Structural basis of the phosphorylation-independent recognition of cyclin D1 by the SCFFBXO31 ubiquitin ligase.Li, Y., Jin, K., Bunker, E., Zhang, X., Luo, X., Liu, X., Hao, B.
(2018) Proc. Natl. Acad. Sci. U.S.A. 115: 319-324
- PubMed: 29279382
- DOI: 10.1073/pnas.1708677115
- Primary Citation of Related Structures:
- PubMed Abstract:
Ubiquitin-dependent proteolysis of cyclin D1 is associated with normal and tumor cell proliferation and survival. The SCF <sup>FBXO31 </sup> (Skp1-Cul1-Rbx1-FBXO31) ubiquitin ligase complex mediates genotoxic stress-induced cyclin D1 degradation. Pre ...
Ubiquitin-dependent proteolysis of cyclin D1 is associated with normal and tumor cell proliferation and survival. The SCF FBXO31 (Skp1-Cul1-Rbx1-FBXO31) ubiquitin ligase complex mediates genotoxic stress-induced cyclin D1 degradation. Previous studies have suggested that cyclin D1 levels are maintained at steady state by phosphorylation-dependent nuclear export and subsequent proteolysis in the cytoplasm. Here we present the crystal structures of the Skp1-FBXO31 complex alone and bound to a phosphorylated cyclin D1 C-terminal peptide. FBXO31 possesses a unique substrate-binding domain consisting of two β-barrel motifs, whereas cyclin D1 binds to FBXO31 by tucking its free C-terminal carboxylate tail into an open cavity of the C-terminal FBXO31 β-barrel. Biophysical and functional studies demonstrate that SCF FBXO31 is capable of recruiting and ubiquitinating cyclin D1 in a phosphorylation-independent manner. Our findings provide a conceptual framework for understanding the substrate specificity of the F-box protein FBXO31 and the mechanism of FBXO31-regulated cyclin D1 protein turnover.
Department of Molecular Biology and Biophysics, University of Connecticut Health Center, Farmington, CT 06030; firstname.lastname@example.org.,Department of Molecular Biology and Biophysics, University of Connecticut Health Center, Farmington, CT 06030.,Biomolecular Resource Facility, University of Texas Medical Branch, Galveston, TX 77555.,Department of Chemistry and Biochemistry, University of Colorado, Boulder, CO 80309.