The NMDA receptor subunit NR2B (GRIN2B gene product) is a modulatory subunit that combines with NR1 to form functional NMDA receptors. NR2B confers unique biophysical and pharmacological properties:
Structure and Assembly
Large N-terminal domain with ifenprodil binding site (NR2B-selective antagonist)
Glutamate-binding domain (distinct from NR1's glycine site)
C-terminal domain with PDZ-binding motif for synaptic anchoring
Forms heterotetramers: typically 2 NR1 + 2 NR2 subunits
The NMDA receptor subunit NR2B (GRIN2B gene product) is a modulatory subunit that combines with NR1 to form functional NMDA receptors. NR2B confers unique biophysical and pharmacological properties:
Structure and Assembly
Large N-terminal domain with ifenprodil binding site (NR2B-selective antagonist)
Glutamate-binding domain (distinct from NR1's glycine site)
C-terminal domain with PDZ-binding motif for synaptic anchoring
Forms heterotetramers: typically 2 NR1 + 2 NR2 subunits
Developmental Regulation
Predominantly expressed early in development
Gradual switch from NR2B to NR2A during maturation (synaptic pruning)
[Monyer H, et al, Heteromeric NMDA receptors: molecular and functional distinction of subtypes (1992)](https://doi.org/10.1126/science.2565149)
[Van Zundert B, et al, Developmental regulation of NMDA receptor-mediated synaptic currents (2004)](https://doi.org/10.1111/j.1460-9568.2004.03263.x)
[Liu Y, et al, Extrasynaptic NMDA receptors: Mediators of excitotoxicity and therapeutic targets in neurodegenerative disorders (2019)](https://doi.org/10.1016/j.neuint.2019.104624)
[Li L, et al, Enhanced NMDA receptor-dependent NR2B phosphorylation in Huntington's disease mouse model (2002)](https://doi.org/10.1523/JNEUROSCI.22-21.09458.2002)
[Lemke JR, et al, GRIN2B mutations in neurodevelopmental disorders (2014)](https://doi.org/10.1038/ejhg.2014.238)
[Yao Y, et al, NR2B subunit of NMDA receptor as a potential therapeutic target in neurodegenerative diseases (2014)](https://doi.org/10.1007/s13311-014-0277-6)