Using fission yeast to unravel co-transcriptional 3' end processing and transcription termination

3 '端加工是RNA多聚腺苷化之前基因表达的一个基本步骤，与转录终止密切相关。3 '端加工是RNA聚合酶II （RNAPII）最大亚基的羧基末端结构域（CTD）募集RNA成熟因子的共转录过程。尽管对涉及RNA加工的参与者进行了一些公平的评估，但关于它们与转录周期整合的调节机制仍有很多未知。3 '端加工和转录终止尤其如此。事实上，最近的转录组研究表明，多个聚腺苷酸化位点（PAS）用于大多数真核基因，如在人类、小鼠、植物、苍蝇和酵母中所证明的那样。这一过程被称为选择性聚腺苷酸化（APA），是基因调控的一个主要层面，允许包含或排除控制mrna定位、稳定性和翻译的序列。然而，PAS识别的机制以及PAS选择如何与转录终止协调仍不清楚。这个

3’ end processing is a fundamental step of gene expression that precedes RNA polyadenylation and that is intimately associated with transcription termination. 3’ end processing is a co-transcriptional process that involves the recruitment of RNA maturation factors by the carboxy-terminal domain (CTD) of the largest subunit of RNA polymerase II (RNAPII). Despite a somewhat fair assessment of the players implicated in RNA processing, much is still unknown about the regulatory mechanisms underlying their integration with the transcription cycle. This is particularly true for 3’ end processing and transcription termination. Indeed, recent transcriptome-wide studies indicate that multiple polyadenylation sites (PAS) are used at most eukaryotic genes, as demonstrated in humans, mouse, plants, flies, and yeast. This process, known as alternative polyadenylation (APA), is emerging as a major layer of gene regulation, allowing the inclusion or exclusion of sequences that control the localization, stability, and translation of mRNAs. However, the mechanism of PAS recognition and how PAS selection is coordinated with transcription termination remains unclear. The