The COP9 signalosome: an assembly and maintenance platform for cullin ubiquitin ligases?
The COP9 signalosome (CSN) is a highly conserved protein complex implicated in diverse biological functions that involve ubiquitin-mediated proteolysis. Paradoxically, conserved enzymatic activities associated with CSN inhibit cullin ubiquitin ligase activity in vitro, whereas mutational analysis suggests that CSN promotes cullin-dependent proteolysis in vivo. This apparent paradox can be resolved in a model that proposes CSN-mediated cullin inhibition is a prerequisite for the proper assembly and maintenance of active cullin ubiquitin ligase complexes.
Wolf
Dieter A
DA
Department of Genetics and Complex Diseases, Harvard School of Public Health, Boston, MA 02115, USA. dwolf@hsph.harvard.edu
Zhou
Chunshui
C
Wee
Susan
S
D000818:Animals; D000075686:COP9 Signalosome Complex; D044842:Cullin Proteins / Q000378:metabolism*; D006801:Humans; D046911:Macromolecular Substances; D046912:Multiprotein Complexes; D010447:Peptide Hydrolases / Q000378:metabolism*; D021122:Protein Subunits / Q000378:metabolism; D011506:Proteins / Q000378:metabolism*; D015398:Signal Transduction / Q000502:physiology; D014452:Ubiquitins / Q000378:metabolism*
D044842:Cullin Proteins; D046911:Macromolecular Substances; D046912:Multiprotein Complexes; D021122:Protein Subunits; D011506:Proteins; D014452:Ubiquitins; D010447:Peptide Hydrolases; D000075686:COP9 Signalosome Complex