Regulation of DARPP-32 dephosphorylation at PKA- and Cdk5-sites by NMDA and AMPA receptors: Distinct roles of calcineurin and protein phosphatase-2A

Akinori Nishi, James A. Bibb, Seiichiro Matsuyama, Miho Hamada, Hideho Higashi, Angus C. Nairn, Paul Greengard

Research output: Contribution to journalArticle

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Glutamatergic inputs from corticostriatal and thalamostriatal pathways have been shown to modulate dopaminergic signaling in neostriatal neurons. DARPP-32 (dopamine- and cAMP-regulated phosphoprotein of Mr 32 kDa) is a signal transduction molecule that regulates the efficacy of dopamine signaling in neostriatal neurons. Dopamine signaling is mediated in part through phosphorylation of DARPP-32 at Thr34 by cAMP-dependent protein kinase, and antagonized by phosphorylation of DARPP-32 at Thr75 by cyclin-dependent protein kinase 5. We have now investigated the effects of the ionotropic glutamate NMDA and AMPA receptors on DARPP-32 phosphorylation in neostriatal slices. Activation of NMDA and AMPA receptors decreased the state of phosphorylation of DARPP-32 at Thr34 and Thr75. The decrease in Thr34 phosphorylation was mediated through Ca2+-dependent activation of the Ca2+-/calmodulin-dependent phosphatase, calcineurin. In contrast, the decrease in Thr75 phosphorylation was mediated through Ca2+-dependent activation of dephosphorylation by protein phosphatase-2A. The results provide support for a complex effect of glutamate on dopaminergic signaling through the regulation of dephosphorylation of different sites of DARPP-32 by different protein phosphatases.

Original languageEnglish (US)
Pages (from-to)832-841
Number of pages10
JournalJournal of Neurochemistry
Issue number4
StatePublished - Aug 5 2002



  • Dopamine
  • Glutamate
  • Intracellular Ca
  • Neostriatal neurons
  • Phosphorylation

ASJC Scopus subject areas

  • Biochemistry
  • Cellular and Molecular Neuroscience

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