COPS5
COPS5 (COP9 signalosome subunit 5, also known as JAB1, CSN5, SGN5 and MOV-34) is a probable protease subunit of the COP9 signalosome. It acts as the catalytic centre that removes Nedd8 from cullins, regulating the ubiquitin conjugation pathway. Browse Assay Genie's current range of COPS5 research reagents below, or read on for the biology behind the target.
COPS5 is a probable protease subunit of the COP9 signalosome complex (CSN), which is involved in various cellular and developmental processes. The CSN complex is an essential regulator of the ubiquitin (Ubl) conjugation pathway. It mediates deneddylation of the cullin subunits of SCF-type E3 ligase complexes, which decreases the Ubl ligase activity of complexes such as SCF, CSA and DDB2. Within the complex, COPS5 probably acts as the catalytic centre that cleaves Nedd8 from cullins. It has no metalloprotease activity by itself and requires the other CSN subunits.
The CSN complex is also involved in phosphorylation of p53/TP53, c-jun/JUN, IkappaBalpha/NFKBIA, ITPK1 and IRF8, possibly through its association with CK2 and PKD kinases. CSN-dependent phosphorylation of TP53 promotes its degradation by the Ubl system, whereas phosphorylation of JUN protects it from degradation. COPS5 interacts directly with a large number of proteins regulated by the CSN complex, which supports a key role in the assembly. It also promotes the proteasomal degradation of BRSK2. Reported functions include involvement in degradation of the cyclin-dependent kinase inhibitor CDKN1B/p27Kip1 and coactivation of JUN/AP1 transcription factors, increasing their specificity.
The COPS5 gene encodes one of the eight subunits of the highly conserved COP9 signalosome, whose structure and function resemble the 19S regulatory particle of the 26S proteasome. The protein belongs to the peptidase M67A family, CSN5 subfamily, and HGNC places it in the JAMM/MPN+ metallopeptidase group. Its subcellular locations include the cytosol, nucleus, perinuclear region and synaptic vesicles. The name derives from the Arabidopsis COP9 (constitutive photomorphogenic) locus; the mouse ortholog is Cops5.
COPS5 removes Nedd8 from cullins in SCF-type E3 ligases, making it central to studies of ubiquitin conjugation and ligase regulation.
COPS5 is reported to be involved in degradation of the cyclin-dependent kinase inhibitor CDKN1B/p27Kip1.
COPS5 acts as a coactivator that increases the specificity of JUN/AP1 transcription factors, and the CSN affects JUN phosphorylation.
The CSN complex is involved in phosphorylation of TP53 and IkappaBalpha/NFKBIA, linking COPS5 to protein stability and signalling.
COPS5 is a probable protease subunit of the COP9 signalosome and is thought to be its catalytic centre. It mediates cleavage of Nedd8 from cullins, reducing the activity of SCF-type E3 ligases. It has no metalloprotease activity alone and requires the other CSN subunits.
COPS5 is also called JAB1, CSN5, SGN5 and MOV-34. Earlier HGNC names referred to the Arabidopsis COP9 (constitutive photomorphogenic) homolog subunit 5. The UniProt name is COP9 signalosome complex subunit 5, and the protein is classed in the CSN5 subfamily of peptidase M67A.
The COP9 signalosome is described as a highly conserved complex, and the gene name reflects an Arabidopsis homolog. COPS5 has a mouse ortholog, Cops5. Check the datasheet of any product for its validated reactivity.
Other COP9 signalosome subunits that work with COPS5 in cullin deneddylation and ubiquitin pathway regulation.
Gene and protein annotations from HGNC, NCBI Gene and UniProt Q92905; product specifications from Assay Genie datasheets.