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Preparation of Synaptic Plasma Membrane and Postsynaptic Density Proteins Using a Discontinuous Sucrose Gradient
Published on: September 3, 2014
Identification of novel phosphorylation sites on postsynaptic density proteins
H Jaffe1, L Vinade, A Dosemeci
1Protein and Peptide Sequencing Facility, NIH/NINDS, Bethesda, MD, USA.
Biochemical and Biophysical Research Communications
|September 11, 2004
Summary
Researchers identified key phosphorylation sites on postsynaptic density (PSD) proteins, revealing a common RXXSPV motif. This finding suggests proline-directed kinases play a crucial role in regulating synaptic structure and function.
Area of Science:
- Neuroscience
- Molecular Biology
- Biochemistry
Background:
- The postsynaptic density (PSD) is a critical protein complex regulating synaptic function.
- Phosphorylation of PSD components is a key mechanism for modulating synaptic plasticity and structure.
Purpose of the Study:
- To identify novel phosphorylation sites on PSD proteins using mass spectrometry.
- To elucidate the role of specific kinases in PSD protein regulation.
Main Methods:
- Proteomic analysis of PSD fractions using liquid chromatography and tandem mass spectrometry.
- Immobilized metal affinity chromatography for phosphopeptide enrichment.
- In vitro phosphorylation assays with Ca2+/calmodulin.
Main Results:
- Identified phosphorylation sites on SynGAP (S-1058) and Shank3 (S-1662, S-1668) in vitro.
- Detected phosphorylation at homologous sites S-295 (PSD-95) and S-365 (PSD-93), and S-367 (beta-CaMKII) in control samples.
- Discovered a conserved RXXSPV phosphorylation motif in PSD-95, PSD-93, and Shank3, suggesting a role for proline-directed kinases.
Conclusions:
- Phosphorylation of PSD proteins is a dynamic process regulating synaptic function.
- The RXXSPV motif highlights specific kinase-substrate interactions in PSD regulation.
- Proline-directed kinases are likely involved in modulating PSD protein activity and synaptic signaling.
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