Linked Life Data

16045761

Source:http://linkedlifedata.com/resource/pubmed/id/16045761

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
15
pubmed:dateCreated
2005-7-27
pubmed:abstractText
The COP9 signalosome (CSN) occurs in all eukaryotic cells. It is a regulatory particle of the ubiquitin (Ub)/26S proteasome system. The eight subunits of the CSN possess sequence homologies with the polypeptides of the 26S proteasome lid complex and just like the lid, the CSN consists of six subunits with PCI (proteasome, COP9 signalosome, initiation factor 3) domains and two components with MPN (Mpr-Pad1-N-terminal) domains. Here we show that the CSN directly interacts with the 26S proteasome and competes with the lid, which has consequences for the peptidase activity of the 26S proteasome in vitro. Flag-CSN2 was permanently expressed in mouse B8 fibroblasts and Flag pull-down experiments revealed the formation of an intact Flag-CSN complex, which is associated with the 26S proteasome. In addition, the Flag pull-downs also precipitated cullins indicating the existence of super-complexes consisting of the CSN, the 26S proteasome and cullin-based Ub ligases. Permanent expression of a chimerical subunit (Flag-CSN2-Rpn6) consisting of the N-terminal 343 amino acids of CSN2 and of the PCI domain of S9/Rpn6, the paralog of CSN2 in the lid complex, did not lead to the assembly of an intact complex showing that the PCI domain of CSN2 is important for complex formation. The consequence of permanent Flag-CSN2 overexpression was de-novo assembly of the CSN complex connected with an accelerated degradation of p53 and stabilization of c-Jun in B8 cells. The possible role of super-complexes composed of the CSN, the 26S proteasome and of Ub ligases in the regulation of protein stability is discussed.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
http://linkedlifedata.com/resource/pubmed/chemical/ATP dependent 26S protease, http://linkedlifedata.com/resource/pubmed/chemical/Arabidopsis Proteins, http://linkedlifedata.com/resource/pubmed/chemical/COP9 signalosome complex, http://linkedlifedata.com/resource/pubmed/chemical/CSN2 protein, Arabidopsis, http://linkedlifedata.com/resource/pubmed/chemical/Endopeptidases, http://linkedlifedata.com/resource/pubmed/chemical/FLAG peptide, http://linkedlifedata.com/resource/pubmed/chemical/Multiprotein Complexes, http://linkedlifedata.com/resource/pubmed/chemical/Peptide Hydrolases, http://linkedlifedata.com/resource/pubmed/chemical/Peptides, http://linkedlifedata.com/resource/pubmed/chemical/Proteasome Endopeptidase Complex, http://linkedlifedata.com/resource/pubmed/chemical/Recombinant Fusion Proteins, http://linkedlifedata.com/resource/pubmed/chemical/Rpn6 protein, S cerevisiae, http://linkedlifedata.com/resource/pubmed/chemical/Saccharomyces cerevisiae Proteins
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
1742-464X
pubmed:author
pubmed:issnType
Print
pubmed:volume
272
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
3909-17
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2005
pubmed:articleTitle
Consequences of COP9 signalosome and 26S proteasome interaction.
pubmed:affiliation
Division of Molecular Biology, Department of Surgery, Charité, Universitätsmedizin Berlin, Germany.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't