Related Experiment Video

Updated: Jul 19, 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

A network of p73, p53 and Egr1 is required for efficient apoptosis in tumor cells

J Yu1, V Baron, D Mercola

  • 1Burnham Institute for Medical Research, Cancer Research Center, La Jolla, CA 92037, USA.

Cell Death and Differentiation
|September 23, 2006
PubMed

Insights

The transcription factor p73, particularly the TAp73 form, is upregulated by Egr1 in response to genotoxic stress. This interaction, along with feedback loops, sustains p53 family gene expression for efficient apoptosis.

Area of Science:

  • Molecular Biology
  • Cancer Biology
  • Genetics

Background:

  • p73 is a transcription factor regulating p53 target genes involved in cellular responses to genotoxic stress, including growth arrest and apoptosis.
  • Two main forms of p73 exist: TAp73, which mimics p53 functions, and DeltaNp73, which can be oncogenic.

Purpose of the Study:

  • To investigate the regulatory mechanisms of TAp73 and DeltaNp73 expression.
  • To elucidate the role of Egr1 in the transcriptional regulation of p73.
  • To understand the feedback loops governing p53 family gene expression under stress.

Main Methods:

  • Analysis of Egr1-binding sites on the TP73 P1 promoter.
  • Investigating the induction of TAp73 and DeltaNp73 by Egr1, TAp73, and p53.
  • In vivo studies in mice to assess Egr1's role in TAp73 induction by genotoxic stress.
  • Identification of non-consensus p53-binding sites in p73, p53, and Egr1 promoters.

Main Results:

  • The TP73 P1 promoter, producing TAp73, contains five Egr1-binding sites that upregulate TAp73 transcription.
  • The TP73 P2 promoter, transcribing DeltaNp73, is not induced by Egr1 but is induced by TAp73 and p53.
  • Egr1 is essential for TAp73 induction by genotoxic stress in vivo in mice.
  • Novel p53-binding sites in p73, p53, and Egr1 promoters reveal complex inter-regulatory networks.

Conclusions:

  • Egr1 plays a crucial role in the stress-induced upregulation of TAp73.
  • Inter-regulating networks and feedback loops involving p53 family members and Egr1 ensure sustained gene expression and efficient apoptosis.
  • These findings highlight a complex regulatory network essential for cellular response to DNA damage.

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

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...
The Intrinsic Apoptotic Pathway01:31

The Intrinsic Apoptotic Pathway

Internal cellular stress, such as cellular injury or hypoxia, triggers intrinsic apoptosis. The B-cell lymphoma 2 (Bcl-2) family of proteins are the primary regulators of the intrinsic apoptotic pathway. For example, during DNA damage, checkpoint proteins, such as Ataxia Telangiectasia Mutated (ATM protein) and Checkpoints Factor-2 (Chk2) proteins, are activated. These proteins phosphorylate p53 which further activates pro-apoptotic proteins, such as Bax, Bak, PUMA, and Noxa, and inhibits...
Interactions Between Signaling Pathways01:19

Interactions Between Signaling Pathways

Signaling cascades usually lack linearity. Multiple pathways interact and regulate one another, allowing cells to integrate and respond to diverse environmental stimuli.
Convergence and divergence, and cross-talk between signaling pathways
Two distinct signaling pathways can converge on a single functional unit, which may either be a single protein or a complex of proteins. The response is either functionally distinct or synergistic between the two pathways but different from the response...
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.