Component of the COP9 signalosome complex (CSN), a complex involved in various cellular and developmental processes. The CSN complex is an essential regulator of the ubiquitin (Ubl) conjugation pathway by mediating the deneddylation of the cullin subunits of SCF-type E3 ligase complexes, leading to decrease the Ubl ligase activity of SCF-type complexes such as SCF, CSA or DDB2. The complex is also involved in phosphorylation of p53/TP53, JUN, I-kappa-B-alpha/NFKBIA, ITPK1 and IRF8/ICSBP, possibly via its association with CK2 and PKD kinases. CSN-dependent phosphorylation of TP53 and JUN promotes and protects degradation by the Ubl system, respectively (By similarity). Component of the CSN complex, composed of COPS1/GPS1, COPS2, COPS3, COPS4, COPS5, COPS6, COPS7 (COPS7A or COPS7B) and COPS8 and COPS9 (PubMed:9707402). In the complex, it probably interacts directly with COPS1, COPS2, COPS4, COPS5, COPS6 and COPS8. Interacts with EIF3S6 (By similarity). Belongs to the CSN7/EIF3M family. CSN7 subfamily.