High-resolution mapping of transcribing RNAPIII by CRAC upon mutation or depletion of Sen1 [Experiment 1]

Here we report high-resolution analyses of transcribing RNAPIII in either a wild-type (WT) background , a sen1-3 mutant or a Sen1 auxin-inducible degron (AID) strain in which Sen1 can be rapidly depleted upon addition of the auxin analogue Indole-3-acetic acid (IAA). Sen1 is a well-characterized transcription termination factor for RNAPII-dependent genes in budding yeast. Here we show that the presence of three point mutations in sen1-3 that abrogate the interaction of Sen1 with RNAPIII, as well as the depletion of Sen1 provoke global transcription termination defects at RNAPIII-dependent genes. These results indicate that Sen1 is also a transcription termination factor for RNAPIII transcription units.本研究报道了在三种遗传背景下对转录中RNA聚合酶III（RNAPIII）的高分辨率分析：野生型（WT）背景、sen1-3突变体，以及Sen1生长素诱导降解（AID）菌株——该菌株中，加入生长素类似物吲哚-3-乙酸（IAA）后可快速降解Sen1蛋白。Sen1是酿酒酵母中已被充分表征的、依赖RNA聚合酶II（RNAPII）的基因的转录终止因子。本研究发现，sen1-3中存在的三个可阻断Sen1与RNAPIII相互作用的点突变，以及Sen1的降解，均会在依赖RNAPIII的基因处引发全局转录终止缺陷。上述结果表明，Sen1同时也是RNAPIII转录单元的转录终止因子。