A p53-phosphoinositide signalosome regulates nuclear AKT activation

Nat Cell Biol. 2022 Jul;24(7):1099-1113. doi: 10.1038/s41556-022-00949-1. Epub 2022 Jul 7.

Abstract

The tumour suppressor p53 and PI3K-AKT pathways have fundamental roles in the regulation of cell growth and apoptosis, and are frequently mutated in cancer. Here, we show that genotoxic stress induces nuclear AKT activation through a p53-dependent mechanism that is distinct from the canonical membrane-localized PI3K-AKT pathway. Following genotoxic stress, a nuclear PI3K binds p53 in the non-membranous nucleoplasm to generate a complex of p53 and phosphatidylinositol 3,4,5-trisphosphate (PtdIns(3,4,5)P3), which recruits AKT, PDK1 and mTORC2 to activate AKT and phosphorylate FOXO proteins, thereby inhibiting DNA damage-induced apoptosis. Wild-type p53 activates nuclear AKT in an on/off fashion following stress, whereas mutant p53 dose-dependently stimulates high basal AKT activity. The p53-PtdIns(3,4,5)P3 complex is dephosphorylated to p53-phosphatidylinositol 4,5-bisphosphate by PTEN to inhibit AKT activation. The nuclear p53-phosphoinositide signalosome is distinct from the canonical membrane-localized pathway and insensitive to PI3K inhibitors currently in the clinic, which underscores its therapeutic relevance.

Publication types

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

MeSH terms

  • Cell Nucleus / metabolism
  • Phosphatidylinositol 3-Kinases / metabolism
  • Phosphatidylinositols
  • Proto-Oncogene Proteins c-akt* / genetics
  • Proto-Oncogene Proteins c-akt* / metabolism
  • Tumor Suppressor Protein p53* / genetics
  • Tumor Suppressor Protein p53* / metabolism

Substances

  • Phosphatidylinositols
  • Tumor Suppressor Protein p53
  • Proto-Oncogene Proteins c-akt