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Differential subcellular localization of two dopamine D 2 receptor isoforms in transfected NG108‐15 cells
Author(s) -
Takeuchi Yusuke,
Fukunaga Kohji
Publication year - 2003
Publication title -
journal of neurochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.75
H-Index - 229
eISSN - 1471-4159
pISSN - 0022-3042
DOI - 10.1046/j.1471-4159.2003.01763.x
Subject(s) - subcellular localization , gene isoform , cytoplasm , cytosol , transfection , biology , golgi apparatus , fatty acid binding protein , microbiology and biotechnology , immunoprecipitation , green fluorescent protein , biochemistry , gene , endoplasmic reticulum , enzyme
The dopamine D 2 receptor (D2R) is target for antipsychotic drugs and associated with several neuropsychiatric disorders. D2R has a long third cytoplasmic loop and a short carboxyl‐terminal cytoplasmic tail. It exists as two alternatively spliced isoforms, termed D2LR and D2SR, which differ in the presence and absence, respectively, of a 29 amino acid insert in the third cytoplasmic loop. To evaluate the differential roles of the two D2R isoforms, we transfected both isoforms into NG108‐15 cells and observed their subcellular localization by a confocal laser scanning light microscope. D2SR was predominantly localized at the plasma membrane, whereas D2LR was mostly retained in the perinuclear region around the Golgi apparatus. Using a yeast two hybrid system with a mouse brain cDNA library and coimmunoprecipitation assay, we found that heart‐type fatty acid binding protein (H‐FABP) interacts with D2LR but not with D2SR. H‐FABP is a cytosolic protein involved in binding and transport of fatty acids. Overexpressed H‐FABP and endogenous H‐FABP were colocalized with the intracellular D2LR in NG108‐15 cells. Furthermore, in the rat striatum, H‐FABP was detected in the D2R‐expressing neurons. From these results, H‐FABP is associated with D2LR, and may thereby modulate the subcellular localization and function of D2LR.