Structural and kinetic analysis of the COP9-Signalosome activation and the cullin-RING ubiquitin ligase deneddylation cycle
Ruzbeh Mosadeghi,
Kurt M Reichermeier,
Martin Winkler,
Anne Schreiber,
Justin M Reitsma,
Yaru Zhang,
Florian Stengel,
Junyue Cao,
Minsoo Kim,
Michael J Sweredoski,
Sonja Hess,
Alexander Leitner,
Ruedi Aebersold,
Matthias Peter,
Raymond J Deshaies,
Radoslav I Enchev
Affiliations
Ruzbeh Mosadeghi
Keck School of Medicine, University of Southern California, Los Angeles, United States; Combined MD/PhD Program, California Institute of Technology, Pasadena, United States; Division of Biology and Biological Engineering, California Instittute of Technology, Pasadena, United States
Kurt M Reichermeier
Division of Biology and Biological Engineering, California Instittute of Technology, Pasadena, United States
Martin Winkler
Department of Biology, Institute of Biochemistry, Swiss Federal Institute of Technology, Zurich, Switzerland
Anne Schreiber
Department of Biology, Institute of Biochemistry, Swiss Federal Institute of Technology, Zurich, Switzerland
Justin M Reitsma
Division of Biology and Biological Engineering, California Instittute of Technology, Pasadena, United States
Yaru Zhang
Division of Biology and Biological Engineering, California Instittute of Technology, Pasadena, United States
Florian Stengel
Department of Biology, Institute of Molecular Systems Biology, Swiss Federal Institute of Technology, Zürich, Switzerland
Junyue Cao
Division of Biology and Biological Engineering, California Instittute of Technology, Pasadena, United States
Minsoo Kim
Division of Biology and Biological Engineering, California Instittute of Technology, Pasadena, United States
Michael J Sweredoski
Proteome Exploration Lab, Beckman Institute, California Institute of Technology, Pasadena, United States
Sonja Hess
Proteome Exploration Lab, Beckman Institute, California Institute of Technology, Pasadena, United States
Alexander Leitner
Department of Biology, Institute of Molecular Systems Biology, Swiss Federal Institute of Technology, Zürich, Switzerland
Ruedi Aebersold
Department of Biology, Institute of Molecular Systems Biology, Swiss Federal Institute of Technology, Zürich, Switzerland; Faculty of Science, University of Zurich, Zurich, Switzerland
Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, United States; Howard Hughes Medical Institute, California Institute of Technology, Pasadena, United States
Radoslav I Enchev
Department of Biology, Institute of Biochemistry, Swiss Federal Institute of Technology, Zurich, Switzerland
The COP9-Signalosome (CSN) regulates cullin–RING ubiquitin ligase (CRL) activity and assembly by cleaving Nedd8 from cullins. Free CSN is autoinhibited, and it remains unclear how it becomes activated. We combine structural and kinetic analyses to identify mechanisms that contribute to CSN activation and Nedd8 deconjugation. Both CSN and neddylated substrate undergo large conformational changes upon binding, with important roles played by the N-terminal domains of Csn2 and Csn4 and the RING domain of Rbx1 in enabling formation of a high affinity, fully active complex. The RING domain is crucial for deneddylation, and works in part through conformational changes involving insert-2 of Csn6. Nedd8 deconjugation and re-engagement of the active site zinc by the autoinhibitory Csn5 glutamate-104 diminish affinity for Cul1/Rbx1 by ~100-fold, resulting in its rapid ejection from the active site. Together, these mechanisms enable a dynamic deneddylation-disassembly cycle that promotes rapid remodeling of the cellular CRL network.
