Abstract/Summary

Death-associated protein kinase 1 (DAPK1) is a multidomain cell signalling macromolecule which has been implicated in a plethora of biological processes. The domain topology of this protein comprises a calcium/calmodulin dependent serine/threonine kinase, a Ras of complex proteins (ROC) GTPase and a number of further protein-protein interaction (PPI) interfaces. The precise role and regulation of DAPK1 is unclear although it appears to be complex. Due to the potential for targeting this protein for therapeutic intervention, most notably in relation to cancer and neurodegeneration, understanding the physiological function of DAPK1 is important. Developing our understanding of protein function in the wider cellular context can be achieved by defining its proximal interactome. In this research a PPI network analysis of the human ROCO proteins was performed utilising literature-derived PPI data and novel experimental data to shed light on the commonalities and distinctions within the interaction and functional profiles of these structurally related proteins. This was facilitated by the development of a PPI query resource, termed Protein Interaction Network Online Tool (PINOT), for extracting and processing PPI data from a number of major molecular interaction data repositories. The pursuit of defining the DAPK1 interactome was then translated into the context of the Caenorhabditis elegans proteome for predictive and evidence based mapping of the DAPK-1 interactome. This revealed intriguing novel DAPK-1 interactors, MEP-1, SYD-9 and UNC-14, for further investigation. In addition, a number of mutant dapk-1 C. elegans strains, FLAG-dapk-1, dapk-1 K57W and dapk-1 T715N, were engineered to further assess the role and regulation of DAPK-1 in vivo. Initial phenotypic analysis provided insight into novel DAPK-1 related functions for future examination. Collectively, the analyses performed and resources developed throughout the course of this research project contribute to our understanding of the DAPK1/DAPK-1 interactomes and will guide future investigation into the complex functionality of this protein.