GENETIC REGULATION OF YEAST CELL TYPE

这项建议研究了差异基因表达的分子基础。 在简单的真核生物中，酵母是酿酒酵母。 具体地说，这项建议的目标是了解 酵母接合相关基因的调控。接合(交配) 发生在两种不同的酵母细胞类型a和α之间，而 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，每种细胞类型分泌的多肽信息素也 影响交配所需的一些基因的表达。我们一直专注于一个 特定基因STE3，只有阿尔法细胞才需要它来交配。 STE3有两种调控方式：该基因产生的RNA需要 Alpha交配型基因座的MATAlpha1产物和来自 α细胞处理后STE3的表达增加 信息素，一个因素。 我们的具体目标是使用 基因、分子克隆和生化方法的结合。这个 赋予STE3基因独特调控功能的区域 将通过体外诱变来定义。MATAlpha1产品的作用 将通过确定其亚细胞位置和 它是否与STE3 DNA序列直接相互作用。其他潜力 除了MATAlpha1以外的调节子将通过体内突变来鉴定。 最后，将对STE3产品的作用进行调查。初步 有证据表明，它是a因子受体的一种成分。这 VIEW将通过确定STE3的亚细胞位置进行测试 产物以及α-因子是否与STE3依赖的Alpha细胞结合 举止。

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.