Anionic Phospholipids Control Mechanisms of GPCR-G Protein Recognition

Thakur, N.; Ray, A.; Sharp, L.; Jin, B.; Duong, A.; Gopal Pour, N.; Obeng, S.; Wijesekara, A.; Gao, Z.-G.; McCurdy, C.; Jacobson, K. A.; Lyman, E.; Eddy, M.

doi:10.1101/2023.01.11.523010

bioRxiv · 10.1101/2023.01.11.523010

Anionic Phospholipids Control Mechanisms of GPCR-G Protein Recognition

Thakur, N.·Ray, A.·Sharp, L.·Jin, B.·Duong, A.·Gopal Pour, N.·Obeng, S.·Wijesekara, A.·Gao, Z.-G.·McCurdy, C.·Jacobson, K. A.·Lyman, E.·Eddy, M.

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Abstract

G protein-coupled receptors (GPCRs) are embedded in phospholipids that strongly influence drug-stimulated signaling. Anionic lipids are particularly important for GPCR signaling complex formation, but a mechanism for this role is not understood. Using NMR spectroscopy, we visualized the impact of anionic lipids on the function-related conformational equilibria of the human A2A adenosine receptor (A2AAR) in bilayers containing defined mixtures of zwitterionic and anionic phospholipids. Anionic lipids primed the receptor to form complexes with G proteins through a conformational selection process. Without anionic lipids, signaling complex formation proceeded through a less favorable induced fit mechanism. In computational models, anionic lipids mimicked interactions between a G protein and positively charged residues in A2AAR at the receptor intracellular surface, stabilizing a pre-activated receptor conformation. Replacing these residues strikingly altered the receptor response to anionic lipids in experiments. High sequence conservation of the same residues among all GPCRs supports a general role for lipid-receptor charge complementarity in signaling.

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Thakur, N., Ray, A., Sharp, L., Jin, B., Duong, A., Gopal Pour, N., Obeng, S., Wijesekara, A., Gao, Z.-G., McCurdy, C., Jacobson, K. A., Lyman, E., Eddy, M.. 2023-01-13. Anionic Phospholipids Control Mechanisms of GPCR-G Protein Recognition. https://doi.org/10.1101/2023.01.11.523010

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