A Subcomplex of the Proteasome Regulatory Particle Required for Ubiquitin-Conjugate Degradation and Related to the COP9-signalosome and eIF3

Cell. 1998 Sep 4;94(5):615-23. doi: 10.1016/s0092-8674(00)81603-7.


The proteasome consists of a 20S proteolytic core particle (CP) and a 19S regulatory particle (RP), which selects ubiquitinated substrates for translocation into the CP. An eight-subunit subcomplex of the RP, the lid, can be dissociated from proteasomes prepared from a deletion mutant for Rpn10, an RP subunit. A second subcomplex, the base, contains all six proteasomal ATPases and links the RP to the CP. The base is sufficient to activate the CP for degradation of peptides or a nonubiquitinated protein, whereas the lid is required for ubiquitin-dependent degradation. By electron microscopy, the base and the lid correspond to the proximal and distal masses of the RP, respectively. The lid subunits share sequence motifs with components of the COP9/signalosome complex and eIF3, suggesting that these functionally diverse particles have a common evolutionary ancestry.

Publication types

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

MeSH terms

  • COP9 Signalosome Complex
  • Carrier Proteins / physiology
  • Cysteine Endopeptidases / chemistry*
  • Cysteine Endopeptidases / physiology*
  • Cysteine Endopeptidases / ultrastructure
  • DNA-Binding Proteins*
  • Fungal Proteins / chemistry
  • Fungal Proteins / physiology
  • Fungal Proteins / ultrastructure
  • Microscopy, Electron
  • Multienzyme Complexes / chemistry*
  • Multienzyme Complexes / physiology*
  • Multienzyme Complexes / ultrastructure
  • Multiprotein Complexes
  • Peptide Hydrolases
  • Plant Proteins / physiology*
  • Proteasome Endopeptidase Complex
  • Proteins*
  • Proto-Oncogene Proteins / physiology*
  • Proto-Oncogene Proteins c-ets
  • Saccharomyces cerevisiae
  • Saccharomyces cerevisiae Proteins
  • Sequence Homology, Amino Acid
  • Signal Transduction / physiology
  • Transcription Factors / physiology*
  • Ubiquitins / metabolism*
  • Ubiquitins / physiology


  • Carrier Proteins
  • DNA-Binding Proteins
  • ELF3 protein, human
  • Fungal Proteins
  • Multienzyme Complexes
  • Multiprotein Complexes
  • Plant Proteins
  • Proteins
  • Proto-Oncogene Proteins
  • Proto-Oncogene Proteins c-ets
  • RPN10 protein, S cerevisiae
  • Saccharomyces cerevisiae Proteins
  • Transcription Factors
  • Ubiquitins
  • Peptide Hydrolases
  • COP9 Signalosome Complex
  • Cysteine Endopeptidases
  • Proteasome Endopeptidase Complex