Grewal Shiv I S, Moazed Danesh
Laboratory of Molecular Cell Biology, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA.
Science. 2003 Aug 8;301(5634):798-802. doi: 10.1126/science.1086887.
Eukaryotic DNA is organized into structurally distinct domains that regulate gene expression and chromosome behavior. Epigenetically heritable domains of heterochromatin control the structure and expression of large chromosome domains and are required for proper chromosome segregation. Recent studies have identified many of the enzymes and structural proteins that work together to assemble heterochromatin. The assembly process appears to occur in a stepwise manner involving sequential rounds of histone modification by silencing complexes that spread along the chromatin fiber by self-oligomerization, as well as by association with specifically modified histone amino-terminal tails. Finally, an unexpected role for noncoding RNAs and RNA interference in the formation of epigenetic chromatin domains has been uncovered.
真核生物的DNA被组织成结构上不同的结构域，这些结构域调控基因表达和染色体行为。异染色质的表观遗传可遗传结构域控制着大染色体结构域的结构和表达，并且是正确的染色体分离所必需的。最近的研究已经鉴定出许多共同作用以组装异染色质的酶和结构蛋白。组装过程似乎以逐步方式发生，涉及由沉默复合物进行的组蛋白修饰的连续轮次，这些沉默复合物通过自我寡聚化沿着染色质纤维扩散，以及通过与特异性修饰的组蛋白氨基末端尾巴结合。最后，非编码RNA和RNA干扰在表观遗传染色质结构域形成中的意外作用已被发现。
