Distinct domains within PSD-95 mediate synaptic incorporation, stabilization, and activity-dependent trafficking. The Journal of neuroscience : the official journal of the Society for Neuroscience [J Neurosci] Journal article | | Title | Distinct domains within PSD-95 mediate synaptic incorporation, stabilization, and activity-dependent trafficking. | | Author(s) | Sturgill JF, Steiner P, Czervionke BL, Sabatini BL | | Institution | Howard Hughes Medical Institute, Department of Neurobiology, Harvard Medical School, Boston, Massachusetts 02115, USA. | | Source | J Neurosci 2009 Oct 14; 29(41):12845-54. | | MeSH | Animals
Animals, Newborn
Calcium-Calmodulin-Dependent Protein Kinase Kinase
Dendritic Spines
Excitatory Amino Acid Agonists
Green Fluorescent Proteins
Hippocampus
Immunosuppressive Agents
Intracellular Signaling Peptides and Proteins
Lipoylation
Membrane Proteins
Mutation
N-Methylaspartate
Organ Culture Techniques
PDZ Domains
Protein Structure, Tertiary
Protein Transport
Rats
Receptors, AMPA
Signal Transduction
Synapses
Tacrolimus
Time Factors
Transfection
| | Abstract | The postsynaptic density (PSD) consists of a lattice-like array of interacting proteins that organizes and stabilizes receptors, ion channels, structural, and signaling proteins necessary for synaptic function. To study the stabilization of proteins within this structure and the contribution of these proteins to the integrity of the PSD, we tagged synaptic proteins with PAGFP (photoactivatable green fluorescent protein) and used combined two-photon laser-scanning microscopy and two-photon laser photoactivation to measure their rate of turnover in individual spines of rat CA1 pyramidal neurons. We find that PSD-95 is highly stable within the spine, more so than other PSD-associated proteins such as CaMKIIalpha, CaMKIIbeta, GluR2, and Stargazin. Analysis of a series of PSD-95 mutants revealed that distinct domains stabilize PSD-95 within the PSD and contribute to PSD formation. Stabilization of PSD-95 within the PSD requires N-terminal palmitoylation and protein interactions mediated by the first and second PDZ domains, whereas formation of a stable lattice of PSD-95 molecules within the PSD additionally requires the C-terminal SH3 domain. Furthermore, in a PDZ domain 1 and 2 dependent manner, activation of NMDA receptors with a chemical long-term depression protocol rapidly destabilizes PSD-95 and causes a subset of the PSD-95 molecules previously anchored in the spine to be released. Thus, through the analysis of rates of exchange of synaptic PSD-95, we determine separate domains of PSD-95 that play specific roles in establishing a stable postsynaptic lattice, in allowing proteins to enter this lattice, and in reorganizing this structure in response to plasticity-inducing stimuli. | | Language | eng | | Pub Type(s) | In Vitro
Journal Article
Research Support, N.I.H., Extramural
Research Support, Non-U.S. Gov't
| | PubMed ID | 19828799 |
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