Related Experiment Video

Updated: May 26, 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

p53 and DNA-dependent protein kinase catalytic subunit independently function in regulating actin damage-induced

Hee-Don Chae1, So Youn Kim, Sang Eun Park

  • 1Department of Microbiology and Immunology, Dankook University College of Medicine, Cheonan 330-714, Korea.

Experimental & Molecular Medicine
|December 27, 2011
PubMed

Insights

DNA-PKcs is crucial for maintaining tetraploid G1 arrest after actin damage, acting independently of p53. This prevents polyploidy and apoptosis, highlighting distinct roles in cell cycle regulation.

Area of Science:

  • Cell Biology
  • Molecular Biology
  • Cancer Research

Background:

  • The p53 tumor suppressor protein is vital for tetraploid G1 arrest following actin cytoskeleton damage.
  • The roles of ATM and DNA-PKcs in this process were previously unclear.

Purpose of the Study:

  • To investigate the involvement of p53, ATM, and DNA-PKcs in tetraploid G1 arrest induced by actin damage.
  • To elucidate the specific functions and independence of these proteins in cell cycle regulation.

Main Methods:

  • Treatment of cells with actin-damaging agents (e.g., pectenotoxin-2).
  • Assessment of p53 phosphorylation at specific residues (Ser-15, Ser-37, Ser-20).
  • Gene knockdown of ATM and DNA-PKcs to observe effects on cell cycle arrest, polyploidy, and apoptosis.

Main Results:

  • Actin damage increases p53 phosphorylation at Ser-15 and Ser-37, but not Ser-20.
  • ATM and DNA-PKcs knockdown do not affect p53 phosphorylation.
  • DNA-PKcs knockdown, unlike ATM knockdown, disrupts tetraploid G1 arrest, leading to polyploidy and apoptosis.
  • p53 induction is linked to tetraploidy, not actin damage itself.

Conclusions:

  • DNA-PKcs is essential for maintaining actin damage-induced tetraploid G1 arrest in a p53-independent manner.
  • p53 and DNA-PKcs function independently to ensure tetraploid G1 arrest and prevent polyploidy.
  • These findings clarify distinct pathways in cell cycle control following cytoskeletal disruption.

More Related Videos

Detection and Visualization of DNA Damage-induced Protein Complexes in Suspension Cell Cultures Using the Proximity Ligation Assay13:10

Detection and Visualization of DNA Damage-induced Protein Complexes in Suspension Cell Cultures Using the Proximity Ligation Assay

Published on: June 9, 2017

Establishment of Proliferative Tetraploid Cells from Nontransformed Human Fibroblasts10:04

Establishment of Proliferative Tetraploid Cells from Nontransformed Human Fibroblasts

Published on: January 8, 2017

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...
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.
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...
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...
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...