RNA polymerase II elongation factors Spt4p and Spt5p play roles in transcription elongation by RNA polymerase I and rRNA processing
RNA polymerase II elongation factors Spt4p and Spt5p play roles in transcription elongation by RNA polymerase I and rRNA processing
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DOI：
10.1073/pnas.0605686103
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发表时间：
2006-08-22
影响因子：
11.1
通讯作者：
Nomura, M.
中科院分区：
文献类型：
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作者：
Schneider, D. A.;French, S. L.;Nomura, M.
以前的研究控制RNA聚合酶（Pol）I转录的机制主要集中在转录起始的过程中，因此很少有人知道转录周期中的postinitiation步骤。Spt4p和Spt5p在整个真核生物中是保守的，并且它们影响Pol II的延伸。我们发现这两种蛋白在体内与Pol I共纯化并与rDNA结合。Spt4p基因的破坏导致在允许温度30摄氏度下生长和rRNA合成速率的适度下降。此外，生物化学和EM分析显示rRNA加工存在明显缺陷。这些数据表明，Spt 4p、Spt 5p以及潜在的Pol I转录延伸的其他调节因子在将rRNA转录偶联到其加工和核糖体组装中发挥重要作用。
Previous investigations into the mechanisms that control RNA Polymerase (Pol) I transcription have primarily focused on the process of transcription initiation, thus little is known regarding postinitiation steps in the transcription cycle. Spt4p and Spt5p are conserved throughout eukaryotes, and they affect elongation by Pol II. We have found that these two proteins copurify with Pol I and associate with the rDNA in vivo. Disruption of the gene for Spt4p resulted in a modest decrease in growth and rRNA synthesis rates at the permissive temperature, 30 degrees C. Furthermore, biochemical and EM analyses showed clear defects in rRNA processing. These data suggest that Spt4p, Spt5p, and, potentially, other regulators of Pol I transcription elongation play important roles in coupling rRNA transcription to its processing and ribosome assembly.