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Updated: Jul 4, 2025
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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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Identification and Characterization of HIRIP3 as a Histone H2A Chaperone
Maria Ignatyeva1, Abdul Kareem Mohideen Patel1, Abdulkhaleg Ibrahim1
1Département de Génomique Fonctionnelle et Cancer, Institut de Génétique et Biologie Moléculaire et Cellulaire (IG-BMC), CNRS UMR7104, INSERM U964, Université de Strasbourg, 67404 Illkirch, France.
Cells
|February 9, 2024
Summary
Mammalian HIRIP3 protein functions as an H2A histone chaperone. It facilitates H2A phosphorylation by CK2 kinase and aids in depositing histones onto DNA.
Area of Science:
- Molecular Biology
- Epigenetics
- Chromatin Biology
Background:
- HIRIP3 is a mammalian protein similar to yeast Chz1, a histone chaperone.
- The precise function of HIRIP3 and its interaction mechanisms in histone deposition are not fully understood.
Purpose of the Study:
- To investigate the function of HIRIP3 in mammalian cells.
- To identify HIRIP3 interacting partners and elucidate its role in histone deposition.
Main Methods:
- Co-immunoprecipitation assays in HeLa cells to identify interacting partners.
- Bacterial expression and purification of recombinant HIRIP3.
- In vitro assays to assess binding affinities and histone deposition activity.
Main Results:
- HIRIP3 interacts in vivo with H2A-H2B dimers and CK2 kinase.
- Recombinant HIRIP3 binds H2A and H2A.Z similarly, but associated CK2 kinase prefers H2A phosphorylation at serine 1.
- HIRIP3 interacts with the H2A αC helix and is crucial for depositing core histones onto DNA.
Conclusions:
- Mammalian HIRIP3 functions as an H2A histone chaperone.
- HIRIP3 assists CK2 kinase in selectively phosphorylating H2A at serine 1.
- This process facilitates the deposition of H2A onto chromatin.
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