Related Experiment Video

Updated: Aug 24, 2026

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

p53's double life: transactivation-independent repression of homologous recombination

Pascale Bertrand1, Yannick Saintigny, Bernard S Lopez

  • 1UMR CEA/CNRS 217, CEA, Direction des Sciences du Vivant, Département de Radiobiologie et Radiopathologie, 18 route du panorama, 92265, Fontenay-aux-Roses, Cedex, France.

Trends in Genetics : TIG
|May 18, 2004
PubMed

Insights

The tumor suppressor protein p53 directly suppresses homologous recombination (HR), a DNA repair process. This transcription-independent function helps maintain genome stability and protect against tumors.

Area of Science:

  • Molecular Biology
  • Genetics
  • Cancer Research

Background:

  • The tumor suppressor protein p53 is known to regulate cell cycle checkpoints and apoptosis.
  • Emerging evidence suggests p53 has additional roles beyond gene transactivation.

Purpose of the Study:

  • To investigate the transcription-independent role of p53 in suppressing homologous recombination (HR).
  • To elucidate the mechanisms by which p53 directly impacts HR and its implications for genome stability.

Main Methods:

  • Analysis of genetic and physical interactions between p53 and HR proteins (RAD51, RAD54).
  • Examination of p53's effect on early and late stages of DNA recombination.
  • Comparison of p53's function with the MSH2 mismatch-repair system.

Main Results:

  • p53 directly interacts with HR proteins and DNA intermediates, suppressing HR.
  • p53 influences HR by controlling processing segments and reversing recombination intermediates.
  • p53 balances BLM and RAD51 pathways to maintain genome stability during DNA damage.

Conclusions:

  • p53 plays a direct, transcription-independent role in suppressing homologous recombination.
  • This function of p53 is crucial for maintaining genome stability, particularly when replication forks are stalled.
  • The direct suppression of HR by p53 has implications for tumor protection and potentially speciation.

More Related Videos

Detection of Aggregation-Prone Behavior in Mutant P53 V157F Breast Cancer Cells Using Multipoint Thioflavin T Fluorescence04:56

Detection of Aggregation-Prone Behavior in Mutant P53 V157F Breast Cancer Cells Using Multipoint Thioflavin T Fluorescence

Published on: December 30, 2025

Purification of Ubiquitinated p53 Proteins from Mammalian Cells10:55

Purification of Ubiquitinated p53 Proteins from Mammalian Cells

Published on: March 21, 2022

Related Concept Videos

Abnormal Proliferation02:23

Abnormal Proliferation

Under normal conditions, most adult cells remain in a non-proliferative state unless stimulated by internal or external factors to replace lost cells. Abnormal cell proliferation is a condition in which the cell's growth exceeds and is uncoordinated with normal cells. In such situations, cell division persists in the same excessive manner even after cessation of the stimuli, leading to persistent tumors. The tumor arises from the damaged cells that replicate to pass the damage to the daughter...
DNA Damage can Stall the Cell Cycle02:36

DNA Damage can Stall the Cell Cycle

In response to DNA damage, cells can pause the cell cycle to assess and repair the breaks. However, the cell must check the DNA at certain critical stages during the cell cycle. If the cell cycle pauses before DNA replication, the cells will contain twice the amount of DNA. On the other hand, if cells arrest after DNA replication but before mitosis, they will contain four times the normal amount of DNA. With a host of specialized proteins at their disposal,cells must use the right protein at...
DNA Damage Can Stall the Cell Cycle02:36

DNA Damage Can Stall the Cell Cycle

In response to DNA damage, cells can pause the cell cycle to assess and repair the breaks. However, the cell must check the DNA at certain critical stages during the cell cycle. If the cell cycle pauses before DNA replication, the cells will contain twice the amount of DNA. On the other hand, if cells arrest after DNA replication but before mitosis, they will contain four times the normal amount of DNA. With a host of specialized proteins at their disposal,cells must use the right protein at...
Negative Regulator Molecules01:23

Negative Regulator Molecules

Positive regulators allow a cell to advance through cell cycle checkpoints. Negative regulators have an equally important role as they terminate a cell’s progression through the cell cycle—or pause it—until the cell meets specific criteria.
Conservative Site-specific Recombination and Phase Variation02:53

Conservative Site-specific Recombination and Phase Variation

Because the DNA segments are cut and reorganized in a direction-specific manner, site-specific recombination has emerged as an efficient genetic engineering technique. Flippase and Cyclization recombinases or Flp and Cre, respectively, are two members of the tyrosine recombinase family derived from bacteriophages, that are used to mediate site-specific DNA insertions, deletions, and targeted expression of proteins in mammalian cell lines.
The recognition sites for Cre recombinase called LoxP...
Homologous Recombination02:31

Homologous Recombination

The basic reaction of homologous recombination (HR) involves two chromatids that contain DNA sequences sharing a significant stretch of identity. One of these sequences uses a strand from another as a template to synthesize DNA in an enzyme-catalyzed reaction. The final product is a novel amalgamation of the two substrates. To ensure an accurate recombination of sequences, HR is restricted to the S and G2 phases of the cell cycle. At these stages, the DNA has been replicated already and the...