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Chromatin Immunoprecipitation (ChIP) of Histone Modifications from Saccharomyces cerevisiae
Published on: December 29, 2017
Global histone acetylation and deacetylation in yeast
1Department of Biological Chemistry, UCLA School of Medicine and the Molecular Biology Institute, University of California, Los Angeles 90095, USA.
Nature
|December 2, 2000
Summary
Histone modifications, including acetylation and deacetylation, are widespread across yeast genomes. Targeted gene regulation occurs within a broader context of global histone changes, impacting basal transcription.
Area of Science:
- Molecular Biology
- Epigenetics
- Gene Regulation
Background:
- Histone acetyltransferases (HATs) and deacetylases (HDACs) regulate gene expression by modifying histones.
- Specific HATs (e.g., GCN5) and HDACs (e.g., RPD3) are recruited to DNA by transcription factors.
- The PHO5 gene's expression is repressed by nucleosomes and regulated by GCN5, but not UME6.
Purpose of the Study:
- To investigate whether histone acetylation and deacetylation are promoter-specific at the PHO5 gene.
- To examine the acetylation state of the PHO5 gene region and its surrounding areas.
- To understand the interplay between targeted and global histone modifications.
Main Methods:
- Chromatin immunoprecipitation (ChIP) assays.
- Antibodies against acetylated lysine residues.
- Analysis of a 4.25-kilobase region surrounding the PHO5 gene and other chromosomal regions.
Main Results:
- The PHO5 gene region is extensively acetylated by ESA1 and GCN5 and deacetylated by HDA1 and RPD3.
- Widespread histone modification was observed across three distinct chromosomal regions, totaling 22kb.
- Targeted histone modification occurs against a background of global acetylation and deacetylation.
Conclusions:
- Global histone acetylation and deacetylation reduce basal transcription levels.
- This global modification allows for a rapid return to the initial acetylation state upon removal of targeting factors.
- Histone modification is a dynamic process involving both targeted and global mechanisms.
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