PEPD is a pivotal regulator of p53 tumor suppressor

Nat Commun. 2017 Dec 12;8(1):2052. doi: 10.1038/s41467-017-02097-9.

Abstract

p53 tumor suppressor responds to various cellular stresses and regulates cell fate. Here, we show that peptidase D (PEPD) binds and suppresses over half of nuclear and cytoplasmic p53 under normal conditions, independent of its enzymatic activity. Eliminating PEPD causes cell death and tumor regression due to p53 activation. PEPD binds to the proline-rich domain in p53, which inhibits phosphorylation of nuclear p53 and MDM2-mediated mitochondrial translocation of nuclear and cytoplasmic p53. However, the PEPD-p53 complex is critical for p53 response to stress, as stress signals doxorubicin and H2O2 each must free p53 from PEPD in order to achieve robust p53 activation, which is mediated by reactive oxygen species. Thus, PEPD stores p53 for the stress response, but this also renders cells dependent on PEPD for survival, as it suppresses p53. This finding provides further understanding of p53 regulation and may have significant implications for the treatment of cancer and other diseases.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Apoptosis / physiology*
  • Cell Line, Tumor
  • Cell Nucleus / metabolism
  • Cell Survival / drug effects
  • Cell Survival / physiology
  • Cytoplasm / metabolism
  • Dipeptidases / genetics
  • Dipeptidases / physiology*
  • Doxorubicin / pharmacology
  • Enzyme Assays
  • Gene Knockdown Techniques
  • Humans
  • Hydrogen Peroxide / pharmacology
  • Mitochondria / metabolism
  • Mutagenesis, Site-Directed
  • Phosphorylation
  • Protein Binding / physiology
  • Protein Domains
  • Proto-Oncogene Proteins c-mdm2 / metabolism
  • Reactive Oxygen Species / pharmacology
  • Stress, Physiological / physiology*
  • Stress, Physiological / radiation effects
  • Tumor Suppressor Protein p53 / antagonists & inhibitors*
  • Tumor Suppressor Protein p53 / genetics
  • Tumor Suppressor Protein p53 / metabolism

Substances

  • Reactive Oxygen Species
  • TP53 protein, human
  • Tumor Suppressor Protein p53
  • Doxorubicin
  • Hydrogen Peroxide
  • MDM2 protein, human
  • Proto-Oncogene Proteins c-mdm2
  • Dipeptidases
  • PEPD protein, human
  • proline dipeptidase