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Yeast As a Chassis for Developing Functional Assays to Study Human P53
14:57

Yeast As a Chassis for Developing Functional Assays to Study Human P53

Published on: August 4, 2019

Transcription-independent pro-apoptotic functions of p53

Ute M Moll1, Sonja Wolff, Daniel Speidel

  • 1Department of Pathology, Stony Brook University, Stony Brook, New York 11794, USA.

Current Opinion in Cell Biology
|October 18, 2005
PubMed

Insights

The p53 protein suppresses tumors by inducing apoptosis, a programmed cell death. It can trigger apoptosis independently of its transcription factor role through distinct mechanisms in the cytosol or at the mitochondria.

Area of Science:

  • Molecular Biology
  • Cell Biology
  • Cancer Research

Background:

  • The p53 protein is a critical tumor suppressor.
  • p53's tumor-suppressing function is largely mediated by inducing apoptosis (programmed cell death).
  • p53 can induce apoptosis through both transcription-dependent and transcription-independent pathways.

Purpose of the Study:

  • To elucidate the mechanisms of non-transcriptional, pro-apoptotic p53 activities.
  • To understand how p53 initiates apoptosis independent of its role as a transcription factor.
  • To explore p53's function within the intrinsic, mitochondria-mediated apoptosis pathway.

Main Methods:

  • Investigated p53's role in apoptosis independent of its transcriptional activity.
  • Examined distinct cellular localizations of p53 (cytosol and mitochondria).
  • Analyzed the convergence of different non-transcriptional apoptosis induction mechanisms.

Main Results:

  • Two distinct transcription-independent mechanisms of p53-mediated apoptosis have been identified.
  • These mechanisms operate either in the cytosol or directly at the mitochondria.
  • Both pathways converge by activating pro-apoptotic proteins Bax or Bak, leading to outer mitochondrial membrane permeabilization.

Conclusions:

  • p53 utilizes transcription-independent pathways to induce apoptosis.
  • These pathways, localized in the cytosol or at mitochondria, ultimately activate Bax/Bak.
  • This highlights a crucial, non-transcriptional role of p53 in tumor suppression via mitochondrial apoptosis.

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