BioProject

Cellular senescence is a stable cell growth arrest that is characterized by silencing of proliferation-promoting genes through compaction of individual chromosomes into senescence-associated heterochromatin foci (SAHF). More...

Cellular senescence is a stable cell growth arrest that is characterized by silencing of proliferation-promoting genes through compaction of individual chromosomes into senescence-associated heterochromatin foci (SAHF). Paradoxically, senescence is also accompanied by increased expression of certain secreted factors such as cytokines and chemokines, known as senescence-associated secretory phenotype (SASP). How SASP genes are excluded from SAHF-mediated global gene silencing remains unclear. Here we report that HMGB2 orchestrates the chromatin landscape of SASP gene loci. HMGB2 preferentially localizes to SASP gene loci during senescence. Loss of HMGB2 during senescence blunts SASP gene expression by allowing for spreading of repressive heterochromatin into SASP gene loci. This correlated with incorporation of SASP gene loci into SAHF. Our results establish HMGB2 as a novel master regulator that orchestrates SASP through preventing heterochromatin spreading to allow for exclusion of SASP gene loci from a global heterochromatin environment during senescence. Overall design: HMGB2 CHIP-seq in senescent and growing IMR90 cells Less...