Department of Anesthesiology

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DARPP-32, a dopamine- and adenosine 3':5'-monophosphate-regulated phosphoprotein enriched in dopamine-innervated brain regions. II. Purification and characterization of the phosphoprotein from bovine caudate nucleus.

TitleDARPP-32, a dopamine- and adenosine 3':5'-monophosphate-regulated phosphoprotein enriched in dopamine-innervated brain regions. II. Purification and characterization of the phosphoprotein from bovine caudate nucleus.
Publication TypeJournal Article
Year of Publication1984
AuthorsHemmings HC, Nairn AC, Aswad DW, Greengard P
JournalJ Neurosci
Volume4
Issue1
Pagination99-110
Date Published1984 Jan
ISSN0270-6474
KeywordsAmino Acids, Animals, Cattle, Caudate Nucleus, Cyclic AMP, Dopamine, Dopamine and cAMP-Regulated Phosphoprotein 32, Electrophoresis, Polyacrylamide Gel, Isoelectric Focusing, Molecular Weight, Nerve Tissue Proteins, Phosphoproteins, Phosphorylation, Protein Conformation
Abstract

DARPP-32 is a neuronal phosphoprotein of Mr = 32,000, originally identified in rat brain (Walaas, S.I., D.W. Aswad, and P. Greengard (1983) Nature 301: 69-72). This protein has now been identified in bovine caudate nucleus cytosol and purified 435-fold to apparent homogeneity as judged by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The purification procedure involved acid extraction at pH 2, CM-cellulose chromatography, DEAE-cellulose chromatography, hydroxylapatite chromatography, and gel filtration on Ultrogel AcA 44. The purified catalytic subunit of cAMP-dependent protein kinase catalyzed the incorporation of 0.96 mol of phosphate/mol of purified DARPP-32. Phosphorylation occurred exclusively on threonine. The isoelectric point of dephospho-DARPP-32 was 4.7, and that of phospho-DARPP-32 was 4.6. The amino acid composition showed a high content of glutamate/glutamine and proline, and a low content of hydrophobic amino acids. DARPP-32 was found to have a Stokes radius of 34 A and a sedimentation coefficient of 2.05 S, indicating that it exists as an elongated monomer.

Alternate JournalJ. Neurosci.
PubMed ID6319628
Grant ListGM-02044 / GM / NIGMS NIH HHS / United States
MH-17387 / MH / NIMH NIH HHS / United States
NS-08440 / NS / NINDS NIH HHS / United States