HIGHER ORDER PROTEIN-DNA COMPLEXES IN GENE REGULATION

这个项目的目标是发现“有翼螺旋”转录 因子重组和定位核小体结构， 调节基因表达的高级蛋白质-DNA复合物。 调节因子可以在定位的核小体上起作用， 转录增强子元件，但目前尚不清楚核小体如何 在适当的发展时间和地点定位， 它们是否是转录激活所必需的。 的 调查人员现在可以解决这些问题，并提供一些最新进展： 研究人员的研究发现， 因子HNF 3足以将核小体核心定位在 血清白蛋白基因的转录增强子;已定义 翼螺旋DNA结合内外的特定氨基酸 结构域是HNF 3与核小体核心结合的关键， 影响颗粒结构，并设计了系统来严格评估 核小体重组与染色质功能关系 in vivo. 私家侦探建议将这些调查结果扩展到以下方面 具体目的：1）探讨HNF 3 影响核小体核心沿着DNA的位置。2)揭示 带翼螺旋蛋白如何影响核小体核心的DNA进入， 从而增强或抑制其它蛋白质的结合。3)到 选择性干扰HNF 3的核小体重组特性， 评估内源性细胞染色质的功能后果。

The goal of this project is to discover how "winged helix" transcription factors reorganize and position nucleosome structure, thereby creating higher-order protein-DNA complexes that regulate gene expression. Regulatory factors can function on positioned nucleosomes at transcriptional enhancer elements, yet it is unknown how nucleosomes become positioned at the appropriate developmental time and place, and whether they are required for transcriptional activation. The investigator can now address these issues, give some recent advances: the investigator's studies discovered that binding of the winged helix factor HNF3 is sufficient to position a nucleosome core at the transcriptional enhancer of the serum albumin gene; have defined specific amino-acids within and outside the winged helix DNA binding domain that are critical for HNF3 binding to nucleosome cores and to affect particle structure and have devised systems to critically assess the relationship between nucleosome reorganizing and chromatin function in vivo. The P.I. proposes to extend these findings with the following specific aims: 1) To investigate the biochemical mechanism by which HNF3 influences the position of a nucleosome core along the DNA. 2) To reveal how winged helix proteins affect DNA access of the nucleosome core and thereby enhance or inhibit the binding of other proteins. 3) To selectively perturb the nucleosome reorganizing properties of HNF3 and assess the functional consequences in endogenous cell chromatin.