FUNCTIONS OF C-FOS PROTEIN IN CELLULAR PHYSIOLOGY

原癌基因有可能产生 癌症已经引起了对这些功能的极大兴趣， 正常的细胞基因 c-fos蛋白是特别重要的 因为它的核位置，DNA结合能力， 在细胞增殖过程中调节表达， 分化 然而，正常c-fos蛋白的功能 不明 本提案的总体目标是阐明 c-fos蛋白的特殊功能。 拟议的研究 将采用遗传学方法来创造和分析细胞突变体 改变c-fos的表达，以及cDNA克隆技术， 鉴定受c-fos表达调控的基因。 的 有待检验的假设是c-fos蛋白是 特定的细胞过程，因为它改变了表达 具有重要功能的基因 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）为了确定 正常c-fos蛋白的功能结构域是必需的 用于胚胎干细胞增殖和/或分化; 3） 目的：鉴定c-fos表达调控基因。 这些 研究的重点是两者的功能意义 c-fos蛋白结构的改变和诱导假定的 c-fos调控基因。 这些建议的研究正常 非转换功能域是可行的，基于 初步数据表明，突变体（反义RNA fos基因恢复增殖功能的反义 c-fos RNA抑制成纤维细胞。 实验将分析 c-fos蛋白特异性突变的功能意义 (e.g.假定磷酸化位点的改变，DNA结合 区域，必要的转化结构域）作为确定 这种蛋白质在细胞过程中的作用， 增殖，生长因子诱导的DNA合成，创伤 反应和分化。 cDNA克隆技术将是 用于鉴定受c-fos调控的基因 表情 最终的目标是将c-fos蛋白 功能域是改变表达所必需的， 特定的基因（AIM 3），与所需的结构域， 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.