Characterization of the RNA polymerases of Trypanosoma brucei: trypanosomal mRNAs are composed of transcripts derived from both RNA polymerase II and III.
Characterization of the RNA polymerases of Trypanosoma brucei: trypanosomal mRNAs are composed of transcripts derived from both RNA polymerase II and III.
复制标题
布氏锥虫 RNA 聚合酶的表征：锥虫 mRNA 由来自 RNA 聚合酶 II 和 III 的转录物组成。
作者：
E. Grondal;R. Evers;K. Kosubek;A. Cornelissen
为了分析布鲁氏锥虫的转录，我们对锥体RNA聚合酶进行了鉴定。在这里，我们介绍了我们的结果，它允许区分不同类别的RNA聚合酶在核运行实验中通过聚合酶抑制剂和对Mn2+的依赖。我们还描述了用层析分离锥虫RNA聚合酶，证明布氏锥虫含有RNA聚合酶I-III。我们的实验结果表明，布氏锥虫的VSG基因不是像以前报道的那样由RNA聚合酶I转录，而是由RNA聚合酶II转录。我们提出了一个额外的因子修饰RNA聚合酶II，导致VSG基因的α-Amanitin抗性转录。我们的数据还表明，编码每个锥虫mRNA 5‘端的微型外显子基因可能是由RNA聚合酶III转录的。
To analyze transcription in Typanosoma brucei, we have characterized the trypanosomal RNA polymerases. Here we present our results, which allow a discrimination between the different classes of RNA polymerases in nuclear run‐on experiments by polymerase inhibitors and Mn2+ dependence. We also describe the separation of trypanosomal RNA polymerases by chromatography, demonstrating that T. brucei contains RNA polymerases I‐III. The outcome of our experiments suggests that the VSG genes of T. brucei are not transcribed by RNA polymerase I, as previously reported, but by RNA polymerase II. We propose that an additional factor modifies RNA polymerase II, resulting in the alpha‐amanitin‐resistant transcription of VSG genes. Our data also suggest that the mini‐exon genes, which encode the 5′ end of each trypanosomal mRNA, are probably transcribed by RNA polymerase III.