N-methyl-D-aspartate receptor subunit GluN1 (GluN1)

The N-methyl-D-aspartate receptor subunit GluN1 (abbreviated GluN1, gene symbol GRIN1) is an obligatory subunit of the NMDA receptor, a ligand-gated ion channel critical for excitatory synaptic transmission in the central nervous system[1][5]. Functional NMDA receptors are heterotetramers consisting of two GluN1 and two GluN2 (and sometimes GluN3) subunits; GluN1 is essential for the assembly and function of all native NMDARs[1][3][5]. The GluN1 subunit binds glycine or D-serine as a co-agonist, while the GluN2 subunit binds glutamate; co-binding is required for channel opening, resulting in calcium and sodium influx[1][5][6][7]. The receptor plays a fundamental role in synaptic plasticity, learning, memory, and broader neuronal development. Dysfunction of GluN1-containing NMDARs is implicated in a wide range of neurological and psychiatric diseases, which has made the receptor (and thus GluN1) an important therapeutic target[5]. Drugs such as ketamine and memantine interact with the NMDAR channel pore, inhibiting its function for various neuropsychiatric and neurodegenerative disorders, though the receptor’s critical physiological roles mean that modulation carries substantial safety concerns[5]. Alternative splicing of the GluN1 subunit (encoded by the GRIN1 gene) produces multiple isoforms with distinct regulatory and signaling properties[1][5].

Other names

NMDA receptor subunit GluN1NR1GRIN1 (gene symbol)NMDAR1Glycine-binding NMDA receptor subunitNMDAR GluN1

Uncompetitive NMDA receptor antagonism (e.g., ketamine, memantine, dextromethorphan, PCP, MK-801); Channel pore blocking (bind in open channel, block calcium influx); Glycine site antagonism/agonism (targeting the co-agonist binding on GluN1 as with some investigational compounds); Allosteric modulation.