8ZME

Protease-activated receptor-2 (PAR2)/miniG13 complex

Summary for 8ZME

• Entry DOI: 10.2210/pdb8zme/pdb
• EMDB information: 60244
• Descriptor: engineered G13, Guanine nucleotide-binding protein G(I)/G(S)/G(T) subunit beta-1, scFv16, ... (5 entities in total)
• Functional Keywords: gpcr-g-protein complex, membrane protein
• Biological source: Homo sapiens; More
• Total number of polymer chains: 5
• Total formula weight: 142801.54

Authors

He, Y.,Zhu, X. (deposition date: 2024-05-23, release date: 2025-05-28, Last modification date: 2025-12-10)

Primary citation

Zhu, X.,Xia, R.,Zhang, A.,Guo, C.,Xu, Z.,He, Y.
Structural basis of protease-activated receptor 2 activation and biased agonism.
Cell Discov, 11:96-96, 2025

PubMed Abstract: Protease-activated receptor 2 (PAR2) is a transmembrane receptor that is irreversibly activated by proteolytic cleavage of its N-terminus via extracellular proteases, resulting in the release of the tethered ligand (TL), which binds to and activates the receptor. PAR2 plays a pivotal role in the inflammatory response and pain sensation and is a promising drug target for treating arthritis, asthma, and neuronal pain. Here, we present the cryo-electron microscopy structures of active PAR2 complexed with miniG and miniG. Combining functional assays with structural analysis, our study revealed that TL forms a parallel β-sheet with the extracellular loop 2 of PAR2 to engage the receptor. The binding of TL triggers a conformational rearrangement in the transmembrane core, releasing the inhibitory ion lock and allowing receptor activation. Furthermore, we provide structural insights into the engagement of G and G with PAR2, highlighting that a hydrophobic interaction mediated by the last methionine residue of Gα is crucial for G coupling selectivity. In combination with molecular dynamics simulations and mutagenesis, we identified the I39/D62 interaction at the pocket side of the receptor as a key determinant of G signaling. Disrupting this interaction significantly inhibits G signaling while preserving G activity, enabling us to design a biased peptide ligand that selectively activates G signaling. The information revealed in this study provides a framework for understanding PAR2 signaling and offers a rational basis for the design of biased PAR2 ligands.

PubMed: 41330898
DOI: 10.1038/s41421-025-00851-8

Experimental method

ELECTRON MICROSCOPY (3.2 Å)