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Deciphering UBE4B phosphorylation dynamics: a key mechanism in p53 accumulation and cancer cell response to DNA

Yasser Abuetabh1, H Helena Wu1, Habib Al Yousef1

  • 1370 Heritage Medical Research Center, Department of Laboratory Medicine and Pathology, University of Alberta, Edmonton, AB, T6G 2S2, Canada.

Cell Death Discovery
|April 2, 2025
PubMed

Insights

UBE4B protein regulates the tumor suppressor p53. DNA damage triggers UBE4B phosphorylation, reducing p53 binding and activating p53. Wip1 dephosphorylation stabilizes UBE4B, impacting cancer cell growth.

Area of Science:

  • Molecular Biology
  • Cancer Research
  • Cellular Signaling

Background:

  • p53 tumor suppressor is vital for eliminating oncogenic threats via cell cycle arrest, DNA repair, senescence, and apoptosis.
  • UBE4B negatively regulates p53 under normal conditions and after DNA damage, targeting phosphorylated p53 for degradation.
  • The regulation of UBE4B in response to DNA damage in cancer remains poorly understood.

Purpose of the Study:

  • To investigate the phosphorylation and dephosphorylation mechanisms regulating UBE4B in response to DNA damage in cancer.
  • To elucidate the role of Wip1 in UBE4B dephosphorylation and its impact on p53 stability.
  • To explore the therapeutic potential of targeting UBE4B regulation in cancer treatment.

Main Methods:

  • Investigated UBE4B phosphorylation and dephosphorylation in response to DNA damage.
  • Assessed the binding affinity between UBE4B and p53 under different phosphorylation states.
  • Utilized Wip1 inhibition to study its effect on UBE4B activity and p53 accumulation.
  • Examined ATR-mediated signaling in UBE4B phosphorylation.

Main Results:

  • UBE4B phosphorylation, mediated by ATR signaling, reduces its binding affinity to p53, leading to p53 accumulation.
  • Wip1 dephosphorylates UBE4B, stabilizing its activity in response to DNA damage.
  • Inhibition of Wip1 significantly increases UBE4B phosphorylation, causing greater p53 accumulation and reduced cell growth.
  • UBE4B regulation via phosphorylation/dephosphorylation is critical for p53 stability and cancer cell proliferation.

Conclusions:

  • UBE4B phosphorylation/dephosphorylation is a key regulatory mechanism for p53 stability in response to DNA damage.
  • Wip1 plays a critical role in dephosphorylating UBE4B, influencing p53 levels and cancer cell growth.
  • Targeting UBE4B regulation in cancer cells could offer novel therapeutic strategies for improving patient outcomes.

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