RT Journal Article
SR Electronic
T1 Signaling Pathways Leading to Phosphorylation of Akt and GSK-3β by Activation of Cloned Human and Rat Cerebral D<sub>2</sub> and D<sub>3</sub> Receptors
JF Molecular Pharmacology
JO Mol Pharmacol
FD American Society for Pharmacology and Experimental Therapeutics
SP 91
OP 105
DO 10.1124/mol.110.065409
VO 79
IS 1
A1 Mannoury la Cour, Clotilde
A1 Salles, Marie-Josèphe
A1 Pasteau, Valérie
A1 Millan, Mark J.
YR 2011
UL http://molpharm.aspetjournals.org/content/79/1/91.abstract
AB 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.