Abstract
Although dopamine (DA) regulates the serine/threonine kinase Akt and its downstream substrate glycogen synthase kinase-3β (GSK-3β), the direct influence of dopaminergic receptors remains poorly characterized. Short-term incubation of Chinese hamster ovary (CHO)-expressed human (h)D2L and hD3 receptors with DA (maximal effect, 5–10 min) phosphorylated Akt (Thr308 and Ser473) and GSK-3β (Ser9), actions blocked by the selective D2 and D3 antagonists, 3-[4-(4-chlorophenyl)-4-hydroxypiperidin-l-yl]methyl-1H-indole (L741,626) and (3aR,9bS)-N[4-(8-cyano-1,3a,4,9b-tetrahydro-3H-benzopyrano[3,4-c]pyrrole-2-yl)-butyl] (4-phenyl)benzamide (S33084), respectively. Similar findings were acquired with the specific D2/D3 receptor agonist quinelorane, which also enhanced (10 min after administration) levels of p-Akt and p-GSK-3β in rat nucleus accumbens, an action blocked by the D2/D3 receptor antagonist raclopride. Akt and GSK-3β phosphorylation mediated via CHO-expressed hD2L and hD3 receptors was prevented by pertussis toxin and by inhibitors of insulin-like growth factor-1 receptors as well as phosphatidylinositol 3-kinase and Src. Likewise, chelation of intracellular Ca2+ and interference with an “atypical” phorbol ester-insensitive protein kinase C (PKC) abolished recruitment of Akt and GSK-3β. Inactivation of PKCμ blocked Akt and GSK-3β phosphorylation at hD2L receptors. However, blockade of conventional PKC isoforms attenuated the actions of DA at hD3 receptors only. Furthermore, phospholipase C (PLC), calmodulin, and Akt inhibitors abolished DA-induced GSK-3β phosphorylation by hD3 receptors, whereas phosphorylation by hD2L receptors partially involved calmodulin, Akt, and extracellular signal-regulated kinase (ERK) 1/2. In conclusion, at both hD2L and hD3 receptors, DA elicited a Gi/o- and Ca2+/calmodulin-dependent phosphorylation of Akt and GSK-3β via transactivation of insulin-like growth factor 1 receptor. However, significant differences were seen regarding the involvement of PLC, calmodulin, and ERK1/2.
Footnotes
Article, publication date, and citation information can be found at http://molpharm.aspetjournals.org.
doi:10.1124/mol.110.065409.
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ABBREVIATIONS:
- 10-DEBC
- 10-[4′-(N,N-diethylamino)butyl]-2-chlorophenoxazine
- AG1024
- 3-bromo-5-t-butyl-4-hydroxy-benzildenemalonitrile
- AG1433
- 2-(3,4-dihydroxyphenyl)-6,7-dimethoxyquinoxaline
- AG1478
- 4-(3-chloroanilino)-6,7-dimethoxyquinazoline
- BAPTA-AM
- 1,2-bis(o-aminophenoxy)ethane-N,N,N′,N′-tetraacetic acid tetra(acetoxymethyl)ester
- CaMKII
- Ca2+-calmodulin kinase
- CHO
- Chinese hamster ovary
- CTX
- cholera toxin
- DA
- dopamine
- EGF
- epidermal growth factor
- EGF-R
- epidermal growth factor receptor
- ERK1/2
- extracellular signal-regulated kinase
- GAPDH
- glyceraldehyde-3-phosphate dehydrogenase
- Gö6976
- 12-(2-cyanoethyl)-6,7,12,13,-tetrahydro-13-methyl-5-oxo-5H-indolo[2,3-a]pyrrolo[3,4-c]-carbazol
- Gö6983
- 3-[1(3-dimethylamino-propyl)-5-methoxy-1H-indol-3-yl]4-(1H-indol-3-yl)pyrrolidine-2,5-dione
- GSK-3β
- glycogen synthase kinase-3β
- h
- human
- H89
- N-[2-((p-bromocinnamyl)amino)ethyl]-5-isoquinolinesulfonamide
- IGF
- insulin-like growth factor
- IGF-1R
- insulin-like growth factor-1 receptor
- KN93
- 2-(N-[2-hydroxyethyl])-N-(4-methoxybenzenesulfonyl)amino-N-(4-chlorocinnamyl)-N-methylamine
- L741
- 6263-[4-(4-chlorophenyl)-4-hydroxypiperidin-l-yl]methyl-1H-indole
- LY294,002
- 2-(4-morpholinyl)-8-phenyl-4H-1-benzopiran-4-one
- MAPK
- mitogen-activated protein kinase
- MEK
- MAPK-extracellular signal-regulated kinase
- mTORC
- rictor-mammalian target of rapamycin complex
- PAO
- phenylarsine oxide
- PD98059
- 2′-amino-3′-methoxyflavone
- PDGF
- platelet-derived growth factor
- PDGF-R
- platelet-derived growth factor receptor
- PDK1
- phosphatidylinositol 3,4,5-trisphosphate-dependent protein kinase 1
- PI3-K
- phosphatidyl inositol-3-kinase
- PKA
- protein kinase A
- PKC
- protein kinase C
- PLC
- phospholipase C
- PMA
- phorbol 12-myristate 13-acetate
- PP2
- 4-amino-5-(4-chlorophenyl)-7-(t-butyl)pyrazolo[3,4-d]pyrimidine
- PTX
- pertussis toxin
- Ro-31-7549
- 2-[1-3(aminopropyl)indol-3-yl]-3(1-methyl-1H-indol-3-yl-maleimide, acetate
- S33084
- (3aR,9bS)-N[4-(8-cyano-1,3a,4,9b-tetrahydro-3H-benzopyrano[3,4-c]pyrrole-2-yl)-butyl] (4-phenyl)benzamide)
- U0126
- 1,4-diamino-2,3-dicyano-1,4-bis(2-aminophenylthio)butadiene
- U73122
- 1-[6-((17β-3-methoxyestra-1,3,5(10)-trien-17-yl)amino)hexyl]-1H-pyrrole-2,5-dione
- W7
- N-(6-aminohexyl)-5-chloro-1-naphthalenesulfonamide
- Wnt
- Wingless.
- Received April 7, 2010.
- Accepted October 14, 2010.
- Copyright © 2011 The American Society for Pharmacology and Experimental Therapeutics
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