title: Diversity of COP9 signalosome structures and functional consequences.
abstract: The COP9 signalosome (CSN) is a regulator of the ubiquitin (Ub) proteasome system (UPS). It interacts with hundreds of cullin-RING ubiquitin E3 ligases (CRLs) and regulates their activity by removing the Ub-like protein Nedd8 from cullins. In mammalian cells 7 different cullins exist which form CRLs with adaptor proteins and with a large number of substrate recognition subunits such as F-box and BTB proteins. This large variety of CRL-complexes is deneddylated by the CSN. The capacity of the CSN to interact with numerous types of CRL complexes can be explained by its structural diversity, which allows different CSN variants to interact with different binding partners and substrates and enables different subunit expression profiles. Diversity of CSN complexes presumably occurs by: (1) flexibility of CSN holo complex structure; (2) formation of CSN mini complexes and free CSN subunits and (3) generation of CSN variants via integration of CSN subunit isoforms. In this review we will discuss the structural diversity of the CSN complex and possible functional consequences.
authors.affiliation: Institute of Experimental Internal Medicine, Medical Faculty, Otto von Guericke University, Leipziger Str. 44, 39120 Magdeburg, Germany.
authors.forename: Dawadschargal
authors.initials: D
authors.lastname: Dubiel
authors.affiliation: Department of Molecular Structural Biology, Max-Planck-Institute of Biochemistry, 82152 Martinsried, Germany.
authors.forename: Beate
authors.initials: B
authors.lastname: Rockel
authors.affiliation: Institute of Experimental Internal Medicine, Medical Faculty, Otto von Guericke University, Leipziger Str. 44, 39120 Magdeburg, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Naumann
authors.affiliation: Department of General, Visceral, Vascular and Thoracic Surgery, Division of Molecular Biology, Charité - Universitätsmedizin Berlin, Charitéplatz 1, 10117 Berlin, Germany. Electronic address: wolfgang.dubiel@charite.de.
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Dubiel
mesh_terms: D000818:Animals; D000075686:COP9 Signalosome Complex; D006801:Humans; D008958:Models, Molecular; D046912:Multiprotein Complexes / Q000737:chemistry*; D010447:Peptide Hydrolases / Q000737:chemistry*; D011485:Protein Binding; D020033:Protein Isoforms / Q000737:chemistry; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D021122:Protein Subunits / Q000737:chemistry
chemical_list: D046912:Multiprotein Complexes; D020033:Protein Isoforms; D021122:Protein Subunits; D010447:Peptide Hydrolases; D000075686:COP9 Signalosome Complex
keywords: 3D structure; COP9 signalosome; CSN subunit isoform; CSN5; Deneddylation