Semiquantitative proteomic analysis of rat forebrain postsynaptic density fractions by mass spectrometry.
The postsynaptic density (PSD) of central excitatory synapses plays a key role in postsynaptic signal transduction and contains a high concentration of glutamate receptors and associated scaffold and signaling proteins. We report here a comprehensive analysis of purified PSD fractions by liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS). We identified 374 different proteins that copurified with the PSD structure and discovered thirteen phosphorylated sites from eight proteins. These proteins were classified into numerous functional groups, implying that the signaling pathways in the PSD are complex and diverse. Furthermore, using quantitative mass spectrometry, we measured the molar concentration and relative stoichiometries of a number of glutamate receptor subunits and scaffold proteins in the postsynaptic density. Thus this proteomic study reveals crucial information about molecular abundance as well as molecular diversity in the PSD, and provides a basis for further studies on the molecular mechanisms of synaptic function and plasticity.
Peng
Junmin
J
Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA. jpeng@genetics.emory.edu
Kim
Myung Jong
MJ
Cheng
Dongmei
D
Duong
Duc M
DM
Gygi
Steven P
SP
Sheng
Morgan
M
D000595:Amino Acid Sequence; D000818:Animals; D002853:Chromatography, Liquid; D013058:Mass Spectrometry; D008969:Molecular Sequence Data; D009419:Nerve Tissue Proteins / Q000032:analysis* / Q000737:chemistry; D010446:Peptide Fragments / Q000737:chemistry; D016548:Prosencephalon / Q000502:physiology*; D020543:Proteome; D051381:Rats; D013569:Synapses / Q000737:chemistry* / Q000502:physiology
D009419:Nerve Tissue Proteins; D010446:Peptide Fragments; D020543:Proteome