Journal of Neitrorhemutry Raven Press, Ltd., New York 0 I992 International Society for Neurochemistry
Characterization of Neuronal Protein Phosphatases in Aplysia californica Shogo Endo, *Shirish Shenolikar, ?Arnold Eskin, ?Ray E. Zwartjes, and John H. Byrne Departments of Neurobiology and Anatomy, and *Pharmacology, University of Texas Medical School, and ?Department of Biochemical and Biophysical Sciences, University of Houston, Houston, Texas, U S A .
Abstract: Biochemical properties of neuronal protein phosphatases from Aplysza californica were characterized. Dephosphorylation of phosphorylase a 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 @-subunitof phosphorylase kinase and its inhibition by the protein, inhibitor-2. Type-2A protein phosphatase (PrP-2A) was demonstrated by the dephosphorylation of the a-subunit of phosphorylase kinase, which was insensitive to inhibitor2. As in vertebrate tissues, only four enzymes, PrP-1 (47%), PrP-2A (42%), PrP-2B (1 I%), and PrP-2C (
Characterization of Neuronal Protein Phosphatases in Aplysia californica Shogo Endo, *Shirish Shenolikar, ?Arnold Eskin, ?Ray E. Zwartjes, and John H. Byrne Departments of Neurobiology and Anatomy, and *Pharmacology, University of Texas Medical School, and ?Department of Biochemical and Biophysical Sciences, University of Houston, Houston, Texas, U S A .
Abstract: Biochemical properties of neuronal protein phosphatases from Aplysza californica were characterized. Dephosphorylation of phosphorylase a 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 @-subunitof phosphorylase kinase and its inhibition by the protein, inhibitor-2. Type-2A protein phosphatase (PrP-2A) was demonstrated by the dephosphorylation of the a-subunit of phosphorylase kinase, which was insensitive to inhibitor2. As in vertebrate tissues, only four enzymes, PrP-1 (47%), PrP-2A (42%), PrP-2B (1 I%), and PrP-2C (
