RAS MEDIATED SIGNAL TRANSDUCTION IN C ELEGANS

我们的目标是了解细胞的控制和执行机制， 动物发育过程中的分化和形态发生。研究 在这项资助的支持下，以及其他实验室的工作， 表明C. elegans是由Ras控制的， 介导的信号转导途径，与 与哺乳动物细胞信号和癌症有关。但如何 许多常用的基因产物的活性被精确地 对特定功能的调节仍然知之甚少。此外，委员会认为， 发生在信号通路下游的事件，包括执行 细胞分化和形态发生的机制还未被探索。在 本建议除了继续分析 Ras和Raf，我们将使用遗传和分子方法来识别和 描述了一些新的基因在调节 信号通路和执行外阴分化， 形态发生具体目的是：（1）克隆和分析 两个新发现的基因可能是正调控因子 并进行新的筛选以确定新的监管机构。我们 将确定几种新分离的 Raf突变并分析突变体Raf和Ras之间的相互作用 proteins.我们还将尝试确定Ras的Raf-independent函数。 (2)我们将进行一系列的分子和基因实验， 确定sur-2基因的功能和调节， Ras/MAPK在外阴信号转导中的下游。我们将调查 其表达模式，剖析其基因和蛋白质结构， 确定其监管机构和目标。(3)我们将进行基因筛查 温度敏感（TS）和非TS突变体，以确定新的基因 其作用是执行外阴分化和形态发生。我们将 通过遗传学、微观和生物学方法表征由这些突变体定义的基因， 分子方法细胞相互作用的分子基础研究 发展模式的确定与研究 癌症和其他人类疾病。外阴发育为我们提供了一个 分析系统，以确定将难以确定的因素， 哺乳动物并阐明其体内功能。

Our goal is to understand the mechanism of control and execution of cell differentiation and morphogenesis during animal development. Research supported by this grant, as well as work from other laboratories, has shown that vulval differentiation in C. elegans is controlled by a Ras- mediated signal transduction pathway that is extremely similar to pathways that are involved in mammalian cell signaling and cancers. However, how the activities of many commonly used gene products are accurately regulated for specific functions is still poorly understood. Moreover, events occurring downstream of the signaling pathway including execution of cell differentiation and morphogenesis remain largely unexplored. In this proposal, besides continuing to analyze the regulation and function of Ras and Raf, we will use genetic and molecular methods to identify and characterize a number of new genes for their functions in regulating the signaling pathway and in executing vulval differentiation and morphogenesis. The specific aims are: (1) We will clone and analyze the function of two newly identified genes that are likely positive regulators of the pathway and carry out new screens to identify new regulators. We will determine the genetic and molecular nature of several newly isolated Raf mutations and analyze the interaction between the mutant Raf and Ras proteins. We will also try to identify Raf-independent functions of Ras. (2) We will carry out a series of molecular and genetic experiments to determine the function and regulation of the sur-2 gene which acts downstream of Ras/MAPK in vulval signal transduction. We will investigate its expression pattern, dissect its gene and protein structure, and identify its regulators and targets. (3) We will carry out genetic screens for temperature sensitive (TS) and nonTS mutants to identify new genes that act to execute vulval differentiation and morphogenesis. We will characterize genes defined by these mutants by genetic, microscopic and molecular methods. Study of the molecular basis of cell interaction in specifying developmental pattern is closely related to the study of cancers and other human disease. Vulval development provides us a specific assay system to identify factors that would be difficult to identify in mammals and to elucidate their in vivo functions.