The nucleoporin RanBP2 has SUMO1 E3 ligase activity

Cell. 2002 Jan 11;108(1):109-20. doi: 10.1016/s0092-8674(01)00633-x.

Abstract

Posttranslational modification with SUMO1 regulates protein/protein interactions, localization, and stability. SUMOylation requires the E1 enzyme Aos1/Uba2 and the E2 enzyme Ubc9. A family of E3-like factors, PIAS proteins, was discovered recently. Here we show that the nucleoporin RanBP2/Nup358 also has SUMO1 E3-like activity. RanBP2 directly interacts with the E2 enzyme Ubc9 and strongly enhances SUMO1-transfer from Ubc9 to the SUMO1 target Sp100. The E3-like activity is contained within a 33 kDa domain of RanBP2 that lacks RING finger motifs and does not resemble PIAS family proteins. Our findings place SUMOylation at the cytoplasmic filaments of the NPC and suggest that, at least for some substrates, modification and nuclear import are linked events.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antibodies
  • Antigens, Nuclear*
  • Autoantigens / metabolism
  • Bacterial Proteins / metabolism
  • Cell Nucleus / metabolism
  • Cytoplasm / enzymology
  • GTPase-Activating Proteins / immunology
  • GTPase-Activating Proteins / metabolism
  • Goats
  • Ligases / metabolism*
  • Luminescent Proteins / metabolism
  • Molecular Chaperones
  • Nuclear Pore Complex Proteins / immunology
  • Nuclear Pore Complex Proteins / metabolism*
  • Nuclear Proteins / metabolism
  • Protein Processing, Post-Translational / physiology
  • Rabbits
  • SUMO-1 Protein / metabolism*
  • Ubiquitin-Conjugating Enzymes*
  • Ubiquitin-Protein Ligases
  • Zinc Fingers / physiology

Substances

  • Antibodies
  • Antigens, Nuclear
  • Autoantigens
  • Bacterial Proteins
  • GTPase-Activating Proteins
  • Luminescent Proteins
  • Molecular Chaperones
  • Nuclear Pore Complex Proteins
  • Nuclear Proteins
  • SUMO-1 Protein
  • ran-binding protein 2
  • yellow fluorescent protein, Bacteria
  • Sp100 protein, human
  • Ubiquitin-Conjugating Enzymes
  • Ubiquitin-Protein Ligases
  • Ligases
  • ubiquitin-conjugating enzyme UBC9