EXPRESSION CONTROL OF YEAST GLUCOAMYLASE GENES

对编码作用于多糖的酶的基因的调节， 在酵母中没有被广泛研究。 在基因层面上， 葡萄糖淀粉酶（STA）基因在酿酒酵母变种的调控。 糖化酶的调节机制复杂而不同， 在诱导型系统如SUC、MAL和GAL中观察到。 该提案 解决了控制STA表达的调节机制， S.酿酒变种糖化物 STA基因受GAM 1、GAM 2和GAM 3正向调节， STA 10和MATa/MATa依赖性抑制呈阴性。 此外，本发明还 已经提出鉴定为IST 1、IST 2、INH 1和SGL 1的基因是 STA基因表达的阻遏物;然而，它们与每个 其他的，并探讨了它们对STA基因表达的影响机制。 未知 STA基因也受到碳分解代谢物抑制。 有趣的是，发现STA 2基因含有共有RAP 1蛋白， 在其5'上游区域以及在其编码内的结合位点 地区 STA 2基因在S.酿酒变种diastaticus将用于调查 直接的，间接的和发育的调控信号，控制 葡糖淀粉酶多基因家族成员的表达。 拟议 研究将解决几个问题，涉及如何监管 对STA 2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 功能、发育和进化意义。 具体 拟议项目的目标如下： 1. 为了确定STA 10是否作为STA 2的激活物或阻遏物起作用， 基因表达。 目的：克隆STA 10基因，并对其进行鉴定。 以生成 在STA基因的表达中受到影响的突变体库。 2. 确定STA 10蛋白是否为DNA蛋白。 以确定 这些蛋白质与STA 10响应性顺式作用元件相互作用。 3. 对STA基因进行基因定位。 4.确定调控基因的顺式作用序列， STA 2的阳性对照。 为了分离和克隆阳性作用的 与STA 2上游序列相互作用的因子。 5. 确定RAP 1蛋白对STA 2表达的影响。 6. 表征STA 2的MATa/MAT α依赖性抑制。 7. 为了鉴定影响葡糖淀粉酶基因表达的其他基因， 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.