glutamate receptor 3; GluR-3; GluR-C; GluR-K3; glutamate receptor ionotropic, AMPA 3; AMPA-selective glutamate receptor 3 (GRIA3, GLUR3, GLURC)

Function: - ionotropic glutamate receptor - binding of the excitatory neurotransmitter L-glutamate induces a conformation change, leading to the opening of the cation channel, & thereby converts the chemical signal to an electrical impulse - the receptor then desensitizes rapidly & enters a transient inactive state, characterized by the presence of bound agonist - palmitoylated a) depalmitoylated upon glutamate stimulation b) Cys-621 palmitoylation leads to Golgi retention & decreased cell surface expression c) in contrast, Cys-847 palmitoylation does not affect cell surface expression but regulates stimulation- dependent endocytosis (putative) - interacts with PRKCABP, GRIP1 & GRIP2 (putative) - binds to PDZ domain of GRIP1 via C-terminal SVKI motif - receptor binds AMPA (quisqualate) > glutamate > kainate Structure: - homotetramer or heterotetramer of pore-forming glutamate receptor subunits - tetramers may be formed by the dimerization of dimers - belongs to the glutamate-gated ion channel (TC 1.A.10) family Compartment: - cell membrane - cell junction, synapse, postsynaptic cell membrane Alternative splicing: named isoforms=2 Pathology: - defects in GRIA3 are the cause of mental retardation X-linked type 94 Note: uncertain whether Met-1 or Met-7 is initiator

General

glycoprotein ionotropic receptor subunit phosphoprotein

Properties

SIZE: entity length = 894 aa MW = 101 kD COMPARTMENT: plasma membrane MOTIF: exoplasmic domain {1-552} MOTIF: signal sequence {1-28} N-glycosylation site {N63} N-glycosylation site {N266} N-glycosylation site {N380} N-glycosylation site {N415} N-glycosylation site {N422} Glutamate binding {508-510} binding site SITE: 515-515 FOR-BINDING-OF: Glutamate transmembrane domain {553-573} cytoplasmic loop {574-635} MOTIF: cysteine residue {C621} MODIFICATION: palmitate COMPARTMENT: membrane transmembrane domain {636-656} exoplasmic loop {657-823} MOTIF: Glutamate binding {686-687} binding site SITE: 737-737 FOR-BINDING-OF: Glutamate transmembrane domain {824-844} cytoplasmic domain {845-894} MOTIF: cysteine residue {C847} MODIFICATION: palmitate COMPARTMENT: membrane Tyr phosphorylation site {Y877} Tyr phosphorylation site {Y887}

Database Correlations

OMIM correlations UniProt P42263 PFAM correlations Entrez Gene 2892

References

UniProt :accession P42263