Abstract
The irreversible nature of mitotic entry is due to the activation of mitosis specific kinases such as cdk1/cyclin B. Cdk1/cyclin B induces activation of mitosis by promoting phosphatases while suppressing inhibitory factors such as the tyrosine kinase wee1. Since wee1 inactivates cdk1/cyclin B during the S and G2 phases, its activity must be downregulated for mitotic progression to occur. One mechanism of suppressing wee1 activity is ubiquitin-dependent proteolysis. Cdk1/cyclin B1 phosphorylates wee1, targeting it for recognition by ubiquitin ligases and subsequent proteasomal degradation. One of the ubiquitin ligases promoting wee1 destruction during mitosis is the SCFβ-trcp complex. We demonstrate that this complex, and a second SCF complex containing the F-box protein Tome-1, regulate wee1 degradation during the S and G2 phases of the cell cycle. Therefore, redundant ubiquitin ligase activities promote efficient mitotic entry of eukaryotic cells.
Original language | English (US) |
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Pages (from-to) | 2795-2799 |
Number of pages | 5 |
Journal | Cell Cycle |
Volume | 6 |
Issue number | 22 |
DOIs | |
State | Published - Nov 15 2007 |
Externally published | Yes |
Keywords
- β-TRCP
- Degradation
- F-box
- Mitosis
- Tome-1
- Wee1
ASJC Scopus subject areas
- Cell Biology
- Biochemistry
- Molecular Biology