Human Gene GRIA3 (uc004etr.4) Description and Page Index
Description: Homo sapiens glutamate receptor, ionotropic, AMPA 3 (GRIA3), transcript variant 2, mRNA. RefSeq Summary (NM_000828): Glutamate receptors are the predominant excitatory neurotransmitter receptors in the mammalian brain and are activated in a variety of normal neurophysiologic processes. These receptors are heteromeric protein complexes composed of multiple subunits, arranged to form ligand-gated ion channels. The classification of glutamate receptors is based on their activation by different pharmacologic agonists. The subunit encoded by this gene belongs to a family of AMPA (alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionate)-sensitive glutamate receptors, and is subject to RNA editing (AGA->GGA; R->G). Alternative splicing at this locus results in different isoforms, which may vary in their signal transduction properties. [provided by RefSeq, Jul 2008]. Transcript (Including UTRs) Position: hg19 chrX:122,318,096-122,624,766 Size: 306,671 Total Exon Count: 16 Strand: + Coding Region Position: hg19 chrX:122,318,388-122,616,895 Size: 298,508 Coding Exon Count: 15
ID:GRIA3_HUMAN DESCRIPTION: RecName: Full=Glutamate receptor 3; Short=GluR-3; AltName: Full=AMPA-selective glutamate receptor 3; AltName: Full=GluR-C; AltName: Full=GluR-K3; AltName: Full=Glutamate receptor ionotropic, AMPA 3; Short=GluA3; Flags: Precursor; FUNCTION: Receptor for glutamate that functions as ligand-gated ion channel in the central nervous system and plays an important role in excitatory synaptic transmission. 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. SUBUNIT: Homotetramer or heterotetramer of pore-forming glutamate receptor subunits. Tetramers may be formed by the dimerization of dimers. Interacts with PRKCABP, GRIP1 and GRIP2 (By similarity). Found in a complex with GRIA1, GRIA2, GRIA4, CNIH2, CNIH3, CACNG2, CACNG3, CACNG4, CACNG5, CACNG7 and CACNG8. Interacts with CACNG5 (By similarity). SUBCELLULAR LOCATION: Cell membrane; Multi-pass membrane protein. Cell junction, synapse, postsynaptic cell membrane; Multi-pass membrane protein. Note=Interaction with CNIH2 and CNIH3 promotes cell surface expression (By similarity). PTM: Palmitoylated. Depalmitoylated upon glutamate stimulation. Cys-621 palmitoylation leads to Golgi retention and decreased cell surface expression. In contrast, Cys-847 palmitoylation does not affect cell surface expression but regulates stimulation-dependent endocytosis (By similarity). DISEASE: Defects in GRIA3 are the cause of mental retardation X- linked type 94 (MRX94) [MIM:300699]. Mental retardation is characterized by significantly sub-average general intellectual functioning associated with impairments in adaptative behavior and manifested during the developmental period. MRX94 patients have moderate mental retardation. Other variable features are macrocephaly, seizures, myoclonic jerks, autistic behavior, asthenic body habitus, distal muscle weakness and hyporeflexia. MISCELLANEOUS: 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. SIMILARITY: Belongs to the glutamate-gated ion channel (TC 1.A.10.1) family. GRIA3 subfamily. CAUTION: It is uncertain whether Met-1 or Met-7 is the initiator.
Genetic Association Studies of Complex Diseases and Disorders
The RNAfold program from the Vienna RNA Package is used to perform the secondary structure predictions and folding calculations. The estimated folding energy is in kcal/mol. The more negative the energy, the more secondary structure the RNA is likely to have.
Pfam Domains: PF00060 - Ligand-gated ion channel PF00497 - Bacterial extracellular solute-binding proteins, family 3 PF01094 - Receptor family ligand binding region PF10613 - Ligated ion channel L-glutamate- and glycine-binding site
SCOP Domains: 53822 - Periplasmic binding protein-like I 53850 - Periplasmic binding protein-like II
ModBase Predicted Comparative 3D Structure on P42263
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Orthologous Genes in Other Species
Orthologies between human, mouse, and rat are computed by taking the best BLASTP hit, and filtering out non-syntenic hits. For more distant species reciprocal-best BLASTP hits are used. Note that the absence of an ortholog in the table below may reflect incomplete annotations in the other species rather than a true absence of the orthologous gene.