Proteomic and structural profiling of PXXP-SH3 interactions as key regulators of membrane receptor activity

Membrane receptor signalling occurs upon growth factor stimulation. I have shown that fibroblast growth factor receptor 2 signalling can also be triggered without stimulation. This occurs when proteins with Src homology 3 (SH3) domain bind its C-terminal proline-rich-motif (PXXP) and modulate its activity to induce a homeostatic or oncogenic response. Whether this occurs in other receptors remains unclear.

I will test the hypothesis that these interactions are abundant and critical for functional regulation of receptors which dictates cellular response. I will use two model receptors to extract bound proteins from cell lysates and I will use mass-spectrometry to determine the identity of the SH3 domain-containing hits. I will run pilot biophysical experiments such as microscale thermophoresis to reduce confounding elements and evaluate functional modulation of receptors by running reverse-phase-protein-array and functional assays.

This project will set the foundation for characterising novel interactions to enhance our understanding of signalling mechanisms, particularly structural modelling of receptors. This may highlight new approaches for cancer therapy.