Abstract
During synaptic development, proteins aggregate at specialized pre- and postsynaptic structures. Mechanisms that mediate protein clustering at these sites remain unknown. To investigate this process, we analyzed synaptic targeting of a postsynaptic density protein, PSD-95, by expressing green fluorescent protein- (GFP-) tagged PSD-95 in cultured hippocampal neurons. We find that postsynaptic clustering relies on three elements of PSD-95: N-terminal palmitoylation, the first two PDZ domains, and a C-terminal targeting motif. In contrast, disruptions of PDZ3, SH3, or guanylate kinase (GK) domains do not affect synaptic targeting. Palmitoylation is sufficient to target the diffusely expressed SAP-97 to synapses, and palmitoylation cannot be replaced with alternative membrane association motifs, suggesting that a specialized synaptic lipid environment mediates postsynaptic clustering. The requirements for PDZ domains and a C-terminal domain of PSD-95 indicate that protein-protein interactions cooperate with lipid interactions in synaptic targeting.
Publication types
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Research Support, Non-U.S. Gov't
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Research Support, U.S. Gov't, Non-P.H.S.
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Research Support, U.S. Gov't, P.H.S.
MeSH terms
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Animals
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Cells, Cultured
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Cloning, Molecular
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Disks Large Homolog 4 Protein
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Fluorescent Antibody Technique
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Green Fluorescent Proteins
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Guanylate Kinases
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Hippocampus / cytology
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Hippocampus / physiology
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Intracellular Signaling Peptides and Proteins
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Lipid Metabolism
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Lipids / physiology*
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Luminescent Proteins / genetics
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Membrane Proteins
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Mutation
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Nerve Tissue Proteins / genetics
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Nerve Tissue Proteins / metabolism
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Nerve Tissue Proteins / physiology*
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Neuronal Plasticity / physiology
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Neurons / metabolism
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Neurons / physiology*
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Palmitic Acid / metabolism
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Rats
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Recombinant Fusion Proteins / genetics
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Recombinant Fusion Proteins / metabolism
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Synapses / metabolism
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Synapses / physiology*
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Transfection
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Tumor Suppressor Proteins
Substances
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Disks Large Homolog 4 Protein
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Dlg4 protein, rat
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Intracellular Signaling Peptides and Proteins
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Lipids
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Luminescent Proteins
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Membrane Proteins
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Nerve Tissue Proteins
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Recombinant Fusion Proteins
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Tumor Suppressor Proteins
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postsynaptic density proteins
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Green Fluorescent Proteins
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Palmitic Acid
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DLG2 protein, human
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Guanylate Kinases