Kainate-type ionotropic glutamate receptor (KAR) (KAR)

Kainate-type ionotropic glutamate receptors (KARs) are a distinct class of ligand-gated ion channels that mediate fast excitatory neurotransmission and modulate synaptic plasticity throughout the central nervous system [1][2]. They are formed by the tetrameric assembly of five subunits, GluK1 through GluK5, which are encoded by the GRIK1–GRIK5 genes [1][4]. Unlike other ionotropic glutamate receptors, KARs are unique for their dual role in both postsynaptic excitation and the presynaptic regulation of neurotransmitter release, including both glutamate and GABA [2][3]. These receptors are widely distributed in brain regions such as the hippocampus and cerebral cortex, where they play a critical role in maintaining the balance of neural circuit excitability [3]. Dysregulation of KAR signaling is strongly implicated in various neurological and psychiatric conditions, most notably epilepsy, chronic pain, and schizophrenia [3][4]. Pharmacological targeting of KARs, particularly through subtype-selective antagonists like those targeting GluK1, offers potential therapeutic avenues for treating hyperexcitability disorders [4]. However, drug development is often challenged by the need for high selectivity to avoid disrupting normal cognitive functions or inducing excitotoxicity [2]. Sources: [1] UniProt (GRIK family); [2] StatPearls: Physiology, Glutamate Receptors; [3] PubMed: Kainate receptors in health and disease (Contractor et al., 2011); [4] IUPHAR/BPS Guide to Pharmacology.

Other names

Kainate receptoriGluRGlutamate receptor, ionotropic, kainateGRIKGlutamate ionotropic receptor kainate type

Competitive antagonism or agonism at the glutamate binding site to modulate ion channel opening and subsequent neuronal depolarization or presynaptic neurotransmitter release.