Abstract
Calcium-calmodulin-dependent protein kinase II (CaMKII) is thought to increase synaptic strength by phosphorylating postsynaptic density (PSD) ion channels and signaling proteins. It is shown that N-methyl-D-aspartate (NMDA) receptor stimulation reversibly translocates green fluorescent protein-tagged CaMKII from an F-actin-bound to a PSD-bound state. The translocation time was controlled by the ratio of expressed beta-CaMKII to alpha-CaMKII isoforms. Although F-actin dissociation into the cytosol required autophosphorylation of or calcium-calmodulin binding to beta-CaMKII, PSD translocation required binding of calcium-calmodulin to either the alpha- or beta-CaMKII subunits. Autophosphorylation of CaMKII indirectly prolongs its PSD localization by increasing the calmodulin-binding affinity.
Publication types
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Research Support, U.S. Gov't, P.H.S.
MeSH terms
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Actins / metabolism
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Animals
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Calcium / pharmacology
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Calcium-Calmodulin-Dependent Protein Kinase Type 2
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Calcium-Calmodulin-Dependent Protein Kinases / metabolism*
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Cells, Cultured
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Cytosol / metabolism
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Dendrites / enzymology*
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Electric Stimulation
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Glutamic Acid / pharmacology
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Green Fluorescent Proteins
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Hippocampus / cytology
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Hippocampus / enzymology*
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Isoenzymes / metabolism
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Luminescent Proteins
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Microscopy, Fluorescence
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Nerve Tissue Proteins / analysis
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Neurons / enzymology*
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Phosphorylation
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Rats
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Receptors, N-Methyl-D-Aspartate / metabolism*
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Synapses / enzymology*
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Tumor Cells, Cultured
Substances
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Actins
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Isoenzymes
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Luminescent Proteins
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Nerve Tissue Proteins
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Receptors, N-Methyl-D-Aspartate
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postsynaptic density proteins
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Green Fluorescent Proteins
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Glutamic Acid
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Calcium-Calmodulin-Dependent Protein Kinase Type 2
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Calcium-Calmodulin-Dependent Protein Kinases
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Calcium