Ran alters nuclear pore complex conformation

J Mol Biol. 2000 Jul 14;300(3):519-29. doi: 10.1006/jmbi.2000.3891.

Abstract

Transport across the nuclear membranes occurs through the nuclear pore complex (NPC), and is mediated by soluble transport factors including Ran, a small GTPase that is generally GDP-bound during import and GTP-bound for export. The dynamic nature of the NPC structure suggests a possible active role for it in driving translocation. Here we show that RanGTP but not RanGDP causes alterations of NPC structure when injected into the cytoplasm of Xenopus oocytes, including compaction of the NPC and extension of the cytoplasmic filaments. RanGTP caused accumulation of nucleoplasmin-gold along the length of extended cytoplasmic filaments, whereas RanGDP caused accumulation around the cytoplasmic rim of the NPC. This suggests a possible role for Ran in altering the conformation of the cytoplasmic filaments during transport.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Substitution / genetics
  • Animals
  • Binding Sites
  • Biological Transport
  • Cytoplasm / chemistry
  • Cytoplasm / metabolism
  • Cytoplasm / ultrastructure
  • Gold
  • Guanosine Diphosphate / metabolism
  • Guanosine Triphosphate / metabolism
  • Microscopy, Electron
  • Models, Molecular
  • Nuclear Envelope / chemistry
  • Nuclear Envelope / metabolism*
  • Nuclear Envelope / ultrastructure*
  • Nuclear Proteins / metabolism
  • Nucleoplasmins
  • Oocytes
  • Osmolar Concentration
  • Phosphoproteins / metabolism
  • Protein Binding
  • Protein Structure, Quaternary
  • Recombinant Fusion Proteins / genetics
  • Recombinant Fusion Proteins / metabolism
  • Xenopus laevis
  • ran GTP-Binding Protein / genetics
  • ran GTP-Binding Protein / metabolism*

Substances

  • Nuclear Proteins
  • Nucleoplasmins
  • Phosphoproteins
  • Recombinant Fusion Proteins
  • Guanosine Diphosphate
  • Gold
  • Guanosine Triphosphate
  • ran GTP-Binding Protein