mGluR1/A0103

The metabotropic glutamate receptor 1 (mGluR1, also known as GRM1 or A0103), is a non-ionotropic G-coupled protein glutamate receptor.

The metabotropic glutamate receptor 1 (mGluR1, also known as GRM1 or A0103), is a non-ionotropic G-coupled protein glutamate receptor. It is expressed in neurons, with the highest levels in the cerebellum and cortex and elsewhere in the brain. There is little or no expression in the spinal cord or corpus collosum. mGluR1 is localized post- (and extra-) synaptically and functionally couples to the phospholipase C (PLC), inositol 1,4,5-triphosphate (IP3) / calcium signaling pathway. GRM1 is capable of agonist-independent/constitutive activity. The ligand-binding domain (LBD) and cysteine-rich domain of the close homologue, mGluR5, have been crystallized. The LBD shows homology to the glutamate binding domain of ionotropic glutamate receptors and induces dimerization of mGluR1. There is also a 7-pass transmembrane domain and a C-terminal tail that interacts with HOMER, to regulate constitutive activity. mGluR1 knock-out mice retained apparent normal brain anatomy, but impaired long-term potentiation (LTP), cerebellar LDP and associative learning.