The Multifunctional Sorting Protein PACS-2 Regulates SIRT1-Mediated Deacetylation of p53 to Modulate p21-Dependent Cell-Cycle Arrest

Autor: Katelyn M. Atkins, Laura L. Thomas, Jonathan Barroso-González, Laurel Thomas, Sylvain Auclair, Jun Yin, Hyeog Kang, Jay H. Chung, Jimmy D. Dikeakos, Gary Thomas
Jazyk: angličtina
Rok vydání: 2014
Předmět:
Zdroj: Cell Reports, Vol 8, Iss 5, Pp 1545-1557 (2014)
Druh dokumentu: article
ISSN: 2211-1247
DOI: 10.1016/j.celrep.2014.07.049
Popis: SIRT1 regulates the DNA damage response by deacetylating p53, thereby repressing p53 transcriptional output. Here, we demonstrate that the sorting protein PACS-2 regulates SIRT1-mediated deacetylation of p53 to modulate the DNA damage response. PACS-2 knockdown cells failed to efficiently undergo p53-induced cell-cycle arrest in response to DNA damage. Accordingly, p53 acetylation was reduced both in PACS-2 knockdown cells and thymocytes from Pacs-2−/− mice, thereby blunting induction of the cyclin-dependent kinase inhibitor p21 (CDKN1A). The SIRT1 inhibitor EX-527 or SIRT1 knockdown restored p53 acetylation and p21 induction as well as p21-dependent cell-cycle arrest in PACS-2 knockdown cells. Trafficking studies revealed that cytoplasmic PACS-2 shuttled to the nucleus, where it interacted with SIRT1 and repressed SIRT1-mediated p53 deacetylation. Correspondingly, in vitro assays demonstrated that PACS-2 directly inhibited SIRT1-catalyzed p53 deacetylation. Together, these findings identify PACS-2 as an in vivo mediator of the SIRT1-p53-p21 axis that modulates the DNA damage response.
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