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Purification of Ubiquitinated p53 Proteins from Mammalian Cells
10:55

Purification of Ubiquitinated p53 Proteins from Mammalian Cells

Published on: March 21, 2022

Def defines a conserved nucleolar pathway that leads p53 to proteasome-independent degradation

Ting Tao1, Hui Shi, Yihong Guan

  • 1Key Laboratory for Molecular Animal Nutrition, College of Animal Sciences, Ministry of Education, Zhejiang University, Hangzhou, Zhejiang 310058, China.

Cell Research
|January 30, 2013
PubMed

Insights

Digestive organ expansion factor (Def) regulates p53 protein levels via a novel nucleolar pathway. This proteasome-independent process involves Calpain3 and impacts organogenesis and tumorigenesis.

Area of Science:

  • Molecular Biology
  • Developmental Biology
  • Cellular Biology

Background:

  • p53 protein turnover is crucial for regulating its transcriptional activity.
  • The role of proteasome-independent pathways in p53 regulation remains largely unknown.
  • Digestive organ expansion factor (Def) is essential for digestive organ development.

Purpose of the Study:

  • To investigate the relationship between Def and p53.
  • To elucidate the mechanism of p53 regulation by Def.
  • To identify novel pathways governing p53 turnover.

Main Methods:

  • Zebrafish model system for loss-of-function studies.
  • Immunofluorescence to detect p53 localization.
  • Biochemical assays to assess protein degradation pathways.

Main Results:

  • Loss of Def function in zebrafish upregulates p53 protein levels.
  • p53 protein accumulates in the nucleoli upon Def loss.
  • Def mediates p53 degradation through a proteasome-independent pathway dependent on Calpain3 activity.

Conclusions:

  • Def regulates p53 turnover via a novel nucleolar pathway.
  • This pathway is independent of the proteasome but relies on Calpain3.
  • Findings advance understanding of p53's role in organogenesis and tumorigenesis.

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