B-arrestins are multifunctional proteins that are recruited to G protein-coupled receptors (GCPRs) following agonist stimulation. While the classical role of (3-arrestin is to mediate receptor desensitization, work by investigators of this PPG have recently shown that P-arrestin can stimulate signaling in the absence of classical G protein activation. The existence of B-arrestin-mediated signaling independent of G proteins requires that receptors adopt multiple """"""""active"""""""" conformations or """"""""ligand selective states"""""""". The ability of unique ligand-receptor conformations to promote preferential B-arrestin signaling is an emerging concept known as """"""""biased signaling"""""""". The molecular mechanisms that underlie p-an-estin-biased signaling for the p-adrenergic receptor of (PAR), and its physiological consequences in the heart, are not known. In this proposal, we will test the hypothesis that mutant p i - and P2 can be engineered that will selectively stimulate p-arrestinbiased signaling independent of G protein activation, and that p-arrestin-biased signaling will promote cardiomyocyte cell survival to limit the development of heart failure in response to pathological stimuli. Accordingly, the specific aims of the study are:
Aim 1 : To engineerBp1 AR mutants that show selective bias for p-arrestin recruitment.
Aim 2 : To identify the mechanism of activation and signaling pathways activated by P1AR and B2AR mutants in the absence of G protein activation.
Aim 3 : To test in adult cardiomyocytes whether p-arrestin-biasedBP2AR TYY and B1 AR mutants activate cardioprotective signaling in response to agonist stimulation and ischemia.
Aim 4 : To test in vivo whether the B-arrestin-biased Bp2AR TYY and pi AR mutant activities cardioprotective pathways under conditions of pathological stress. By exploring these aims, we will define the pathways by which G protein-Independent activation of BARs may lead to stimulation of cardioprotective signaling. If our hypothesis is correct, we will show that ligandstimulated PARS, which selectively activate B-arrestin signaling pathways, are cardioprotecitve. Since, by definition, the administration of a ligand that does not stimulate G protein signaling is B-blackade, we will have demonstrated proof-of concept for the development of an entirely novel class of receptor blockers. We believe these data will provide considerable impetus for the development of novel p-arrestin-biased therapeutic agents to treat human heart failure.
|Abraham, Dennis M; Davis 3rd, Robert T; Warren, Chad M et al. (2016) Î²-Arrestin mediates the Frank-Starling mechanism of cardiac contractility. Proc Natl Acad Sci U S A 113:14426-14431|
|Hullmann, Jonathan; Traynham, Christopher J; Coleman, Ryan C et al. (2016) The expanding GRK interactome: Implications in cardiovascular disease and potential for therapeutic development. Pharmacol Res 110:52-64|
|Zhang, Rongli; Hess, Douglas T; Reynolds, James D et al. (2016) Hemoglobin S-nitrosylation plays an essential role in cardioprotection. J Clin Invest 126:4654-4658|
|Woodall, Meryl C; Woodall, Benjamin P; Gao, Erhe et al. (2016) Cardiac Fibroblast GRK2 Deletion Enhances Contractility and Remodeling Following Ischemia/Reperfusion Injury. Circ Res 119:1116-1127|
|Feldman, Arthur M; Gordon, Jennifer; Wang, JuFang et al. (2016) BAG3 regulates contractility and Ca(2+) homeostasis in adult mouse ventricular myocytes. J Mol Cell Cardiol 92:10-20|
|Adachi, Naoko; Hess, Douglas T; McLaughlin, Precious et al. (2016) S-Palmitoylation of a Novel Site in the Î²2-Adrenergic Receptor Associated with a Novel Intracellular Itinerary. J Biol Chem 291:20232-46|
|Hodavance, Sima Y; Gareri, Clarice; Torok, Rachel D et al. (2016) G Protein-coupled Receptor Biased Agonism. J Cardiovasc Pharmacol 67:193-202|
|Waldschmidt, Helen V; Homan, Kristoff T; Cruz-RodrÃguez, Osvaldo et al. (2016) Structure-Based Design, Synthesis, and Biological Evaluation of Highly Selective and Potent G Protein-Coupled Receptor Kinase 2 Inhibitors. J Med Chem 59:3793-807|
|Carr 3rd, Richard; Schilling, Justin; Song, Jianliang et al. (2016) Î²-arrestin-biased signaling through the Î²2-adrenergic receptor promotes cardiomyocyte contraction. Proc Natl Acad Sci U S A 113:E4107-16|
|Watson, Lewis J; Alexander, Kevin M; Mohan, Maradumane L et al. (2016) Phosphorylation of Src by phosphoinositide 3-kinase regulates beta-adrenergic receptor-mediated EGFR transactivation. Cell Signal 28:1580-92|
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