par Faull, Sarah SV;Lau, Andy M C;Martens, Chloé 
;Ahdash, Zainab;Hansen, Kjetil;Yebenes, Hugo;Schmidt, Carla;Beuron, Fabienne;Cronin, Nora NB;Morris, Edward P;Politis, Argyris
Référence Nature communications, 10, 1, page (3814)
Publication Publié, 2019-08-01
;Ahdash, Zainab;Hansen, Kjetil;Yebenes, Hugo;Schmidt, Carla;Beuron, Fabienne;Cronin, Nora NB;Morris, Edward P;Politis, ArgyrisRéférence Nature communications, 10, 1, page (3814)
Publication Publié, 2019-08-01
Article révisé par les pairs
| Résumé : | Cullin-Ring E3 Ligases (CRLs) regulate a multitude of cellular pathways through specific substrate receptors. The COP9 signalosome (CSN) deactivates CRLs by removing NEDD8 from activated Cullins. Here we present structures of the neddylated and deneddylated CSN-CRL2 complexes by combining single-particle cryo-electron microscopy (cryo-EM) with chemical cross-linking mass spectrometry (XL-MS). These structures suggest a conserved mechanism of CSN activation, consisting of conformational clamping of the CRL2 substrate by CSN2/CSN4, release of the catalytic CSN5/CSN6 heterodimer and finally activation of the CSN5 deneddylation machinery. Using hydrogen-deuterium exchange (HDX)-MS we show that CRL2 activates CSN5/CSN6 in a neddylation-independent manner. The presence of NEDD8 is required to activate the CSN5 active site. Overall, by synergising cryo-EM with MS, we identify sensory regions of the CSN that mediate its stepwise activation and provide a framework for understanding the regulatory mechanism of other Cullin family members. |
