COPS8
Description
The COPS8 (COP9 signalosome subunit 8) is a protein-coding gene located on chromosome 2.
COPS8 is a protein encoded by the COPS8 gene in humans. It is the smallest subunit of the COP9 signalosome, a highly conserved protein complex involved in regulating multiple signaling pathways. The COP9 signalosome shares structural and functional similarities with the 19S regulatory particle of the 26S proteasome. It interacts with SCF-type E3 ubiquitin ligases and acts as a positive regulator of these ligases. The gene can produce distinct isoforms through alternative splicing.
The COP9 signalosome (CSN) complex is involved in various cellular and developmental processes. It plays a critical role in regulating the ubiquitin (Ubl) conjugation pathway by mediating the removal of NEDD8 (a Ubl) from cullin subunits of SCF-type E3 ligase complexes. This removal reduces the Ubl ligase activity of SCF-type complexes like SCF, CSA, and DDB2. The CSN complex is also involved in the phosphorylation of various proteins, including p53/TP53, c-jun/JUN, IkappaBalpha/NFKBIA, ITPK1, and IRF8/ICSBP. This phosphorylation is likely mediated through interactions with CK2 and PKD kinases. CSN-dependent phosphorylation of TP53 promotes degradation by the Ubl system, while phosphorylation of JUN protects it from degradation.
COPS8 is also known as COP9, CSN8, SGN8.
