BACKGROUND AND PURPOSE: The angiotensin II type 1 (AT(1)) receptor belongs to family A of 7 transmembrane (7TM) receptors. The receptor has important roles in the cardiovascular system and is commonly used as a drug target in cardiovascular diseases. Interaction of 7TM receptors with G proteins or beta-arrestins often induces higher binding affinity for agonists. Here, we examined interactions between AT(1A) receptors and beta-arrestins to look for differences between the AT(1A) receptor interaction with beta-arrestin1 and beta-arrestin2. EXPERIMENTAL APPROACH: Ligand-induced interaction between AT(1A) receptors and beta-arrestins was measured by Bioluminescence Resonance Energy Transfer 2. AT(1A)-beta-arrestin1 and AT(1A)-beta-arrestin2 fusion proteins were cloned and tested for differences using immunocytochemistry, inositol phosphate hydrolysis and competition radioligand binding. KEY RESULTS: Bioluminescence Resonance Energy Transfer 2 analysis showed that beta-arrestin1 and 2 were recruited to AT(1A) receptors with similar ligand potencies and efficacies. The AT(1A)-beta-arrestin fusion proteins showed attenuated G protein signalling and increased agonist binding affinity, while antagonist affinity was unchanged. Importantly, larger agonist affinity shifts were observed for AT(1A)-beta-arrestin2 than for AT(1A)-beta-arrestin1. CONCLUSION AND IMPLICATIONS: beta-Arrestin1 and 2 are recruited to AT(1A) receptors with similar ligand pharmacology and stabilize AT(1A) receptors in distinct high-affinity conformations. However, beta-arrestin2 induces a receptor conformation with a higher agonist-binding affinity than beta-arrestin1. Thus, this study demonstrates that beta-arrestins interact with AT(1A) receptors in different ways and suggest that AT(1) receptor biased agonists with the ability to recruit either of the beta-arrestins selectively, would be possible to design.
BACKGROUND AND PURPOSE: The angiotensin II type 1 (AT(1)) receptor belongs to family A of 7 transmembrane (7TM) receptors. The receptor has important roles in the cardiovascular system and is commonly used as a drug target in cardiovascular diseases. Interaction of 7TM receptors with G proteins or beta-arrestins often induces higher binding affinity for agonists. Here, we examined interactions between AT(1A) receptors and beta-arrestins to look for differences between the AT(1A) receptor interaction with beta-arrestin1 and beta-arrestin2. EXPERIMENTAL APPROACH: Ligand-induced interaction between AT(1A) receptors and beta-arrestins was measured by Bioluminescence Resonance Energy Transfer 2. AT(1A)-beta-arrestin1 and AT(1A)-beta-arrestin2 fusion proteins were cloned and tested for differences using immunocytochemistry, inositol phosphate hydrolysis and competition radioligand binding. KEY RESULTS: Bioluminescence Resonance Energy Transfer 2 analysis showed that beta-arrestin1 and 2 were recruited to AT(1A) receptors with similar ligand potencies and efficacies. The AT(1A)-beta-arrestin fusion proteins showed attenuated G protein signalling and increased agonist binding affinity, while antagonist affinity was unchanged. Importantly, larger agonist affinity shifts were observed for AT(1A)-beta-arrestin2 than for AT(1A)-beta-arrestin1. CONCLUSION AND IMPLICATIONS: beta-Arrestin1 and 2 are recruited to AT(1A) receptors with similar ligand pharmacology and stabilize AT(1A) receptors in distinct high-affinity conformations. However, beta-arrestin2 induces a receptor conformation with a higher agonist-binding affinity than beta-arrestin1. Thus, this study demonstrates that beta-arrestins interact with AT(1A) receptors in different ways and suggest that AT(1) receptor biased agonists with the ability to recruit either of the beta-arrestins selectively, would be possible to design.
Authors: Alice C Holloway; Hongwei Qian; Luisa Pipolo; James Ziogas; Shin-ichiro Miura; Sadashiva Karnik; Bridget R Southwell; Michael J Lew; Walter G Thomas Journal: Mol Pharmacol Date: 2002-04 Impact factor: 4.436
Authors: Jennifer L Whistler; Basil O Gerber; Elaine C Meng; Thomas J Baranski; Mark von Zastrow; Henry R Bourne Journal: Traffic Date: 2002-12 Impact factor: 6.215
Authors: Huijun Wei; Seungkirl Ahn; Sudha K Shenoy; Sadashiva S Karnik; László Hunyady; Louis M Luttrell; Robert J Lefkowitz Journal: Proc Natl Acad Sci U S A Date: 2003-08-29 Impact factor: 11.205
Authors: Marie Mi Bonde; Jonas Tind Hansen; Samra Joke Sanni; Stig Haunsø; Steen Gammeltoft; Christina Lyngsø; Jakob Lerche Hansen Journal: PLoS One Date: 2010-11-30 Impact factor: 3.240
Authors: N Suleymanova; C Crudden; T Shibano; C Worrall; I Oprea; A Tica; G A Calin; A Girnita; L Girnita Journal: Oncogene Date: 2017-06-05 Impact factor: 9.867