Anti-NMDAR-2B: Rabbit N-Methyl-D-Aspartate Receptor 2B Antibody

Both types of subunits have a large COOH-terminal intracellular domain, suggesting that the large cytoplasmic domain may directly interact with proteins that regulate NMDA receptor function. For example, it was suggested that postsynaptic density protein PSD95 directly interacts with NMDA receptors, although the biological significance of the interaction has not been established. The intracellular domain of NR1, NR2A, and NR2B contains serine residues that can be phosphorylated by protein kinases. Protein kinase C (PKC) phosphorylates serine residues 889, 890, and 896 within the C1 exon of the NR1 subunit; protein kinase A (PKA) phosphorylates serine residue 897. PKC can directly phosphorylate S1303 and S1323 in the NR2B C terminus, leading to enhanced currents through NMDA receptor channels.² Protein phosphatase 1 and protein phosphatase 2A dephosphorylate phospho-Ser1303 on NR2B.³ The NMDA receptor-mediated current is regulated by several protein kinases and phosphatases. In addition, CaM binds to NR1 in a Ca²⁺-dependent manner and that the binding inactivates NMDA channels. This feedback system regulates the amount of Ca²⁺ influx through the NMDA receptors. PKC-mediated phosphorylation on serine residues of NR1 decreases its CaM binding affinity and prevents inactivation of NMDA channels by Ca²⁺.⁴