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In Vitro Characterization of Histone Chaperones using Analytical, Pull-Down and Chaperoning Assays
Published on: December 29, 2021
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UBR7 acts as a histone chaperone for post-nucleosomal histone H3
Ann K Hogan1, Kizhakke M Sathyan2, Alexander B Willis1
1Department of Biochemistry and Molecular Genetics, Northwestern University Feinberg School of Medicine, Chicago, IL, USA.
The EMBO Journal
|November 17, 2021
Summary
UBR7 acts as a histone chaperone, managing histone H3.1 supply. It prevents the accumulation of stored histones, promoting their reincorporation into chromatin and maintaining histone H3K4me3 levels.
Area of Science:
- Molecular Biology
- Epigenetics
- Chromatin Biology
Background:
- Histone chaperones are critical for maintaining histone stability throughout their lifecycle, from synthesis to DNA incorporation and recycling.
- Post-translational modifications on histones, such as H3K4me3 and H3K9me3, play vital roles in chromatin regulation.
- The non-nucleosomal histone chaperone NASP (Nuclear Autoantigenic Sperm Protein) is involved in histone storage.
Purpose of the Study:
- To identify and characterize the role of UBR7 as a histone chaperone.
- To investigate the interaction of UBR7 with specific histone modifications and other chaperones.
- To elucidate the function of UBR7 in regulating the supply and reincorporation of post-nucleosomal histones.
Main Methods:
- Biochemical assays to determine UBR7's binding interactions with histones and NASP.
- Analysis of histone modifications (H3K4me3, H3K9me3) in the presence and absence of UBR7.
- Assessment of chromatin composition and histone pools.
Main Results:
- UBR7 functions as a histone H3.1 chaperone, modulating the availability of post-nucleosomal histone complexes.
- UBR7 directly binds to H3K4me3 and H3K9me3 modified histones via its UBR box and PHD domains.
- UBR7 interacts with the histone chaperone NASP, preventing the accumulation of NASP-bound histones and maintaining H3K4me3 levels in chromatin.
Conclusions:
- UBR7 plays a crucial role in the dynamic regulation of histone supply and chromatin integrity.
- The interaction between UBR7 and NASP opposes NASP's histone storage function, promoting histone reincorporation.
- UBR7 is essential for maintaining appropriate levels of H3K4me3-modified histones in chromatin, impacting epigenetic regulation.
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