Location-biased β-arrestin conformations direct GPCR signaling

Pham, U.; Chundi, A.; Stepniewski, T. M.; Darbha, S.; Eiger, D. S.; Gazula, S.; Gardner, J.; Hicks, C.; Selent, J.; Rajagopal, S.

doi:10.1101/2024.09.24.614742

bioRxiv · 10.1101/2024.09.24.614742

Location-biased β-arrestin conformations direct GPCR signaling

Pham, U.·Chundi, A.·Stepniewski, T. M.·Darbha, S.·Eiger, D. S.·Gazula, S.·Gardner, J.·Hicks, C.·Selent, J.·Rajagopal, S.

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Abstract

{beta}-arrestins are multifunctional intracellular proteins that regulate the desensitization, internalization and signaling of over 800 different G protein-coupled receptors (GPCRs) and interact with a diverse array of cellular partners1,2. Beyond the plasma membrane, GPCRs can initiate unique signaling cascades from various subcellular locations, a phenomenon known as "location bias"3,4. Here, we investigate how {beta}-arrestins direct location-biased signaling of the angiotensin II type I receptor (AT1R). Using novel bioluminescence resonance energy transfer (BRET) conformational biosensors and extracellular signal-regulated kinase (ERK) activity reporters, we reveal that in response to the endogenous agonist Angiotensin II and the {beta}-arrestin-biased agonist TRV023, {beta}-arrestin 1 and {beta}-arrestin 2 adopt distinct conformations across different subcellular locations, which are intricately linked to differential ERK activation profiles. We also uncover a population of receptor-free catalytically activated {beta}-arrestins in the plasma membrane that exhibits insensitivity to different agonists and promotes ERK activation on the plasma membrane independent of G proteins. These findings deepen our understanding of GPCR signaling complexity and also highlight the nuanced roles of {beta}-arrestins beyond traditional G protein pathways.

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Pham, U., Chundi, A., Stepniewski, T. M., Darbha, S., Eiger, D. S., Gazula, S., Gardner, J., Hicks, C., Selent, J., Rajagopal, S.. 2024-09-26. Location-biased β-arrestin conformations direct GPCR signaling. https://doi.org/10.1101/2024.09.24.614742

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