Mapping AT1R biased signaling using proximity-labeling and proteomics identifies diverse actions of biased agonists

ABSTRACT: Angiotensin II type 1 receptors (AT1Rs) are one of the most widely studied G protein-coupled receptors. To fully appreciate the diversity in cellular signaling profiles activated by AT1R transducer-biased ligands, we utilized peroxidase-catalyzed proximity labeling to capture proteins in close proximity to AT1Rs in response to six different ligands: Angiotensin II (full agonist), S1I8 (partial agonist), TRV055 and TRV056 (G protein-biased agonists), TRV026 and TRV027 (β-arrestin biased agonists) at 90s, 10min, and 60min after stimulation. We systematically analyzed the kinetics of AT1R trafficking and determined that distinct ligands lead AT1R to different cellular compartments for downstream signaling activation and receptor degradation/recycling. Distinct proximity labelling of proteins from a number of functional classes, including GTPases, adaptor proteins, and kinases were activated by different ligands suggesting unique signaling and physiological roles of the AT1R. Ligands within the same class, i.e. either G protein-biased or -arrestin-biased, shared high similarity in their labelling profiles. Comparison between ligand classes revealed distinct signaling activation such as greater labeling by G protein biased ligands on ESCRT-0 complex proteins that act as sorting machinery for ubiquitinated proteins. Our study provides a comprehensive analysis of AT1R receptor trafficking kinetics and signaling activation profiles induced by distinct classes of ligands.

INSTRUMENT(S): Orbitrap Fusion Lumos, Orbitrap Fusion

ORGANISM(S): Homo Sapiens (human)

TISSUE(S): Cell Culture

SUBMITTER: Joao Paulo  

LAB HEAD: Steven P. Gygi

PROVIDER: PXD023814 | Pride | 2021-03-25

REPOSITORIES: Pride