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

• Applicant: Dr. Martin Zeidler
• Subject Area: Cell Biology
• Term: from 2005 to 2008
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 5446281

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.

• DFG Programme: Research Grants
• International Connection: United Kingdom