Signaling Mechanisms of the Drosophila JAK/STAT Pathway

描述(申请人提供)：这项研究的长期目标是了解果蝇JAK/STAT途径的分子和遗传作用机制。在哺乳动物中，这一途径对造血和免疫反应至关重要，信号活性的放松可能会导致人类的免疫性疾病和白血病。果蝇已经成为一种遗传范式，系统地剖析了这一途径的组成部分，并研究了它们在体内的作用。提出了三个具体的调查目标。在特定的目标1中，将使用果蝇JAK激酶Hopscotch中的缺失突变、功能丧失和功能获得突变来验证正负调控结构域都影响Hop激酶活性的假设；激活特异性抗体将用于检查这一途径在体内何时何地被激活。在特定的目标2中，进行了全基因组的遗传筛查，从中分离出了几个候选的抑制子缺陷。我们将利用缺陷区的突变等位基因来鉴定反应性抑制基因，并对这些抑制基因的作用和相互作用机制进行研究。在具体目标3中，将利用基因表达系列分析(SAGE)技术识别Hop/Stat92E途径的靶基因，并研究它们的功能作用。这些研究将为了解Hop/Stat92E通路在果蝇发育中的调控提供重要的洞察力，也可能有助于理解JAK/STAT通路在人类中的过度激活所导致的肿瘤发生。

DESCRIPTION (provided by applicant): The long-term goal of this study is to understand the molecular and genetic mechanisms of action of the Drosophila JAK/STAT pathway. In mammals, this pathway is critical for hematopoiesis and immune responses, and deregulation of the signaling activity can cause immune disease and leukemia in humans. The fruit fly Drosophila melanogaster has emerged as a genetic paradigm for systematically dissecting the components in this pathway and studying their roles in vivo. Three specific aims are proposed for investigation. In specific aim 1, deletion mutants, and loss of function and gain of function mutations in the Drosophila JAK kinase Hopscotch will be used to test the hypothesis that both positive and negative regulatory domains affect the kinase activity of Hop; activation-specific antibodies will be used to examine where and when this pathway is activated in vivo. In specific aim 2, a genome-wide genetic screen has been conducted, from which several candidate suppressor deficiencies have been isolated. The responsive suppressor genes will be identified using mutant alleles in the deficiency region; the roles of these suppressor genes will be characterized and the mechanism of interaction will be studied. In specific aim 3, target genes of the Hop/Stat92E pathway will be identified using the serial analyses of gene expression (SAGE) technique, and their functional roles studied. These studies should provide important insight into the regulation of the Hop/Stat92E pathway in Drosophila development and may also help to understand oncogenesis caused by hyperactivation of the JAK/STAT pathway in humans.