p53 governs telomere regulation feedback too, via TRF2

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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

Izumi Horikawa1, Kaori Fujita, Curtis C Harris

  • 1Laboratory of Human Carcinogenesis, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA.

Aging
|January 27, 2011
PubMed

Insights

p53 regulates cellular responses to damaged telomeres by inhibiting TRF2, creating a feedback loop. Siah1 targets TRF2 for degradation, amplifying this response to uncapped telomeres.

Area of Science:

  • Molecular biology
  • Cellular senescence
  • DNA damage response

Background:

  • p53 is crucial for regulating carcinogenesis and aging.
  • Dysfunctional telomeres trigger DNA damage, activating ATM kinase and p53.
  • p53 induces cellular senescence or apoptosis in response to DNA damage.

Purpose of the Study:

  • To investigate the role of p53 in telomere damage signaling.
  • To elucidate the feedback mechanisms regulating p53-mediated cellular responses.
  • To identify key regulators in the p53-TRF2 interaction.

Main Methods:

  • Investigated p53's interaction with the telomere-capping complex.
  • Assessed the impact of TRF2 inhibition on ATM activation.
  • Examined the role of Siah1 in TRF2 degradation.

Main Results:

  • p53 inhibits TRF2, a component of the telomere-capping complex.
  • TRF2 inhibition leads to ATM activation, forming a positive feedback loop.
  • Siah1, a p53-inducible E3 ligase, targets TRF2 for ubiquitination and degradation.

Conclusions:

  • A novel positive feedback loop amplifies p53-mediated responses to uncapped telomeres.
  • Siah1 is a key regulator in this feedback loop, targeting TRF2.
  • Understanding this mechanism has potential therapeutic implications for aging and cancer.

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