Related Experiment Video
Updated: Oct 3, 2025
06:53
In Vivo Monitoring of Transcriptional Activity During Metabolic Transition Using a Bioluminescent Reporter in Yeast
Published on: February 21, 2025
584
Exceptional origin activation revealed by comparative analysis in two laboratory yeast strains
Ishita Joshi1, Jie Peng1, Gina Alvino2
1Department of Biochemistry and Molecular Biology, SUNY Upstate Medical University, Syracuse, New York, United States of America.
Plos One
|February 14, 2022
Summary
Hydroxyurea challenges yeast replication origins, revealing that S-phase checkpoint control, particularly Rad53 activity, significantly impacts origin activation and DNA replication fork progression. New Rad53-dependent origins were identified.
Area of Science:
- Molecular Biology
- Genetics
- Cell Biology
Background:
- DNA replication origin activation is crucial for genome stability.
- Hydroxyurea (HU) inhibits ribonucleotide reductase, stalling replication forks and activating checkpoints.
- Understanding factors influencing origin activation under stress is vital.
Purpose of the Study:
- To comparatively analyze replication origin activation in two yeast strains under HU stress.
- To investigate the roles of S-phase checkpoint control, DNA sequence polymorphisms, and gene positioning in origin activation.
- To identify novel origins regulated by checkpoint proteins.
Main Methods:
- Genome-wide single-stranded DNA mapping in yeast strains W303 and A364a.
- Analysis of fork progression, Rad53 phosphorylation, and its localization.
- Comparative assessment of origin usage and DNA sequence variations.
Main Results:
- Wild type W303 exhibited reduced fork progression and elevated Rad53 activity compared to A364a.
- A rad53K227A mutant showed increased origin activation and reduced ssDNA globally.
- DNA sequence polymorphisms had a minor effect; a new class of Rad53-dependent origins was discovered.
Conclusions:
- S-phase checkpoint control, mediated by Rad53, is a major determinant of replication origin activation under HU stress.
- Replication origin usage is strain-specific and influenced by checkpoint proficiency.
- The identification of Rad53-dependent origins provides new insights into DNA replication regulation.
Related Concept Videos
01:28Yeast Signaling
16.2K
Yeasts are single-celled organisms, but unlike bacteria, they are eukaryotes (cells with a nucleus). Cell signaling in yeast is similar to signaling in other eukaryotic cells. A ligand, such as a protein or a small molecule released from a yeast cell, attaches to a receptor on the cell surface. The binding stimulates second-messenger kinases to activate or inactivate transcription factors that further regulate gene expression. Many of the yeast intracellular signaling cascades have similar...
16.2K
02:40Chromosome Structure
24.0K
A functional eukaryotic chromosome must contain three elements: a centromere, telomeres, and numerous origins of replication.
The centromere is a DNA sequence that links sister chromatids. This is also where kinetochores, protein complexes to which spindle microtubules attach, are constructed after the chromosome is replicated. The kinetochores allow the spindle microtubules to move the chromosomes within the cell during cell division.
Telomeres consist of non-coding repetitive nucleotide...
The centromere is a DNA sequence that links sister chromatids. This is also where kinetochores, protein complexes to which spindle microtubules attach, are constructed after the chromosome is replicated. The kinetochores allow the spindle microtubules to move the chromosomes within the cell during cell division.
Telomeres consist of non-coding repetitive nucleotide...
24.0K