Related Experiment Video
Updated: May 27, 2026
10:59
Visualizing and Quantifying Endonuclease-Based Site-Specific DNA Damage
Published on: August 21, 2021
Eukaryotic DNA damage checkpoint activation in response to double-strand breaks
Karen Finn1, Noel Francis Lowndes, Muriel Grenon
1Centre for Chromosome Biology, School of Natural Sciences, National University of Ireland Galway, Galway, Ireland.
Cellular and Molecular Life Sciences : CMLS
|November 16, 2011
Summary
DNA double-strand breaks (DSBs) trigger a DNA damage response (DDR) involving cell cycle checkpoints. This review explores how yeast Saccharomyces cerevisiae repairs DSBs to maintain genome stability.
Area of Science:
- Molecular Biology
- Cell Biology
- Genetics
Background:
- DNA double-strand breaks (DSBs) represent a critical form of DNA damage.
- Unrepaired DSBs can lead to genomic instability and diseases like cancer.
- The DNA damage response (DDR) is essential for detecting and repairing DSBs.
Purpose of the Study:
- To review the molecular mechanisms of the DNA damage checkpoint in response to DSBs.
- To provide a comprehensive overview of DSB repair pathways in Saccharomyces cerevisiae.
- To highlight the conserved nature of these pathways from yeast to humans.
Main Methods:
- Literature review focusing on Saccharomyces cerevisiae as a model organism.
- Analysis of conserved signaling pathways involved in DNA damage response.
- Extrapolation of findings from yeast to vertebrate systems.
Main Results:
- DNA damage checkpoints are crucial surveillance mechanisms that induce cell cycle arrest.
- These checkpoints allow adequate time for the repair of DSBs.
- Highly conserved pathways govern the cellular response to DSBs across eukaryotes.
Conclusions:
- Understanding DSB repair in yeast provides insights into maintaining genome stability in all eukaryotic cells.
- The DNA damage response pathways are critical for preventing diseases associated with genomic instability.
- Saccharomyces cerevisiae serves as a valuable model for dissecting complex DNA repair networks.
Related Concept Videos
02:04Fixing Double-strand Breaks
The double-stranded structure of DNA has two major advantages. First, it serves as a safe repository of genetic information where one strand serves as the back-up in case the other strand is damaged. Second, the double-helical structure can be wrapped around proteins called histones to form nucleosomes, which can then be tightly wound to form chromosomes. This way, DNA chains up to 2 inches long can be contained within microscopic structures in a cell. A double-stranded break not only damages...
02:04Fixing Double-strand Breaks
The double-stranded structure of DNA has two major advantages. First, it serves as a safe repository of genetic information where one strand serves as the back-up in case the other strand is damaged. Second, the double-helical structure can be wrapped around proteins called histones to form nucleosomes, which can then be tightly wound to form chromosomes. This way, DNA chains up to 2 inches long can be contained within microscopic structures in a cell. A double-stranded break not only damages...
02:36DNA 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...
02:36DNA 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...
02:31Homologous 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...
01:38Nucleotide Excision Repair
DNA Distortion and Damage
Cells are regularly exposed to mutagens—factors in the environment that can damage DNA and generate mutations. UV radiation is one of the most common mutagens and is estimated to introduce a significant number of changes in DNA. These include bends or kinks in the structure, which can block DNA replication or transcription. If these errors are not fixed, the damage can cause mutations, which in turn can result in cancer or disease depending on which sequences are...
Cells are regularly exposed to mutagens—factors in the environment that can damage DNA and generate mutations. UV radiation is one of the most common mutagens and is estimated to introduce a significant number of changes in DNA. These include bends or kinks in the structure, which can block DNA replication or transcription. If these errors are not fixed, the damage can cause mutations, which in turn can result in cancer or disease depending on which sequences are...