Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

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, a...
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, a...
Telomeres and Telomerase02:41

Telomeres 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.
Telomeres and Telomerase02:41

Telomeres 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.
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 forks, one in...
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 forks, one in...

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

From mobile DNA to medicine: Fusion Conference highlights the therapeutic potential of endogenous retroelements in human disease.

Trends in genetics : TIG·2026
Same author

Bone-derived Osterix+ osteolineage cells are a source of tumor-promoting myofibroblastic cancer-associated fibroblasts in breast cancer.

Nature communications·2026
Same author

Genome-Wide Histone Acetylation Underlies Tumor Intrinsic Immune Signaling Induced by Photothermal Therapy in Ovarian Cancer.

Research square·2026
Same author

Inflammaging in aged tissues drives remodeling of the CD8<sup>+</sup> T cell compartment.

Cell reports·2026
Same author

Transposable Element Activation: A Hallmark of Cancer.

Cancer discovery·2026
Same author

Rethinking ovarian cancer III: the past decade and future directions.

Nature reviews. Cancer·2026

Related Experiment Video

Updated: Jun 12, 2026

Analyzing Telomeric Protein-DNA Interactions Using Single-Molecule Magnetic Tweezers
11:21

Analyzing Telomeric Protein-DNA Interactions Using Single-Molecule Magnetic Tweezers

Published on: August 30, 2024

FEN1 ensures telomere stability by facilitating replication fork re-initiation.

Abhishek Saharia1, Daniel C Teasley1, Julien P Duxin1

  • 1Department of Cell Biology and Physiology, Washington University School of Medicine, St. Louis, Missouri 63110.

The Journal of Biological Chemistry
|June 17, 2010
PubMed
Summary

Flap endonuclease 1 (FEN1) is crucial for telomere stability by enabling replication fork re-initiation. FEN1 depletion causes telomere fragility and loss, highlighting its unique role at chromosome ends.

More Related Videos

Visualization of DNA Replication in the Vertebrate Model System DT40 using the DNA Fiber Technique
07:18

Visualization of DNA Replication in the Vertebrate Model System DT40 using the DNA Fiber Technique

Published on: October 27, 2011

Detection of DNA Breaks in Dividing Human Cells by Neutral Comet Assay
05:55

Detection of DNA Breaks in Dividing Human Cells by Neutral Comet Assay

Published on: August 23, 2024

Related Experiment Videos

Last Updated: Jun 12, 2026

Analyzing Telomeric Protein-DNA Interactions Using Single-Molecule Magnetic Tweezers
11:21

Analyzing Telomeric Protein-DNA Interactions Using Single-Molecule Magnetic Tweezers

Published on: August 30, 2024

Visualization of DNA Replication in the Vertebrate Model System DT40 using the DNA Fiber Technique
07:18

Visualization of DNA Replication in the Vertebrate Model System DT40 using the DNA Fiber Technique

Published on: October 27, 2011

Detection of DNA Breaks in Dividing Human Cells by Neutral Comet Assay
05:55

Detection of DNA Breaks in Dividing Human Cells by Neutral Comet Assay

Published on: August 23, 2024

Area of Science:

  • Molecular Biology
  • Genetics
  • Cell Biology

Background:

  • Telomeres are essential repetitive DNA sequences at chromosome ends.
  • Telomere stability depends on proteins and DNA replication/repair machinery.
  • Flap endonuclease 1 (FEN1) was previously shown to be vital for lagging strand telomere replication.

Purpose of the Study:

  • To investigate the role of FEN1 in replication fork re-initiation and telomere stability.
  • To determine the specific FEN1 activities and interactions critical for telomere maintenance.
  • To understand why FEN1 depletion impacts telomeres more than other genomic regions.

Main Methods:

  • Depletion of FEN1 in cells.
  • Analysis of telomere fragility and sister telomere loss.
  • Assessment of replication fork re-initiation.
  • In vitro DNA replication assays.
  • Investigation of FEN1's interaction with RecQ helicases.

Main Results:

  • FEN1 is essential for efficient re-initiation of stalled replication forks.
  • FEN1 depletion leads to telomere fragility and sister telomere loss.
  • FEN1's gap endonuclease activity and interaction with RecQ helicases are vital for telomere stability.
  • FEN1's role in Okazaki fragment processing is not required for telomere replication.
  • FEN1 depletion does not affect cell cycle progression or replication of non-telomeric DNA.

Conclusions:

  • FEN1's primary role at telomeres is facilitating replication fork re-initiation, not Okazaki fragment processing.
  • FEN1's gap endonuclease activity and RecQ helicase interaction are key to maintaining telomere stability.
  • Other nucleases compensate for FEN1 loss genome-wide but not at telomeres.
  • FEN1 ensures high-fidelity telomere replication by aiding progression through the G-rich lagging strand.