Double-strand breaks can be caused by a variety of physical and chemical factors, such as ionizing radiation and radiomimetic medicines, but they can also develop as secondary lesions during replication and DNA repair after exposure to a variety of genotoxins. Repair proteins aggregate at damaged areas in response to double strand breaks (DSB), forming membrane-less subnuclear foci, supporting DNA repair (25773265).
Rad52 DNA repair proteins assemble in liquid droplets at distinct DNA damage sites, which then fuse into a repair centre droplet. Together with the repair centre droplet, Rad52 concentrates tubulin and projects short aster-like DIMs (aster-DIMs), which connect the repair center to longer DIMs, allowing damaged DNA to be mobilized to the nuclear periphery for repair. Collaboration between Rad52 liquid droplets and different types of nuclear filaments aids in the formation and function of the DNA repair centre (32019927).
Rothkamm K, Barnard S, Moquet J, Ellender M, Rana Z, Burdak-Rothkamm S. DNA damage foci: Meaning and significance. Environ Mol Mutagen. 2015 Jul;56(6):491-504. doi: 10.1002/em.21944. Epub 2015 Mar 12. PMID: 25773265.
Oshidari R, Huang R, Medghalchi M, Tse EYW, Ashgriz N, Lee HO, Wyatt H, Mekhail K. DNA repair by Rad52 liquid droplets. Nat Commun. 2020 Feb 4;11(1):695. doi: 10.1038/s41467-020-14546-z. PMID: 32019927; PMCID: PMC7000754.