MOLECULAR BASIS OF GENE EXPRESSION IN YEAST

在酿酒酵母中，阿尔法1蛋白负责 一组细胞类型特异性基因的表达，即阿尔法特异性基因 基因。三个这样的基因，Mf(Alpha)1和Mf(Alpha)2和STE3， 已经被识别并编码了蛋白质所需的 阿尔法细胞类型的特殊功能。我们的目标是 了解阿尔法1的两个方面的分子基础 蛋白质的调节活性：1)α1蛋白的特异性 和2)阿尔法通过的机制 1蛋白实现其对基因表达的激活。我们会 使用我们对α1蛋白作用的分析结果 关于MF(α)1，启动子是如何分开的 酵母启动子的元件是相互协调的。 为了分析阿尔法1蛋白的活性，我们将从 提纯阿尔法1蛋白。我们将测试阿尔法的想法 1蛋白是激活Mf(α)1表达的特异性蛋白 因为它与该基因附近的序列结合。如果是的话，是不是？ 仅仅是α1蛋白的性质或是其他酵母蛋白 有牵连吗？由于启动子是一个多组分系统，它 似乎阿尔法1蛋白通过相互作用来发挥其作用 与其他转录成分；通过鉴定和 通过表征这些相互作用的蛋白质，我们可以了解到 不是与不同启动子元件相互作用的蛋白质 和彼此在一起。 要了解独立的序列元素(及其 相关蛋白)在启动子功能上是协调的，我们将 确定与MF(α)1相互作用的其他蛋白质 推动者。我们将推动转录复合体的形成 DNA结合蛋白和阿尔法1蛋白和Will 尝试复制特定的依赖于α1的转录 体外培养。 除了我们对阿尔法1蛋白如何起作用感兴趣外，我们还 对阿尔法1蛋白是如何调节的也很感兴趣。一些人 酵母菌株可以频繁地切换交配类型；快速的 通过新交换的信元获得专门的信元功能 是旧的细胞类型调节因子，即阿尔法调节因子 1(和其他)在细胞类型转换后迅速失活 发生。我们建议研究α1的失活 蛋白质，以辨别这种假定的活动是如何调节的。

In the yeast S. cerevisiae, the alpha 1 protein is responsible for expression of a set of cell-type specific genes, the alpha-specific genes. Three such genes, MF(alpha)1, and MF(alpha)2, and STE3, have been identified and code for proteins required for the specialized functions of the alpha cell type. Our goal is to understand the molecular basis for two aspect of the alpha 1 protein's regulatory activity: 1) the specificity of alpha 1 protein for the alpha-specific genes and 2) the mechanism by which alpha 1 protein implements its activation of gene expression. We will use the results of our analysis of the action of the alpha 1 protein on the MF(alpha)1, promoter to understand how the separate elements of a yeast promoter are coordinated. To analyze the activity of the alpha 1 protein, we will begin by purifying the alpha 1 protein. We will test the idea that the alpha 1 protein is specific for activating expression of the MF(alpha)1 gene because it binds to sequences near this gene. If so, is it solely a property of alpha 1 protein or are other yeast proteins involved? Since the promoter is a multi-component system, it seems likely that alpha 1 protein exerts its effects by interacting with other transcription components; by identifying and characterizing these interacting proteins we may learn whether or not proteins that bind to separate promoter elements interact with each other. To understand how the separate sequence elements (and their associated proteins) are coordinated in promoter function, we will identify other proteins that interact with the MF(alpha)1 promoter. We will drive formation of a transcription complex with the DNA binding proteins and alpha 1 protein and will attempt to reproduce specific alpha 1 dependent transcription in vitro. In addition to our interest in how the alpha 1 protein acts, we are also interested in how the alpha 1 protein is regulated. Some strains of yeast can switch mating type frequently; the rapid acquisition of specialized cell function by the newly switched cell is suggestive evidence that the old cell type regulators, i.e., alpha 1 (and others) are rapidly inactivated after the cell type switch occurs. We propose to examine the inactivation of the alpha 1 protein to discern how this putative activity is regulated.