1. Cyclin F suppresses B-Myb activity to promote cell cycle checkpoint control
- Author
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Karen A. O'Hanlon, Baptiste Rolland, Juri Rappsilber, Arne Nedergaard Kousholt, Kurt Engeland, Ditte Kjærsgaard Klein, Heike I. Rösner, Johanna K. Ahlskog, Tobias Menzel, Marianne Quaas, Jens Vilstrup Johansen, Brian D Larsen, Michael Lees, Saskia Hoffmann, Claus Storgaard Sørensen, and David Walter
- Subjects
Cell cycle checkpoint ,Cyclin E ,DNA Repair ,Cyclin D ,Cyclin A ,Immunoblotting ,Cyclin B ,General Physics and Astronomy ,Fluorescent Antibody Technique ,Cell Cycle Proteins ,General Biochemistry, Genetics and Molecular Biology ,Cell Line, Tumor ,Cyclins ,Humans ,Immunoprecipitation ,CHEK1 ,RNA, Small Interfering ,Luciferases ,DNA Primers ,Multidisciplinary ,biology ,Chemistry ,Ubiquitination ,General Chemistry ,Cell Cycle Checkpoints ,G2-M DNA damage checkpoint ,Flow Cytometry ,Cell biology ,HEK293 Cells ,biology.protein ,Mutagenesis, Site-Directed ,Trans-Activators ,RNA Interference ,Cyclin A2 - Abstract
Cells respond to DNA damage by activating cell cycle checkpoints to delay proliferation and facilitate DNA repair. Here, to uncover new checkpoint regulators, we perform RNA interference screening targeting genes involved in ubiquitylation processes. We show that the F-box protein cyclin F plays an important role in checkpoint control following ionizing radiation. Cyclin F-depleted cells initiate checkpoint signalling after ionizing radiation, but fail to maintain G2 phase arrest and progress into mitosis prematurely. Importantly, cyclin F suppresses the B-Myb-driven transcriptional programme that promotes accumulation of crucial mitosis-promoting proteins. Cyclin F interacts with B-Myb via the cyclin box domain. This interaction is important to suppress cyclin A-mediated phosphorylation of B-Myb, a key step in B-Myb activation. In summary, we uncover a regulatory mechanism linking the F-box protein cyclin F with suppression of the B-Myb/cyclin A pathway to ensure a DNA damage-induced checkpoint response in G2.
- Published
- 2014