Subunit-subunit interactions in the human 26S proteasome

Proteomics. 2008 Feb;8(3):508-20. doi: 10.1002/pmic.200700588.


Ubiquitin-dependent proteolysis is mediated by the proteasome. To understand the structure and function of the human 26S proteasome, we cloned complete ORFs of 32 human proteasome subunits and conducted a yeast two-hybrid analysis of their interactions with each other. We observed that there are 114 interacting-pairs in the human 26S proteasome. About 10% (11/114) of these interacting-pairs was confirmed by the GST-pull down analysis. Among these observed interacting subunits, 58% (66/114) are novel and the rest 42% (48/114) has been reported previously in human or in other species. We observed new interactions between the 19S regulatory particle and the beta-rings of the 20S catalytic particle and therefore proposed a modified model of the 26S proteasome.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Humans
  • Models, Biological*
  • Open Reading Frames / genetics
  • Proteasome Endopeptidase Complex / genetics
  • Proteasome Endopeptidase Complex / metabolism*
  • Protein Binding / physiology*
  • Protein Subunits / genetics
  • Protein Subunits / metabolism*


  • Protein Subunits
  • Proteasome Endopeptidase Complex
  • ATP dependent 26S protease