FUNCTIONS OF C-FOS PROTEIN IN CELLULAR PHYSIOLOGY

原癌基因具有生产潜力的发现 癌症已经引起了人们对这些功能的极大兴趣 正常的细胞基因。C-fos蛋白特别重要 因为它的核位置、DNA结合能力以及 细胞增殖过程中基因表达的调控 差异化。然而，正常的c-fos蛋白的功能 是未知的。这项提议的总体目标是澄清 C-fos蛋白的特定功能。建议进行的研究 将使用遗传方法来创造和分析细胞突变 通过改变c-fos的表达和cDNA克隆技术来 确定受c-fos表达调控的基因。这个 需要检验的假设是c-fos蛋白是 特定的细胞过程，因为它改变了 具有基本功能的基因。具体目标是：1) 确定正常c-fos蛋白的功能结构域 是成纤维细胞增殖所必需的；2)确定 正常c-fos蛋白的功能域是必需的 用于胚胎干细胞增殖和/或分化；3) 寻找受c-fos表达调控的基因。这些 研究集中在两者的功能意义上。 C-fos蛋白结构的改变及其可能的诱导作用 C-fos调控基因。这些建议的正常研究 非转换功能域是可行的，基于 初步数据表明，一种突变体(反义RNA Fos基因反义恢复增殖功能 C-fos RNA抑制成纤维细胞生长。实验将分析 C-fos蛋白特异性突变的功能意义 (例如，假定的磷酸化位点的改变、DNA结合 区域、基本转换域)作为确定 这种蛋白质在细胞过程中的作用，如对数 增殖，生长因子诱导的DNA合成，创伤 回应，和差异化。CDNA克隆技术将是 用于识别受c-fos调控的基因 表情。最终目标是将c-fos蛋白与 基因表达改变所必需的功能结构域 特定基因(AIM 3)，以及需要的结构域 增殖和/或分化。

The discovery that proto-oncogenes have the potential to produce cancer has created substantial interest in the functions of these normal cellular genes. c-fos protein is of particular importance because of its nuclear location, DNA binding capacity, and modulation of expression during cellular proliferation and differentiation. However, the function of the normal c-fos protein is unknown. The overall goal of this proposal is to elucidate specific functions for the c-fos protein. The proposed studies will employ genetic methods to create and analyze cellular mutants with altered c-fos expression, and cDNA cloning techniques to identify genes which are regulated by c-fos expression. The hypothesis to be tested is that c-fos protein is required for specific cellular processes because it alters the expression of genes with essential functions. The specific aims are: 1) To determine the Functional Domains of the normal c-fos protein which are necessary for fibroblast Proliferation; 2) To determine the Functional Domains of the normal c-fos protein which are necessary for Embryonal stem cell Proliferation and/or Differentiation; 3) To identify Genes which are regulated by c-fos expression. These studies are focused on the functional significance of both alterations in c-fos protein structure and induction of putative c-fos regulated genes. These proposed studies of normal nontransforming functional domains are feasible, based on preliminary data indicating that a mutant (anti-sense RNA resistant) fos gene restores proliferative function to anti-sense c-fos RNA inhibited fibroblasts. Experiments will analyze the functional significance of specific mutations in c-fos protein (e.g. alteration of putative phosphorylation sites, DNA binding regions, essential transforming domains) as a means to determine the role of this protein in such cellular processes as logarithmic proliferation, growth factor-induced DNA synthesis, wounding response, and differentiation. cDNA cloning techniques will be employed for identification of genes which are regulated by c-fos expression. The ultimate goal is to correlate the c-fos protein functional domains which are essential for altered expression of specific genes (AIM 3), with the domains which are required for proliferation and/or differentiation.