Our PhD projects will involve investigating small G protein-effector complexes. We use structural biology, biophysics, biochemistry and cell biology techniques to study protein-protein interactions. Specifically we work on small G proteins from the Ras and Rho families. These proteins are crucial switches that control a myriad of signalling pathways and are thus vital to the cell. The aim of our lab is to understand how the small G proteins control these pathways via their immediate downstream effector partners. We endeavour to characterize these pathways at a functional level but also to elucidate the atomic details of the protein-protein interactions that govern them. Therefore we simultaneously generate data to help understand protein-protein interactions generally. We have utilised loss-of-function mutations extensively to look at the thermodynamics of binding in these complexes guided by our structural studies. We are now engineering gain-of-function mutations into these proteins. These data are being used to design peptides that we can introduce into cells to further study the role of these interactions in cellular signalling pathways by interfering with small G protein interactions. Two projects are available: 1. The Cdc42-ACK pathway. At a cellular level we have identified a series of new signalling pathways downstream of Cdc42-ACK. These will be validated in cell culture assays and the consequences of these novel interactions will be elucidated. 2. The Ral-RLIP pathway. We have solved the structure of the RalB-RLIP76 complex. This information will inform the design of peptides to interrogate the Ras-Ral-RLIP pathway.
- Hutchinson, C.L., Lowe, P.N., McLaughlin, S.H., Mott, H.R. and Owen, D. (2011). Mutational analysis reveals a single binding interface between RhoA and its effector, PRK1. Biochemistry 50(14): 2860-2869
- Rajasekar, K.V., Campbell, L.J., Nietlispach, D., Owen, D. and Mott, H.R. (2013). The structure of the RLIP76 (RalBP1) RhoGAP domain-Ral binding domain dyad: fixed position of the domains leads to dual engagement of small G proteins at the membrane. Structure 21:2131–2142
- Hutchinson, C.L., Lowe, P.N., McLaughlin, S.H., Mott, H.R.and Owen, D. (2013). Differential binding of RhoA, B and C to the PRK isoforms PRK1, 2 and 3: PRKs have highest affinity for RhoB. Biochemistry 52(45):7999-8011