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Characterization of neuronal protein phosphatases in Aplysia californica.

Publication ,  Journal Article
Endo, S; Shenolikar, S; Eskin, A; Zwartjes, RE; Byrne, JH
Published in: J Neurochem
March 1992

Biochemical properties of neuronal protein phosphatases from Aplysia californica were characterized. Dephosphorylation of phosphorylase alpha by extracts of abdominal ganglia and clusters of sensory neurons from pleural ganglia was demonstrated. Type-1 protein phosphatase (PrP-1) was identified in these extracts by the dephosphorylation of the beta-subunit of phosphorylase kinase and its inhibition by the protein, inhibitor-2. Type-2A protein phosphatase (PrP-2A) was demonstrated by the dephosphorylation of the alpha-subunit of phosphorylase kinase, which was insensitive to inhibitor-2. As in vertebrate tissues, only four enzymes, PrP-1 (47%), PrP-2A (42%), PrP-2B (11%), and PrP-2C (less than 1%), accounted for all the cellular protein phosphatase activity dephosphorylating phosphorylase kinase. Aplysia PrP-1 and PrP-2A were potently inhibited by okadaic acid, with PrP-1 being approximately 20-fold more sensitive than PrP-2A. By comparison, purified PrP-2A from rabbit skeletal muscle was 15- to 20-fold more sensitive to okadaic acid than PrP-1 from the same source. Only PrP-1 was associated with the particulate fractions from Aplysia neurons, whereas PrP-1 and PrP-2A, -2B, and -2C were all present in the cytosol. Extraction of the particulate PrP-1 decreased its sensitivity to okadaic acid by sixfold, suggesting that cellular factor(s) affect its sensitivity to this inhibitor. In most respects, protein phosphatases from Aplysia neurons resemble their mammalian counterparts, and their biochemical characterization sets the stage for examining the role of these enzymes in neuronal plasticity, and in learning and memory.

Duke Scholars

Published In

J Neurochem

DOI

ISSN

0022-3042

Publication Date

March 1992

Volume

58

Issue

3

Start / End Page

975 / 982

Location

England

Related Subject Headings

  • Substrate Specificity
  • Subcellular Fractions
  • Proteins
  • Phosphoprotein Phosphatases
  • Okadaic Acid
  • Neurons
  • Neurology & Neurosurgery
  • Ganglia
  • Ethers, Cyclic
  • Aplysia
 

Citation

APA
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Endo, S., Shenolikar, S., Eskin, A., Zwartjes, R. E., & Byrne, J. H. (1992). Characterization of neuronal protein phosphatases in Aplysia californica. J Neurochem, 58(3), 975–982. https://doi.org/10.1111/j.1471-4159.1992.tb09351.x
Endo, S., S. Shenolikar, A. Eskin, R. E. Zwartjes, and J. H. Byrne. “Characterization of neuronal protein phosphatases in Aplysia californica.J Neurochem 58, no. 3 (March 1992): 975–82. https://doi.org/10.1111/j.1471-4159.1992.tb09351.x.
Endo S, Shenolikar S, Eskin A, Zwartjes RE, Byrne JH. Characterization of neuronal protein phosphatases in Aplysia californica. J Neurochem. 1992 Mar;58(3):975–82.
Endo, S., et al. “Characterization of neuronal protein phosphatases in Aplysia californica.J Neurochem, vol. 58, no. 3, Mar. 1992, pp. 975–82. Pubmed, doi:10.1111/j.1471-4159.1992.tb09351.x.
Endo S, Shenolikar S, Eskin A, Zwartjes RE, Byrne JH. Characterization of neuronal protein phosphatases in Aplysia californica. J Neurochem. 1992 Mar;58(3):975–982.
Journal cover image

Published In

J Neurochem

DOI

ISSN

0022-3042

Publication Date

March 1992

Volume

58

Issue

3

Start / End Page

975 / 982

Location

England

Related Subject Headings

  • Substrate Specificity
  • Subcellular Fractions
  • Proteins
  • Phosphoprotein Phosphatases
  • Okadaic Acid
  • Neurons
  • Neurology & Neurosurgery
  • Ganglia
  • Ethers, Cyclic
  • Aplysia