Heterochromatic repeat clustering imposes a physical barrier on homologous recombination to prevent chromosomal translocations.

ABSTRACT: Mouse pericentromeric DNA is composed of tandem major satellite repeats, which are heterochromatinized and cluster together to form chromocenters. These clusters are refractory to DNA repair through homologous recombination (HR). The mechanisms by which pericentromeric heterochromatin imposes a barrier on HR and the implications of repeat clustering are unknown. Here, we compare the spatial recruitment of HR factors upon double-stranded DNA breaks (DSBs) induced in human and mouse pericentromeric heterochromatin, which differ in their capacity to form clusters. We show that while DSBs increase the accessibility of human pericentromeric heterochromatin by disrupting HP1α dimerization, mouse pericentromeric heterochromatin repeat clustering imposes a physical barrier that requires many layer

SUBMITTER: Mitrentsi I 

PROVIDER: S-EPMC9616805 | biostudies-literature | 2022 Jun

REPOSITORIES: biostudies-literature