X chromosome inactivation (XCI) is the process whereby one of the X chromosomes in female mammalian cells is silenced to equalize X-linked gene expression with males. XCI depends on the long noncoding RNA Xist, which coats the inactive X chromosome in cis and triggers a cascade of events that ultimately lead to chromosome-wide transcriptional silencing that is stable for the lifetime of an organism. In recent years, the discovery of proteins that interact with Xist have led to new insights into how the initiation of XCI occurs. Nevertheless, there are still various unknowns about the mechanisms by which Xist orchestrates and maintains stable X-linked silencing. Here, we review recent work elucidating the role of Xist and its protein partners in mediating chromosome-wide transcriptional repression, as well as discuss a model by which Xist may compartmentalize proteins across the inactive X chromosome to enable both the initiation and maintenance of XCI.

中文翻译：

---

Xist驱动DNA和蛋白质的空间分隔，以协调X灭活的起始和维持。

X染色体失活（XCI）是这样的过程，在该过程中，雌性哺乳动物细胞中的X染色体之一被沉默，以平衡雄性与X连锁的基因表达。XCI依赖于长的非编码RNA Xist，该RNA顺时针覆盖无活性的X染色体并触发一系列事件，最终导致整个生物体稳定的全染色体转录沉默。近年来，与Xist相互作用的蛋白质的发现导致人们对XCI的启动方式有了新的认识。尽管如此，关于Xist协调并维持稳定的X连锁沉默的机制仍存在各种未知数。在这里，我们回顾了最近的工作，阐明了Xist及其蛋白伴侣在介导全染色体转录抑制中的作用，