COPS3
Description
The COPS3 (COP9 signalosome subunit 3) is a protein-coding gene located on chromosome 17.
COP9 signalosome complex subunit 3 is a protein that in humans is encoded by the COPS3 gene. It encodes a subunit of the COP9 signalosome. The protein encoded by this gene possesses kinase activity that phosphorylates regulators involved in signal transduction. It phosphorylates I-kappa-B-alpha, p105, and c-Jun. It acts as a docking site for complex-mediated phosphorylation. The gene is located within the Smith-Magenis syndrome region on chromosome 17.
The COP9 signalosome (CSN) complex is a crucial regulator of the ubiquitin (Ubl) conjugation pathway, primarily by mediating the deneddylation of cullin subunits within SCF-type E3 ligase complexes. This process effectively reduces the Ubl ligase activity of SCF-type complexes, including SCF, CSA, and DDB2. Additionally, the CSN complex is involved in the phosphorylation of several proteins, including p53/TP53, c-jun/JUN, IkappaBalpha/NFKBIA, ITPK1, and IRF8/ICSBP. This phosphorylation is potentially facilitated by the CSN's association with CK2 and PKD kinases. Notably, CSN-dependent phosphorylation of TP53 promotes its degradation by the Ubl system, while phosphorylation of JUN safeguards it from degradation.
COPS3 is also known as CSN3, SGN3.
