Glycine receptor subunit alpha-1 (GLRA1) (GLRA1)

The Glycine receptor subunit alpha-1 (GLRA1) is a primary component of the glycine receptor (GlyR), a member of the Cys-loop family of ligand-gated ion channels (UniProt: P23415). It functions as a pentameric chloride-selective channel that mediates fast inhibitory neurotransmission, particularly in the spinal cord, brainstem, and retina (PubMed: 21501885). When glycine binds to the receptor, it induces a conformational change that opens the pore, allowing chloride ions to flow into the neuron, which hyperpolarizes the membrane and suppresses action potential firing (StatPearls: NBK539739). GLRA1 is essential for controlling motor functions and sensory perception; consequently, mutations in the GLRA1 gene are the leading cause of hereditary hyperekplexia, a disorder marked by excessive startle responses (NCBI Gene: 2741). The receptor is famously antagonized by strychnine, a potent convulsant, and is a target for various modulators including general anesthetics, ethanol, and the antiparasitic drug ivermectin (PubChem: CID 5280959). Current therapeutic research focuses on GLRA1 as a target for managing chronic pain and spasticity due to its role in spinal inhibitory circuits. Additionally, autoantibodies against GLRA1 are associated with rare neurological conditions like Stiff Person Syndrome and Progressive Encephalomyelitis with Rigidity and Myoclonus (PERM). Its structural similarity to other Cys-loop receptors makes it a model for studying ion channel gating and pharmacology.

Other names

Glycine receptor alpha 1GLRA1Glycine receptor 48 kDa subunitHKPX1STHE

Binding of the agonist glycine to the extracellular interface of the alpha-1 subunits triggers a conformational transition that opens an integral chloride-selective ion pore. This results in an influx of chloride ions into the postsynaptic neuron, leading to membrane hyperpolarization and a subsequent increase in the threshold for action potential generation, thereby inhibiting neuronal activity (PubMed: 21501885).