Abstract
Ca2+/calmodulin-dependent protein kinase II (CaMKII) is a serine/threonine protein kinase that regulates long-term potentiation and other forms of neuronal plasticity. Functional differences between the neuronal CaMKIIalpha and CaMKIIbeta isoforms are not yet known. Here, we use green fluorescent protein-tagged (GFP-tagged) CaMKII isoforms and show that CaMKIIbeta is bound to F-actin in dendritic spines and cell cortex while CaMKIIalpha is largely a cytosolic enzyme. When expressed together, the two isoforms form large heterooligomers, and a small fraction of CaMKIIbeta is sufficient to dock the predominant CaMKIIalpha to the actin cytoskeleton. Thus, CaMKIIbeta functions as a targeting module that localizes a much larger number of CaMKIIalpha isozymes to synaptic and cytoskeletal sites of action.
Publication types
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Research Support, Non-U.S. Gov't
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Research Support, U.S. Gov't, P.H.S.
MeSH terms
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3T3 Cells
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Actins / metabolism*
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Animals
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Calcium-Calmodulin-Dependent Protein Kinase Type 2
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Calcium-Calmodulin-Dependent Protein Kinases / chemistry*
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Calcium-Calmodulin-Dependent Protein Kinases / genetics
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Calcium-Calmodulin-Dependent Protein Kinases / metabolism*
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Cloning, Molecular
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Cytoskeleton / metabolism
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Dendrites / metabolism*
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Green Fluorescent Proteins
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Isoenzymes / analysis
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Isoenzymes / metabolism
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Luminescent Proteins / metabolism
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Macromolecular Substances
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Mice
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Nerve Fibers / metabolism
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Nerve Fibers / ultrastructure
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Neurons / cytology
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Neurons / metabolism*
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Phosphorylation
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Protein Biosynthesis
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Rats
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Recombinant Fusion Proteins / chemistry
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Recombinant Fusion Proteins / metabolism
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Synapses / metabolism*
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Synapses / ultrastructure
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Transcription, Genetic
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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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Macromolecular Substances
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Recombinant Fusion Proteins
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Green Fluorescent Proteins
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Calcium-Calmodulin-Dependent Protein Kinase Type 2
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Calcium-Calmodulin-Dependent Protein Kinases