Metabotropic glutamate receptor 1 and Metabotropic glutamate receptor 5 (mGluR1 and mGluR5)

Metabotropic glutamate receptor 1 (mGluR1) and metabotropic glutamate receptor 5 (mGluR5) are closely related members of the Group I metabotropic glutamate receptors, which are G protein-coupled receptors (GPCRs) primarily activated by glutamate, the main excitatory neurotransmitter in the central nervous system[1][4][7]. These receptors are structurally characterized by large extracellular "Venus flytrap" ligand-binding domains linked to seven-transmembrane regions, operate as obligatory dimers, and are largely found post-synaptically in the brain[1][8]. Upon glutamate binding, mGluR1 and mGluR5 primarily couple to Gq proteins, activating phospholipase C and downstream signaling cascades involving inositol trisphosphate (IP3) and diacylglycerol, which modulate neuronal excitability and synaptic plasticity[3][4]. mGluR1 and mGluR5 are involved in learning, memory, neuroprotection, and neuroinflammation; dysfunction or dysregulation of these receptors has been implicated in a spectrum of CNS diseases including neurodegenerative, psychiatric, epileptic, and developmental disorders, as well as in various cancers where they can promote cell proliferation and survival[2][4]. They are considered promising therapeutic targets with numerous investigational modulators in preclinical and clinical development for neurological, psychiatric, and oncological indications[2][4][6].

Other names

mGluR1 (also known as GRM1, Glutamate receptor, metabotropic 1)mGluR5 (also known as GRM5, Glutamate receptor, metabotropic 5)Group I metabotropic glutamate receptors

Negative allosteric modulation (e.g., mGluR5 negative allosteric modulators inhibit receptor signaling by binding to allosteric sites); Orthosteric antagonism (blocking glutamate binding); Agonism or positive allosteric modulation (enhancing receptor activity)