Promoter Regulation in Response to Environmental Stress

描述（由申请人提供）：真核基因的调控涉及数百种蛋白质。它们是如何在组成基因组的数千个基因中协同工作的尚不清楚。当细胞基因组被重编程以响应诸如环境压力之类的信号事件时，这种相互作用是如何变化的，我们知之甚少。本文提出的工作是一个项目的继续，该项目广泛调查了真核生物模型酿酒酵母（Saccharomcyes cerevisiae）基因组中转录调节蛋白的位置，以及当基因组受到环境信号（如热休克和其他应激）重编程时，它们会转移到哪里。热休克为细胞提供了一个快速而简单的编程事件。目前对这一项目的研究已经揭示了基因调控的新见解，表明起始前复合物部分组装在无核小体启动子区域。然而，完全组装需要去除位于启动子上游的“-1”核小体。在正常和热休克条件下，用ChIP-chip低分辨率测定了约200个基因和染色质调控蛋白的基因组定位。目前正在分析这些数据。通过对ChIP-seq的ChIP-chip库进行改造，可以实现高分辨率的映射。使用试剂修剪ChIP DNA，将在一组选定的因子上实现更高分辨率的制图。结合事件之间的关系将为转录复合体的组装和调控提供新的见解。

DESCRIPTION (provided by applicant): The regulation of eukaryotic genes involves many hundreds of proteins. How they work together at the many thousands of genes that comprise a genome is not known. Little is known about how this interplay changes as cellular genomes are reprogrammed in response to signaling events such as environmental stress. The work proposed here is a continuation of a project to broadly survey where transcriptional regulatory proteins are located throughout the genome of the model eukaryotic organism Saccharomcyes cerevisiae, and where they translocate to when the genome is reprogrammed by environmental signals, such as heat shock and other stresses. Heat shock provides a rapid and simple programming event for the cell. Current studies on this project have already revealed novel insights into gene regulation by demonstrating that pre-initiation complexes partially assemble in nucleosome-free promoter regions. However, full assembly requires removal of the "-1" nucleosome located on the upstream side of the promoter. The genomic location of ~200 gene- and chromatin-regulatory proteins have been determined at low resolution by ChIP-chip, under normal and heat shock conditions. The data is now being analyzed. High resolution mapping will be achieved by retrofitting the ChIP-chip libraries for ChIP-seq. Even higher resolution mapping will be achieved on a select set of factors using reagents to trim the ChIP DNA. Relationships among binding events will provide new insights into transcription complex assembly and regulation.