EXPRESSION CONTROL OF YEAST GLUCOAMYLASE GENES

对作用于多糖的酶的编码基因的调节 在酵母中没有得到广泛的研究。在基因层面上， 酿酒酵母中糖淀粉酶基因的调控。 舒张期看起来很复杂，与调节机制不同。 在SUC、MAL和GAL等可诱导系统中观察到。这项建议 阐述了控制STA表达的调控机制 酿酒酵母中的基因。舒张性。 STA基因受GAM 1、GAM2和GAM3的正调控， 负向受STA10和MATA/MATα依赖的抑制。另外， 被鉴定为IST1、IST2、.INH1和SGL1的基因被认为是 STA基因表达的抑制因子；然而，它们与各自的关系 其他及其影响STA基因表达的机制有 未知。STA基因也受到碳分解代谢抑制。 有趣的是，STA2基因被发现含有共同的RAP1蛋白 其5‘上游区域和编码区的结合位点 区域。 对酿酒酵母的STA2基因进行了克隆。舒张压将被用于调查 直接、间接和发展的调控信号，控制着 糖淀粉酶多基因家族成员的表达。建议数 研究将解决与如何监管相关的几个问题 对STA2表达施加控制，目的是表征 监管网络的组成部分，并可能解释其 具有功能性、发展性和进化性。具体的 拟议项目的目标如下： 1.确定STA10是作为STA2的激活因子还是抑制因子 基因表达。目的克隆并鉴定STA10基因。要生成一个 影响STA基因表达的突变库。 2.确定STA10蛋白是否为DNA蛋白。要确定 哪些蛋白质与STA10反应的顺式作用元件相互作用。 3.对STA基因进行遗传定位。 4.确定负责的顺式作用调控序列 STA2阳性对照。分离和克隆积极作用的人 与STA2上游序列相互作用的因子。 5.检测RAP1蛋白对STA2表达的影响。 6.研究STA2的MATA/MATα依赖的抑制作用。 7.确定影响糖化酶基因表达的其他基因，并 确定它们是否与已知基因同义。

The regulation of genes encoding enzymes that act on polysaccharides has not been studied extensively in yeast. On the genetic level, the regulation of the glucoamylase (STA) genes in Saccharomyces cerevisiae var. diastaticus appears complex and different from the regulatory mechanisms observed in inducible systems such as SUC, MAL and GAL. The proposal addresses the regulatory mechanisms that control the expression of the STA genes in S. cerevisiae var. diastaticus. The STA genes are regulated both positively by GAM], GAM2 and GAM3 and negatively by STA10 and MATa/MATalpha-dependent repression. Additionally, genes identified as IST1, IST2,.INH1 and SGL1 have been proposed to be repressors of STA gene expression; however, their relationship to each other and the mechanism of their effects on STA gene expression are unknown. The STA genes are also subject to carbon-catabolite repression. Interestingly, the STA2 gene was found to contain consensus RAP1 protein binding sites in its 5' upstream region as well as within its coding region. The STA2 gene of S. cerevisiae var. diastaticus will be used to investigate the direct, indirect and developmental regulatory signals that control the expression of members of the glucoamylase multigene family. The proposed research will address several questions that relate to how regulatory control is imposed on STA2 expression with the goal of characterizing components of the regulatory network and possibly to explain their functional, developmental and evolutionary significance. The specific goals of the proposed project are as follows: 1. To determine whether STA10 acts as an activator or repressor of STA2 gene expression. To clone and characterize the STA10 gene. To generate a bank of mutants that are affected in the expression of the STA genes. 2. To determine whether the STA10 protein is a DNA protein. To determine which proteins interact with STA10-responsive cis-acting elements. 3. To genetically map the STA genes. 4.To determine the cis-acting regulatory sequences responsible for the positive control of STA2. To isolate and clone the positively-acting factors that interact with the STA2 upstream sequence. 5. To determine the effect of the RAP1 protein on the expression of STA2. 6. To characterize the MATa/MATalpha-dependent repression of STA2. 7. To identify other genes that affect glucoamylase gene expression and to determine whether they are synonymous with known genes.