Hao B, et al. (2007) Structure of a Fbw7-Skp1-cyclin E complex: multisite-phosphorylated substrate recognition by SCF ubiquitin ligases. Mol Cell 26(1):131-43
Abstract: The ubiquitin-mediated proteolysis of cyclin E plays a central role in cell-cycle progression, and cyclin E accumulation is a common event in cancer. Cyclin E degradation is triggered by multisite phosphorylation, which induces binding to the SCF(Fbw7) ubiquitin ligase complex. Structures of the Skp1-Fbw7 complex bound to cyclin E peptides identify a doubly phosphorylated pThr380/pSer384 cyclin E motif as an optimal, high-affinity degron and a singly phosphorylated pThr62 motif as a low-affinity one. Biochemical data indicate that the closely related yeast SCF(Cdc4) complex recognizes the multisite phosphorylated Sic1 substrate similarly and identify three doubly phosphorylated Sic1 degrons, each capable of high-affinity interactions with two Cdc4 phosphate binding sites. A model that explains the role of multiple cyclin E/Sic1 degrons is provided by the findings that Fbw7 and Cdc4 dimerize, that Fbw7 dimerization enhances the turnover of a weakly associated cyclin E in vivo, and that Cdc4 dimerization increases the rate and processivity of Sic1 ubiquitination in vitro.
|Status: Published||Type: Journal Article | Research Support, N.I.H., Extramural | Research Support, Non-U.S. Gov't||PubMed ID: 17434132|
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Number of different genes curated to this paper: 3
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