Functional modulation of PTH1R activation and signaling by RAMP2

Nemec, Katarina; Schihada, Hannes; Kleinau, Gunnar; Zabel, Ulrike; Grushevskyi, Eugene O.; Scheerer, Patrick; Lohse, Martin J.; Maiellaro, Isabella

Abstract

Receptor-activity-modifying proteins (RAMPs) are ubiquitously expressed membrane proteins that associate with different G protein-coupled receptors (GPCRs), including the parathyroid hormone 1 receptor (PTH1R), a class B GPCR and an important modulator of mineral ion homeostasis and bone metabolism. However, it is unknown whether and how RAMP proteins may affect PTH1R function. Using different optical biosensors to measure the activation of PTH1R and its downstream signaling, we describe here that RAMP2 acts as a specific allosteric modulator of PTH1R, shifting PTH1R to a unique preactivated state that permits faster activation in a ligand-specific manner. Moreover, RAMP2 modulates PTH1R downstream signaling in an agonistdependent manner, most notably increasing the PTH-mediated Gi3 signaling sensitivity. Additionally, RAMP2 increases both PTH- and PTHrP-triggered β-arrestin2 recruitment to PTH1R. Employing homology modeling, we describe the putative structural molecular basis underlying our functional findings. These data uncover a critical role of RAMPs in the activation and signaling of a GPCR that may provide a new venue for highly specific modulation of GPCR function and advanced drug design.

Citation

Nemec, K., Schihada, H., Kleinau, G., Zabel, U., Grushevskyi, E. O., Scheerer, P., Lohse, M. J., & Maiellaro, I. (2022). Functional modulation of PTH1R activation and signaling by RAMP2. Proceedings of the National Academy of Sciences, 119(32), Article e2122037119. https://doi.org/10.1073/pnas.2122037119

• Journal Article Type: Article
• Acceptance Date: Mar 28, 2022
• Online Publication Date: Aug 1, 2022
• Publication Date: Aug 9, 2022
• Deposit Date: Sep 21, 2022
• Publicly Available Date: Sep 21, 2022
• Journal: Proceedings of the National Academy of Sciences of the United States of America
• Print ISSN: 0027-8424
• Electronic ISSN: 1091-6490
• Publisher: National Academy of Sciences
• Peer Reviewed: Peer Reviewed
• Volume: 119
• Issue: 32
• Article Number: e2122037119
• DOI: https://doi.org/10.1073/pnas.2122037119
• Public URL: https://nottingham-repository.worktribe.com/output/9589005
• Publisher URL: https://www.pnas.org/doi/full/10.1073/pnas.2122037119