Exploring the Role of Orphan G Protein-Coupled Receptors in Health and Disease

Sammanfattning

G protein-coupled receptors (GPCR) are interesting drug targets. In this degree project the focus is on GPR183 and GPR61 which play a role in immune cell trafficking and metabolic regulation respectively. This project aims to test specific mutations from both blood cancer and high obesity samples, with the goal of seeing any different behaviors compared to wild type receptors. Behavior in this case pertains to differences in expression and activation, both constitutively and in the presence of ligands. The project employs a plethora of different physical instruments to obtain these results. The use of Bioluminescence Resonance Energy Transfer (BRET), Fluorescence Resonance Energy Transfer (FRET) and a combination of multiple different assays together form a robust way of measuring both expression and activation for different mutations. The main takeaways for GPR183 were that the mutation, L125P, found in Non-Hodgkin lymphoma samples, differ significantly in both expression and activation compared to wild type. Specifically at the native membrane domain. There were also results that speculated that this mutation might induce misfold, hindering its transportation to the membrane from the inner compartments of the cell.For GPR61, a majority of the mutations investigated showed lower expression compared to the wild type counterpart, and only a few saw a significant reduction in activation. Ligand experiments on GPR61 did not yield any increase in constitutive activity, prompting further assessment in the future. Overall, the project gained interesting results that prompts further investigation of GPR183 mutations, and signaling, specifically in the realm of G_α signaling. The project also narrows down the large magnitude of GPR61 mutations interesting for further research. This provides a solid foundation into GPCR signaling in said diseases.