Abstract
The topology of cell membranes attracts increasing attention as a potential regulator of numerous vital cellular functions such as protein sorting, association and localization [1,2,3]. To examine the influence of membrane shape on GPCR oligomerization we developed a fluorescence-based assay, employing a model membrane system with the prototypical GPCR, human β2-adrenergic receptor, β2AR, reconstituted in liposomes [4]. We monitored receptor oligomerization by intermolecular FRET between β2AR-Cy3 and β2AR-Cy5 in membranes of different curvature (75-400 nm in diameter) at the single proteoliposome level by the use of confocal microscopy. We report that oligomer assembly is highly affected by the shape of the membrane. Physiological occurring membrane curvatures (1/75 nm−1) drive dissociation of stable oligomers formed in flat membranes (1/400 nm−1), reducing the absolute EFRET by ∼60%, which corresponds to ∼60% reduction of oligomeric clusters. Thus we propose that changes in geometrical membrane curvature, during e.g. receptor internalization upon agonist stimulation, are a potential allosteric regulator of GPCR assembly. 1. Hatzakis, ND. et al. Nature Chemical Biology 5, 835-841 (2009). 2. Bhatia, VD. et al. EMBO Journal 28, 3303-3314 (2009). 3. McMahon H.T. and Gallop J.L., Nature 438, 590-6 (2005). 4. Fung, J.J. et al. EMBO J 28, 3315-3328 (2009).
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call