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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

MDM2-ARF complex regulates p53 sumoylation

Lihong Chen1, Jiandong Chen

  • 1Molecular Oncology Program, H Lee Moffitt Comprehensive Cancer Center and Research Institute, 12902 Magnolia Drive, Tampa, FL 33612, USA.

Oncogene
|August 15, 2003
PubMed

Insights

The p53 tumor suppressor protein

Area of Science:

  • Molecular Biology
  • Cell Biology
  • Cancer Research

Background:

  • The p53 tumor suppressor is regulated by MDM2-mediated ubiquitination and degradation.
  • ARF inhibits MDM2's E3 ligase function, impacting p53 ubiquitination.
  • p53 undergoes modification via SUMO-1 conjugation.

Purpose of the Study:

  • To investigate the regulation of p53 sumoylation.
  • To determine the roles of MDM2 and ARF in p53 sumoylation.
  • To explore the influence of nucleolar targeting on p53 sumoylation.

Main Methods:

  • Analysis of p53 mutants deficient for MDM2 binding.
  • Overexpression studies of MDM2 and ARF.
  • Investigation of ARF's conserved region (102-116) and its role in nucleolar targeting.
  • Utilizing an MDM2 deletion mutant with an activated nucleolar localization signal.

Main Results:

  • A p53 mutant lacking MDM2 binding showed reduced sumoylation.
  • MDM2 overexpression increased p53 sumoylation, further enhanced by ARF.
  • ARF's exon 2 region and nucleolar targeting capability were crucial for stimulating p53 sumoylation.
  • An engineered MDM2 mutant promoted p53 sumoylation via nucleolar targeting independently of ARF.

Conclusions:

  • p53 sumoylation is regulated by MDM2 and ARF.
  • Nucleolar targeting of p53, mediated by MDM2 and ARF, enhances its sumoylation.
  • This study elucidates a novel mechanism controlling p53 post-translational modification.

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