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Updated: Aug 20, 2025
10:14
Biochemical Assays for Analyzing Activities of ATP-dependent Chromatin Remodeling Enzymes
Published on: October 25, 2014
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H2A.Z deposition by SWR1C involves multiple ATP-dependent steps
Jiayi Fan1,2, Andrew T Moreno3, Alexander S Baier1,4
1Program in Molecular Medicine, University of Massachusetts Chan Medical School, Worcester, MA, 01605, USA.
Nature Communications
|November 17, 2022
Summary
Histone variant H2A.Z deposition involves three ATP-dependent phases. The chromatin remodeler SWR1C uses ATP for nucleosome editing, priming, and H2A/H2B dimer release, enabling precise genomic regulation.
Area of Science:
- Chromatin biology
- Molecular genetics
- Biochemistry
Background:
- Histone variant H2A.Z is crucial for nucleosomes at protein-coding genes.
- ATP-dependent chromatin remodelers, like yeast SWR1C, mediate H2A.Z deposition.
- The mechanism of ATP utilization by these remodelers is not fully understood.
Purpose of the Study:
- To elucidate the ATP-dependent mechanism of H2A.Z deposition by SWR1C.
- To identify distinct phases of the nucleosome editing reaction.
- To understand how ATP concentration influences the reaction rates.
Main Methods:
- Single-molecule and ensemble biochemical assays.
- Real-time analysis of nucleosome remodeling events.
- Investigation of ATP concentration effects on reaction kinetics.
Main Results:
- Identified three distinct ATP-dependent phases in H2A.Z deposition.
- Observed an initial ATP-dependent priming step involving DNA unwrapping and octamer deformation.
- Demonstrated that both priming and H2A/H2B dimer release rates are sensitive to ATP concentration.
Conclusions:
- The H2A.Z deposition reaction proceeds through a complex, multi-phase pathway.
- ATP hydrolysis drives specific conformational changes and histone exchange.
- The reaction's sensitivity to ATP offers regulatory control points for H2A.Z localization.
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