Hanna-Rose W, Hansen U
Department of Microbiology and Molecular Genetics, Harvard Medical School, Boston, MA 02115, USA.
Trends Genet. 1996 Jun;12(6):229-34. doi: 10.1016/0168-9525(96)10022-6.
Regulators of transcription and, in particular, transcriptional repressors, play central roles in vital biological processes, such as development and the regulation of cell growth. A major class of transcriptional repressors consists of DNA-binding proteins that interact with specific promoter elements and repress transcription via small, portable repression 'domains'. Such transcriptional inhibition, first identified only five years ago, has been termed active repression, because it is not mediated simply by steric hindrance mechanisms. It is unknown how interaction(s) between such a repressor and the RNA polymerase II basal or regulatory transcription machinery can derail the formation or competency of a transcription complex at a promoter. However, the recent progress toward identification of molecular targets suggests several specific mechanisms for achieving active repression.
转录调节因子，尤其是转录抑制因子，在诸如发育和细胞生长调控等重要生物学过程中发挥着核心作用。一类主要的转录抑制因子由与特定启动子元件相互作用并通过小的、可移动的抑制“结构域”抑制转录的DNA结合蛋白组成。这种转录抑制，仅仅在五年前才首次被发现，被称为主动抑制，因为它不是简单地由空间位阻机制介导的。目前尚不清楚这种抑制因子与RNA聚合酶II基础转录或调控转录机制之间的相互作用是如何破坏启动子处转录复合物的形成或活性的。然而，最近在确定分子靶点方面取得的进展提示了几种实现主动抑制的具体机制。
