Primary map and fitted model (9iyb) viewed along the X-axis. Credit: Jiuyin Xu et al

Recent advancements in understanding the molecular basis of the prostaglandin D2 receptor (DP2) have significant implications for developing new anti-inflammatory and anti-allergic therapeutics. DP2, as a G protein-coupled receptor, plays a crucial role in mediating allergic responses and inflammation. However, the clinical application of several DP2-targeted drugs remains limited.

published in PNAS, a research team led by Eric H. Xu (Xu Huaqiang) and Wu Canrong from the Shanghai Institute of Materia Medica (SIMM) of the Chinese Academy of Sciences presented (cryo-EM) structures of apo DP2-Gi complex, a DP2-Gi complex bound to endogenous ligand PGD2, and a DP2-Gi complex bound to indomethacin, a ligand known to favor β-arrestin signaling.

These structures revealed distinct binding modes and provided critical insights into the receptor's activation and signaling bias, highlighting the role of lipid interactions.

Using advanced cryo-EM techniques, researchers resolved the structures of various DP2-Gi complexes at high resolutions, specifically ranging from 2.3 Ã… to 2.8 Ã…. They identified a phospholipid binding site at the DP2-G protein interface, which modulates interactions between DP2 and G proteins. This lipid regulation played a crucial role in influencing the receptor's activation state and signaling outcomes.

The researchers found that PGD2 primarily activates DP2 through the Gαi signaling pathway, while indomethacin preferentially activates the β-arrestin pathway. This signaling bias was further elucidated through functional assays and , demonstrating the unique pharmacological profiles of both ligands.

The study paves the way for rational design of safer and more effective anti-allergy drugs. By understanding how lipid interactions regulate DP2 activity, researchers can develop targeted therapies that minimize side effects.

More information: Jiuyin Xu et al, Molecular basis of lipid and ligand regulation of prostaglandin receptor DP2, Proceedings of the National Academy of Sciences (2024).

Journal information: Proceedings of the National Academy of Sciences