Nucleosome remodeler exclusion by histone deacetylation enforces heterochromatic silencing and epigenetic inheritance
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ABSTRACT: Heterochromatin enforces transcriptional gene silencing and can be epigenetically inherited, but the underlying mechanism has remained unclear.Here we show that histone deacetylation, a conserved feature of heterochromatin domains, blocks SWI/SNF subfamily remodelers involved in chromatin unraveling, thereby stabilizing modified nucleosomes that preserve gene silencing. Histone hyperacetylation, resulting from either the loss of a histone deacetylase (HDAC) or the direct targeting of histone acetyltransferase to heterochromatin, permits remodeler access, leading to silencing defects.The requirement for HDAC in heterochromatin silencing can be bypassedby impeding SWI/SNF activity. Highlighting the crucial role of remodelers, merely targeting SWI/SNF to heterochromatin, even in cells with functional HDAC, increases nucleosome turnover, causing defective gene silencing and compromised epigenetic inheritance. This study elucidates a fundamental mechanism whereby histone hypoacetylation, maintained by high HDAC levels in heterochromatic regions, ensures stable gene silencing and epigenetic inheritance,providing significant insights into genome regulation relevant to human diseases.
ORGANISM(S): Schizosaccharomyces pombe
PROVIDER: GSE269243 | GEO | 2024/08/05
REPOSITORIES: GEO
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