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Updated: May 22, 2026
05:35
Immunofluorescence Analysis of Endogenous and Exogenous Centromere-kinetochore Proteins
Published on: March 3, 2016
The unconventional structure of centromeric nucleosomes.
Steven Henikoff1, Takehito Furuyama
1Howard Hughes Medical Institute and Basic Sciences Division, Fred Hutchinson Cancer Research Center, 1100 Fairview Avenue North, Seattle, WA 98109-1024, USA. steveh@fhcrc.org
Chromosoma
|May 4, 2012
Summary
The centromere
Area of Science:
- Eukaryotic cell biology
- Chromatin structure
- Molecular genetics
Background:
- The centromere is essential for chromosome segregation during cell division.
- Centromeric chromatin is defined by the histone H3 variant, centromeric histone H3 (cenH3).
- The precise structure of the cenH3 nucleosome remains debated, with models including octasomes, hexamers, and hemisomes.
Purpose of the Study:
- To resolve the structural controversy surrounding the cenH3 nucleosome.
- To determine the fundamental unit of centromeric chromatin in budding yeast.
- To investigate the functional implications of cenH3 nucleosome structure.
Main Methods:
- Topology analysis of budding yeast centromeric DNA.
- High-resolution mapping of cenH3 nucleosomes.
- Investigating the effects of cenH3 overproduction on genome-wide nucleosome incorporation.
Main Results:
- A single right-handed cenH3 hemisome occupies the CDEII region of budding yeast centromeres.
- Overproduction of cenH3 results in octasome-sized particle incorporation in non-centromeric regions.
- Partially unwrapped left-handed cenH3 octamers exhibit inherent instability.
Conclusions:
- The right-handed cenH3 hemisome represents the universal unit of centromeric chromatin.
- The instability of left-handed cenH3 octamers may prevent neocentromere formation.
- This structural understanding clarifies centromere function and regulation.
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