GAGA FACTOR AND HEAT SHOCK PROMOTER POTENTIATION

GAGA 因子和热休克启动子增强作用

• 批准号: 6385053
• 负责人: ERIK D ANDRULIS
• 金额: $ 4.02万
• 依托单位: CORNELL UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-04-01 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/6385053
• 关键词: Drosophilidae; arthropod genetics; chromatin; fungal genetics; genetic promoter element; protein binding; protein protein interaction; protein structure function; stress proteins; transcription factor; yeast two hybrid system

The heat shock response of Drosophila melanogaster is characterized by the rapid and robust activation of the major heat shock genes. Although much is known about heat shock promoter architecture and the transcription factors which recognize the promoters, the mechanistic detail of heat shock gene transcription remain unclear. Two transcription factors, GAGA factor (GAF) and TATA-binding protein, and RNA polymerase II (Pol II) occupy the uninduced heat shock promoters. Pol II, although capable of producing small transcripts, is paused at the heat shock promoter. It is thought that the protein-protein and protein-DNA interactions among these factors play an important role in the maintenance of the open chromatin structure at the promoter and in retention of the paused polymerase. To address this hypothesis, DNA-binding domain and interaction domain mutants of GAF will be constructed and subjected to rigorous in vivo and in vitro analysis. Given the similarities between heat shock promoter sequences and those of other promoters, and the presence of a paused polymerase on several non-heat shock genes in Drosophila and in mammalian cells, studies with these GAF mutants may provide a general understanding of promoter architecture, polymerase pausing, and gene activation.

果蝇的热休克反应的特点是主要的热休克基因被快速而有力地激活。虽然关于热休克基因启动子的结构和识别启动子的转录因子已知很多，但热休克基因转录的机制细节仍不清楚。Gaga因子(GAF)和TATA结合蛋白(TATA结合蛋白)和RNA聚合酶II(POL II)两个转录因子占据未诱导的热休克启动子。POL II虽然能够产生小的转录本，但在热休克启动子处暂停。人们认为，这些因子之间的蛋白质-蛋白质和蛋白质-DNA相互作用在维持启动子的开放染色质结构和保留暂停的聚合酶方面起着重要作用。为了解决这一假设，将构建GAF的DNA结合域和相互作用域突变体，并进行严格的体内和体外分析。鉴于热休克启动子序列与其他启动子序列的相似性，以及果蝇和哺乳动物细胞中几个非热休克基因上存在一个暂停的聚合酶，对这些GAF突变体的研究可能会提供对启动子结构、聚合酶暂停和基因激活的总体理解。