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Impaired p53 expression, function, and nuclear localization in calreticulin-deficient cells

Nasrin Mesaeli1, Clark Phillipson

  • 1Division of Stroke and Vascular Disease, St. Boniface General Hospital Research Centre, University of Manitoba, Winnipeg, Canada R2H 2A6. nmasaeli@sbrc.ca

Molecular Biology of the Cell
|February 10, 2004
PubMed

Insights

Calreticulin (CRT) is essential for the stability and nuclear localization of the tumor suppressor p53. CRT deficiency impairs p53 function, impacting apoptosis regulation.

Area of Science:

  • Molecular Biology
  • Cell Biology
  • Cancer Research

Background:

  • The tumor suppressor p53 is a transcription factor regulating gene expression, apoptosis, and cell cycle arrest.
  • DNA damage stabilizes p53, promoting nuclear localization and apoptosis.
  • Calreticulin (CRT) levels correlate with apoptosis rates.

Purpose of the Study:

  • To investigate the role of Calreticulin (CRT) in regulating apoptosis by modulating p53 function and expression.
  • To determine if CRT is necessary for p53 stability and localization.

Main Methods:

  • Comparison of p53 function in CRT-deficient (crt-/-) cells versus wild-type cells.
  • Assessment of p53 stability and nuclear localization.
  • Immunocytochemical analysis to investigate Mdm2 (murine double minute gene) localization.

Main Results:

  • CRT-deficient cells exhibit significantly decreased basal and DNA damage-induced p53 functions.
  • CRT is demonstrated to be required for p53 protein stability and proper nuclear localization.
  • CRT deficiency leads to nuclear accumulation of Mdm2 in cells.

Conclusions:

  • Calreticulin (CRT) regulates p53 function by influencing its degradation rate and nuclear localization.
  • CRT plays a critical role in maintaining p53 stability and function, impacting apoptosis pathways.

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