G Protein-Coupled Receptors (GPCRs) regulate important signaling pathways in humans, including neurological and cardiological activity, circadian cycles, hormonal signaling, and light and taste senses. Of the receptors in this superfamily, the adenosine receptor subfamily is important in modulating blood pressure, and more recently has been implicated in cancer and diabetes. Cholesterol binding sites have been identified on adenosine A2A receptor both via X-ray crystallography and molecular dynamics simulation, but their role in ligand binding and signaling is little studied to date. Given this evidence for direct interactions, it may not be surprising that with many of these membrane-bound receptors, there is growing evidence that the membrane composition plays a role in modulating intracellular signaling. Although much is known about the signaling pathways of these receptors, the role of the direct chemical and mechanical properties of the plasma membrane in GPCR-mediated signaling has yet to be well defined.Here, we have examined the proximity of cholesterol in liposomes to the adenosine receptor A2A. The receptor was tagged with a fluorescent protein and monitored for direct proximity to a fluorescent cholesterol species, using F�rster Resonance Energy Transfer (FRET) measurements. Titrations of cholesterol, both labeled and unlabeled, allow the specific binding of cholesterol molecules to be examined. The effects of ligand binding on this receptor-lipid interaction are then further explored using this system.

Cholesterol effects on the ligand binding activity of recombinant human G Protein-Coupled Receptors

247th National Meeting (2014)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.