Related Experiment Video
Updated: Nov 24, 2025
10:17
The Tail Suspension Test
Published on: January 28, 2012
82.1K
The end protection problem-an unexpected twist in the tail
1The Francis Crick Institute, London NW1 1AT, United Kingdom.
Genes & Development
|December 28, 2020
Summary
This perspective explores telomere protection, focusing on shelterin and t-loops. It supports a dynamic t-loop model critical for preventing DNA damage, alongside other protective mechanisms.
Area of Science:
- Cellular biology
- Genetics
- Molecular biology
Background:
- Telomeres protect chromosome ends from degradation and fusion.
- Shelterin complex plays a key role in telomere maintenance and protection.
- Telomere dysfunction is linked to aging and cancer.
Purpose of the Study:
- To review and update the t-loop model of telomere end protection.
- To discuss the role of shelterin, ATM activation, and NHEJ at telomeres.
- To explore telomere protection mechanisms in pluripotent cells.
Main Methods:
- Literature review and synthesis of existing data.
- Discussion of proposed models for telomere end protection.
- Analysis of evidence supporting the t-loop model.
Main Results:
- Evidence supports a critical role for t-loops in preventing NHEJ and ATM activation.
- Other mechanisms are also involved in telomere end protection.
- Telomere protection mechanisms may differ across cell states, including pluripotent cells.
Conclusions:
- The t-loop model is supported, but requires updates to include dynamic structures and additional mechanisms.
- Understanding telomere protection is crucial for aging and cancer research.
- Further research is needed to fully elucidate diverse telomere end protection strategies.
Related Concept Videos
01:45Tail-anchoring of Proteins in the ER Membrane
3.5K
Tail-anchored, or TA, proteins are estimated to make up to 3-5% of membrane proteins found in the eukaryotic cell. Such proteins have a single transmembrane domain located approximately 30 amino acid residues upstream from the C-terminal end. As a result, the signal recognition particle (SRP) cannot guide a TA protein to the ER membrane for cotranslational insertion. Hence, they are integrated into the ER membrane post-translationally using their C-terminal end as the anchor. TA proteins...
3.5K
02:37Restarting Stalled Replication Forks
6.1K
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
02:41Telomeres and Telomerase
25.9K
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...
25.9K
01:12Hindsight Biases
4.1K
Hindsight bias leads you to believe that the event you just experienced was predictable, even though it really wasn’t. In other words, you knew all along that things would turn out the way they did. Can you relate this to the phrase "Hindsight is 20/20" now?
4.1K
01:35Pre-mRNA Processing: Modification of pre-mRNA Ends
13.0K
In eukaryotic cells, transcripts made by RNA polymerase are modified and processed before exiting the nucleus. Unprocessed RNA is called precursor mRNA or pre-mRNA to distinguish it from mature mRNA.
Once about 20-40 ribonucleotides have been joined together by RNA polymerase, a group of enzymes adds a cap to the 5' end of the growing transcript. In this process, a 5' phosphate is replaced by modified guanosine that has a methyl group attached (7-methyl guanosine). This 5' cap helps...
Once about 20-40 ribonucleotides have been joined together by RNA polymerase, a group of enzymes adds a cap to the 5' end of the growing transcript. In this process, a 5' phosphate is replaced by modified guanosine that has a methyl group attached (7-methyl guanosine). This 5' cap helps...
13.0K
01:13Angle of Twist: Problem Solving
578
An electric motor applies a torque of 700 N·m to an aluminum shaft, triggering a stable rotation. Two pulleys, B and C, are subjected to torques of 300 N·m and 400 N·m, respectively. The modulus of rigidity is provided as 25 GPa. With the knowledge of the length and diameter of each segment, the twist angle between the two pulleys can be computed. First, a section cut is made between pulleys B and C, and the cut cross-section is analyzed using a free-body diagram. Given that the torque...
578