Open AccessRegulation of phosphorylation of proteins I, IIIa, and IIIb in rat neurohypophysis in vitro by electrical stimulation and by neuroactive agents.
Author(s) -
Kang Tsou,
Paul Greengard
Publication year - 1982
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.011
H-Index - 771
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.79.19.6075
Subject(s) - phosphorylation , stimulation , dopamine , protein phosphorylation , chemistry , medicine , in vitro , endocrinology , biology , biochemistry , protein kinase a
The state of phosphorylation of proteins I, IIIa, and IIIb--neuron-specific phosphoproteins--was studied in neurosecretory endings of the neurohypophysis in vitro. Brief periods (a few seconds) of electrical stimulation caused large increases in the state of phosphorylation of all three proteins. The three proteins were dephosphorylated within 1 min after termination of the stimulation. High potassium, 8-bromo-cAMP, and dopamine also stimulated the phosphorylation of the three proteins. The effect of dopamine was blocked by the dopamine antagonist fluphenazine. Peptide mapping of protein I revealed that electrical stimulation or high potassium increased the state of phosphorylation of two regions of the molecule, whereas 8-bromo-cAMP and dopamine increased the state of phosphorylation of only one of these regions.