Jaensch Elizabeth S, Kundu Sharmistha, Kingston Robert E
Department of Molecular Biology, Massachusetts General Hospital, Boston, Massachusetts, 02114, USA.
Genes Dev. 2017 Jun 1;31(11):1069-1072. doi: 10.1101/gad.303206.117.
Development requires the expression of master regulatory genes necessary to specify a cell lineage. Equally significant is the stable and heritable silencing of master regulators that would specify alternative lineages. This regulated gene silencing is carried out by Polycomb group (PcG) proteins, which must be correctly recruited only to the subset of their target loci that requires lineage-specific silencing. A recent study by Erceg and colleagues (pp. 590-602) expands on a key aspect of that targeting: The same DNA elements that recruit PcG complexes to a repressed locus also encode transcriptional enhancers that function in different lineages where that locus must be expressed. Thus, PcG targeting elements overlap with enhancers.
发育需要表达指定细胞谱系所必需的主调控基因。同样重要的是，那些会指定其他谱系的主调控因子要实现稳定且可遗传的沉默。这种受调控的基因沉默是由多梳蛋白家族（PcG）蛋白执行的，这些蛋白必须仅被正确招募到其需要谱系特异性沉默的目标基因座子集中。Erceg及其同事最近的一项研究（第590 - 602页）扩展了这种靶向的一个关键方面：将PcG复合物招募到一个抑制基因座的相同DNA元件，同时也编码转录增强子，这些增强子在该基因座必须表达的不同谱系中发挥作用。因此，PcG靶向元件与增强子重叠。
