title: Phosphorylation of AMPA-type glutamate receptors by calcium/calmodulin-dependent protein kinase II and protein kinase C in cultured hippocampal neurons.
abstract: Phosphorylation of glutamate receptors (GluRs) is emerging as an important regulatory mechanism. In this study 32P labeling of non-NMDA GluRs was investigated in cultured hippocampal neurons stimulated 2-15 min with agonists that selectively stimulate either Ca2+/calmodulin-dependent protein kinase II (CaM-kinase II), Ca2+/phospholipid-dependent protein kinase C (PKC), or cAMP-dependent protein kinase A (PKA). Treatment of hippocampal neurons with glutamate/glycine (Glu/Gly), ionomycin, or 12-O-tetradecanoylphorbol 13-acetate (TPA) increased 32P labeling of immunoprecipitated alpha-amino-3-hydroxy-5-methyl-4-isoxazoleproprionate (AMPA)-type GluRs by 145%, 180%, and 227%, respectively, of control values. This increased phosphorylation of GluRs was predominantly 32P-Ser with little 32P-Thr and no detectable 32P-Tyr. Glu/Gly and ionomycin, but not TPA, also increased 32P labeling of CaM-kinase II by 175% and 195%, respectively, of control values. Of these three agonists, only TPA stimulated phosphorylation of MARCKS (225% of control), a specific substrate of PKC. Forskolin treatment gave a three- to fourfold increase in the active catalytic subunit of PKA but did not result in the 32P labeling of AMPA-type GluRs, CaM-kinase II, or MARCKS. Phosphorylation of GluRs in response to Glu/Gly was blocked by a specific NMDA receptor/ion channel antagonist (DL-2-amino-5-phosphonovaleric acid) or by a cell-permeable inhibitor of CaM-kinase II (1-[N,O-bis(1,5-isoquinolinesulfonyl)-N-methyl-L-tyrosyl]-4- phenylpiperazine, KN-62). These results are consistent with the hypothesis that Ca2+ influx through the NMDA-type ion channel can activate CaM-kinase II, which in turn can phosphorylate and regulate AMPA-type GluR ion channels (McGlade-McCulloh et al., 1993).(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Vollum Institute, Oregon Health Sciences University, Portland 97201.
authors.forename: S E
authors.initials: SE
authors.lastname: Tan
authors.forename: R J
authors.initials: RJ
authors.lastname: Wenthold
authors.forename: T R
authors.initials: TR
authors.lastname: Soderling
mesh_terms: D000818:Animals; D054732:Calcium-Calmodulin-Dependent Protein Kinase Type 2; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000378:metabolism / Q000494:pharmacology*; D005576:Colforsin / Q000494:pharmacology; D017868:Cyclic AMP-Dependent Protein Kinases / Q000378:metabolism / Q000494:pharmacology; D005971:Glutamates / Q000494:pharmacology; D018698:Glutamic Acid; D005998:Glycine / Q000494:pharmacology; D006624:Hippocampus / Q000187:drug effects / Q000378:metabolism*; D047908:Intracellular Signaling Peptides and Proteins; D015759:Ionomycin / Q000494:pharmacology; D008565:Membrane Proteins; D000076250:Myristoylated Alanine-Rich C Kinase Substrate; D010766:Phosphorylation; D011493:Protein Kinase C / Q000378:metabolism / Q000494:pharmacology*; D011506:Proteins / Q000378:metabolism; D051381:Rats; D017470:Receptors, Glutamate / Q000187:drug effects / Q000378:metabolism*; D016194:Receptors, N-Methyl-D-Aspartate / Q000187:drug effects; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D018350:alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid / Q000737:chemistry*
chemical_list: D005971:Glutamates; D047908:Intracellular Signaling Peptides and Proteins; C000619712:Marcks protein, rat; D008565:Membrane Proteins; D011506:Proteins; D017470:Receptors, Glutamate; D016194:Receptors, N-Methyl-D-Aspartate; D000076250:Myristoylated Alanine-Rich C Kinase Substrate; D005576:Colforsin; D018698:Glutamic Acid; D015759:Ionomycin; D018350:alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid; D017868:Cyclic AMP-Dependent Protein Kinases; D011493:Protein Kinase C; D054732:Calcium-Calmodulin-Dependent Protein Kinase Type 2; D017871:Calcium-Calmodulin-Dependent Protein Kinases; D013755:Tetradecanoylphorbol Acetate; D005998:Glycine