Glutamate receptor ionotropic NMDA type subunit 1 (GluN1) glycine site (GluN1)

The Glutamate receptor ionotropic NMDA type subunit 1 (GluN1) is the essential, pore-forming subunit of the N-methyl-D-aspartate (NMDA) receptor, a complex ligand-gated ion channel that mediates the slow component of excitatory synaptic transmission in the central nervous system [1, 2]. A defining feature of the NMDA receptor is its requirement for two different agonists: glutamate, which binds to the GluN2 subunit, and glycine (or D-serine), which binds to the GluN1 subunit at the strychnine-insensitive glycine co-agonist site [2, 3]. This site is a fundamental regulator of the receptor's open-probability and is crucial for synaptic plasticity mechanisms like long-term potentiation (LTP), which underlies learning and memory [3, 4]. Dysregulation of GluN1-mediated signaling is implicated in a wide range of disorders, including schizophrenia (hypofunction), Alzheimer's disease, and chronic pain [2, 3]. Pharmacological agents targeting the GluN1 glycine site include agonists and partial agonists designed to improve cognitive function and treat mood disorders, as well as antagonists aimed at preventing neurodegeneration and alleviating neuropathic pain [3, 4].

Other names

GRIN1NMDA receptor subunit 1NR1Glycine-B siteStrychnine-insensitive glycine siteGlutamate ionotropic receptor NMDA type subunit 1

The GluN1 glycine site is an obligatory co-agonist site; binding of glycine or D-serine is required alongside glutamate binding to the GluN2 subunit to allow the ion channel to open and permit cation influx (Ca2+, Na+, K+) [1, 2, 3].