Nuclear Compartments

An RNA-dependent and phase-separated active subnuclear compartment safeguards repressive chromatin domains

“…The classical view for the presence of diverse nuclear compartments is that they serve to locally establish high concentrations of factors, allowing a much greater efficiency of specific reactions. 37 In this work, we have provided an additional layer of function and regulation by showing that BAZ2A, which binds active chromatin, gets sequestered into bodies to limit its invasion into adjacent H3K27me3 chromatin compartments, thereby preserving repressive chromatin and gene expression states ( Figure 7 J). BAZ2A-body formation is mediated by weak interactions between BAZ2A-TAM domain and nascent transcripts but negatively regulated by the strong interaction with the lncRNA Malat1 , which in turn is required for BAZ2A association with active chromatin contacting the nuclear speckles.…”