Repair of Genotoxic Damage in Chromatin

描述：限制获得核小体的巨大影响 DNA到基因转录和DNA修复机制的组成部分不能 言过其实了。CREB结合蛋白(CBP)/p300，是一种共激活因子，可用于许多 包括P53在内的转录因子最近被证明能够增强 RNA聚合酶II转录的许多基因的转录激活。 提示CBP/p300固有的组蛋白乙酰转移酶活性 在解开抑制性染色质中发挥关键作用，并促进 与基因转录相关的事件。这项建议是基于 假设已经确立的DNA转录相关观察 提供了一个有用的和及时的范式来解开 与核苷酸切除修复相关的核小体重排。这个 关于染色质中DNA修复调节的拟议研究是基于 我们最近的数据支持P53通路与DNA修复的联系。这个 总体而言，实验旨在解决特定的假设，即P53 转录激活机制，其中包括P53肿瘤抑制因子 CBP/p300和转录因子IIH是针对散发性病变的蛋白质 通过涉及复杂多蛋白的招募过程确定基因组的位置 DNA修复早期的相互作用。拟议的工作将利用 相关的生化、细胞和分子技术，建立在 申请人？S实验室，具体目标有以下几点。(1)至 建立P53转录激活/DNA损伤识别的形成机制 通过各种成分因子的相互作用，如p53，p300， XPC-hHR23B和TFIIH。(2)确定XPC-hHR23B在 P53转录激活机制对DNA损伤的募集。(3)至 确定XPC和TFIIH组件的物理相互作用区域 P53形成所需的XPB和P62蛋白 转录激活/DNA识别复合体。(4)划定 CBP/p300介导组蛋白超乙酰化与核苷酸的关系 切除修复。(5)证实染色质结构对细胞周期的影响。 靶基因内的定点修复。这些项目的长期目标是 研究是为了揭示几个重要的相互关联的基因的本质 功能及其在维持基因组序列完整性中的作用。 理解有害因素迅速逆转的机制基础 基因组变化，发生在人类细胞中，从暴露到不同的 外源性和内源性致突变致癌物，在 癌症的发病机制。

DESCRIPTION: Formidable effects of the restricted accessibility of nucleosomal DNA to components of gene transcription and DNA repair machinery cannot be overstated. CREB Binding Protein (CBP)/p300, a coactivator for a number of transcription factors including p53, has recently been shown to potentiate transcriptional activation of many genes transcribed by the RNA polymerase II. The intrinsic histone acetyltransferase activity of CBP/p300 is suggested to play a key role in unfolding the repressive chromatin and facilitates the events associated with gene transcription. This proposal is based on the premise that the well-established DNA transcription-associated observations provide a useful and timely paradigm for unraveling the intrinsic mechanism of nucleosome rearrangements associated with nucleotide excision repair. The proposed studies, on the regulation of DNA repair in chromatin, are based upon our recent data that support the linkage of p53 pathway to DNA repair. The overall experiments are designed to address the specific hypothesis that p53 transcription activation machinery, which includes p53 tumor suppressor protein, CBP/p300 and transcription factor IIH, is targeted to scattered lesion sites of the genome via a recruitment process involving complex multiprotein interactions during early stage of DNA repair. The proposed work will utilize relevant biochemical, cellular and molecular technologies, established in the applicant?s laboratory, to address the following specific aims. (1) To establish the formation of p53 transcription activation/DNA damage recognition complex through interaction of various component factors, e.g., p53, p300, XPC-hHR23B and TFIIH. (2) To determine the critical role of XPC-hHR23B in the recruiting of p53 transcription activation machinery to DNA damage. (3) To identify the physically interacting regions of XPC and TFIIH component proteins, XPB and p62, required to function in the formation of p53 transcription activation/DNA recognition complex. (4) To delineate the relationship of CBP/p300 mediated histone hyperacetylation and nucleotide excision repair. (5) To demonstrate the influence of chromatin structure on the site-specific repair within the target gene. The long-term goal of these studies is to reveal the nature of several important interconnected gene functions and their role in the maintenance of genomic sequence integrity. Understanding the mechanistic basis of the prompt reversal of deleterious genomic alterations, occurring in human cells from exposures to diverse exogenous and endogenous mutagenic carcinogens, has clear implications in the pathogenesis of cancer.