Impairment of RNA polymerase I elongation rate induces defects in ribosomal RNA processing and ribosome biogenesis

The objective of this study was to investigate the relationship between Pol I transcription elongation rate and ribosomal RNA processing in vivo by using a yeast strain containing a mutation in Pol I. This mutation, rpa190-F1205H, has been previously characterized to have a reduced elongation rate in vitro. Here, we used native elongating transcript sequencing (NET-seq) to determine the effect of this mutation on Pol I occupancy in vivo. Our findings demonstrate that this mutation induces increased Pol I pausing, especially in the first half of the 35S gene, and causes sequence-specific changes in Pol I occupancy.本研究旨在利用携带RNA聚合酶I（RNA Polymerase I, Pol I）突变的酵母菌株，探究体内（in vivo）RNA聚合酶I转录延伸速率与核糖体RNA加工过程之间的关联。该突变rpa190-F1205H此前已被表征为在体外（in vitro）环境中具有降低的转录延伸速率。本研究采用原生延伸转录本测序（native elongating transcript sequencing, NET-seq）技术，解析该突变对体内RNA聚合酶I结合占据率的影响。研究结果表明，该突变可诱导RNA聚合酶I暂停现象增多，尤其在35S基因的前半段区域更为显著，并引发RNA聚合酶I结合占据率的序列特异性改变。