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Updated: Feb 9, 2026
02:31
Phase Transitions and Effect of Intermolecular Forces
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Cell-cycle-coupled structural oscillation of centromeric nucleosomes in yeast
Manjunatha Shivaraju1, Jay R Unruh, Brian D Slaughter
1Stowers Institute for Medical Research, Kansas City, MO 64110, USA.
Cell
|July 24, 2012
Summary
Budding yeast centromeres contain one copy of the histone variant Cse4 (centromeric nucleosome) for most of the cell cycle. This structure doubles to two copies during anaphase, indicating cell-cycle-coupled changes in centromeric nucleosome structure.
Area of Science:
- Cell Biology
- Molecular Biology
- Genetics
Background:
- The centromere is crucial for accurate chromosome segregation during cell division.
- Centromeres are characterized by specialized nucleosomes containing histone H3 variants.
- In budding yeast, Cse4 is the canonical histone H3 variant found at centromeres.
Purpose of the Study:
- To investigate the copy number and structural dynamics of the centromeric histone H3 variant, Cse4, in live yeast cells.
- To explore cell-cycle-dependent alterations in centromeric nucleosome composition.
Main Methods:
- Developed a novel method combining fluorescence correlation spectroscopy (FCS) and calibrated imaging for quantitative analysis in live yeast.
- Utilized nucleosome reconstitution and ChIP (Chromatin Immunoprecipitation) assays to analyze nucleosome composition.
- Investigated Cse4-Cse4 interactions and the role of Scm3 during the cell cycle.
Main Results:
- Quantified Cse4 copy number at centromeric nucleosomes, revealing one copy during interphase and two copies during anaphase.
- Observed cell-cycle-coupled structural changes in centromeric nucleosomes, with increased Cse4 incorporation and deposition at anaphase.
- Confirmed the presence of H2A/H2B in both Cse4 structures and observed similar anaphase-specific changes in Candida albicans.
Conclusions:
- Centromeric nucleosomes exhibit a cell-cycle-coupled oscillation in their structure, specifically concerning Cse4 copy number.
- The findings support a dynamic model for centromeric nucleosome structure that changes during cell division.
- The observed phenomenon is conserved across different yeast species, suggesting fundamental importance.
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