Related Experiment Video

Updated: Jun 16, 2026

Two- and Three-Dimensional Live Cell Imaging of DNA Damage Response Proteins
10:24

Two- and Three-Dimensional Live Cell Imaging of DNA Damage Response Proteins

Published on: September 28, 2012

Multiple roles of the cell cycle inhibitor p21(CDKN1A) in the DNA damage response

Ornella Cazzalini1, A Ivana Scovassi, Monica Savio

  • 1Dipartimento di Medicina Sperimentale, sez. Patologia Generale "C. Golgi", Università di Pavia, 27100 Pavia, Italy.

Mutation Research
|January 26, 2010
PubMed

Insights

The cyclin-dependent kinase inhibitor p21 (CDKN1A) is crucial for DNA damage response, regulating cell cycle, apoptosis, and transcription. Emerging evidence highlights p21

Area of Science:

  • Molecular Biology
  • Cell Biology
  • Genetics

Background:

  • The cyclin-dependent kinase inhibitor p21 (CDKN1A) is activated upon DNA damage.
  • p21 regulates fundamental cellular processes including cell cycle arrest, DNA replication inhibition, apoptosis, and transcription.
  • p21's functions are mediated through interactions with various proteins involved in these processes.

Purpose of the Study:

  • To review the multifaceted roles of p21 in the DNA damage response.
  • To discuss recent findings on p21's direct involvement in DNA repair mechanisms.
  • To analyze the spatio-temporal dynamics of p21 recruitment to DNA damage sites and its regulatory role.

Main Methods:

  • Literature review of existing studies on p21 function in DNA damage response.
  • Analysis of evidence supporting p21's direct participation in DNA repair pathways (NER, BER, TLS).
  • Examination of post-translational modifications and their impact on p21 stability and function after DNA damage.

Main Results:

  • p21 plays essential roles in cell cycle regulation, apoptosis, and transcription following DNA damage.
  • Evidence suggests p21 directly participates in DNA repair processes like nucleotide excision repair (NER), base excision repair (BER), and DNA translesion synthesis (TLS).
  • p21 interacts with proliferating cell nuclear antigen (PCNA), a key factor in DNA metabolism and cell-cycle regulation, to facilitate these repair functions.

Conclusions:

  • p21 is a critical regulator of the DNA damage response, with established roles in cell cycle control, apoptosis, and transcription.
  • Recent findings strongly support p21's direct involvement in DNA repair pathways, mediated by its interaction with PCNA.
  • Understanding p21's recruitment dynamics and post-translational regulation is crucial for comprehending the overall DNA damage response.

More Related Videos

Visualizing and Quantifying Endonuclease-Based Site-Specific DNA Damage10:59

Visualizing and Quantifying Endonuclease-Based Site-Specific DNA Damage

Published on: August 21, 2021

Visualizing Single-Stranded DNA Foci in the G1 Phase of the Cell Cycle08:30

Visualizing Single-Stranded DNA Foci in the G1 Phase of the Cell Cycle

Published on: December 22, 2023

Related Concept Videos

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...
Inhibition of Cdk Activity02:34

Inhibition of Cdk Activity

The orderly progression of the cell cycle depends on the activation of Cdk protein by binding to its cyclin partner. However, the cell cycle must be restricted when undergoing abnormal changes. Most cancers correlate to the deregulated cell cycle, and since Cdks are a central component of the cell cycle, Cdk inhibitors are extensively studied to develop anticancer agents. For instance, cyclin D associates with several Cdks, such as Cdk 4/6, to form an active complex. The cyclin D-Cdk4/6 complex...
Inhibition of CDK Activity02:34

Inhibition of CDK Activity

The orderly progression of the cell cycle depends on the activation of Cdk protein by binding to its cyclin partner. However, the cell cycle must be restricted when undergoing abnormal changes. Most cancers correlate to the deregulated cell cycle, and since Cdks are a central component of the cell cycle, Cdk inhibitors are extensively studied to develop anticancer agents. For instance, cyclin D associates with several Cdks, such as Cdk 4/6, to form an active complex. The cyclin D-Cdk4/6 complex...
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.
Positive Regulator Molecules02:39

Positive Regulator Molecules

Mitotic cell division results in daughter cells that exactly resemble the parent cell. However, errors in the DNA replication or distribution of genetic material may lead to genetic mutations that may be passed down to every new cell formed from the resulting abnormal cell. Propagation of such mutant cells is restricted through checkpoint mechanisms present at different stages of the cell cycle. These checkpoints involve regulator molecules that either promote or demote cell cycle events.