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Identification of Intracellular Signaling Events Induced in Viable Cells by Interaction with Neighboring Cells Undergoing Apoptotic Cell Death
09:18

Identification of Intracellular Signaling Events Induced in Viable Cells by Interaction with Neighboring Cells Undergoing Apoptotic Cell Death

Published on: December 27, 2016

The PP2A-associated protein alpha4 is an essential inhibitor of apoptosis

Mei Kong1, Casey J Fox, James Mu

  • 1Abramson Family Cancer Research Institute, University of Pennsylvania, Philadelphia, PA 19104, USA.

Science (New York, N.Y.)
|October 23, 2004
PubMed

Insights

The protein phosphatase 2A (PP2A) subunit alpha4 is crucial for cell survival by repressing apoptosis. Its absence triggers proapoptotic gene transcription, highlighting PP2A

Area of Science:

  • Cell biology
  • Molecular biology
  • Biochemistry

Background:

  • Protein kinases are known regulators of apoptosis (programmed cell death).
  • The specific role of phosphatases in regulating cell survival remained unclear.
  • Protein Phosphatase 2A (PP2A) is a key enzyme involved in various cellular processes.

Purpose of the Study:

  • To investigate the role of phosphatases, specifically PP2A, in regulating cell survival.
  • To determine if PP2A subunits are involved in controlling apoptosis.

Main Methods:

  • Deletion of the alpha4 subunit of PP2A in murine cells.
  • Analysis of transcription factors c-Jun and p53 dephosphorylation.
  • Gene expression analysis to identify transcribed proapoptotic genes.
  • Experiments involving inhibition of protein synthesis and Bcl-xL overexpression.

Main Results:

  • The alpha4 subunit of PP2A is essential for repressing apoptosis in murine cells.
  • Alpha4 regulates the dephosphorylation of transcription factors c-Jun and p53.
  • Alpha4 deletion leads to the transcription of multiple proapoptotic genes.
  • Inhibition of protein synthesis or Bcl-xL overexpression counteracted alpha4 deletion-induced apoptosis.

Conclusions:

  • Mammalian cell viability is dependent on the repression of transcription-initiated apoptosis.
  • A component of PP2A, the alpha4 subunit, plays a critical role in this repression.
  • This study establishes a specific role for phosphatases in regulating cell survival.

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