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In Vivo Activation of Kainate Receptors Induces Dephosphorylation of the Heavy Neurofilament Subunit
Author(s) -
Wang Shu,
Hamberger Anders,
Ding Mei,
Haglid Kenneth G.
Publication year - 1992
Publication title -
journal of neurochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.75
H-Index - 229
eISSN - 1471-4159
pISSN - 0022-3042
DOI - 10.1111/j.1471-4159.1992.tb11037.x
Subject(s) - dephosphorylation , phosphorylation , neurofilament , kainate receptor , kainic acid , protein subunit , glutamate receptor , biology , microbiology and biotechnology , nmda receptor , ionotropic effect , biochemistry , receptor , chemistry , ampa receptor , phosphatase , immunohistochemistry , immunology , gene
Injection of kainic acid (KA) into the rat hippocampus reduced the phosphorylation‐related immunoreactivity of the heavy subunit of neurofilament proteins (NF‐H). The effect was demonstrated quantitatively with a dot‐immunobinding assay and qualitatively by immunoblotting with monoclonal antibodies against phosphorylation‐dependent and nonphosphorylation‐related epitopes of NF‐H. The KA‐induced reduction affected 50% of the phosphorylated NF‐H in half of the hippocampus after 48 h. At the same time, the nonphosphorylation‐related NF‐H immunoreactivity increased as revealed by immunoblotting, indicating a shift from phosphorylated to nonphosphorylated NF‐H. The effects on NF‐H preceeded a decrease in content of the neuron‐specific enolase, a soluble neuronal cytoplasmic protein. No alterations of the light subunit of neurofilament proteins occurred, suggesting that KA has a preferential effect on NF‐H phosphorylation. N‐Methyl‐D‐aspartate administered similarly did not lead to a rapid dephosphorylation of NF‐H. We propose that kainate receptor‐mediated dephosphorylation in NF‐H is involved in the signal transduction of excitatory amino acids with consequences for neuronal functions dependent on intermediary filament phosphorylation.