MOLECULAR REGULATION OF CARDIOVASCULAR SEVEN TRANSMEMBRANE RECEPTORS. All aspects of cardiovascular function are regulated by receptors of the seven transmembrane receptor (7TMR or GPCR) family, and they are the commonest target of therapeutic drugs. A universal mechanism regulating these receptors is desensitization of heterotrimeric G protein signaling. Classically, this is mediated by a two- step process in which activated receptors are phosphorylated by G protein-coupled receptor kinases, leading to the binding of a ?-arrestin (?arr) molecule which sterically interdicts further activation of the G protein. More recently it has become clear that ?arrs can also serve as multifunctional adaptors which act as signal transducers in their own right. Moreover, for many receptors ligands can be found which disproportionately activate either G protein- or ?arr-mediated signaling?i.e., biased ligands which may possess greater specificity of action and fewer side effects. Several such drugs, including one for decompensated congestive heart failure which targets the angiotensin II type 1 receptor (AT1R), have reached clinical trials. Accordingly, this proposal has three closely linked aims which involve developing a molecular- and atomic-level understanding of how such ?arr-mediated signaling is generated using as model systems two receptors of great cardiovascular significance, the ?2-adrenergic receptor (?2AR) and the AT1R.
These aims are: 1) To discover novel allosteric stabilizers (nanobodies and small molecules) for biased conformations of the AT1R and ?2AR. 2) To delineate the structural basis for biased conformations of the AT1R by X-ray crystallography and DEER. 3) To determine the structure of GPCR-?arr complexes by cryo-electron microscopy. The insights which we will generate have the potential to guide the design of powerful new cardiovascular drugs and will further our understanding of the conserved signaling mechanisms of the greater GPCR family.

Public Health Relevance

Some of the most important drugs used to treat cardiovascular disease such as '? blockers' (?- adrenergic receptor antagonists) and 'ARBs' (angiotensin receptor blockers) target specific receptors on the outside of cells. Here we seek to understand, at a molecular level, a novel mechanism by which these receptors signal to the inside of cells, laying the basis for next- generation therapeutics for cardiovascular and other diseases.

National Institute of Health (NIH)
National Heart, Lung, and Blood Institute (NHLBI)
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Molecular and Integrative Signal Transduction Study Section (MIST)
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Wong, Renee P
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Duke University
Internal Medicine/Medicine
Schools of Medicine
United States
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Kim, Jihee; Grotegut, Chad A; Wisler, James W et al. (2018) ?-arrestin 1 regulates ?2-adrenergic receptor-mediated skeletal muscle hypertrophy and contractility. Skelet Muscle 8:39
Wisler, James W; Rockman, Howard A; Lefkowitz, Robert J (2018) Biased G Protein-Coupled Receptor Signaling: Changing the Paradigm of Drug Discovery. Circulation 137:2315-2317
Ahn, Seungkirl; Pani, Biswaranjan; Kahsai, Alem W et al. (2018) Small-Molecule Positive Allosteric Modulators of the ?2-Adrenoceptor Isolated from DNA-Encoded Libraries. Mol Pharmacol 94:850-861
Staus, Dean P; Wingler, Laura M; Choi, Minjung et al. (2018) Sortase ligation enables homogeneous GPCR phosphorylation to reveal diversity in ?-arrestin coupling. Proc Natl Acad Sci U S A 115:3834-3839
Smith, Jeffrey S; Lefkowitz, Robert J; Rajagopal, Sudarshan (2018) Biased signalling: from simple switches to allosteric microprocessors. Nat Rev Drug Discov 17:243-260
Stoppel, Laura J; Auerbach, Benjamin D; Senter, Rebecca K et al. (2017) ?-Arrestin2 Couples Metabotropic Glutamate Receptor 5 to Neuronal Protein Synthesis and Is a Potential Target to Treat Fragile X. Cell Rep 18:2807-2814
Cahill 3rd, Thomas J; Thomsen, Alex R B; Tarrasch, Jeffrey T et al. (2017) Distinct conformations of GPCR-?-arrestin complexes mediate desensitization, signaling, and endocytosis. Proc Natl Acad Sci U S A 114:2562-2567
Rein, Lindsay Am; Wisler, James W; Kim, Jihee et al. (2017) ?-Arrestin2 mediates progression of murine primary myelofibrosis. JCI Insight 2:
Ahn, Seungkirl; Kahsai, Alem W; Pani, Biswaranjan et al. (2017) Allosteric ""beta-blocker"" isolated from a DNA-encoded small molecule library. Proc Natl Acad Sci U S A 114:1708-1713
Paek, Jaeho; Kalocsay, Marian; Staus, Dean P et al. (2017) Multidimensional Tracking of GPCR Signaling via Peroxidase-Catalyzed Proximity Labeling. Cell 169:338-349.e11

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