GROWTH-RELATED GENES REGULATED WITH C-FOS

哺乳动物细胞的生长受多肽调节 生长因子 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 通过施用血清或纯化的 生长因子 生长因子与它们之间的相互作用 质膜上的受体导致信号传输 到细胞核，在那里一组特定的转录激活 基因突变迅速发生。 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 活化是生长因子诱导细胞增殖的必要步骤， 增殖 本提案的初步研究部分介绍了 分离对应于10个先前未知的cDNA克隆 这些基因在几分钟内被转录激活， 血小板衍生生长因子，血清中的一种有效促分裂剂。 这些基因的调控发生在转录和转录后。 转录水平，并与调控协调， 原癌基因c-fos或c-myc。 在这些“立即早期” 基因，如此命名的类比，以遗传程序的病毒 发展，是那些预计将成为关键调解人的 增殖反应 了解这些问题的总体性质 基因及其基因的生物活性 产品是本次研究的目标。 这些生长相关的早期基因的表达 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。 其中五个基因 被选中进行进一步研究。 它们的全长cDNA 序列将被确定，并且它们的蛋白质产物主要 结构将被演绎。 抗蛋白质产物的抗血清 将准备;蛋白质产品将在 培养的细胞和相关组织中，及其亚细胞 位置将被定义。 这些基因中的一个 选择进一步关注;基因产物将被纯化， 分析其生化活性。 本构效应 该基因的表达，通过反义RNA失活，和 在细胞周期的各个阶段表达，通常是沉默的 将使用许多重组构建体进行研究。

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.