Abstract - Ferenc

With the cell membrane constituting the majority of the contact surface of G protein-coupled receptors (GPCRs), it is hardly surprising that it influences the signaling of GPCRs, both through variation in its bulk properties, as well as through specific interaction via individual lipid species. In this regard, the lipids that impact the regulation of human neuropeptide Y2 receptor (Y2R), a member of class A GPCRs, present a potential target for various medical applications. We optimized a fluorescence polarization-based ligand binding assay as effective read-out to investigate the changes in the affinity of the Y2 receptor to its biological ligand, the neuropeptide Y (NPY), depending on the net-charge of the membrane. Our results show a substantial increase in the Y2R’s affinity to the NPY with an increased negative netcharge of the membrane. Furthermore, increasing the rigidity of the membrane additionally highlights the role of the negatively charged lipids in the Y2R activation: higher membrane rigidity decreases NPY affinity, which is then rescued by introduction of negatively charged lipids. We therefore suggest that the latter play a central role in aiding with the mobility of the Y2R within the lipid membrane bilayer.

R. Ferenc1, M. Gozzi1, O. Engberg1, D. Huster1 1 University of Leipzig, Institute of Medical Physics and Biophysics, Leipzig, Germany