The histone H3.1 variant regulates TONSOKU-mediated DNA repair during replication.
Davarinejad, H., Huang, Y.C., Mermaz, B., LeBlanc, C., Poulet, A., Thomson, G., Joly, V., Munoz, M., Arvanitis-Vigneault, A., Valsakumar, D., Villarino, G., Ross, A., Rotstein, B.H., Alarcon, E.I., Brunzelle, J.S., Voigt, P., Dong, J., Couture, J.F., Jacob, Y.(2022) Science 375: 1281-1286
- PubMed: 35298257 
- DOI: https://doi.org/10.1126/science.abm5320
- Primary Citation of Related Structures:  
7T7T - PubMed Abstract: 
The tail of replication-dependent histone H3.1 varies from that of replication-independent H3.3 at the amino acid located at position 31 in plants and animals, but no function has been assigned to this residue to demonstrate a unique and conserved role for H3.1 during replication. We found that TONSOKU (TSK/TONSL), which rescues broken replication forks, specifically interacts with H3.1 via recognition of alanine 31 by its tetratricopeptide repeat domain. Our results indicate that genomic instability in the absence of ATXR5/ATXR6-catalyzed histone H3 lysine 27 monomethylation in plants depends on H3.1, TSK, and DNA polymerase theta (Pol θ). This work reveals an H3.1-specific function during replication and a common strategy used in multicellular eukaryotes for regulating post-replicative chromatin maturation and TSK, which relies on histone monomethyltransferases and reading of the H3.1 variant.
Organizational Affiliation: 
Ottawa Institute of Systems Biology, Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, Ontario K1H 8M5, Canada.