?1D-adrenergic receptors (ARs) are essential G protein-coupled receptors (GPCRs) of the sympathetic nervous system, and are a promising therapeutic target for an array of diseases. In the central nervous system, the ?1D- AR tightly regulates stimulus-induced locomotor activity, and is 1 of 13 hypermethylated genes associated with decreased brain volume in schizophrenic patients. The ?1D-AR is critical for blood pressure regulation and stenosis of damaged blood vessels; and negatively impacts urine flow by contracting the prostate in patients suffering from benign prostatic hypertrophy (BPH). Thus, ?1-AR antagonists (??-blockers?) are often used to treat hypertension, urinary incontinence, and most recently with promising success, to prevent reoccurring nightmares in combat veterans afflicted with Post-Traumatic Stress Disorder. Unfortunately, major toxicities can often occur in patients taking ?-blockers. During the ALLHAT trial, ?-blocker therapy was discontinued due to increased patient morbidity. Accordingly, a clearer picture of how the ?1D-AR engages with its cellular environment will provide critical insights towards the further development of small molecule ?1D-AR modulators beneficial for the treatment of PTSD, BPH, and cardiovascular disease. Surprisingly, our basic knowledge of ?1D-AR biochemical processes is lacking within human contexts, primarily because no human cell lines have been identified that express endogenous ?1D-ARs. Without adequate cell culture models and human model cell systems to examine their discrete biochemical interactions, it will continue to be challenging to develop new small molecules targeting ?1D-ARs and to understand their essential molecular and cellular functions. We have made significant progress towards solving some of these mysteries. First, we discovered that ?1D-ARs interact with multiple PSD95/DLG1/Zo-1 (PDZ) domain-containing proteins. Second, we found these interactions are essential for ?1D-ARs to be expressed as functional receptors at the plasma membrane. Remarkably, we found that ?1D-ARs interact with two PDZ-proteins, syntrophin and scribble, in all human cell lines we examined. This novel discovery provides an opportunity to develop small molecule allosteric ligands targeting ?1D-AR:PDZ- protein interaction-interfaces. However, this first requires a thorough characterization of ?1D-AR:PDZ-protein architecture and function. The initial aims we that were proposed were the following:
Aim 1 : Determine whether scribble organizes ?1D-ARs into signaling clusters.
Aim 2 : Identify ?1D-AR:PDZ-protein complex(es) in human cells.

Public Health Relevance

This proposal will be used to obtain cutting-edge cell imaging equipment that can be used to identify cellular mechanisms responsible for trafficking and degrading membrane proteins. This approach can be used as a basis for obtaining information that will spur the development of drugs with novel mechanisms of action for treating human disease.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
3R01GM100893-09S1
Application #
10132165
Study Section
Program Officer
Koduri, Sailaja
Project Start
2012-06-07
Project End
2021-03-31
Budget Start
2020-04-01
Budget End
2021-03-31
Support Year
9
Fiscal Year
2020
Total Cost
Indirect Cost
Name
University of Washington
Department
Pharmacology
Type
Schools of Medicine
DUNS #
605799469
City
Seattle
State
WA
Country
United States
Zip Code
98195
Harris, Dorathy-Ann; Park, Ji-Min; Lee, Kyung-Soon et al. (2017) Label-Free Dynamic Mass Redistribution Reveals Low-Density, Prosurvival ?1B-Adrenergic Receptors in Human SW480 Colon Carcinoma Cells. J Pharmacol Exp Ther 361:219-228
Kountz, Timothy S; Lee, Kyung-Soon; Aggarwal-Howarth, Stacey et al. (2016) Endogenous N-terminal Domain Cleavage Modulates ?1D-Adrenergic Receptor Pharmacodynamics. J Biol Chem 291:18210-21
Camp, Nathan D; Lee, Kyung-Soon; Cherry, Allison et al. (2016) Dynamic mass redistribution reveals diverging importance of PDZ-ligands for G protein-coupled receptor pharmacodynamics. Pharmacol Res 105:13-21
Camp, Nathan D; Lee, Kyung-Soon; Wacker-Mhyre, Jennifer L et al. (2015) Individual protomers of a G protein-coupled receptor dimer integrate distinct functional modules. Cell Discov 1: