Journal Article

Structural basis of Cullin 2 RING E3 ligase regulation by the COP9 signalosome

Lau, Andy M. C., Ahdash, Zainab, Hansen, Kjetil, Cronin, Nora B., Politis, Argyris, Faull, Sarah V., Yebenes, Hugo, Martens, Chloe, Schmidt, Carla, Morris, Edward P., Beuron, Fabienne

2019

Overview

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. The COP9 signalosome (CSN) regulates Cullin-RING Ligase 2 (CRL2) but the molecular basis for their interaction is unknown. Here the authors use structural mass spectrometry and cryo-EM approaches to assess the structures and dynamics of CSN-CRL2 complexes.

• Publisher: Nature Publishing Group UK,Nature Publishing Group,Nature Portfolio
• Subject: 101/58 / 147/28 / 631/1647/296 / 631/337/458/2288 / 631/45/173 / 631/535/1258/1259 / 82/80 / 82/83 / Activation / Adaptor Proteins, Signal Transducing - isolation & purification / Adaptor Proteins, Signal Transducing - metabolism / Animals / Catalysis / COP9 Signalosome Complex - isolation & purification / COP9 Signalosome Complex - metabolism / COP9 Signalosome Complex - ultrastructure / Crosslinking / Cryoelectron Microscopy / Cullin / Deactivation / Deuterium / Electron microscopy / Enzymes / Humanities and Social Sciences / Hydrogen-deuterium exchange / Intracellular Signaling Peptides and Proteins - isolation & purification / Intracellular Signaling Peptides and Proteins - metabolism / Mass Spectrometry / Mass spectroscopy / Medical research / Microscopy / multidisciplinary / Mutation / NEDD8 Protein - isolation & purification / NEDD8 Protein - metabolism / NEDD8 Protein - ultrastructure / Organic chemistry / Peptide Hydrolases - isolation & purification / Peptide Hydrolases - metabolism / Peptide Hydrolases - ultrastructure / Protein Processing, Post-Translational / Proteins / Receptors / Recombinant Proteins - isolation & purification / Recombinant Proteins - metabolism / Recombinant Proteins - ultrastructure / Regulatory mechanisms (biology) / Science / Science (multidisciplinary) / Scientific imaging / Sf9 Cells / Substrates / Ubiquitin-protein ligase / Ubiquitin-Protein Ligases - isolation & purification / Ubiquitin-Protein Ligases - metabolism / Ubiquitin-Protein Ligases - ultrastructure