Ionotropic glutamate receptor. L-glutamate acts as an excitatory neurotransmitter at many synapses in the central nervous system. Binding of the excitatory neurotransmitter L-glutamate induces a conformation change, leading to the opening of the cation channel, and thereby converts the chemical signal to an electrical impulse. The receptor then desensitizes rapidly and enters a transient inactive state, characterized by the presence of bound agonist. In the presence of CACNG4 or CACNG7 or CACNG8, shows resensitization which is characterized by a delayed accumulation of current flux upon continued application of glutamate. Homotetramer or heterotetramer of pore-forming glutamate receptor subunits (By similarity). Tetramers may be formed by the dimerization of dimers (By similarity). Found in a complex with GRIA2, GRIA3, GRIA4, CNIH2, CNIH3, CACNG2, CACNG3, CACNG4, CACNG5, CACNG7 and CACNG8 (By similarity). Interacts with HIP1 and RASGRF2 (PubMed:12839988, PubMed:16407208). Interacts with SYNDIG1 and GRIA2 (PubMed:20152115). Interacts with DLG1 (via C-terminus). Interacts with LRFN1. Interacts with PRKG2. Interacts with CNIH2 and CACNG2. Interacts with CACNG5. Interacts (via C-terminus) with PDLIM4 (via LIM domain); this interaction as well as the interaction of PDLIM4 with alpha-actinin is required for their colocalization in early endosomes. Found in a complex with GRIA2, GRIA3, GRIA4, CNIH2, CNIH3, CACNG2, CACNG3, CACNG4, CACNG5, CACNG7 and CACNG8 (By similarity). Interacts with SNX27 (via PDZ domain); the interaction is required for recycling to the plasma membrane when endocytosed and prevent degradation in lysosomes (PubMed:23524343). Interacts (via PDZ-binding motif) with SHANK3 (via PDZ domain) (PubMed:16606358). Interacts with CACNG3; associates GRIA1 with the adapter protein complex 4 (AP-4) to target GRIA1 to the somatodendritic compartment of neurons (PubMed:18341993). Interaction with CACNG2, CNIH2 and CNIH3 promotes cell surface expression. Colocalizes with PDLIM4 in early endosomes. Displays a somatodendritic localization and is excluded from axons in neurons (PubMed:18341993). Localized to cone photoreceptor pedicles (PubMed:28334377). Expressed in the outer plexiform layer of the retina of the eye (at protein level) (PubMed:28334377). Expressed in the forebrain and hippocampus (at protein level) (PubMed:31651360). The M4 transmembrane segment mediates tetramerization and is required for cell surface expression. Palmitoylated. Depalmitoylated upon glutamate stimulation. ZDHHC3/GODZ specifically palmitoylates Cys-603, which leads to Golgi retention and decreased cell surface expression. In contrast, Cys-829 palmitoylation does not affect cell surface expression but regulates stimulation-dependent endocytosis. Phosphorylated at Ser-645. Phosphorylated at Ser-710 by PKC. Phosphorylated at Ser-849 by PKC, PKA and CAMK2. Phosphorylated at Ser-863 by PKC, PKA and PRKG2 (By similarity). Phosphorylation of Ser-863 is reduced by induction of long-term depression and increased by induction of long-term potentiation (PubMed:23676497). The postsynaptic actions of Glu are mediated by a variety of receptors that are named according to their selective agonists. This receptor binds AMPA (quisqualate) > glutamate > kainate. Belongs to the glutamate-gated ion channel (TC 1.A.10.1) family. GRIA1 subfamily.