title: Ovarian tumor domain-containing protein 1 deubiquitinates and stabilizes p53.
abstract: Ubiquitination and deubiquitination pathways play important roles in the regulation of p53 stability and activity. p53 is ubiquitinated and destabilized by E3 ubiquitin ligases and is deubiquitinated and stabilized by deubiquitinases (DUBs). We screened ovarian tumor (OTU) subfamily proteins to identify novel DUBs that stabilized p53. OTU domain-containing protein 1 (OTUD1) is a DUB belonging to the OTU family; however, its substrates and its role in cells are unknown. Here, we used an overexpression and knockdown system to show that OTUD1 is a novel regulator of p53 stability. OTUD1 overexpression increased p53 stability, whereas OTUD1 knockdown decreased p53 stability. Moreover, we observed that OTUD1 directly interacted with p53. Our results showed that OTUD1 deubiquitinated p53 and that functional OTUD1 was required for p53 stabilization. The deubiquitination activity of OTUD1 was necessary for p53 stabilization, as confirmed using an inactive OTUD1 mutant (C320S OTUD1 mutant). We also found that wild-type OTUD1 upregulated p21 and Mdm2 expression but inactive OTUD1 mutant did not. Furthermore, OTUD1 significantly suppressed colony formation. Next, we confirmed that OTUD1 overexpression increased the cleavage of caspase-3 and PARP and subsequently increased apoptosis. Together, these results suggest that OTUD1 is a novel regulator of p53 stability and activity.
authors.affiliation: Department of Biochemistry and Molecular Biology, College of Medicine, Yeungnam University, South Korea.
authors.forename: Shudong
authors.initials: S
authors.lastname: Piao
authors.affiliation: Department of Biochemistry and Molecular Biology, College of Medicine, Yeungnam University, South Korea.
authors.forename: Han Zhong
authors.initials: HZ
authors.lastname: Pei
authors.affiliation: Department of Biochemistry and Molecular Biology, College of Medicine, Yeungnam University, South Korea.
authors.forename: Bin
authors.initials: B
authors.lastname: Huang
authors.affiliation: Department of Biochemistry and Molecular Biology, College of Medicine, Yeungnam University, South Korea. Electronic address: sbaek@med.yu.ac.kr.
authors.forename: Suk-Hwan
authors.initials: SH
authors.lastname: Baek
mesh_terms: D000595:Amino Acid Sequence; D017209:Apoptosis; D059447:Cell Cycle Checkpoints; D045744:Cell Line, Tumor; D005260:Female; D055785:Gene Knockdown Techniques; D006801:Humans; D010051:Ovarian Neoplasms / Q000378:metabolism* / Q000473:pathology*; D055550:Protein Stability; D059748:Proteolysis; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism*; D064570:Ubiquitin-Specific Proteases / Q000378:metabolism*
chemical_list: D016159:Tumor Suppressor Protein p53; C000591845:OTUD1 protein, human; D064570:Ubiquitin-Specific Proteases
keywords: Cell growth; Deubiquitinase; Ovarian tumor domain-containing protein 1; Ubiquitin; p53