Combining imaging and pharmacology: subcellular monitoring of receptors, ligands and their interactions
Steve Briddon, University of Nottingham
G protein coupled receptors (GPCRs) are the largest family of cell surface receptors and the target of a significant number of clinically used drugs, for example anti-histamines and b-blockers. The importance of cellular location, membrane organisation and allosteric regulation by accessory proteins is becoming increasingly recognised in the way GPCRs signal and interact with effectors, as well as their ligands.
In our group, we are interested in how differences in subcellular location and membrane compartmentalisation can affect receptor pharmacology. To that end, we have focussed on developing advanced imaging methods, particularly those such as fluorescence correlation spectroscopy (FCS) and photon counting histogram (PCH) analysis, to quantify receptor-ligand interactions in small defined areas of cell membrane. This has also required the design and characterisation of new fluorescent small molecule ligands for our receptors of interest.
The talk will cover the principles behind fluctuation spectroscopy techniques, and how we have used FCS, PCH, FRAP and associated techniques to look at the cellular organisation (diffusion, aggregation, dimerization) of GPCRs including the adenosine-A3, b2-adrenergic and m-opioid receptors, including delineating agonist-specific pathways for receptor re-organisation. Using these approaches to study ligand gradients and purified membrane proteins will also be discussed.
Part of the Advanced Image & Analysis Forum.