Steric control of signaling bias in the immunometabolic receptor GPR84

Wang, P.; Zhang, X.; Guseinov, A.-A.; Jenkins, L.; von Hallerstein, C.; Colburn, J. D.; Ives, R.; Luscombe, V. B.; Marsango, S.; Oktavia, L.; Raja, A.; Greaves, D. R.; Biggin, P. C.; Milligan, G.; Zhang, C.; Tikhonova, I.; Russell, A. J.

doi:10.1101/2025.07.30.667614

bioRxiv · 10.1101/2025.07.30.667614

Steric control of signaling bias in the immunometabolic receptor GPR84

Wang, P.·Zhang, X.·Guseinov, A.-A.·Jenkins, L.·von Hallerstein, C.·Colburn, J. D.·Ives, R.·Luscombe, V. B.·Marsango, S.·Oktavia, L.·Raja, A.·Greaves, D. R.·Biggin, P. C.·Milligan, G.·Zhang, C.·Tikhonova, I.·Russell, A. J.

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Abstract

Biased signaling in G protein-coupled receptors offers therapeutic promise, yet rational design of biased ligands remains challenging due to limited mechanistic understanding. Here, we report a molecular framework for controlling signaling bias at the immunometabolic receptor GPR84. We identified three structurally-matched ligands (OX04529, OX04954, and OX04539) with varying steric profiles that exhibit comparable Gi protein activation but dramatically different {beta}-arrestin recruitment capacities. A high- resolution cryo-EM structure of GPR84-Gi in complex with OX04529, complemented by molecular dynamics simulations and targeted mutagenesis, revealed that steric interactions between ligand substituents and Leu3366.52 and Phe1875.47 indirectly disrupt a critical polar network involving Tyr3326.48, Asn1043.36 and Asn3627.45 essential for {beta}-arrestin recruitment. Based on these insights, we developed a steric-dependent model that enabled rational design of G protein-biased agonists with predictable {beta}-arrestin recruitment profiles. This mechanistic framework provides a blueprint for designing biased agonists with customized signaling profiles at GPR84 and potentially other class A GPCRs.

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Wang, P., Zhang, X., Guseinov, A.-A., Jenkins, L., von Hallerstein, C., Colburn, J. D., Ives, R., Luscombe, V. B., Marsango, S., Oktavia, L., Raja, A., Greaves, D. R., Biggin, P. C., Milligan, G., Zhang, C., Tikhonova, I., Russell, A. J.. 2025-08-02. Steric control of signaling bias in the immunometabolic receptor GPR84. https://doi.org/10.1101/2025.07.30.667614

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