High-resolution mapping of transcribing Pol III by CRAC in the WT and C128 mutants

Here we report high-resolution analyses of transcribing RNA polymerase III (Pol III) in a wild-type (WT) strain and three C128 mutants. C128 is the second largest subunit of Pol III, which is the key subunit to recognize termination signal. Mutating key residues in C128 interferes with transcription termination in vitro and affect yeast viability as well, raising the question that whether these mutations provoke Pol III termination defects in vivo. Here we show that C128 mutants display termination defects at most PolIII-dependent genes, indicating that the most disruptive C128 mutations indeed impair Pol III transcription termination in vivo Overall design: Analysis of the effect of the mutations of C128 on Pol III-dependent transcription genome-wide using CRAC

本研究报道了野生型（wild-type，WT）菌株与三株C128突变株中，转录状态下RNA聚合酶III（RNA polymerase III，Pol III）的高分辨率分析结果。C128是Pol III的第二大亚基，亦是识别转录终止信号的关键亚基。对C128的关键残基进行诱变，可在体外干扰转录终止过程，同时也会影响酵母的生存能力，由此提出疑问：此类突变是否会在体内引发Pol III的转录终止缺陷。本研究结果显示，C128突变体在绝大多数依赖Pol III的基因位点均表现出终止缺陷，表明破坏效应最强的C128突变确实会在体内损害Pol III的转录终止功能。整体实验设计：采用CRAC技术，对C128突变在全基因组范围内对依赖Pol III的转录的影响进行分析。