GENETICS AND ISOLATION OF A EUKARYOTIC CONTROL PROTEIN

这项工作的长期目标是了解基因的控制。 在真核细胞中表达。我们用的是尿囊素降解剂 酵母酿酒酵母系统作为这方面的模型系统 调查。尿囊素在这种生物体中的作用是降解的 五种酶的活性，需要四种额外的参与 运输系统。所有负责这些功能的基因都有 已被映射。在过去的工作中，我们已经证明了这五种酶的产生 活动和其中一个运输系统是可诱导的； 途径中的最后一个中间体作为诱导剂。我们最近做了 分离出两类新的突变体。一类菌株(在 Dur5基因座)在缺乏Dir5基因的情况下，构成地产生所有的酶 添加了诱导剂。第二类菌株(在dal6基因座突变)是 无法合成任何一种酶，即使诱导剂可以证明 存在于细胞中。在本申请中，我们建议使用这些 突变体以阐明参与控制这五种病毒的分子事件 与尿囊素降解相关的不同基因。主要领域 研究包括：(1)突变株的特征，在该突变株中产生 尿囊素降解酶已改变(du5和dal6)，(2) 通过遗传学研究阐明控制元件的相互作用和 第二代防治突变体的分离，(3)Dur5和 DAL6基因，(4)DUR5和DAL6基因表达的特征和(5) Dal5和dal6基因产物的纯化。

The long range objective of this work is to understand the control of gene expression in eucaryotic cells. We are using the allantoin degradative system of the yeast Sacchaormyces cerevisiae as a model system for these investigations. Allantoin is degraded in this organism by the action of five enzyme activities and requires the additional participation of four transport systems. All of the genes responsible for these functions have been mapped. In past work we have shown that production of the five enzyme activities and one of the transport systems is inducible; allophanate, the last intermediate in the pathway serves as inducer. We have recently isolated two new classes of mutants. One class of strains (mutated in the dur5 locus) produces all of the enzymes constitutively in the absence of added inducer. The second class of strains (mutated in the dal6 locus) are unable to synthesize any of the enzymes even though inducer can be shown to exist in the cells. In the present application we propose to use these mutants to elucidate the molecular events involved in control of the five distinct genes associated with allantoin degradation. The principal areas of study include: (1) characterization of mutants in which production of the allantoin degrading enzymes has been altered (dur5 and dal6), (2) elucidation of control element interactions by genetic studies and the isolation of second generation control mutants, (3) cloning of the dur5 and dal6 genes, (4) characterization of dur5 and dal6 gene expression and (5) purification of the dur5 and dal6 gene products.