Structural and functional characterisation of human ROCO proteins - How multi-domain proteins work to integrate intracellular signalling pathways

In 2003, the Ras of complex proteins (ROCO) proteins were identified as large multi-domain proteins and have been the subject of intense scrutiny, resulting from their association with a number of human diseases including Parkinson's and cancer. ROCO proteins are unique in the human proteome as they are the only proteins to pair a GTPase domain with a kinase domain in the same open reading frame. As both are key enzymatic domains involved in cell signalling, it is likely that ROCO proteins act as cellular signal transduction hubs. To date, much of the research of the human ROCO proteins has been limited to LRRK2, as a key player in Parkinson's disease, but a general understanding is still lacking. However, ROCO proteins are being actively investigated as potential therapeutic targets for human disease - emphasising the importance of generating structural data for this family of proteins.
The aim of this project is to understand how the ROCO proteins integrate cell-signalling pathways at a structural level, using human ROCO proteins including LRRK2, LRRK1 and DAPK1 as models. To achieve this, a multi-construct multi-host strategy will be adopted to produce full-length and combinations of protein domains prior to structural analysis by crystallography and/or cryo-EM analysis. Analysis of structural dynamics will be supported by a range of techniques including Synchrotron Radiation Circular Dichroism (SR-CD), X-ray diffraction, cryoEM and solution scattering at Diamond Light Source. Additionally, built on the Lewis' group experience, functional mutations will be generated for assays to systematically assess the role/impact of these on activity. In parallel, the constructs will be used for cell biology assays to identify and characterise functional interactions based at the University of Reading.