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 (By similarity). The CSN complex seems to link protein degradation to sexual development. Required for fruit body formation. Component of the COP9 signalosome (CSN) complex. Belongs to the CSN1 family.