Combinatorial Interactions among Eukaryotic Transcription Factors

真核转录因子之间的组合相互作用

• 批准号: 9404721
• 负责人: Henry Baker
• 金额: $ 30万
• 依托单位: University of Florida
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1994
• 资助国家: 美国
• 起止时间: 1994-09-01 至 1998-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9404721&HistoricalAwards=false
• 关键词: Combinatorial; Interactions; among; Eukaryotic; Transcription

Abstract 9404721 Promoters in higher eukaryotes tend to have complex structures. In Saccharomyces cerevisiae the upstream activating sequence (UAS) elements of glycolytic enzyme genes closely resemble enhancers and proximal promoter elements of higher eukaryotes in that they are composed of multiple binding sites for several different transcription factors. Each protein binding site by itself displays little UAS activity, but together they form powerful UAS elements. The transcription factors believed to assemble at the UAS elements of glycolytic genes include Abflp, Reb1p, Rap1p, Gcr1p, Gcr2p, and Ga111p. The individual roles of the proteins and how they interact to form the strongest promoters in yeast are not known. The goal of this study is to provide information as to the precise roles played by several of these transcription factors. Specifically: i) The hypothesis that binding of Abflp and Reb1p functions to clear nucleosomes from adjacent binding sites, thereby allowing other proteins access to their binding sites is tested. ii) The importance of spatial relationships between Rap1p- and Gcr1p- binding sites in the UAS elements of glycolytic genes is investigated. iii) Yeast strains with mutations in gcr2 and gal11 are utilized to assess the roles of the co-factors Gcr2p and Gal11p in displacing nucleosomes from the TATA-box. iv) Environmental factors which may influence the ability of transcription factors to bind at glycolytic gene promoters are investigated. These experiments will provide important new information as to how the individual activator proteins interact in a combinatorial fashion at eukaryotic promoters to mediate high-level expression. *** One of the major control points of gene expression is the regulation of transcription. An enzyme known as RNA polymerase is responsible for converting the genetic information from DNA to RNA. Promoters are regions in the DNA which are required to bring RNA polymerase to genes so they can be t ranscribed. They are made of sequences known as the TATA-box, proximal promoters, and enhancers or upstream activating sequences (UAS). Proximal promoters and enhancers or UAS elements are sites in the DNA to which proteins bind. Proteins that bind at these sequences activate transcription by influencing events that occur at the TATA-box. The focus of this study is to elucidate the precise roles played by the proteins that assemble at the UAS elements of glycolytic enzyme genes in the yeast, Saccharomyces cervisiae. In yeast, genes encoding glycolytic enzymes are the most highly expressed. A number of abundant, multifunctional proteins are required for full expression of yeast glycolytic genes. While combinatorial interactions between these proteins at the UAS elements of glycolytic genes has been well documented, the mechanism(s) governing their interactions have yet to be established. The aims of this study are: i) To test a sequential binding hypothesis. ii) To determine the importance of the spatial relationships. iii) To investigate the role of cofactors which are believed to influence events at the TATA-box. iv) To investigate environmental factors which may influence the ability of transcription factors to bind at glycolytic gene UAS elements, thus regulating expression. %%%

较高真核生物中的摘要9404721启动子倾向于具有复杂的结构。 在酿酒酵母中，糖酵解酶基因的上游激活序列（UAS）元素非常类似于较高真核生物的增强子和近端启动子元素，因为它们由多种不同的转录因子组成。每个蛋白质结合位点本身几乎没有UAS活性，但它们共同形成强大的UAS元素。 据信聚集在糖酵解基因的UAS元素上的转录因子包括ABFLP，REB1P，RAP1P，GCR1P，GCR2P和GA111P。 蛋白质的个别作用及其如何相互作用以形成酵母中最强的启动子。 这项研究的目的是提供有关这些转录因子中几个的确切作用的信息。 具体来说：i）假设ABFLP和REB1P函数与相邻结合位点清除核小体的结合，从而允许其他蛋白质访问其结合位点。 ii）研究了糖酵解基因的UAS元素中Rap1p-和GCR1P结合位点之间空间关系的重要性。 iii）使用GCR2和GAL11突变的酵母菌菌株用于评估副因素GCR2P和GAL11P在tata-box置换核小体中的作用。 iv）研究可能影响转录因子在糖酵解基因启动子上结合的能力的环境因素。 这些实验将提供有关单个激活蛋白如何在真核启动子上以组合方式相互作用以介导高级表达的重要新信息。 ***基因表达的主要控制点之一是转录的调节。 称为RNA聚合酶的酶负责将遗传信息从DNA转化为RNA。 启动子是DNA中的区域，将RNA聚合酶带到基因上，因此可以被解雇。 它们由称为tata-box，近端启动子和增强子或上游激活序列（UAS）的序列制成。 近端启动子和增强子或UAS元素是与蛋白结合的DNA中的位点。 在这些序列上结合的蛋白质通过影响在tata-box上发生的事件激活转录。 这项研究的重点是阐明蛋白质在酵母中糖脂基因糖疗中心糖基因的UAS元素的精确作用。 在酵母中，编码糖酵解酶的基因是最高表达的。 完全表达酵母糖酵解基因需要许多丰富的多功能蛋白质。 虽然在糖酵解基因的UAS元素上，这些蛋白质之间的组合相互作用已得到充分证明，但管理它们相互作用的机制尚未确定。 这项研究的目的是：i）检验顺序结合假设。 ii）确定空间关系的重要性。 iii）研究辅助因子的作用，据信据信会影响塔塔盒中的事件。 iv）研究可能影响转录因子在糖酵解基因上元素结合的能力的环境因素，从而调节表达。 %%%