Molecular Characterization of Transcriptional Activation and Repression in Respon

描述（由申请人提供）：适当的转录调控对于确保细胞对细胞内信号和环境变化做出适当反应至关重要。基因表达的时间或空间缺陷直接影响细胞的生长和分裂、对应激和能量来源的反应以及邻近细胞之间的通讯。在高等真核生物中，转录在控制向特定细胞类型的分化中起着至关重要的作用，这一过程可能导致不受控制的细胞生长和肿瘤形成。理解转录是如何被调控的一个关键部分是充分了解在转录周期的各个步骤中发生的一整套因素和事件。虽然已经确定了许多关键因素，但我们缺乏从分子角度获得激活或抑制靶基因所需步骤的完整视图的链接。我们在理解上的一个主要差距是由于缺乏基于感兴趣的基因组区域而不是调节蛋白本身的分离技术。通过采用Kingston实验室最近开发的一种方法来分离基因组的特定区域及其相关蛋白，我们将详细研究特定基因是如何在以热休克形式出现的环境应激下被激活和抑制的。果蝇强烈调节的热休克反应非常适合分析转录的受控、快速激活和抑制，并揭示同样发生在人类细胞中的转录调节的一般机制。这项研究将允许对新的转录因子进行公正的鉴定，并允许根据其时间角色对已知因子进行表征。热休克途径的阐明将提供有价值的新信息，这将允许重组当前的转录调控模型，并为未来的功能研究打开大门。通过描述应激反应基因的正常激活和抑制的分子细节，我们可以开始理解这些过程在癌症中是如何被破坏的。

DESCRIPTION (provided by applicant): The proper regulation of transcription is essential to ensure that cells respond appropriately to intracellular cues and environmental variations. Temporal or spatial defects in gene expression directly impact cell growth and division, responses to stress and energy sources, and communication between neighboring cells. In higher eukaryotes, transcription plays a vital role in controlling differentiation into specific cell types, a process that can lead to uncontrolled cell growth and tumor formation when misdirected. A crucial part of understanding how transcription is regulated is to have full knowledge of the complete set of factors and events that take place throughout the various steps in the transcription cycle. While many key factors have been identified, we lack the links to gain a complete view in molecular terms of the steps required to achieve activation or repression of a target gene. A major gap in our understanding has been due to the absence of an isolation technique based on the genomic region of interest rather than the regulatory proteins themselves. By adapting a method recently developed by the Kingston laboratory to isolate specific regions of the genome along with their associated proteins, we will study in detail how specific genes are activated and repressed in response to environmental stress in the form of heat shock using the fruit fly Drosophila melanogaster. The robustly regulated heat shock response in Drosophila is ideally suited to analyze the controlled, rapid activation and repression of transcription and to uncover general mechanisms of transcriptional regulation that also occur in human cells. This study will allow for unbiased identification of new transcription factors, and permit the characterization of known factors according to their temporal roles. The elucidation of the heat shock pathway will provide valuable new information that will allow for the restructuring of current models of transcriptional regulation and will open the door for future functional studies. By characterizing in molecular detail the normal activation and repression of stress response genes, we can begin to understand how these processes are disrupted in cancers. ) PUBLIC HEALTH RELEVANCE: Precise control over gene expression is required to ensure that cells behave appropriately during normal processes and also respond to external stimuli quickly, and defects in gene expression can directly and indirectly lead to the development of cancer. Examples of abnormal function of gene regulatory factors have been found in almost all human cancers, so it is important to understand exactly how these factors work to turn on or off a particular gene at the appropriate time and place. The goal of this project is to provide an unbiased, unprecedented view of the molecular events leading to changes in gene expression at specific genes. A well-defined model system will be used to gain detailed information about the factors and steps required to respond appropriately to cellular stress, while also uncovering general mechanisms of gene regulation. This will lead to an overall better understanding of gene regulation under normal conditions, and importantly, what goes wrong in the development of disease.