Related Experiment Video
Updated: May 9, 2026
11:21
Analyzing Telomeric Protein-DNA Interactions Using Single-Molecule Magnetic Tweezers
Published on: August 30, 2024
The telomere deprotection response is functionally distinct from the genomic DNA damage response.
Anthony J Cesare1, Makoto T Hayashi, Laure Crabbe
1Salk Institute for Biological Studies, Molecular and Cell Biology Laboratory, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA.
Molecular Cell
|July 16, 2013
Summary
Telomere erosion, a sign of aging, triggers a unique cellular response distinct from DNA damage. This response prevents genome instability by causing cell cycle arrest in daughter cells.
Area of Science:
- Cellular biology
- Genetics
- Molecular biology
Background:
- Telomere erosion is a key factor in aging and senescence.
- Understanding cellular responses to telomere dysfunction is crucial for aging research.
Purpose of the Study:
- To investigate the cellular response to physiological telomere deprotection.
- To determine if telomere deprotection response differs from genomic DNA damage response.
Main Methods:
- Developed an experimental system to mimic telomere deprotection in human cells.
- Analyzed ataxia telangiectasia mutated (ATM) signaling pathways.
- Assessed cell cycle checkpoint activation (G2/M and G1).
Main Results:
- Telomere deprotection activates a distinct ATM signaling pathway, notably without CHK2 phosphorylation.
- Deprotected telomeres do not induce a G2/M checkpoint.
- Deprotected telomeres induce p53-dependent G1 arrest in daughter cells.
Conclusions:
- The telomere deprotection response is functionally distinct from the genomic DNA damage response.
- Telomere deprotection acts as an epigenetic signal to prevent genome instability by inducing G1 arrest before cell division.
- This mechanism ensures cell cycle arrest occurs in a stable state, safeguarding genomic integrity.
Related Concept Videos
02:41Telomeres and Telomerase
In eukaryotic DNA replication, a single-stranded DNA fragment remains at the end of a chromosome after the removal of the final primer. This section of DNA cannot be replicated in the same manner as the rest of the strand because there is no 3’ end to which the newly synthesized DNA can attach. This non-replicated fragment results in gradual loss of the chromosomal DNA during each cell duplication. Additionally, it can induce a DNA damage response by enzymes that recognize single-stranded DNA.
02:41Telomeres and Telomerase
In eukaryotic DNA replication, a single-stranded DNA fragment remains at the end of a chromosome after the removal of the final primer. This section of DNA cannot be replicated in the same manner as the rest of the strand because there is no 3’ end to which the newly synthesized DNA can attach. This non-replicated fragment results in gradual loss of the chromosomal DNA during each cell duplication. Additionally, it can induce a DNA damage response by enzymes that recognize single-stranded DNA.
01:29Replication in Eukaryotes
In eukaryotic cells, DNA replication is highly conserved and tightly regulated. Multiple linear chromosomes must be duplicated with high fidelity before cell division, so there are many proteins that fulfill specialized roles in the replication process. Replication occurs in three phases: initiation, elongation, and termination, and ends with two complete sets of chromosomes in the nucleus.
Many Proteins Orchestrate Replication at the Origin
Eukaryotic replication follows many of the same...
Many Proteins Orchestrate Replication at the Origin
Eukaryotic replication follows many of the same...
02:31Replication in Eukaryotes
Overview
02:25Overview of DNA Repair
In order to be passed through generations, genomic DNA must be undamaged and error-free. However, every day, DNA in a cell undergoes several thousand to a million damaging events by natural causes and external factors. Ionizing radiation such as UV rays, free radicals produced during cellular respiration, and hydrolytic damage from metabolic reactions can alter the structure of DNA. Damages caused include single-base alteration, base dimerization, chain breaks, and cross-linkage.
Chemically...
Chemically...
02:25Overview of DNA Repair
In order to be passed through generations, genomic DNA must be undamaged and error-free. However, every day, DNA in a cell undergoes several thousand to a million damaging events by natural causes and external factors. Ionizing radiation such as UV rays, free radicals produced during cellular respiration, and hydrolytic damage from metabolic reactions can alter the structure of DNA. Damages caused include single-base alteration, base dimerization, chain breaks, and cross-linkage.
Chemically...
Chemically...