Basis for metabolite-dependent Cullin-RING ligase deneddylation by the COP9 signalosome.
Proc Natl Acad Sci U S A
; 117(8): 4117-4124, 2020 02 25.
Article
em En
| MEDLINE
| ID: mdl-32047038
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 dislodge the E2 CDC34/UBE2R from CRL and to promote CRL deneddylation. IP6 binding-deficient Csn2K70E/K70E knockin mice are embryonic lethal. The same mutation disabled Schizosaccharomyces pombe Csn2 from rescuing UV-hypersensitivity of csn2-null yeast. These data suggest that CRL transition from the E2-bound active state to the CSN-bound sequestered state is critically assisted by an interfacial IP6 small molecule, whose metabolism may be coupled to CRL-CSN complex dynamics.
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Ubiquitina-Proteína Ligases
/
Complexo do Signalossomo COP9
Limite:
Animals
/
Humans
Idioma:
En
Revista:
Proc Natl Acad Sci U S A
Ano de publicação:
2020
Tipo de documento:
Article
País de afiliação:
China