Role of ESE-2 Ets factor in Epithelial biology

描述（由申请人提供）： 细胞增殖和分化之间的平衡对于上皮的生理功能是至关重要的，并且因此部分地通过在这些过程期间控制基因表达的转录因子来良好调节。以前的工作表明，ESE家族的Ets转录因子可能在上皮细胞的发育和功能特化中发挥重要作用。我们已经利用皮肤角质形成细胞作为模型系统来检查ESE-2的生物学作用。我们的初步研究特征的ESE-2启动子已导致一种新的核因子，KSF，其中所有的细胞类型测试是限制角质形成细胞和启动子活性是重要的鉴定。为了深入了解ESE-2的生物学功能，我们已经开始对该蛋白进行结构-功能分析。我们表明，重组ESE-2亚型可以结合到已知的ETS结合位点。然而，ESE-2的最佳DNA靶点（包括核心基序和侧翼序列）仍有待确定。为了确定ESE-2在体内的作用并鉴定其靶基因，我们成功地在胚胎干细胞（ES）克隆中靶向ESE-2基因。我们的研究表明，深入分析ESE-2的作用机制，其生物学作用和识别的因素，调节其表达应该导致更好地了解上皮细胞分化过程。 因此，在本提案中，我们试图鉴定和表征控制ESE-2的上皮特异性表达的调节因子，包括KSF蛋白（目的1），对所有ESE-2同种型进行全面的结构-功能分析，以鉴定其共有结合位点，并表征对其在皮肤表皮中的特异性作用至关重要的潜在激活或抑制结构域（目的2），并采用体内敲除模型系统来评估ESE-2在上皮发育和分化过程中的生物学作用，并鉴定ESE-2靶标（目的3）。我们的研究将提供工具，调查ESE-2控制和塑造上皮细胞的生长和分化的分子机制，并确定这些过程的重要调节剂。因此，所提出的研究将为正常生理条件和异常病理状态下上皮细胞的生物学提供基本的见解。这些知识对于开发新疗法和治愈包括癌症在内的一系列折磨上皮细胞的疾病至关重要。

DESCRIPTION (provided by applicant): The balance between cell proliferation and differentiation is critical to the physiological function of the epithelium and is therefore well regulated, in part by transcription factors that control gene expression during these processes. Previous work has suggested that the ESE family of Ets transcription factors may play an important role in epithelial development and functional specialization. We have utilized skin keratinocytes as a model system to examine the biological role of ESE-2. Our preliminary studies characterizing the ESE-2 promoter have led to identification of a novel nuclear factor, KSF, that among all the cell types tested is restricted to keratinocytes and is important for the promoter activity. In order to gain insights into the biological function of ESE-2, we have begun a structure-function analysis of the protein. We show that recombinant ESE-2 isoforms can bind to known Ets-binding sites. However, the optimum DNA target for ESE-2 including the core motif and the flanking sequences remains to be determined. In order to define the in vivo role of ESE-2 and identify its target genes we have successfully targeted the ESE-2 gene in embryonic stem cell (ES) clones. Our studies indicate that a thorough analysis of the mechanism of action of ESE-2, its biological role and the identification of factors that regulate its expression should lead to a better understanding of epithelial cell differentiation process. Therefore, in the present proposal we seek to identify and characterize the regulatory factors that control the epithelium-specific expression of ESE-2, including the KSF protein (Aim 1), to perform a comprehensive structure-function analysis of all ESE-2 isoforms to identify their consensus binding sites and to characterize potential activation or repression domains that are critical for their specific roles in skin epidermis (Aim 2), and to employ an in vivo knock out model system to assess the biological role of ESE-2 during epithelial development and differentiation and to identify ESE-2 targets (Aim 3). Our studies will provide the tools to investigate the molecular mechanisms by which ESE-2 controls and shapes epithelial growth and differentiation and to identify important modulators of these processes. The studies proposed will thus provide fundamental insights into the biology of epithelial cells during both normal physiological conditions and abnormal pathological states. Such knowledge is vital to developing new therapies and cures for a wide array of diseases that afflict the epithelial cells including cancers.