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Updated: Aug 11, 2026
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Biochemical Assays for Analyzing Activities of ATP-dependent Chromatin Remodeling Enzymes
Published on: October 25, 2014
Chromatin remodeling by nucleosome disassembly in vitro
Yahli Lorch1, Barbara Maier-Davis, Roger D Kornberg
1Department of Structural Biology, Stanford University School of Medicine, CA 94305-5126, USA.
Summary
The RSC chromatin-remodeling complex, with Nap1 and ATP, disassembles nucleosomes in steps, releasing DNA. This mechanism may remove promoter nucleosomes for gene activation.
Area of Science:
- Molecular biology
- Chromatin dynamics
- Gene regulation
Background:
- Nucleosomes are fundamental units of DNA packaging in eukaryotes.
- Chromatin remodeling is crucial for DNA accessibility and gene expression.
- The RSC complex is a key player in chromatin organization.
Purpose of the Study:
- To elucidate the mechanism by which the RSC complex disassembles nucleosomes.
- To investigate the role of the histone chaperone Nap1 in this process.
- To understand the implications for transcriptional regulation in vivo.
Main Methods:
- Biochemical assays to monitor nucleosome disassembly.
- Analysis of histone removal and DNA release.
- In vitro reconstitution experiments.
Main Results:
- The RSC complex, with Nap1 and ATP, mediates complete nucleosome disassembly.
- Disassembly proceeds stepwise: H2A/H2B dimer removal, followed by H3/H4 tetramer removal.
- Naked DNA is released upon complete histone eviction.
Conclusions:
- RSC-mediated nucleosome disassembly is a stepwise process.
- This mechanism likely contributes to the removal of promoter nucleosomes during transcriptional activation.
- The findings provide insights into the dynamic nature of chromatin and gene regulation.
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