Grondal E J, Evers R, Kosubek K, Cornelissen A W
Max-Planck-Institut für Biologie, Molecular Parasitology Unit, Tübingen, FRG.
EMBO J. 1989 Nov;8(11):3383-9. doi: 10.1002/j.1460-2075.1989.tb08502.x.
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.
为了分析布氏锥虫中的转录过程，我们对锥虫的RNA聚合酶进行了表征。在此，我们展示我们的结果，这些结果能够在核转录实验中通过聚合酶抑制剂和对Mn2+的依赖性来区分不同类别的RNA聚合酶。我们还描述了通过色谱法分离锥虫RNA聚合酶的过程，证明布氏锥虫含有RNA聚合酶I - III。我们实验的结果表明，布氏锥虫的VSG基因并非如先前报道的那样由RNA聚合酶I转录，而是由RNA聚合酶II转录。我们提出，一种额外的因子修饰了RNA聚合酶II，导致VSG基因的α-鹅膏蕈碱抗性转录。我们的数据还表明，编码每个锥虫mRNA 5'端的小外显子基因可能由RNA聚合酶III转录。
