Related Experiment Video

Updated: Nov 17, 2025

Author Spotlight: Visualizing Single-Stranded DNA During DNA Repair for Therapeutic Insights
08:30

Author Spotlight: Visualizing Single-Stranded DNA During DNA Repair for Therapeutic Insights

Published on: December 22, 2023

3.0K

The Srs2 helicase dampens DNA damage checkpoint by recycling RPA from chromatin

Nalini Dhingra1, Sahiti Kuppa2, Lei Wei1

  • 1Molecular Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY 10065.

Proceedings of the National Academy of Sciences of the United States of America
|February 19, 2021
PubMed

Insights

The DNA helicase Srs2 dampens DNA damage checkpoint signaling by removing RPA from chromatin. This mechanism is crucial for cell cycle resumption and survival under genotoxic stress.

Area of Science:

  • * Molecular biology
  • * Cell biology
  • * Genetics

Background:

  • * The DNA damage checkpoint is vital for cellular response to genotoxic stress.
  • * Persistent checkpoint signaling can impede cell cycle progression and growth.
  • * Mechanisms for checkpoint dampening are not fully understood.

Purpose of the Study:

  • * To investigate the role of the DNA helicase Srs2 in regulating DNA damage checkpoint signaling.
  • * To elucidate the interaction between Srs2 and the RPA complex in checkpoint control.
  • * To understand how Srs2-mediated checkpoint dampening contributes to cellular survival.

Main Methods:

  • * Genetic interaction analysis in budding yeast (Saccharomyces cerevisiae).
  • * Chromatin immunoprecipitation to assess protein binding.
  • * Analysis of checkpoint kinase activity and cell cycle progression.

Main Results:

  • * Srs2 removes the RPA complex from chromatin, down-regulating checkpoint signaling.
  • * Genetic interactions confirm antagonism between Srs2 and RPA.
  • * Reduced RPA binding to single-strand DNA (ssDNA) rescues checkpoint defects in srs2 mutants.
  • * Srs2's regulation of RPA is distinct from its role in recombinational repair.
  • * This pathway is critical for resistance to genotoxins.

Conclusions:

  • * Srs2-mediated RPA recycling from chromatin is a key mechanism for dampening the DNA damage checkpoint.
  • * This process facilitates cell cycle resumption and enhances survival during genotoxic stress.
  • * The findings have implications for understanding DNA repair and other DNA transactions.
Keywords:
RPA regulationSrs2checkpoint dampeninggenotoxic stressrecombinational repair

More Related Videos

Assessment of Global DNA Double-Strand End Resection using BrdU-DNA Labeling coupled with Cell Cycle Discrimination Imaging06:44

Assessment of Global DNA Double-Strand End Resection using BrdU-DNA Labeling coupled with Cell Cycle Discrimination Imaging

Published on: April 28, 2021

4.3K
Visualization of DNA Repair Proteins Interaction by Immunofluorescence07:55

Visualization of DNA Repair Proteins Interaction by Immunofluorescence

Published on: June 26, 2020

10.7K

Related Concept Videos

Restarting Stalled Replication Forks02:37

Restarting Stalled Replication Forks

DNA replication is initiated at sites containing predefined DNA sequences known as origins of replication. DNA is unwound at these sites by the minichromosome maintenance (MCM) helicase and other factors such as Cdc45 and the associated GINS complex.The unwound single strands are protected by replication protein A (RPA) until DNA polymerase starts synthesizing DNA at the 5’ end of the strand in the same direction as the replication fork. To prevent the replication fork from falling apart,...
6.1K
DNA Damage can Stall the Cell Cycle02:37

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...
9.7K
DNA Damage Can Stall the Cell Cycle02:37

DNA Damage Can Stall the Cell Cycle

2.9K
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...
58.9K
The Spindle Assembly Checkpoint02:19

The Spindle Assembly Checkpoint

The spindle assembly checkpoint is a molecular surveillance mechanism ensuring the fidelity of chromosome segregation during anaphase. The checkpoint monitors the completion of all the prerequisite steps before chromosome segregation to determine whether the segregation process should proceed or be delayed.
Many proteins function together to control the spindle assembly checkpoint. Mutations affecting these proteins may allow cells to proceed into anaphase prematurely, resulting in the...
3.4K
The DNA Replication Fork01:02

The DNA Replication Fork

An organism’s genome needs to be duplicated in an efficient and error-free manner for its growth and survival. The replication fork is a Y-shaped active region where two strands of DNA are separated and replicated continuously. The coupling of DNA unzipping and complementary strand synthesis is a characteristic feature of a replication fork.   Organisms with small circular DNA, such as E. coli, often have a single origin of replication; therefore, they have only two replication...
38.7K