Glutamate receptor ionotropic, NMDA 3B (GRIN3B)

Glutamate receptor ionotropic, NMDA 3B (GRIN3B, also known as GluN3B or NR3B), is a subunit of the NMDA (N-methyl-D-aspartate) receptor, a type of ionotropic glutamate receptor that forms ligand-gated ion channels in the central nervous system. NMDA receptors are heterotetrameric complexes assembled from NR1, NR2 (A-D), and NR3 (A-B) subunits; GRIN3B encodes the GluN3B subunit. When incorporated, GluN3B changes the receptor’s electrophysiological properties—lowering calcium permeability and modifying channel activation and deactivation kinetics. GluN3B is expressed primarily in motor neurons and forms glycine-activated channels with GluN1 and glutamate-activated channels with GluN1 and GluN2. The NMDA receptor is critical for excitatory neurotransmission, synaptic plasticity, learning, and memory. Variants in GRIN3B have been associated with certain neurodevelopmental and neuropsychiatric disorders, though drugs specifically targeting this subunit are not currently available. NMDA receptor antagonists (like memantine and ketamine) act broadly on all NMDA receptor subunits

Other names

GluN3BNR3BNMDAR3BNMDA receptor subunit 3Bglutamate [NMDA] receptor subunit 3BN-methyl-D-aspartate receptor subtype 3Bglutamate ionotropic receptor NMDA type subunit 3BNMDA type glutamate receptor subunit NR3B

Channel blockade (voltage-dependent block by Mg2+ ions is reduced in GluN3B-containing NMDA receptors) - Inhibition of cation (Na+, K+, Ca2+) flux through the ion channel