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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

Stabilization and activation of p53 by the coactivator protein TAFII31

T Buschmann1, Y Lin, N Aithmitti

  • 1Derald H. Ruttenberg Cancer Center, Mount Sinai School of Medicine, New York, New York 10029, USA.

The Journal of Biological Chemistry
|March 30, 2001
PubMed

Insights

The coactivator TAF(II)31 stabilizes the tumor suppressor p53 by blocking mdm2-mediated degradation. This stabilization activates p53

Area of Science:

  • Molecular Biology
  • Cell Biology
  • Cancer Research

Background:

  • p53 is a crucial tumor suppressor whose stability is tightly regulated.
  • MDM2 targets p53 for degradation via the ubiquitin-proteasome pathway.
  • The p53 amino-terminal region is critical for both MDM2 interaction and transcriptional regulation.

Purpose of the Study:

  • To investigate the role of TAF(II)31 in regulating p53 stability and function.
  • To determine if TAF(II)31 can modulate the interaction between p53 and MDM2.

Main Methods:

  • Co-immunoprecipitation assays to assess protein interactions.
  • Western blotting to measure protein levels (p53, TAF(II)31, MDM2).
  • Functional assays measuring p53 transcriptional activity and cell growth arrest.

Main Results:

  • TAF(II)31 expression inhibits MDM2-mediated ubiquitination and degradation of p53.
  • TAF(II)31 stabilizes p53, leading to enhanced p53 transcriptional activity and p53-dependent growth arrest.
  • UV irradiation increases p53-associated TAF(II)31 and decreases MDM2-p53 interaction; a non-binding mutant of TAF(II)31 fails to stabilize p53.

Conclusions:

  • Direct interaction of TAF(II)31 with p53 is essential for p53 stabilization.
  • TAF(II)31 protects p53 from MDM2-mediated degradation, thereby activating p53's tumor-suppressive functions.

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