GENETIC REGULATION OF YEAST CELL TYPE

这项建议探讨了差异基因表达的分子基础 在简单的真核生物中，酿酒酵母。 具体而言，本提案的目标是了解 参与酵母接合的基因的调节。 接合（交配） 发生在两种不同的酵母细胞类型之间，α和α， 交配过程受遗传和生理两方面的控制。 交配所需产物的基因表达受 单个遗传基因座的等位基因，交配型基因座（MATAlpha和 MATa）。 此外，由每种细胞类型分泌的肽信息素也 影响交配所需的某些基因的表达。 我们专注于 一个特殊的基因，STE 3，它是阿尔法细胞交配所必需的。 STE 3以两种方式调节：从该基因产生RNA需要 α交配型基因座的MATAlpha 1产物，以及来自 STE 3响应于用α细胞处理α细胞而增加 费洛蒙，一种因子 我们的具体目标是理解这两种控制模式， 基因、分子克隆和生物化学方法的组合。 的 STE 3基因的一个区域，赋予其调控的独特特征 将通过体外诱变来定义。 MATAlpha 1产品的作用 将通过确定其亚细胞位置和 它是否直接与STE 3 DNA序列相互作用。 其他潜在 通过体内诱变鉴定除MATAlpha 1之外的调节子。 最后，将研究STE 3产品的作用。 初步 有证据表明它是A因子受体的一种成分。 这 将通过确定STE 3的亚细胞位置来测试视图 产物以及α-因子是否在STE 3依赖性细胞中与α细胞结合。 方式

This proposal examines the molecular basis of differential gene expression in the simple eukaryotic organism, the yeast Saccharomyces cerevisiae. Specifically, the goal of this proposal is to understand two facets of the regulation of genes involved in yeast conjugation. Conjugation (mating) occurs between two distinct cell types of yeast, a and Alpha, and the process of mating is under both genetic and physiological controls. Expression of genes whose products are required for mating is regulated by alleles of a single genetic locus, the mating type locus (MATAlpha and MATa). In addition, peptide pheromones secreted by each cell type also affect expression of some genes required for mating. We have focused on a particular gene, STE3, which is required for mating only by Alpha cells. STE3 is regulated in two ways: RNA production from this gene requires the MATAlpha1 product of the Alpha mating type locus, and RNA production from STE3 increases in response to treatment of Alpha cells with the a cell pheromone, a factor. Our specific aims are to understand these two modes of control using a combination of genetic, molecular cloning, and biochemical approaches. The region of the STE3 gene that imparts the unique features of its regulation will be defined by in vitro mutagenesis. The role of the MATAlpha1 product will be investigated by determining both its subcellular location and whether it interacts directly with STE3 DNA sequences. Other potential regulators besides MATAlpha1 will be indentified by in vivo mutagenesis. Finally, the role of the STE3 product will be investigated. Preliminary evidence suggests that it is a component of the a-factor receptor. This view will be tested both by determining the subcellular location of STE3 product and whether a-factor binds to Alpha cells in a STE3-dependent manner.