GRIA2/GRIA3

The glutamate ion receptor AMPA type 2 subunit (ion glutamate receptor 2) is a protein encoded by the GRIA2 (or GLUR2) gene in humans.
Glutamate receptors are the main excitatory neurotransmitter receptors in the mammalian brain and are activated in a variety of normal neurophysiological processes. The gene product belongs to the glutamate receptor family, which is sensitive to propionic acid α-amino-3-hydroxy-5-methyl-4-isoxazole propionate (AMPA) and serves as a ligand-activated cation channel. These channels are assembled from 4 related subunits GRIA1-4. The subunit (GRIA2) encoded by this gene is RNA-edited in the second transmembrane domain (CAG->CGG; Q->R), which is considered to make the Ca(2+) channel impermeable. Human and animal studies have shown that pre-mRNA editing is essential for brain function, and that GRIA2 RNA editing defects at the Q/R site may be related to the cause of amyotrophic lateral sclerosis (ALS). It has been noted that alternative splicing of this gene results in transcript variants encoding different isoforms, including the generation of flips and flip isoforms with different signal transduction properties.