Paused RNA polymerase II inhibits new transcriptional initiation. Paused RNA polymerase II inhibits new transcriptional initiation

RNA polymerase II (Pol II) pauses downstream of the transcription initiation site before beginning productive elongation. This pause is a key component of metazoan gene expression regulation. Some promoters have a strong disposition for Pol II pausing and often mediate faster, more synchronous changes in expression. This requires multiple rounds of transcription and thus cannot rely solely on pause release. But it is unclear how pausing affects the initiation of new transcripts during consecutive rounds of transcription. Using our recently developed ChIP-nexus method, we find that Pol II pausing inhibits new initiation. We propose that paused Pol II helps prevent new initiation between transcription bursts, which may reduce noise. Overall design: Refer to individual Series

RNA聚合酶II（RNA polymerase II，Pol II）会在转录起始位点下游区域发生暂停，随后才启动有效延伸。该暂停现象是后生动物基因表达调控的关键组成部分。部分启动子对Pol II暂停具有极强的倾向性，通常可介导更为快速且同步的基因表达变化。这一调控过程需要多轮转录，因此无法仅依赖暂停解除来完成。但目前尚不清楚在连续多轮转录过程中，Pol II暂停如何影响新转录本的起始。本研究利用我们新近开发的ChIP-nexus技术，发现Pol II暂停会抑制新转录本的起始。我们提出，处于暂停状态的Pol II可在转录爆发间隙阻止新的转录起始，这或许能够降低基因表达的噪声。整体实验设计：详见各独立数据集系列。