Basis for metabolite-dependent Cullin-RING ligase deneddylation by the COP9 signalosome.

ABSTRACT: The Cullin-RING ligases (CRLs) are the largest family of ubiquitin E3s activated by neddylation and regulated by the deneddylase COP9 signalosome (CSN). The inositol polyphosphate metabolites promote the formation of CRL-CSN complexes, but with unclear mechanism of action. Here, we provide structural and genetic evidence supporting inositol hexakisphosphate (IP₆) as a general CSN cofactor recruiting CRLs. We determined the crystal structure of IP₆ in complex with CSN subunit 2 (CSN2), based on which we identified the IP₆-corresponding electron density in the cryoelectron microscopy map of a CRL4A-CSN complex. IP₆ binds to a cognate pocket formed by conserved lysine residues from CSN2 and Rbx1/Roc1, thereby strengthening CRL-CSN interactions to di

SUBMITTER: Lin H 

PROVIDER: S-EPMC7049131 | biostudies-literature | 2020 Feb

REPOSITORIES: biostudies-literature