National Institutes of Health/National Heart, Lung, and Blood Institute (NIH/NHLBI)
HL016037
米国
National Institutes of Health/National Heart, Lung, and Blood Institute (NIH/NHLBI)
T32HL007101
米国
National Institutes of Health/National Heart, Lung, and Blood Institute (NIH/NHLBI)
HL16037-45S1
米国
Human Frontier Science Program (HFSP)
LT000174/2018
フランス
European Molecular Biology Organization (EMBO)
ALTF 1071-2017
European Union
引用
ジャーナル: bioRxiv / 年: 2024 タイトル: Small Molecule Modulators of β-arrestins. 著者: Alem W Kahsai / Natalia Pakharukova / Henry Y Kwon / Kunal S Shah / Jason G Liang-Lin / Caroline T Del Real / Paul J Shim / Mason A Lee / Van A Ngo / Bowie N Shreiber / Samuel Liu / Allison M ...著者: Alem W Kahsai / Natalia Pakharukova / Henry Y Kwon / Kunal S Shah / Jason G Liang-Lin / Caroline T Del Real / Paul J Shim / Mason A Lee / Van A Ngo / Bowie N Shreiber / Samuel Liu / Allison M Schwalb / Emmanuel F Espinoza / Brittany N Thomas / Cal A Kunzle / Jeffrey S Smith / Jialu Wang / Jihee Kim / Xingdong Zhang / Howard A Rockman / Alex R B Thomsen / Lindsay A M Rein / Lei Shi / Seungkirl Ahn / Ali Masoudi / Robert J Lefkowitz 要旨: β-arrestins (βarrs) are key regulators of G protein-coupled receptors (GPCRs), essential for modulating signaling pathways and physiological processes. While current pharmacological strategies ...β-arrestins (βarrs) are key regulators of G protein-coupled receptors (GPCRs), essential for modulating signaling pathways and physiological processes. While current pharmacological strategies target GPCR orthosteric and allosteric sites, as well as G protein transducers, comparable tools for studying βarrs are lacking. Here, we present the discovery and characterization of novel small-molecule allosteric inhibitors of βarrs through comprehensive biophysical, biochemical, pharmacological, and structural analyses. These inhibitors disrupt βarr interactions with agonist-activated GPCRs, impairing receptor internalization, desensitization, and βarr-mediated physiological functions. A cryo-EM structure of βarr1 in complex with the allosteric inhibitor Cmpd-5, complemented by molecular dynamics simulations and mutagenesis studies, reveals that Cmpd-5 binds within a cryptic cleft formed by the middle, C-, and lariat loops-a critical site for βarr activation and recruitment to GPCRs. Thus, Cmpd-5 acts as a molecular lock, hindering βarr1 activation via an allosteric mechanism. These findings introduce novel strategies and tools for probing βarr functions. HIGHLIGHTS: Small molecule strategies for modulating βarr functions in both GPCR-dependent and independent contexts.Modulators disrupt βarr interaction with GPCRs, impairing their critical ...HIGHLIGHTS: Small molecule strategies for modulating βarr functions in both GPCR-dependent and independent contexts.Modulators disrupt βarr interaction with GPCRs, impairing their critical functions.Cryo-EM structures reveal the allosteric inhibitor Cmpd-5 binding to a cryptic pocket between the N and C domains in the central crest of βarr1, inhibiting its activation.Structural analyses, including cryo-EM, MD simulations, and mutagenesis, reveal a unique βarr1 conformation induced by Cmpd-5, shedding light on its mechanism of allosteric inhibition.