Component of the COP9 signalosome (CSN) complex that acts as an regulator of the ubiquitin (Ubl) conjugation pathway by mediating the deneddylation of the cullin subunit of SCF-type E3 ubiquitin-protein ligase complexes. Component of the COP9 signalosome (CSN) complex. Belongs to the CSN7/EIF3M family. CSN7 subfamily.