Dopamine D2 and D3 receptors are linked to the actin cytoskeleton via interaction with filamin A.
We have used a yeast two-hybrid approach to uncover protein interactions involving the D2-like subfamily of dopamine receptors. Using the third intracellular loop of the D2S and D3 dopamine receptors as bait to screen a human brain cDNA library, we identified filamin A (FLN-A) as a protein that interacts with both the D2 and D3 subtypes. The interaction with FLN-A was specific for the D2 and D3 receptors and was independently confirmed in pull-down and coimmunoprecipitation experiments. Deletion mapping localized the dopamine receptor-FLN-A interaction to the N-terminal segment of the D2 and D3 dopamine receptors and to repeat 19 of FLN-A. In cultures of dissociated rat striatum, FLN-A and D2 receptors colocalized throughout neuronal somata and processes as well as in astrocytes. Expression of D2 dopamine receptors in FLN-A-deficient M2 melanoma cells resulted in predominant intracellular localization of the D2 receptors, whereas in FLN-A-reconstituted cells, the D2 receptor was predominantly localized at the plasma membrane. These results suggest that FLN-A may be required for proper cell surface expression of the D2 dopamine receptors. Association of D2 and D3 dopamine receptors with FLN-A provides a mechanism whereby specific dopamine receptor subtypes may be functionally linked to downstream signaling components via the actin cytoskeleton.
Lin
R
R
Neuroscience Graduate Program, Department of Pharmacology, Penn State College of Medicine, Hershey, PA 17033, USA.
Karpa
K
K
Kabbani
N
N
Goldman-Rakic
P
P
Levenson
R
R
D000199:Actins / Q000378:metabolism*; D000818:Animals; D001665:Binding Sites; D002478:Cells, Cultured; D003285:Contractile Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D003599:Cytoskeleton / Q000378:metabolism*; D064448:Filamins; D005455:Fluorescent Antibody Technique; D006801:Humans; D008545:Melanoma; D008840:Microfilament Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D008954:Models, Biological; D017072:Neostriatum / Q000166:cytology / Q000196:embryology / Q000378:metabolism; D011233:Precipitin Tests; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D051381:Rats; D017448:Receptors, Dopamine D2 / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D050637:Receptors, Dopamine D3; D017384:Sequence Deletion; D013379:Substrate Specificity; D014407:Tumor Cells, Cultured; D020798:Two-Hybrid System Techniques
D000199:Actins; D003285:Contractile Proteins; C493593:DRD3 protein, human; C493595:Drd3 protein, rat; D064448:Filamins; D008840:Microfilament Proteins; D017448:Receptors, Dopamine D2; D050637:Receptors, Dopamine D3