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

Published on: August 4, 2019

JFK, a Kelch domain-containing F-box protein, links the SCF complex to p53 regulation

Luyang Sun1, Lei Shi, Wenqian Li

  • 1Department of Biochemistry and Molecular Biology, Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Peking University Health Science Center, Beijing, China.

Proceedings of the National Academy of Sciences of the United States of America
|June 11, 2009
PubMed

Insights

JFK, a novel F-box protein, targets the p53 tumor suppressor for degradation via the Skp1-Cul1-F-box complex. Depleting JFK stabilizes p53, promoting apoptosis and sensitizing cells to radiation.

Area of Science:

  • Molecular Biology
  • Cell Biology
  • Cancer Research

Background:

  • The p53 tumor suppressor is crucial for maintaining genome integrity and regulating cell proliferation in response to cellular stress.
  • Several ubiquitin ligases, including MDM2, Pirh2, COP1, and ARF-BP1, are known to degrade p53.
  • Understanding p53 regulation is vital for cancer therapy.

Purpose of the Study:

  • To identify novel regulators of p53.
  • To investigate the role of the F-box protein JFK in p53 regulation.
  • To elucidate the mechanism by which JFK affects p53 stability and function.

Main Methods:

  • Identification and characterization of the F-box protein JFK.
  • Assays to determine JFK's effect on p53 ubiquitination and degradation.
  • Analysis of JFK's role in p53-dependent transcription and cellular processes.
  • Depletion studies using siRNA to assess the in vivo function of JFK.

Main Results:

  • JFK, a human Kelch domain-containing F-box protein, was identified.
  • JFK promotes the ubiquitination and degradation of p53.
  • Unlike other ligases, JFK functions through the Skp1-Cul1-F-box complex to destabilize p53.
  • JFK depletion leads to p53 stabilization, G1 cell cycle arrest, apoptosis, and increased sensitivity to ionizing radiation.

Conclusions:

  • JFK is a critical negative regulator of p53.
  • JFK contributes to maintaining low p53 levels in unstressed cells.
  • This study links the Skp1-Cul1-F-box system to the regulation of p53, offering new insights into cancer biology.

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