Multiple Coupling of Human D5 Dopamine Receptors to Guanine Nucleotide Binding Proteins GS and Gz
| Autor: | Misook Uh, Anita Sidhu, Shutish Patel, Kazuhiro Kimura, Beatrix H. White |
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| Rok vydání: | 2002 |
| Předmět: |
P2Y receptor
G protein Blotting Western Biology Transfection Biochemistry Cell Line Cellular and Molecular Neuroscience Chemokine receptor GTP-Binding Proteins Heterotrimeric G protein GTP-Binding Protein alpha Subunits Gs Animals Humans Receptors Dopamine D5 Receptor G protein-coupled receptor Immune Sera Receptors Dopamine D1 Cell Membrane Heterotrimeric GTP-Binding Proteins Precipitin Tests GTP-Binding Protein alpha Subunits Guanine Nucleotides Rats Cell biology Metabotropic receptor Solubility Dopamine receptor Pituitary Gland |
| Zdroj: | Journal of Neurochemistry. 70:2459-2467 |
| ISSN: | 1471-4159 0022-3042 |
| Popis: | We have demonstrated previously that D1 dopamine receptors are coupled to both Gs alpha and Go alpha. We examine here the coupling between human D5 dopamine receptors and G proteins in transfected rat pituitary GH4C1 cells. Similar to D1 receptors, cholera toxin treatment of cells reduced, but did not abolish, D5 agonist high-affinity binding sites, indicating D5 receptors couple to both Gs alpha and cholera toxin-insensitive G proteins. The interaction between D5 receptors and Gs alpha was confirmed by immunoprecipitation studies and by the ability of D5 receptors to stimulate adenylyl cyclase. Unlike D1 receptors, D5 receptors did not display any pertussis toxin-sensitive G-protein coupling to Go alpha or Gi alpha. D5 receptors were also not coupled to Gq alpha and were unable to mediate phosphatidylinositol metabolism. Instead, D5 sites appeared to be coupled to an AIF(-)4-sensitive, N-ethylmaleimide-resistant G protein. Anti-Gz alpha caused immunoprecipitation of 24.2 +/- 5.2% of G protein-associated D5 receptors, indicating coupling between D5 and Gz alpha. The coupling to Gz alpha was specific for D5 receptors, because similar associations were not detected between D1 receptors and Gz alpha. |
| Databáze: | OpenAIRE |
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