RT Journal Article
SR Electronic
T1 Investigation of the Fate of Type I Angiotensin Receptor after Biased Activation
JF Molecular Pharmacology
JO Mol Pharmacol
FD American Society for Pharmacology and Experimental Therapeutics
SP mol.114.097030
DO 10.1124/mol.114.097030
A1 Gyongyi Szakadati
A1 Andras D Toth
A1 Ilona Olah
A1 Laszlo S Erdelyi
A1 Tamas Balla
A1 Peter Varnai
A1 Laszlo Hunyady
A1 Andras Balla
YR 2015
UL http://molpharm.aspetjournals.org/content/early/2015/03/24/mol.114.097030.abstract
AB Biased agonism on the type I angiotensin receptor (AT1-R) can achieve different outcomes, via activation of G protein-dependent and -independent cellular responses. In this study, we investigated whether the biased activation of the AT1-R can lead to different regulation and intracellular processing of the receptor. We analyzed β-arrestin binding, endocytosis and subsequent trafficking steps such as early and late phases of recycling of the AT1-R in HEK293 cells expressing wild type or biased mutant receptors in response to different ligands. We used Renilla luciferase tagged receptors and yellow fluorescent protein (YFP) tagged β-arrestin2, Rab5, Rab7 and Rab11 proteins in bioluminescence resonance energy transfer (BRET) measurements to follow the fate of the receptor after stimulation. We found that not only is the signaling of the receptor different upon using selective ligands, but the fate within the cells is also determined by the type of the stimulation. β-arrestin binding and the internalization kinetics of the angiotensin II (AngII)-stimulated AT1-R differed from those stimulated by the biased agonists. Similarly, AngII-stimulated wild type AT1-R showed differences compared to a biased mutant AT1-R (DRY/AAY AT1-R) regarding β-arrestin binding and endocytosis. We suggest that the differences in the internalization kinetics of the receptor in response to biased agonist stimulation are due to the differences in plasma membrane PtdIns(4,5)P2 depletion. Moreover, the stability of the β-arrestin binding is a major determinant of the later fate of the internalized AT1-R receptor.