title: G protein-coupled receptor kinase regulates dopamine D3 receptor signaling by modulating the stability of a receptor-filamin-beta-arrestin complex. A case of autoreceptor regulation.
abstract: In addition to its postsynaptic role, the dopamine D3 receptor (D3R) serves as a presynaptic autoreceptor, where it provides continuous feedback regulation of dopamine release at nerve terminals for processes as diverse as emotional tone and locomotion. D3R signaling ability is supported by an association with filamin (actin-binding protein 280), which localizes the receptor with G proteins in plasma membrane lipid rafts but is not appreciably antagonized in a classical sense by the ligand-mediated activation of G protein-coupled receptor kinases (GRKs) and beta-arrestins. In this study, we investigate GRK-mediated regulation of D3R.filamin complex stability and its effect on D3R.G protein signaling potential. Studies in HEK-293 cells show that in the absence of agonist the D3R immunoprecipitates in a complex containing both filamin A and beta-arrestin2. Moreover, the filamin directly interacts with beta-arrestin2 as assessed by immunoprecipitation and yeast two-hybrid studies. With reductions in basal GRK2/3 activity, an increase in the basal association of filamin A and beta-arrestin2 with D3R is observed. Conversely, increases in the basal GRK2/3 activity result in a reduction in the interaction between the D3R and filamin but a relative increase in the agonist-mediated interaction between beta-arrestin2 and the D3R. Our data suggest that the D3R, filamin A, and beta-arrestin form a signaling complex that is destabilized by agonist- or expression-mediated increases in GRK2/3 activity. These findings provide a novel GRK-based mechanism for regulating D3R signaling potential and provide insight for interpreting D3R autoreceptor behavior.
authors.affiliation: Department of Pharmacology, College of Pharmacy, Chonnam National University, Kwang-Ju, Korea.
authors.forename: Kyeong-Man
authors.initials: KM
authors.lastname: Kim
authors.forename: Raul R
authors.initials: RR
authors.lastname: Gainetdinov
authors.forename: Stephane A
authors.initials: SA
authors.lastname: Laporte
authors.forename: Marc G
authors.initials: MG
authors.lastname: Caron
authors.forename: Larry S
authors.initials: LS
authors.lastname: Barak
mesh_terms: D000818:Animals; D019390:Arrestins / Q000378:metabolism*; D019556:COS Cells; D002460:Cell Line; D002462:Cell Membrane / Q000378:metabolism; D003285:Contractile Proteins / Q000737:chemistry; D000242:Cyclic AMP / Q000378:metabolism; D017868:Cyclic AMP-Dependent Protein Kinases / Q000378:metabolism / Q000502:physiology*; D004305:Dose-Response Relationship, Drug; D004591:Electrophoresis, Polyacrylamide Gel; D064448:Filamins; D005786:Gene Expression Regulation; D016244:Guanosine 5'-O-(3-Thiotriphosphate) / Q000378:metabolism; D006801:Humans; D047468:Immunoprecipitation; D008024:Ligands; D021962:Membrane Microdomains; D008840:Microfilament Proteins / Q000737:chemistry; D018613:Microscopy, Confocal; D010766:Phosphorylation; D010957:Plasmids / Q000378:metabolism; D011485:Protein Binding; D017448:Receptors, Dopamine D2 / Q000378:metabolism*; D050637:Receptors, Dopamine D3; D015398:Signal Transduction; D014162:Transfection; D020798:Two-Hybrid System Techniques; D051552:beta-Adrenergic Receptor Kinases; D000071557:beta-Arrestins
chemical_list: D019390:Arrestins; D003285:Contractile Proteins; C493593:DRD3 protein, human; C578661:FLNC protein, human; D064448:Filamins; D008024:Ligands; D008840:Microfilament Proteins; D017448:Receptors, Dopamine D2; D050637:Receptors, Dopamine D3; D000071557:beta-Arrestins; D016244:Guanosine 5'-O-(3-Thiotriphosphate); D000242:Cyclic AMP; D017868:Cyclic AMP-Dependent Protein Kinases; D051552:beta-Adrenergic Receptor Kinases