Receptor for glutamate. L-glutamate acts as an excitatory neurotransmitter at many synapses in the central nervous system. The postsynaptic actions of Glu are mediated by a variety of receptors that are named according to their selective agonists. Promotes synaptogenesis and mediates the D-Serine-dependent long term depression signals and AMPA receptor endocytosis of cerebellar parallel fiber-Purkinje cell (PF-PC) synapses through the beta-NRX1-CBLN1-GRID2 triad complex. Tetramer; dimer of dimers (By similarity). Interacts with AP4M1 (PubMed:14572453). Interacts with EML2 (PubMed:11829466). Interacts with MAGI2 (via PDZ domains) (PubMed:12589829). Interacts with BECN1, GOPC, GRID2IP, SHANK1 and SHANK2. Interacts with CBLN2, but not with CBLN4 (By similarity). Interacts with CBLN1 (via C1q domain); the interaction is CBLN1-NRX1 complex formation-dependent; CBLN1-binding is calcium-independent; CBLN1 hexamers anchor GRID2 N-terminal domain dimers to monomeric NRXN1 isoform beta; promotes synaptogenesis and mediates the D-Serine-dependent long term depression signals and AMPA receptor endocytosis (By similarity). Expressed at high levels in the cerebellar Purkinje cell layer, almost absent in the forebrain. The PDZ-binding motif mediates interaction with GOPC. Belongs to the glutamate-gated ion channel (TC 1.A.10.1) family. GRID2 subfamily.