Schimmel, Joost3; Eifler, Karolin3; Sigurdsson, Jón Otti6; Cuijpers, Sabine A G3; Hendriks, Ivo A3; Verlaan-de Vries, Matty3; Kelstrup, Christian D6; Francavilla, Chiara6; Medema, René H4; Olsen, Jesper Velgaard6; Vertegaal, Alfred C O5
1 Proteomics Program, Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, Københavns Universitet2 Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, Københavns Universitet3 Department of Molecular Cell Biology, Leiden University Medical Center, Albinusdreef 2, 2333 ZA Leiden, the Netherlands.4 Department of Cell Biology, Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX Amsterdam, the Netherlands.5 Department of Molecular Cell Biology, Leiden University Medical Center, Albinusdreef 2, 2333 ZA Leiden, the Netherlands. Electronic address: firstname.lastname@example.org Proteomics Program, Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, Københavns Universitet
Loss of small ubiquitin-like modification (SUMOylation) in mice causes genomic instability due to the missegregation of chromosomes. Currently, little is known about the identity of relevant SUMO target proteins that are involved in this process and about global SUMOylation dynamics during cell-cycle progression. We performed a large-scale quantitative proteomics screen to address this and identified 593 proteins to be SUMO-2 modified, including the Forkhead box transcription factor M1 (FoxM1), a key regulator of cell-cycle progression and chromosome segregation. SUMOylation of FoxM1 peaks during G2 and M phase, when FoxM1 transcriptional activity is required. We found that a SUMOylation-deficient FoxM1 mutant was less active compared to wild-type FoxM1, implying that SUMOylation of the protein enhances its transcriptional activity. Mechanistically, SUMOylation blocks the dimerization of FoxM1, thereby relieving FoxM1 autorepression. Cells deficient for FoxM1 SUMOylation showed increased levels of polyploidy. Our findings contribute to understanding the role of SUMOylation during cell-cycle progression.
Molecular Cell, 2014, Vol 53, Issue 6, p. 1053-1066