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Purification of Ubiquitinated p53 Proteins from Mammalian Cells
10:55

Purification of Ubiquitinated p53 Proteins from Mammalian Cells

Published on: March 21, 2022

Ursodeoxycholic acid modulates the ubiquitin-proteasome degradation pathway of p53

Joana D Amaral1, Rui E Castro, Susana Solá

  • 1Research Institute for Medicines and Pharmaceutical Sciences, Faculty of Pharmacy, University of Lisbon, Lisbon 1649-003, Portugal.

Biochemical and Biophysical Research Communications
|September 3, 2010
PubMed

Insights

Ursodeoxycholic acid (UDCA) protects cells from apoptosis by targeting the p53 protein. UDCA promotes p53 degradation through the Mdm-2-ubiquitin-proteasome pathway, thereby reducing p53 stability and function.

Area of Science:

  • Cell Biology
  • Biochemistry
  • Molecular Biology

Background:

  • The p53 protein is a critical regulator of apoptosis.
  • The Mdm-2 protein targets p53 for degradation.
  • Ursodeoxycholic acid (UDCA) is known to interact with the p53/Mdm-2 pathway.

Purpose of the Study:

  • To investigate the role of UDCA in downregulating p53 stability and function.
  • To elucidate the mechanism by which UDCA affects p53 degradation.
  • To determine if UDCA protects against p53-induced apoptosis.

Main Methods:

  • Primary rat hepatocytes were treated with UDCA.
  • Protein half-life, ubiquitination, and degradation assays were performed.
  • Immunoprecipitation, proteasome inhibition, and siRNA gene silencing were utilized.
  • p53-induced apoptosis was assessed under various experimental conditions.

Main Results:

  • UDCA reduced p53 protein stability by decreasing its half-life.
  • UDCA promoted p53 ubiquitination, leading to increased degradation via the proteasome.
  • Mdm-2 was confirmed to be essential for UDCA-mediated p53 degradation.
  • UDCA's protective effect against p53-induced apoptosis was dependent on Mdm-2 and proteasome activity.

Conclusions:

  • UDCA protects cells from p53-mediated apoptosis.
  • This protection is achieved by promoting p53 degradation through the Mdm-2-ubiquitin-proteasome pathway.
  • UDCA represents a potential therapeutic agent for conditions involving p53-mediated apoptosis.

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