Transcription-independent pro-apoptotic functions of p53

Curr Opin Cell Biol. 2005 Dec;17(6):631-6. doi: 10.1016/ Epub 2005 Oct 13.


Induction of apoptosis is one of the central activities by which p53 exerts its tumor-suppressing function. Aside from its primary function as a transcription factor, it can promote apoptosis independent of transcription. Recent studies have started to define the mechanisms of non-transcriptional pro-apoptotic p53 activities operating within the intrinsic mitochondria-mediated pathway of apoptosis. So far, two different mechanisms have been described, each of which was assigned to a specific localization of the p53 protein, either in the cytosol or directly at the mitochondria. Although mechanistically different, both transcription-independent modes of apoptosis induction converge, as they both initiate permeabilization of the outer mitochondrial membrane via activation of the pro-apoptotic Bcl-2 family members Bax or Bak.

Publication types

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

MeSH terms

  • Apoptosis*
  • Cytosol / metabolism
  • Humans
  • Mitochondrial Proteins / physiology
  • Nuclear Proteins / metabolism
  • Transcription Factors / physiology*
  • Tumor Suppressor Protein p53 / physiology*


  • Mitochondrial Proteins
  • Nuclear Proteins
  • Transcription Factors
  • Tumor Suppressor Protein p53