Platelet activation and aggregation represent pivotal events in hemostasis and thrombosis. Prostaglandin E2 (PGE
2
) receptor subtype 3 (EP3), the most abundantly expressed PGE
2
receptor in platelets, regulates platelet activation. Yet, the underlying mechanisms remain incompletely defined. Glycosylation, one of the most common post-translational modifications, plays a crucial role in maintaining platelet function. However, the specific contribution of EP3 glycosylation in platelets has not yet been investigated. We identified N16 and N193 of the EP3α isoform as sites for N-linked glycosylation and demonstrated that EP3α glycosylation stabilizes its capacity for G
i
coupling and sustains G
i
-mediated cAMP and Ca
2+
flux, both key modulators of platelet function. In contrast, EP3α mutants impaired U46619-, ADP- and thrombin- induced platelet aggregation and thrombin-induced clot retraction. Notably, both EP3α mutants and EP3 deficiency attenuated FeCl
3
-induced arterial thrombosis. Mechanistically, EP3α glycosylation enhanced its binding to PGE
2
and supports efficient G
i
coupling. The study concludes that N-linked glycosylation of EP3α is critical for platelet regulation through modulation of PGE
2
/EP3α/G
i
-mediated cAMP and Ca
2+
signaling.
Yuhong Wang, Yizhe Li, Junyan Wang et al.· Communications Biology· 0 citations
Blockade of signaling through the angiotensin II type 1 receptor (AT1R), a prototypical G protein-coupled receptor (GPCR), by angiotensin receptor blockers (ARBs) is a major therapeutic approach to treating a wide variety of cardiovascular and renal diseases1. Like most GPCRs, the AT1R signals through two transducers, G proteins and β-arrestins2,3. Previous reports have described β-arrestin-biased peptide orthosteric agonists for the AT1R with potential therapeutic advantages over currently available unbiased ARBs4–6. Here we report the DNA- encoded library screening-guided isolation and pharmacological characterization of the first small molecule AT1R allosteric ligands. We use cryo-electron microscopy, double electron- electron resonance spectroscopy, molecular dynamics simulations, and targeted mutagenesis to determine their binding sites, binding modes and conformational mechanisms driving their unique and divergent modulatory effects on G protein and β-arrestin pathways. Our findings uncover new mechanisms for precisely controlling the dynamic behavior of the AT1R with implications for drug development targeting this pathophysiologically important receptor family.
Samuel Liu, Peng Xiao, M. Elgeti et al.· bioRxiv· 0 citations
We use cookies to run the site and, with your consent, for analytics and to show ads.
See our Cookie Policy.
