Dynamic mass redistribution reveals diverging importance of PDZ-ligands for G protein-coupled receptor pharmacodynamics. (March 2016)

• Record Type: Journal Article
• Authors: Camp, Nathan D.; Lee, Kyung-Soon; Cherry, Allison; Wacker-Mhyre, Jennifer L.; Kountz, Timothy S.; Park, Ji-Min; Harris, Dorathy-Ann; Estrada, Marianne; Stewart, Aaron; Stella, Nephi; Wolf-Yadlin, Alejandro; Hague, Chris
• Is Part Of: Pharmacological research. Volume 105(2016:Mar.)
• Page Start: 13
• Page End: 21
• Publication Date: 2016-03
• Subjects: ADRA1D α1Dadrenergic receptor -- ADRA2B α2Badrenergic receptor -- ADRB1 β1-adrenergic receptor -- ADRB2 β2adrenergic receptor -- C3AR1 Complement Component 3a Receptor 1 -- CXCR1 chemokine receptor 1 -- CXCR2 chemokine receptor 2 -- CXCR3 chemokine receptor 3 -- CXCR5 chemokine receptor 5 -- GALR1 galanin receptor 1 -- HRH3 histamine receptor H3 -- HTR2A 5-hydroxytryptamine (serotonin) receptor 2A -- HTR2B 5-hydroxytryptamine (serotonin) receptor 2B -- HTR2C 5-hydroxytryptamine (serotonin) receptor 2C -- LPAR2 lysophosphatidic acid receptor 2 -- MCHR2 Melanin-Concentrating Hormone Receptor 2 -- P2RY1 purinergic receptor P2Y1 -- P2RY1 2purinergic receptor P2Y12 -- S1PR2 sphingosine-1-phosphate receptor 2 -- SSTR1 somatostatin receptor 1 -- SSTR2 somatostatin receptor 2 -- SSTR3 somatostatin receptor 3 -- SSTR4 somatostatin receptor 4 -- SSTR5 somatostatin receptor 5; G protein-coupled receptor -- Label-free signaling -- PDZ domain -- Pharmacology; Pharmacology -- Periodicals; Pharmacology -- Periodicals; Research -- Periodicals; Médicaments -- Recherche -- Périodiques; Pharmacologie -- Périodiques; 615.105
• DOI: 10.1016/j.phrs.2016.01.003
• Languages: English
• ISSNs: 1043-6618

Abstract

Graphical abstract: Abstract: G protein-coupled receptors (GPCRs) are essential membrane proteins that facilitate cell-to-cell communication and co-ordinate physiological processes. At least 30 human GPCRs contain a Type I PSD-95/DLG/Zo-1 (PDZ) ligand in their distal C-terminal domain; this four amino acid motif of X-[S/T]-X-[φ] sequence facilitates interactions with PDZ domain-containing proteins. Because PDZ protein interactions have profound effects on GPCR ligand pharmacology, cellular localization, signal-transduction effector coupling and duration of activity, we analyzed the importance of Type I PDZ ligands for the function of 23 full-length and PDZ-ligand truncated (ΔPDZ) human GPCRs in cultured human cells. SNAP-epitope tag polyacrylamide gel electrophoresis revealed most Type I PDZ GPCRs exist as both monomers and multimers; removal of the PDZ ligand played minimal role in multimer formation. Additionally, SNAP-cell surface staining indicated removal of the PDZ ligand had minimal effects on plasma membrane localization for most GPCRs examined. Label-free dynamic mass redistribution functional responses, however, revealed diverging effects of the PDZ ligand. While no clear trend was observed across all GPCRs tested or even within receptor families, a subset of GPCRs displayed diminished agonist efficacy in the absence of a PDZ ligand (i.e. HT2RB, ADRB1), whereas others demonstrated enhanced agonist efficacies (i.e. LPAR2, SSTR5). These results demonstrate the utility of label-free functional assays to tease apart the contributions of conserved protein interaction domains for GPCR signal-transduction coupling in cultured cells.