Related Experiment Video
Updated: Feb 27, 2026

Identification of Cyclin-dependent Kinase 1 Specific Phosphorylation Sites by an In Vitro Kinase Assay
Published on: May 3, 2018
Sequential phosphorylation of CST subunits by different cyclin-Cdk1 complexes orchestrate telomere replication
Veena Gopalakrishnan1, Cherylin Ruiling Tan2, Shang Li1,3
1a Program in Cancer and Stem Cell Biology , Duke-NUS Medical School , Singapore.
Cyclins regulate telomere length by controlling the phosphorylation of Cdc13 and Stn1 proteins. This ensures proper telomere maintenance and genomic stability by balancing telomere elongation and capping processes.
Area of Science:
- Cell Biology
- Molecular Biology
- Genetics
Background:
- Telomeres protect chromosome ends and maintain genomic integrity.
- Telomere length is regulated by a balance between telomerase and the CST complex.
- Cdc13 phosphorylation by Cdk1 promotes telomere elongation, while Stn1 phosphorylation inhibits it.
Purpose of the Study:
- To elucidate the mechanism by which Cdk1 phosphorylates Cdc13 and Stn1 at distinct times.
- To investigate the role of cyclins in telomere maintenance and replication.
Main Methods:
- Budding yeast model system.
- Cell cycle analysis.
- Phosphorylation site mapping.
- Telomere length assays.
Main Results:
- S phase cyclins are crucial for telomere maintenance.
- S phase and mitotic cyclins differentially regulate Cdc13 and Stn1 phosphorylation.
- Cyclin-dependent phosphorylation acts as a molecular switch, directing Cdc13 to either telomerase or the CST complex.
Conclusions:
- Cyclins play a critical, previously unappreciated role in telomere replication.
- Temporal control of Cdc13 and Stn1 phosphorylation by cyclins ensures proper telomere homeostasis.
- This mechanism balances telomere elongation and capping for genomic stability.
More Related Videos
08:33Combining Mitotic Cell Synchronization and High Resolution Confocal Microscopy to Study the Role of Multifunctional Cell Cycle Proteins During Mitosis
Published on: December 5, 2017
12:02Studying Cell Cycle-regulated Gene Expression by Two Complementary Cell Synchronization Protocols
Published on: June 6, 2017
Related Concept Videos
S-Cdk Initiates DNA Replication
Two states at the origin of replication
In eukaryotes, the initiation of replication occurs at many sites on the chromosomes, called the origins of...
Positive Regulator Molecules
Positive Regulator Molecules
Separation of Sister Chromatids
At the onset of anaphase, separase, a proteolytic enzyme, is...
Telomeres and Telomerase
DNA Damage can Stall the Cell Cycle