GS PATHWAYS IN DROSOPHILA EPITHIAL CELLS

描述：本提案的目的是定义如何激活 果蝇G蛋白Gs α亚基（DGs）的表达对 一种特殊的细胞类型的发展和功能， 范例 研究人员使用一种复杂的体内表达系统， 基于GAL 4控制元素，注意到 DGs的激活突变体（DGs*）导致许多复杂的表型。 其中最简单和最一致的观察是形成翅膀 水泡由GAL 4系介导的表达，在翅上皮细胞， 蛹的后期 建议起泡是由于 通过整合素介导的粘附失败的跨膜连接 在机翼扩张过程中。 非常有趣的是，依赖DG * 的 甚至在蛋白激酶A不存在（无效突变）的情况下也发生起泡， 这表明DG * 利用cAMP非依赖性途径或cAMP， 不是PKA。 第一个目的是检验假设， 翅上皮细胞是产生水疱所必需的。 一 用于基于一种或多种细胞因子的表达监测细胞内cAMP水平的系统 将建立β-半乳糖苷酶报告基因，然后调节cAMP 通过腺苷酸环化酶（芜菁甘蓝）的过表达，或 磷酸二酯酶（笨蛋）。 第二个目标是识别分子 其是翅上皮细胞中DGs* 激活途径的组分。 研究人员假设，一个亚组的分子介导下游 影响存在于一个关键的水平，并将利用这一事实， 果蝇中的大多数基因都是剂量补偿的， 筛选以确定基因，当存在于一个拷贝中时， 水泡形成。 第三个目的是检验 翅上皮细胞内的Gs通路是调节 整合素分子的性质。 翅膀形态发生的特殊方面 将被检查，因为将基因的遗传操作的能力， 编码整联蛋白以增强或抑制水疱形成。

DESCRIPTION: The objective of this proposal is to define how the activation of the G protein Gs alpha subunit (DGs) in Drosophila impacts on the development and function of a specific cell type using wing blistering as a paradigm. The investigator, using a sophisticated in vivo expression system based on GAL4 control elements, has noted that the expression of an activated mutant of DGs (DGs*) results in numerous and complex phenotypes. One of the simplest and most consistently observed is the formation of wing blisters by GAL4 lines that mediate expression in wing epithelium during late pupal periods. The blistering is proposed to occur from rupture of transalar connections through the failure of integrin-mediated adhesion processes during wing expansion. Of great interest, the DGs*-dependent blistering occurs even in the absence (null mutation) of protein kinase A, suggesting that DGs* utilizes either a cAMP-independent pathway or cAMP but not PKA. The first aim is to test the hypothesis that elevation of cAMP in wing epithelial cells is required for the generation of blistering. A system for monitoring intracellular cAMP levels based on expression of a beta-galactosidase reporter will be established, then cAMP will be modulated through overexpression of an adenylyl cyclase (rutabaga) or phosphodiesterase (dunce). The second aim will be to identify molecules which are components of the DGs*-activated pathway in wing epithelial cells. The investigator assumes that a subset of molecules mediating downstream effects exist at a critical level and will take advantage of the fact that most genes in Drosophila are dosage-compensated, in developing deficiency screens to identify genes which, when present in one copy, can suppress blister formation. The third aim is to test the idea that the function of the Gs pathway within wing epithelial cells is to regulate the adhesive properties of integrin molecules. Specific aspects of wing morphogenesis will be examined, as will the ability of genetic manipulations of genes encoding integrin proteins to enhance or suppress blister formation.