GENETIC CONTROL OF MAMMALIAN CELL SURFACE FUNCTIONS

这项研究项目的最终目标是确定基因和 受体介导的信号转导机制的分子基础 多肽激素和生长因子，特别是胰岛素和表皮 组织培养细胞中的生长因子(EGF)我们还感兴趣的还有 肿瘤促进剂的促生长活性。我们快到了 通过使用体细胞突变来实现拟议的目标 与分子生物学和生化技术相结合。通过 选择在各个步骤中有缺陷或异常的突变体 胰岛素、EGF与肿瘤作用机制的研究进展 启动子，我们希望从基因上定义和表征这条途径 从生化角度来看。此外，我们利用这些遗传变异来定位 参与荷尔蒙结合、内化和 细胞内处理，受体的聚集和循环，以及各种 通过细胞杂交分析受体后的功能。的具体目标 我们的调查如下：(1)继续表征 分离的遗传变异以确定它们的遗传和生化 损伤；(2)细胞内激素-毒素结合的命运更好 了解它们的进入机制；(3)分离新的变异体系列 通过将细胞毒性结合物应用于诱变细胞 在细胞周期的特定阶段同步的种群或 暂时使用特定的内吞机制抑制剂；(4) 在分离的变异体之间或与其他细胞形成细胞杂交 进行互补群分析和染色体定位 相应的基因；(5)人类受体基因图谱 胰岛素、转化生长因子、MSA和IGFS的交联技术；(6) A431细胞EGF受体过度表达的遗传和分子基础 细胞，特别是易位染色体M4和 产生截短的变异型3kb的mRNA和110kd的EGF受体片段； (7)可能的染色体重排和基因检测 各种人类肿瘤来源细胞的变化，这些细胞过度生产或 利用EGF受体/erbB基因探针检测EGF受体缺陷 致癌基因。最近发现的一个转化生长因子家族 与癌基因产物有关暗示着复杂的遗传调控 它们的受体系统。尽管这些基因的细胞遗传学方法 受体系统仍处于初级阶段，它提供了独特的实验 研究细胞生长调控的系统。

The ultimate goal of this research project is to determine the genetic and molecular basis of receptor-mediated signal transfer mechanisms of polypeptide hormones and growth factors, particularly insulin and epidermal growth factor (EGF) in tissue cultured cells. We are also interested in the growth promoting activity of the tumor promoters. We are approaching the proposed goals through the use of somatic cell mutagenesis in combination with molecular biological and biochemical techniques. By selecting mutants that are defective or extraordinary in the various steps of the mechanisms involved in the action of insulin, EGF and tumor promoters, we hope to define and characterize the pathway both genetically and biochemically. Furthermore, we utilize these genetic variants to map genes that are involved in hormone's binding, internalization, and intracellular processing, receptor's clustering and recycling, and various post-receptor functions by cell hybridization analysis. Specific aims of our investigation are the following: (1) continued characterization of the isolated genetic variants to determine their genetic and biochemical lesions; (2) intracellular fate of the hormone-toxin conjugates to better understand their entry mechanisms; (3) isolation of new series of variants by the application of cytotoxic conjugates to the mutagenized cell populations which are synchronized at a certain stage of cell cycle or temporarily treated with specific inhibitors of endocytic mechanisms; (4) formation of cell hybrids between the isolated variants or with other cells to perform complementation group analysis and chromosomal localization of the corresponding genes; (5) mapping of the human receptor genes for insulin, TGFs, MSA, and IGFs by crosslinking techniques; (6) studies on the genetic and molecular basis of the EGF receptor-overproduction in A431 cells, particularly the relation between translocation chromosome M4 and production of truncated variant 3kb mRNA and 110kd EGF receptor fragments; (7) examination of the possible chromosome rearrangements and gene alterations in various human tumor-derived cells which are overproducing or deficient in EGF receptors using cDNA probes for EGF receptor/erbB oncogene. The recent discovery of a family of transforming growth factors in relation to oncogene products implies a complex genetic regulation of their receptor systems. Although the cell genetic approach to these receptor systems is still in its infancy, it provides unique experimental systems by which regulation of cell growth is studied.