1. The ubiquitin-specific protease USP17 prevents cellular senescence by stabilizing the methyltransferase SET8 and transcriptionally repressing p21
- Author
-
Nobumichi Ohoka, Muneshige Tokugawa, Hidetoshi Hayashi, Masayuki Komada, Yasumichi Inoue, Shin Watanabe, Daisuke Morishita, Chiharu Miyajima, and Keishi Fukuura
- Subjects
Cyclin-Dependent Kinase Inhibitor p21 ,0301 basic medicine ,Senescence ,Aging ,Ubiquitin-Protein Ligases ,Biochemistry ,Cell Line ,Histones ,Histone H4 ,03 medical and health sciences ,Ubiquitin ,Chlorocebus aethiops ,Endopeptidases ,Histone methylation ,Animals ,Humans ,Molecular Biology ,Cell Proliferation ,Gene knockdown ,030102 biochemistry & molecular biology ,biology ,Kinase ,Cell growth ,Chemistry ,Cell Cycle ,Ubiquitination ,Histone-Lysine N-Methyltransferase ,Methyltransferases ,Cell Biology ,Cell cycle ,HCT116 Cells ,Cell biology ,030104 developmental biology ,Protein Synthesis and Degradation ,COS Cells ,MCF-7 Cells ,biology.protein ,Protein Processing, Post-Translational - Abstract
Su(var)3–9, Enhancer-of-zeste, and Trithorax (SET) domain-containing protein 8 (SET8) is the sole enzyme that monomethylates Lys-20 of histone H4 (H4K20). SET8 has been implicated in the regulation of multiple biological processes, such as gene transcription, the cell cycle, and senescence. SET8 quickly undergoes ubiquitination and degradation by several E3 ubiquitin ligases; however, the enzyme that deubiquitinates SET8 has not yet been identified. Here we demonstrated that ubiquitin-specific peptidase 17–like family member (USP17) deubiquitinates and therefore stabilizes the SET8 protein. We observed that USP17 interacts with SET8 and removes polyubiquitin chains from SET8. USP17 knockdown not only decreased SET8 protein levels and H4K20 monomethylation but also increased the levels of the cyclin-dependent kinase inhibitor p21. As a consequence, USP17 knockdown suppressed cell proliferation. We noted that USP17 was down-regulated in replicative senescence and that USP17 inhibition alone was sufficient to trigger cellular senescence. These results reveal a regulatory mechanism whereby USP17 prevents cellular senescence by removing ubiquitin marks from and stabilizing SET8 and transcriptionally repressing p21.
- Published
- 2019