Abstract
The dopamine D2 receptor (DRD2) is a key receptor that mediates dopamine-associated brain functions such as mood, reward, and emotion. Cyclin-dependent kinase 5 (Cdk5) is a proline-directed serine/threonine kinase whose function has been implicated in the brain reward circuit. In this study, we revealed that the serine 321 residue (S321) in the third intracellular loop of DRD2 (D2i3) is a novel regulatory site of Cdk5. Cdk5-dependent phosphorylation of S321 in the D2i3 was observed in in vitro and cell culture systems. We further observed that the phosphorylation of S321 impaired the agonist-stimulated surface expression of DRD2 and decreased G protein coupling to DRD2. Moreover, the downstream cAMP pathway was affected in the heterologous system and in primary neuronal cultures from p35 knockout embryos likely due to the reduced inhibitory activity of DRD2. These results indicate that Cdk5-mediated phosphorylation of S321 inhibits DRD2 function, providing a novel regulatory mechanism for dopamine signaling.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Animals
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Brain / metabolism*
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Catalytic Domain / genetics
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Chromatography, Liquid
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Cyclin-Dependent Kinase 5 / metabolism*
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DNA Primers / genetics
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GTP-Binding Proteins / metabolism
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Genotype
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Immunohistochemistry
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Immunoprecipitation
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Mice
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Mice, Knockout
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Phosphorylation
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Receptors, Dopamine D2 / metabolism*
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Signal Transduction / physiology*
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Tandem Mass Spectrometry
Substances
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DNA Primers
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Receptors, Dopamine D2
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Cyclin-Dependent Kinase 5
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GTP-Binding Proteins
Grants and funding
This work was supported by the grants (NRF-2012R1A2A2A01012923 and NRF-2012R1A4A1028200) from the Korean government (MSIP) and also supported under the framework of international cooperation program managed by NRF of Korea (2012K2A1A2033117) and the Korea Brain Research Institute (KBRI) Basic Research Program of MSIP (2031-415). SKP was a recipient of the 2004 and 2006 National Alliance for Research on Schizophrenia and Depression (NARSAD) Young Investigator Awards. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.