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DNA damage-induced regulatory interplay between DAXX, p53, ATM kinase and Wip1 phosphatase
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SYSNO ASEP 0442490 Document Type J - Journal Article R&D Document Type Journal Article Subsidiary J Článek ve WOS Title DNA damage-induced regulatory interplay between DAXX, p53, ATM kinase and Wip1 phosphatase Author(s) Bražina, Jan (UMG-J)
Švadlenka, Jan (UMG-J)
Macůrek, Libor (UMG-J) RID, ORCID
Anděra, Ladislav (UMG-J) RID
Hodný, Zdeněk (UMG-J) RID
Bártek, Jiří (UMG-J) RID
Hanzlíková, Hana (UMG-J) RIDSource Title Cell Cycle. - : Taylor & Francis - ISSN 1538-4101
Roč. 14, č. 3 (2015), s. 375-387Number of pages 13 s. Language eng - English Country US - United States Keywords ATM ; DAXX ; DNA damage ; p53 ; Wip1 Subject RIV EB - Genetics ; Molecular Biology R&D Projects GPP305/11/P683 GA ČR - Czech Science Foundation (CSF) Institutional support UMG-J - RVO:68378050 UT WOS 000350137100016 DOI 10.4161/15384101.2014.988019 Annotation Death domain-associated protein 6 (DAXX) is a histone chaperone, putative regulator of apoptosis and transcription, and candidate modulator of p53-mediated gene expression following DNA damage. DAXX becomes phosphorylated upon DNA damage, however regulation of this modification, and its relationship to p53 remain unclear. Here we show that in human cells exposed to ionizing radiation or genotoxic drugs etoposide and neocarzinostatin, DAXX became rapidly phosphorylated in an ATM kinase-dependent manner. Our deletion and site-directed mutagenesis experiments identified Serine 564 (S564) as the dominant ATM-targeted site of DAXX, and immunofluorescence experiments revealed localization of S564-phosphorylated DAXX to PML nuclear bodies. Furthermore, using a panel of human cell types, we identified the p53-regulated Wip1 protein phosphatase as a key negative regulator of DAXX phosphorylation at S564, both in vitro and in cells. Consistent with the emerging oncogenic role of Wip1, its DAXX-dephosphorylating impact was most apparent in cancer cell lines harboring gain-of-function mutant and/or overexpressed Wip1. Unexpectedly, while Wip1 depletion increased DAXX phosphorylation both before and after DNA damage and increased p53 stability and transcriptional activity, knock-down of DAXX impacted neither p53 stabilization nor p53-mediated expression of Gadd45a, Noxa, Mdm2, p21, Puma, Sesn2, Tigar or Wip1. Consistently, analyses of cells with genetic, TALEN-mediated DAXX deletion corroborated the notion that neither phosphorylated nor non-phosphorylated DAXX is required for p53-mediated gene expression upon DNA damage. Overall, we identify ATM kinase and Wip1 phosphatase as opposing regulators of DAXX-S564 phosphorylation, and propose that the role of DAXX phosphorylation and DAXX itself are independent of p53-mediated gene expression. Workplace Institute of Molecular Genetics Contact Nikol Škňouřilová, nikol.sknourilova@img.cas.cz, Tel.: 241 063 217 Year of Publishing 2015
Number of the records: 1