Our hosting provider will be performing UPS maintenance on Tuesday, Oct 25, 2016 between 8 AM and 5 PM PDT. SciCrunch searching services will be down during this time.

Preparing your results

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

Forgot Password

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

The ubiquitin ligase Triad1 inhibits myelopoiesis through UbcH7 and Ubc13 interacting domains.


Ubiquitination plays a major role in many aspects of hematopoiesis. Alterations in ubiquitination have been implicated in hematological cancer. The ubiquitin ligase Triad1 controls the proliferation of myeloid cells. Here, we show that two RING (really interesting new gene) domains in Triad1 differentially bind ubiquitin-conjugating enzymes, UbcH7 and Ubc13. UbcH7 and Ubc13 are known to catalyze the formation of different poly-ubiquitin chains. These chains mark proteins for proteasomal degradation or serve crucial non-proteolytic functions, respectively. In line with the dual Ubc interactions, we observed that Triad1 catalyzes the formation of both types of ubiquitin chains. The biological relevance of this finding was studied by testing Triad1 mutants in myeloid clonogenic assays. Full-length Triad1 and three mutants lacking conserved domains inhibited myeloid colony formation by over 50%. Strikingly, deletion of either RING finger completely abrogated the inhibitory effect of Triad1 in clonogenic growth. We conclude that Triad1 exhibits dual ubiquitin ligase activity and that both of its RING domains are crucial to inhibit myeloid cell proliferation. The differential interaction of the RINGs with Ubcs strongly suggests that the ubiquitination mediated through UbcH7 as well as Ubc13 plays a major role in myelopoiesis.

Pubmed ID: 19340006


  • Marteijn JA
  • van der Meer LT
  • Smit JJ
  • Noordermeer SM
  • Wissink W
  • Jansen P
  • Swarts HG
  • Hibbert RG
  • de Witte T
  • Sixma TK
  • Jansen JH
  • van der Reijden BA



Publication Data

August 12, 2009

Associated Grants


Mesh Terms

  • Animals
  • Binding Sites
  • COS Cells
  • Cell Line
  • Cercopithecus aethiops
  • Humans
  • Kidney
  • Mice
  • Myelopoiesis
  • NIH 3T3 Cells
  • Protein Binding
  • Protein Interaction Mapping
  • Protein Processing, Post-Translational
  • RING Finger Domains
  • Recombinant Fusion Proteins
  • Structure-Activity Relationship
  • Two-Hybrid System Techniques
  • U937 Cells
  • Ubiquitin-Conjugating Enzymes
  • Ubiquitin-Protein Ligases
  • Ubiquitination