NEW ASPECTS OF DNA RECOGNITION BY NUCLEAR RECEPTORS

我们的最终目标是更好地理解不同的核能 激素受体识别不同的靶DNA序列。核子 激素受体是配体调节的转录因子，并且 调节特定靶基因的表达以响应小分子 疏水激素，如类固醇、甲状腺激素和 维甲酸。每种受体的DNA识别特性都发挥了作用 确定特定的靶基因谱系的关键作用 它们对特定的荷尔蒙做出反应。然而，我们对此的理解 不完整的核受体，它通常拥有 相似的锌指结构域，表现出必要的特异性 识别天生不同的靶基因集合。最近的工作由 我们自己和其他人已经透露：(A) 锌指结构域在DNA中扮演着关键和意想不到的角色 序列特异性，(B)核激素受体识别DNA 结合位点不仅作为蛋白质二聚体，而且还通过新的 涉及单体和高阶低聚络合物的机理， 翻译后蛋白质修饰可以改变DNA 承认。这些观察结果证实了 核受体对DNA的识别以前从未出现过 探索并提出了可信的机制，通过这些机制， 产生针对不同靶基因的不同受体，并且 已定义。我们将调查： 答：不同的核受体如何识别不同的DNA 网站？ B.蛋白质单体、二聚体和蛋白质的不同作用 核内不同成员识别DNA的寡聚体 激素受体家族。 C.是核识别DNA的模式和特异性 翻译后修饰改变的受体，可选 剪接，还是染色体易位？ 核激素受体在后生动物的动态平衡中起着核心作用， 发展和差异化。异常的人类受体已经被 与许多内分泌和肿瘤疾病有关。我们的 实验将有助于解决核激素的重要方面 受体信号和生理学，也将有助于 更广泛地理解DNA识别的特异性是如何实现的 通过其他转录因子。

Our ultimate goal is to better understand how different nuclear hormone receptors recognize different target DNA sequences. Nuclear hormone receptors are ligand-regulated transcription factors, and modulate the expression of specific target genes in response to small hydrophobic hormones, such as steroids, thyroid hormones, and retinoids. The DNA recognition properties of each receptor play the critical role of defining the particular repertoire of target genes which respond to a given hormone. However, our understanding in incomplete of how the nuclear receptors, which posses generally similar zinc-finger domains, manifest the specificity necessary to recognize inherently distinct sets of target genes. Recent work by ourselves and others has revealed that: (A) regions outside of the zinc-finger domain play critical and unanticipated roles in DNA sequence-specificity, (B) nuclear hormone receptors recognize DNA binding sites not only as protein dimers, but also by novel mechanisms involving monomers and high-order oligomeric complexes, and ~ post-translational protein modifications can alter DNA recognition. These observations confirm that important elements of DNA recognition by nuclear receptors have not been previously explored, and suggest plausible mechanisms by which the specificity of different receptors for different target genes is generated and defined. We will investigate: A. How do different nuclear receptors recognize distinct DNA half- sites? B. What are the different roles of protein monomers, dimers and oligomers in DNA recognition by different members of the nuclear hormone receptor family. C. Is the mode and specificity of DNA recognition by nuclear receptors altered by post-translational modification, alternative splicing, or chromosomal translocations? Nuclear hormone receptors play central roles in metazoan homeostasis, development, and differentiation. Aberrant human receptors have been implicated in many endocrine and neoplastic diseases. Our experiments will help resolve important aspects of nuclear hormone receptor signaling and physiology, and will also contribute toward a broader comprehension of how DNA recognition specificity is achieved by other transcription factors.