REGULATION OF NITROGEN CATABOLIC GENE EXPRESSION

这项工作的长期目标是了解生物化学 调节尿囊素系统转录的反应 运输基因。这一分解代谢抑制的重要组成部分。 尿囊酸渗透酶基因DAL5被选为模型系统 用什么来研究这类监管。我们已经确定了上游的 负责转录激活的激活序列(UAS) DAL5，并证明它能与一种或多种蛋白质结合。该计划的目标是 目前的建议是显著加深我们对无人机的理解 通过改变已经证明的12-15个碱基来构建 转录激活功能上所必需的。这些因素的影响 支持转录激活和蛋白质的能力的改变 与UAS的结合将与嘌呤的影响一起进行测量 蛋白质结合上的甲基化。编码结合蛋白的基因 到DAL5的无人机将使用几个拟议战略之一进行克隆。 我们将讨论氮分解代谢抑制(NCR)的机制。 使用涉及DAL5和CAR1的多种策略 基因。DAL5 UAS已被证明是唯一的DNA序列 DAL5基因表达对NCR敏感性所需的信息。在……里面 相比之下，上游抑制元素(URS)的行为类似于 操作员，已被牵连到CAR1基因的NCR。我们已经提议 详细的实验以确定URS是否是唯一的顺式作用 NCR敏感度所需的CAR1元素。然后再进行实验 建议确定蛋白质磷酸化是否与 CAR1和DAL5基因对NCR的敏感性。

The long term objective of this work is to understand the biochemical reactions responsible for regulated transcription of the allantoin system transport genes. An important component of this catabolite repression. The allantoate permease gene, DAL5, has been chosen as a model system with which to study this type of regulation. We have identified the upstream activation sequence (UAS) responsible for transcriptional activation of DAL5 and shown that it binds one or more proteins. The objective of the present proposals is to significantly refine our understanding of the UAS structure by altering the 12-15 bases that have been shown to be functionally required for transcriptional activation. The effects of these alterations on ability to support transcriptional activation and protein binding to the UAS will be measured along with the effects of purine methylation on protein binding. The gene encoding the protein that binds to the DAL5 UAS will be cloned using one of several proposed strategies. The mechanisms of nitrogen catabolite repression (NCR) will be addressed using multiple strategies involving the use of both the DAL5 and CAR1 genes. The DAL5 UAS has been demonstrated to be the only DNA sequence information required for sensitivity of DAL5 gene expression to NCR. In contrast, an upstream repression element (URS), which behaves like an operator, has been implicated in NCR of the CAR1 gene. We have proposed detailed experiments to ascertain whether the URS is the only cis-acting element of CAR1 required for NCR sensitivity. Experiments are then proposed to determine whether protein phosphorylation is associated with NCR sensitivity of the CAR1 and DAL5 genes.