COP9 signalosome revisited: a novel mediator of protein degradation

Trends Cell Biol. 2001 Oct;11(10):420-6. doi: 10.1016/s0962-8924(01)02091-8.


The COP9 signalosome is an evolutionarily conserved multiprotein complex that was first identified as an essential complex that represses light-regulated development in Arabidopsis. The COP9 signalosome has similarity to the lid of the 19S regulatory particle of the 26S proteasome and has recently been shown to interact with SCF-type E3 ubiquitin ligases. Although its precise role in the process of protein degradation remains to be established, the COP9 signalosome is a positive regulator of E3 ubiquitin ligases that functions at least in part by mediating the deconjugation of the NEDD8/RUB-modification from the cullin subunit of SCF-type E3 complexes. Here, we discuss these recent findings, which add an additional component to the biology of substrate-specific protein degradation.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.
  • Review

MeSH terms

  • Animals
  • Arabidopsis
  • Arabidopsis Proteins
  • COP9 Signalosome Complex
  • Drosophila / metabolism
  • Drosophila Proteins
  • Humans
  • Ligases / metabolism
  • Models, Biological
  • Multiprotein Complexes
  • NEDD8 Protein
  • Peptide Hydrolases / chemistry
  • Peptide Hydrolases / metabolism
  • Proteasome Endopeptidase Complex*
  • Protein Structure, Tertiary
  • Protein Subunits
  • Proteins / chemistry
  • Proteins / genetics
  • Proteins / metabolism*
  • Proteins / physiology*
  • Schizosaccharomyces
  • Signal Transduction
  • Ubiquitin-Protein Ligases
  • Ubiquitins / metabolism*


  • Arabidopsis Proteins
  • Drosophila Proteins
  • Multiprotein Complexes
  • NEDD8 Protein
  • NEDD8 protein, human
  • Nedd8 protein, Drosophila
  • Protein Subunits
  • Proteins
  • RUB1 protein, Arabidopsis
  • Ubiquitins
  • Ubiquitin-Protein Ligases
  • Peptide Hydrolases
  • COP9 Signalosome Complex
  • Proteasome Endopeptidase Complex
  • ATP dependent 26S protease
  • Ligases