Our hosting provider will be undergoing maintenance on Tuesday, August 30 between 8am and 5pm PDT. SciCrunch services may be offline during the maintenance.

Preparing your results

Our searching services are busy right now. Your search will reload in five seconds.

X
Forgot Password

If you have forgotten your password you can enter your email here and get a temporary password sent to your email.

Modification of Ran GTPase-activating protein by the small ubiquitin-related modifier SUMO-1 requires Ubc9, an E2-type ubiquitin-conjugating enzyme homologue.

Covalent modification of the Ran GTPase-activating protein RanGAP1 with the ubiquitin-related protein SUMO-1 promotes its association with Nup358, a component of the cytoplasmic fibrils emanating from the nuclear pore complex (1,2). In Xenopus egg extracts, Nup358 can be found in a complex with Ubc9 (3), a structural homologue of the E2-type ubiquitin-conjugating enzymes (UBCs). Here we show that a subset of the human homologue of Ubc9 (HsUbc9) colocalizes with RanGAP1 at the nuclear envelope. HsUbc9 forms thiolester conjugates with recombinant SUMO-1, but not with recombinant ubiquitin, indicating that it is functionally distinct from E2-type UBCs. Finally, HsUbc9 is required for the modification of RanGAP1 by SUMO-1. These results suggest that HsUbc9 is a component of a novel enzymatic cascade that modifies RanGAP1, and possibly other substrates, with SUMO-1.

Pubmed ID: 9497385

Authors

  • Lee GW
  • Melchior F
  • Matunis MJ
  • Mahajan R
  • Tian Q
  • Anderson P

Journal

The Journal of biological chemistry

Publication Data

March 13, 1998

Associated Grants

None

Mesh Terms

  • Adenosine Triphosphate
  • Animals
  • Binding Sites
  • Carrier Proteins
  • GTPase-Activating Proteins
  • Humans
  • Ligases
  • Mutation
  • Nuclear Envelope
  • Precipitin Tests
  • Protein Binding
  • Rats
  • SUMO-1 Protein
  • Substrate Specificity
  • Sulfhydryl Compounds
  • Ubiquitin-Conjugating Enzymes
  • Ubiquitins
  • Xenopus Proteins