title: The multifunctional sorting protein PACS-2 regulates SIRT1-mediated deacetylation of p53 to modulate p21-dependent cell-cycle arrest.
abstract: 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.
authors.affiliation: Department of Cell and Developmental Biology, Oregon Health & Science University, Portland, OR 97239, USA.
authors.forename: Katelyn M
authors.initials: KM
authors.lastname: Atkins
authors.affiliation: Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, PA 15219, USA.
authors.forename: Laura L
authors.initials: LL
authors.lastname: Thomas
authors.affiliation: Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, PA 15219, USA.
authors.forename: Jonathan
authors.initials: J
authors.lastname: Barroso-González
authors.affiliation: Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, PA 15219, USA.
authors.forename: Laurel
authors.initials: L
authors.lastname: Thomas
authors.affiliation: Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, PA 15219, USA.
authors.forename: Sylvain
authors.initials: S
authors.lastname: Auclair
authors.affiliation: Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, PA 15219, USA.
authors.forename: Jun
authors.initials: J
authors.lastname: Yin
authors.affiliation: Laboratory of Obesity and Aging Research, Genetics and Development Biology Center, National Heart Lung and Blood Institute, NIH, Bethesda, MD 20892, USA.
authors.forename: Hyeog
authors.initials: H
authors.lastname: Kang
authors.affiliation: Laboratory of Obesity and Aging Research, Genetics and Development Biology Center, National Heart Lung and Blood Institute, NIH, Bethesda, MD 20892, USA.
authors.forename: Jay H
authors.initials: JH
authors.lastname: Chung
authors.affiliation: Schulich School of Medicine and Dentistry, University of Western Ontario, London ON N6A 5C1, Canada.
authors.forename: Jimmy D
authors.initials: JD
authors.lastname: Dikeakos
authors.affiliation: Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, PA 15219, USA. Electronic address: thomasg@pitt.edu.
authors.forename: Gary
authors.initials: G
authors.lastname: Thomas
mesh_terms: D000107:Acetylation; D021581:Active Transport, Cell Nucleus; D000818:Animals; D002227:Carbazoles / Q000494:pharmacology; D002453:Cell Cycle; D045744:Cell Line, Tumor; D002467:Cell Nucleus / Q000378:metabolism; D050759:Cyclin-Dependent Kinase Inhibitor p21 / Q000378:metabolism*; D004249:DNA Damage; D057809:HEK293 Cells; D006801:Humans; D051379:Mice; D008810:Mice, Inbred C57BL; D011485:Protein Binding; D056564:Sirtuin 1 / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D060168:Thymocytes / Q000378:metabolism; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism*; D033921:Vesicular Transport Proteins / Q000235:genetics / Q000378:metabolism*
chemical_list: C550547:6-chloro-2,3,4,9-tetrahydro-1H-carbazole-1-carboxamide; D002227:Carbazoles; C493957:Cdkn1a protein, mouse; D050759:Cyclin-Dependent Kinase Inhibitor p21; C529570:Pacs2 protein, mouse; D016159:Tumor Suppressor Protein p53; D033921:Vesicular Transport Proteins; C470545:Sirt1 protein, mouse; D056564:Sirtuin 1