Investigating the role of Paf1 in transcription by RNA polymerase I

Polymerase-associated factor 1 complex (Paf1C) has been identified to promote transcription by Pols I and II and is conserved across eukaryotes. This transcription factor has been well-studied for Pol II, but its role in transcription by Pol I has not been fully characterized. Therefore, the goal of this study was to use a high-resolution technique, native elongating transcript sequencing (NET-seq), to investigate the effect of the loss of two of the five Paf1C subunits (Paf1 and Cdc73) on Pol I occupancy in yeast. Most notably, we found that in both paf1D and cdc73D mutants, there was a significant reduction in Pol I occupancy at the 5’ end of the rDNA template as compared to WT yeast. Overall, our results suggest that Paf1C is an important transcription elongation factor for Pol I.聚合酶相关因子1复合物（Polymerase-associated factor 1 complex, Paf1C）已被证实可促进RNA聚合酶I（Pol I）与RNA聚合酶II（Pol II）介导的转录过程，且在真核生物中具有进化保守性。该转录因子的功能在RNA聚合酶II介导的转录中已得到充分研究，但其在RNA聚合酶I转录中的作用尚未被完全阐明。因此，本研究旨在利用高分辨率技术——原生延伸转录本测序（native elongating transcript sequencing, NET-seq）——探究Paf1C五个亚基中的两个亚基（Paf1与Cdc73）缺失后，对酵母中RNA聚合酶I占据情况的影响。尤为关键的是，本研究发现，与野生型（WT）酵母相比，paf1Δ与cdc73Δ两种突变体中，核糖体DNA（rDNA）模板5'端的RNA聚合酶I占据量均出现显著下降。综上，本研究结果表明，Paf1C是RNA聚合酶I介导的转录过程中重要的转录延伸因子。