Repression of new p53 targets revealed by ChIP on chip experiments

Michele Ceribelli, Myriam Alcalay, Maria Alessandra Viganò, Roberto Mantovani

Research output: Contribution to journalArticle

Abstract

Following DNA-damage, the tumor suppressor p53 activates G1/S blocking and apoptotic genes, and represses other genes, including those involved in G2/M transition. In this latter system, it acts through the CCAAT-binding histone-like NF-Y. Several groups have reported that p53 is associated to promoters in unstressed conditions. We developed an oligo-based array containing 179 human promoters, enriched in genes involved in the DNA-damage and ER-stress response. We performed ChIP on chip experiments with p53 and NF-Y in cells under normal growing conditions. We identified 46 new p53 targets and noted (i) a significant enrichment in genes of the ER-stress response, including crucial regulators such as XBP1 and C/EBPβ; (ii) genes whose products are involved in the regulation of p53 function. Several genes were validated by conventional ChIP. DNA-damage dependent PCAF-mediated acetylation was observed on most, but not all promoters. The effect of p53 activation was checked by RT-PCR and transfections in HCT116 wt, E6 and p53 -/- cells: most promoters were actively repressed upon Adriamycin treatment or following p53 transfection in p53-/- cells. In particular, the behaviour of some of the genes (BRCA1, RAD23 and RAD17) is consistent with a feedback loop regulation on p53 levels. Finally, there is a large overlap (66%) between p53 and NF-Y targets. Our data reinstate the physiological importance of p53 promoter recognition and direct transcriptional repression as a mechanism to cope with DNA-damage.

Original languageEnglish
Pages (from-to)1102-1110
Number of pages9
JournalCell Cycle
Volume5
Issue number10
Publication statusPublished - May 15 2006

Keywords

  • ChIP on chip
  • NF-Y
  • p53
  • Repression

ASJC Scopus subject areas

  • Cell Biology
  • Biochemistry
  • Molecular Biology

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  • Cite this

    Ceribelli, M., Alcalay, M., Viganò, M. A., & Mantovani, R. (2006). Repression of new p53 targets revealed by ChIP on chip experiments. Cell Cycle, 5(10), 1102-1110.