Functional analysis of JAK/STAT signalling using genome-wide RNAi

JAK/STAT信号转导通路参与发育、免疫和疾病，并且在整个进化过程中一直是保守的。虽然果蝇和哺乳动物JAK/STAT通路的组成部分已经通过生物化学和遗传学手段进行了表征，但我们对该通路的理解仍然存在一些重大差距。在这里，我们提出的实验，以全面确定基因参与知之甚少的方面的途径信号作为模型系统使用果蝇。首先，利用一个可用的靶向果蝇基因组中每个基因的RNAi库，我们将筛选果蝇巨噬细胞样细胞中的JAK/STAT组分。为此，我们建立了一个报告基因检测，准确地反映JAK/STAT途径的活动。然后，我们将重新筛选在初步筛选过程中确定的潜在相互作用基因，以确定那些直接涉及我们特定研究领域的基因。这些相互作用的基因将进行评估和优先级分析之前，使用遗传和生化实验。Martin Zeidler将进一步鉴定参与配体修饰、分泌、受体结合和内化的上游过程的基因。这将采用GFP标记的配体，其可以在体内培养的细胞中可视化。将分析影响这些过程的基因突变，以确定其与JAK/STAT依赖性表型的体内相互作用。Michael Boutros将分析新发现的基因在先天免疫中的作用。JAK/STAT信号转导已经被我们认为是果蝇先天免疫应答的一部分，尽管其在体内的功能仍然知之甚少。将在体外研究新组分的功能丧失表型。

The JAK/STAT signal transduction pathway is involved in development, immunity and disease and has been conserved throughout evolution. While components of both the Drosophila and mammalian JAK/STAT pathway have been characterized by biochemical and genetic means, a number of significant gaps in our understanding of the pathway remain. Here we propose experiments to comprehensively identify the genes involved in poorly understood aspects of pathway signalling using Drosophila as a model system. First, using an available RNAi libary targeting every gene in the fly genome, we will sreen for JAK/STAT components in Drosophila macrophage-like cells. To this end, we have established a reporter gene assays that accurately reflects JAK/STAT pathway activity. We will then re-screen the potentially interacting genes identified during the initial screen to determine those directly implicated in our specific fields of research. These interacting genes will be evaluated and prioritized before analysis using genetic and biochemical experiments. Martin Zeidler will further identify genes involved in upstream processes of ligand modification, secretion, receptor binding and internalisation. This will employ a GFP-tagged ligand which can be visualised both in cultured cells in vivo. Mutations in the genes affecting these processes will be analysed to determine their interactions with JAK/STAT dependent phenotypes in vivo. Michael Boutros will analyze newly identified genes for their role during innate immunity. JAK/STAT signalling have been implicated by us as part of the Drosophila innate immune response, although its in vivo function remains poorly understood. Loss-of-function phenotypes of novel components will be studied in vitro.