
  • Evolution, Molecular
  • Glycols / pharmacology
  • Green Fluorescent Proteins / metabolism
  • Humans
  • Hydrophobic and Hydrophilic Interactions / drug effects
  • Kinetics
  • Molecular Sequence Data
  • Nuclear Pore / metabolism*
  • Nuclear Pore Complex Proteins / chemistry*
  • Nuclear Pore Complex Proteins / metabolism*
  • Permeability
  • Phylogeny
  • Protein Structure, Secondary
  • Protein Structure, Tertiary
  • Protein Transport / drug effects
  • Repetitive Sequences, Amino Acid
  • Saccharomyces cerevisiae Proteins / metabolism
  • Species Specificity
  • beta Karyopherins / metabolism

Substances

  • Glycols
  • NUP100 protein, S cerevisiae
  • Nuclear Pore Complex Proteins
  • Saccharomyces cerevisiae Proteins
  • beta Karyopherins
  • Green Fluorescent Proteins

Grant support

The funder had no role in study design, data collection and interpretation, or the decision to submit the work for publication.