beta-Arrestin-biased agonism of the angiotensin receptor induced by mechanical stress.
beta-Arrestins, which were originally characterized as terminators of heterotrimeric guanine nucleotide-binding protein (G protein)-coupled receptor (GPCR) signaling, also act as important signal transducers. An emerging concept in GPCR signaling is beta-arrestin-biased agonism, in which specific ligand-activated GPCR conformational states selectively signal through beta-arrestins, rather than through G proteins. Here, we show that mechanical stretch induced beta-arrestin-biased signaling downstream of angiotensin II type I receptors (AT1Rs) in the absence of ligand or G protein activation. Mechanical stretch triggered an AT1R-mediated conformational change in beta-arrestin similar to that induced by a beta-arrestin-biased ligand to selectively stimulate receptor signaling in the absence of detectable G protein activation. Hearts from mice lacking beta-arrestin or AT1Rs failed to induce responses to mechanical stretch, as shown by blunted extracellular signal-regulated kinase and Akt activation, impaired transactivation of the epidermal growth factor receptor, and enhanced myocyte apoptosis. These data show that the heart responds to acute increases in mechanical stress by activating beta-arrestin-mediated cell survival signals.
Department of Medicine, Duke University Medical Center, DUMC 3104, 226 CARL Building, Durham, NC 27710, USA.
Kriti
K
Rakesh
ByungSu
B
Yoo
Il-Man
IM
Kim
Natasha
N
Salazar
Ki-Seok
KS
Kim
Howard A
HA
Rockman
D000818:Animals; D019390:Arrestins / Q000737:chemistry / Q000502:physiology*; D006801:Humans; D051379:Mice; D011487:Protein Conformation; D021381:Protein Transport; D011945:Receptors, Angiotensin / Q000819:agonists* / Q000378:metabolism; D013314:Stress, Mechanical; D000071557:beta-Arrestins
D019390:Arrestins; D011945:Receptors, Angiotensin; D000071557:beta-Arrestins