Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, Washington 98109; email:
Annu Rev Cell Dev Biol. 2013;29:241-70. doi: 10.1146/annurev-cellbio-101512-122317. Epub 2013 Jul 5.
The repressive compartment of the nucleus is comprised primarily of telomeric and centromeric regions, the silent portion of ribosomal RNA genes, the majority of transposable element repeats, and facultatively repressed genes specific to different cell types. This compartment localizes into three main regions: the peripheral heterochromatin, perinucleolar heterochromatin, and pericentromeric heterochromatin. Both chromatin remodeling proteins and transcription of noncoding RNAs are involved in maintenance of repression in these compartments. Global reorganization of the repressive compartment occurs at each cell division, during early development, and during terminal differentiation. Differential action of chromatin remodeling complexes and boundary element looping activities are involved in mediating these organizational changes. We discuss the evidence that heterochromatin formation and compartmentalization may drive nuclear organization.
核的抑制区主要由端粒和着丝粒区域、核糖体 RNA 基因的沉默部分、大多数转座元件重复序列以及不同细胞类型特有的选择性抑制基因组成。该区域定位于三个主要区域:周边异染色质、核仁周边异染色质和着丝粒周围异染色质。染色质重塑蛋白和非编码 RNA 的转录都参与了这些区域的抑制维持。在每个细胞分裂、早期发育和终末分化过程中,抑制区的全局重组都会发生。染色质重塑复合物的差异作用和边界元件环化活性参与了这些组织变化的介导。我们讨论了异染色质形成和区室化可能驱动核组织的证据。