Identification of activity-regulated proteins in the postsynaptic density fraction.
BACKGROUND
The postsynaptic density (PSD) at synapses is a specialized submembranous structure where neurotransmitter receptors are linked to cytoskeleton and signalling molecules. Activity-dependent dynamic change in the components of the PSD is a mechanism of synaptic plasticity. Identification of the PSD proteins and examination of their modulations dependent on synaptic activity will be valuable for an understanding of the molecular basis of learning and memory.


RESULTS
We attempted here to identify proteins in the PSD fraction by two-dimensional (2D) gel electrophoresis and mass spectrometry. About 1.7 x 103 protein spots were detected on 2D gels. A total of 90 spots were identified, containing 47 different protein species. In addition to previously identified PSD proteins such as PSD-95/SAP90, several new proteins were identified in the PSD fraction. They included stomatin-like protein 2 and NIPSNAP1. We also examined activity-dependent modulations of PSD proteins by 2D gel electrophoresis. The spot concentration of G protein beta subunit 5 and NIPSNAP1 increased 2 h after kainate treatment that caused generalized seizures.


CONCLUSIONS
These results indicate that the combination of 2D gel electrophoresis and mass spectrometry is an excellent tool for the identification of activity-regulated PSD proteins.
Satoh
Keiko
K
KAN Research Institute, Kyoto 600-8815, Japan Laboratory of Seeds Finding Technology, Eisai Co., Ltd, Tsukuba 300-2635, Japan.
Takeuchi
Masakazu
M
Oda
Yoshiya
Y
Deguchi-Tawarada
Maki
M
Sakamoto
Yoshimasa
Y
Matsubara
Kaho
K
Nagasu
Takeshi
T
Takai
Yoshimi
Y
D000818:Animals; D001798:Blood Proteins / Q000378:metabolism*; D015180:Electrophoresis, Gel, Two-Dimensional; D036341:Intercellular Signaling Peptides and Proteins; D013058:Mass Spectrometry; D008565:Membrane Proteins / Q000378:metabolism*; D051379:Mice; D020559:Monomeric GTP-Binding Proteins / Q000378:metabolism*; D054778:NM23 Nucleoside Diphosphate Kinases; D009419:Nerve Tissue Proteins / Q000378:metabolism*; D009701:Nucleoside-Diphosphate Kinase; D000091402:Prohibitins; D016548:Prosencephalon / Q000378:metabolism; D011506:Proteins / Q000378:metabolism*; D012097:Repressor Proteins; D013347:Subcellular Fractions / Q000378:metabolism; D013569:Synapses / Q000378:metabolism*; D014157:Transcription Factors / Q000378:metabolism*
D001798:Blood Proteins; D036341:Intercellular Signaling Peptides and Proteins; D008565:Membrane Proteins; C113197:NIPSNAP1 protein, human; D054778:NM23 Nucleoside Diphosphate Kinases; D009419:Nerve Tissue Proteins; C485133:Nipsnap1 protein, mouse; D000091402:Prohibitins; D011506:Proteins; D012097:Repressor Proteins; C406287:STOML2 protein, human; D014157:Transcription Factors; D009701:Nucleoside-Diphosphate Kinase; D020559:Monomeric GTP-Binding Proteins