IMMUNOLOGICAL EVIDENCE FOR THE ENRICHMENT OF N-METHYL-D-ASPARTATE RECEPTOR SUBUNIT 2A IN THE RAT POSTSYNAPTIC DENSITY

The synapse is a special structure where communication between neurons takes place, One of the postsynaptic structures that is thought to ha ve a regulatory role in synaptic transmission is the postsynaptic dens ity (PSD), As an effort to understand the subcellular localization of N-methyl-D-aspartate (NMDA) receptors, which play an important role in synaptic plasticity, we carried out immunological experiments to stud y whether NMDA receptor subunit 2A (NR2A) is present in the PSD and en riched there, In oder to generate NR2A-specific antibody, we amplified a segment of NR2A gene by polymerase chain reaction and subcloned the fragment into a bacterial expression vector pGEX2T, We expressed the NR2A segment as a glutathione-S-transferase fusion protein in Escheric hia coli, and made anti-NR2A antibodies using the fusion protein, Immu noblot analyses revealed that the molecular size of NR2A is 180 kDa, t hat NR2A contains a similar amount of N-linked oligosaccharide, and th at NR2A is highly enriched in the forebrain PSD fraction, Our data ind icate that NR2A is specifically associated with PSDs reinforcing the i dea that the PSD is a key synaptic regulator.