CONTROL OF TRNA GENE EXPRESSION IN BOMBYX MORI

我们正在分析真核rna转录的机制。 聚合酶III。我们主要关注聚合酶III的转录 来自家蚕的机械，因为有证据表明 该生物体中聚合酶III活性的组织特异性调节。 这是一个基本的生物学问题。所有真核生物都需要 聚合酶III正确转录的产物。而且，因为它是 很可能这三种真核生物都有共同的机械特征 RNA聚合酶，对任何一种酶的分析也应该让我们洞察 其他人。 利用体外诱变，我们已经定义了 指导家蚕聚合酶III转录的顺式作用元件 TRNAA1a基因。我们发现，该地区所需的全部 该基因的转录活性非常大。它包括 编码区，并在其上游和下游延伸。在 我们将确定这样的大型控制元素是否 聚合酶III模板的一般特征，我们将确定 它们提供的功能。我们提出的功能分析利用了 我们操控家蚕聚合酶III组分的能力 转录机器，我们已经解决了。通过改变元素 在配置项中行为，以及在转换中行为，我们将确定如何 这些元素之间的相互作用导致正确的转录 聚合酶III。

We are analyzing the mechanism of transcription by eukaryotic RNA polymerase III. We have focused on the polymerase III transcription machinery from the silkworm, Bombyx mori, because there is evidence for tissue-specific regulation of polymerase III activity in this organism. This is a fundamental biological problem. All eukaryotes require the products of correct transcription by polymerase III. Moreover, since it is likely that there are mechanistic features common to all three eukaryotic RNA polymerases, analysis of any one enzyme should also give insight into the others. Using in vitro mutagenesis we have already defined the boundaries of the cisacting elements that direct polymerase III transcription of a silkworm tRNAA1a gene. We have found that the region required for full transcriptional activity of this gene is remarkably large. It includes the coding region, and extends beyond it both upstream and downstream. In the proposed work we will determine whether such large control elements are general features of polymerase III templates, and we will identify the functions they provide. The functional analyses we propose take advantage of our ability to manipulate the components of the Bombyx polymerase III transcription machinery that we have resolved. By varying the elements that act in cis, as well as those that act in trans, we will determine how interactions between these elements lead to correct transcription by polymerase III.