The phosphorylation state of DARPP-32, a third messenger for dopamine, is regulated by in vivo pharmacological treatments.
It has been recently proposed that DARPP-32 participates, as third messenger, in the mediation of effects induced by dopamine at the cellular level. DARPP-32 is indeed localized almost exclusively on dopaminoceptive neurons bearing the D1 receptor subtype and it is phosphorylated by cAMP-dependent protein kinase. In its phospho-form, DARPP-32 acts as an inhibitor of protein phosphatase-1. In vivo pharmacological treatment with selective D1 agonists and antagonists induces changes in the phosphorylation state of DARPP-32 that can be correlated to changes in cAMP, mediated in turn by D1 and D2 receptors. These data demonstrate that the measurement of the phosphorylation state of DARPP-32 with the back-phosphorylation assay can represent a useful biochemical tool to gain further insight into the sequence of events elicited by specific dopaminergic drugs in vivo.
Institute of Pharmacological Sciences, University of Milano, Italy.
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M
Di Luca
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M
Cimino
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F
Cattabeni
D000818:Animals; D004298:Dopamine / Q000378:metabolism*; D051937:Dopamine and cAMP-Regulated Phosphoprotein 32; D009419:Nerve Tissue Proteins / Q000378:metabolism* / Q000502:physiology; D009474:Neurons / Q000502:physiology; D010750:Phosphoproteins / Q000378:metabolism; D010766:Phosphorylation; D011954:Receptors, Dopamine / Q000145:classification / Q000378:metabolism; D014018:Tissue Distribution
D051937:Dopamine and cAMP-Regulated Phosphoprotein 32; D009419:Nerve Tissue Proteins; D010750:Phosphoproteins; D011954:Receptors, Dopamine; D004298:Dopamine