GROWTH-RELATED GENES REGULATED WITH C-FOS

哺乳动物细胞的生长受多肽的调节 增长因素。了解这些因素如何诱导细胞 增长是理解这些机制的重要一步。 控制细胞增殖和肿瘤形成。 静止的小鼠成纤维细胞可以被刺激重新进入细胞 通过给予血清或纯化的血清在G1期进行周期 增长因素。生长因子与其相互作用 质膜上的受体导致信号传递 到细胞核，在那里特定的一组转录激活 基因的变异迅速发生。在已知的几个基因中， 以这种方式激活的是原癌基因c-fos和c-fos。 MYC。越来越多的证据表明，特定的基因 激活是生长因子诱导细胞的必要步骤 扩散。 在本提案的初步研究部分中描述的是 与10个未知基因对应的cDNA克隆的分离 在几分钟内被转录激活的基因 血小板衍生生长因子，血清中的一种强有力的有丝分裂原。 这些基因的调控发生在转录和转录后。 转录水平，并与转录调控相协调 原癌基因c-fos或c-myc。在这些“即刻-早期”中 基因，通过类比病毒的遗传程序来命名 发展，那些预计将成为 增殖反应。了解这些问题的总体性质 基因这一类及其基因的生物活性 产品是本文提出的研究目标。 这些与生长相关的即刻早期基因的表达 将在生长、发育和分化过程中进行检查 在小鼠和细胞培养模型中。这些基因中有五个 被选中进行进一步的研究。它们的全长cDNA 将确定序列及其主要蛋白质产品 结构将被演绎出来。针对蛋白质产物的抗血清 将被准备好；蛋白质产品将在 培养的细胞和相关组织以及它们的亚细胞 地点将被定义。这些基因中的一个将会是 选择进一步聚焦；基因产物将被提纯并 对其生化活性进行了分析。构造性的影响 该基因的表达，通过反义RNA失活，以及 在细胞周期的各个阶段表达，而细胞周期通常是沉默的 将使用一些重组构建物进行研究。

The growth of mammalian cells is regulated by polypeptide growth factors. Understanding how such factors induce cell growth is an important step toward understanding the mechanisms controlling cell proliferation and neoplasia. Quiescent mouse fibroblasts can be stimulated to re-enter the cell cycle at the G1 phase by the administration of serum or purified growth factors. The interaction of growth factors with their receptors at the plasma membrane results in a signal transmitted to the nucleus, where transcriptional activation of a specific set of genes rapidly occurs. Among several genes known to be activated in this manner are the proto-oncogenes c-fos and c- myc. Accumulating evidence suggests that specific gene activation is a necessary step in growth factor-induced cell proliferation. Described in the preliminary studies section of this proposal is the isolation of cDNA clones corresponding to 10 previously unknown genes that are transcriptionally activated within minutes by platelet-derived growth factor, a potent mitogen in serum. Regulation of these genes occurs on transcriptional and post- transcriptional levels and is coordinate with the regulation of the proto-oncogene c-fos or c-myc. Among these "immediate-early" genes, so named by analogy to the genetic program for viral development, are those anticipated to be key mediators of the proliferative response. Understanding the overall nature of these genes as a class and the biological activities of their gene products is the goal of this proposed research. The expression of these growth-related, immediate-early genes will be examined during growth, development, and differentiation in the mouse and in cell culture models. Five of these genes have been selected for further study. Their full-length cDNA sequences will be determined and their protein product primary structures will be deduced. Antisera against the protein products will be prepared; the protein products will be identified in cultured cells and in relevant tissues, and their subcellular locations will be defined. One of these genes will then be selected for further focus; the gene product will be purified and its biochemical activities analyzed. The effects of constitutive expression of this gene, inactivation by anti-sense RNA, and expression during phases of the cell cycle when it is usually silent will be investigated using a number of recombinant constructs.