Glutamate ionotropic receptor kainate type (KAR) (KAR)

The glutamate ionotropic receptor kainate type (KAR) is a class of ligand-gated ion channels that mediate excitatory neurotransmission in the central nervous system (UniProt: P39086). Composed of various combinations of five subunits (GluK1-GluK5), these receptors are distinct from AMPA and NMDA receptors in their kinetics and physiological roles (Lerma & Marques, Neuron, 2013). KARs function both postsynaptically to mediate excitatory currents and presynaptically to modulate the release of other neurotransmitters like GABA and glutamate (IUPHAR/BPS Guide to Pharmacology, 2023). They play a critical role in synaptic plasticity and the regulation of neuronal circuit excitability. Dysregulation of KAR signaling is implicated in several neurological and psychiatric conditions, including epilepsy, neuropathic pain, and schizophrenia (Jane et al., British Journal of Pharmacology, 2009). Consequently, KARs are significant therapeutic targets, with research focusing on subunit-specific antagonists to treat hyperexcitability disorders without the side effects associated with broad-spectrum glutamate inhibition (StatPearls, 2023).

Other names

Kainate receptoriGluRGRIKIonotropic glutamate receptor kainate typeGRIK1GRIK2GRIK3GRIK4GRIK5

Ligand-gated ion channel activation or inhibition; drugs act as agonists, antagonists, or non-competitive modulators to regulate cation flux (Na+ and K+) across the neuronal membrane (IUPHAR/BPS Guide to Pharmacology, 2023).