Glutamate receptor ionotropic NMDA 3B (GluN3B)

The **Glutamate receptor ionotropic NMDA 3B (GluN3B)** is a subunit of non-conventional N-methyl-D-aspartate receptors (NMDARs), which assemble as heterotetrameric ligand-gated cation channels primarily expressed in motor neurons. Unlike typical synaptic NMDARs, GluN3B-containing receptors exhibit low calcium permeability, reduced voltage-dependent magnesium blockade, and unique activation properties, forming complexes with GluN1 and GluN2 subunits activated by glycine (on GluN1/GluN3B) and glutamate (on GluN2), or excitatory glycinergic complexes with GluN1 alone. GluN3B contributes distinct biophysical attributes including activation, deactivation, desensitization kinetics, pH sensitivity, and interactions with allosteric modulators. Structurally, it integrates into tetrameric assemblies with domains like the amino-terminal domain (NTD), ligand-binding domain (LBD), transmembrane domain (TMD), and carboxyl-terminal domain (CTD), influencing channel gating and ion selectivity. In disease contexts, GluN3B plays roles in calcium mobilization into mitochondria and may contribute to neurodegenerative processes through dominant negative effects on NMDAR function. While not prominently linked to approved drugs, its modulation alters synaptic plasticity and could pose therapeutic challenges due to subdued calcium signaling compared to canonical GluN2-containing NMDARs.

Other names

NMDA receptor subunit 3BN-methyl-D-aspartate receptor subunit 3BGRIN3BNMD3BNR3BNMDAR3B