Merck, MAB397, Anti-Glutamate Receptor 2 Antibody, extracellular, clone 6C4

Glutamate receptors (GluRs) can be categorized as ionotropic or metabotropic and subcatergorized by their agonist preferences (NMDA, AMPA or Kainic acid). There are four types of AMPA selective GluR subunits (GluR1, GluR2, GluR3 and GluR4). Tetrameric or pentameric combinations of different subunits contributes to the functional diversity of AMPA receptors. In general, AMPA receptors mediate fast synaptic current at most excitatory synapses, with stoichiometry characterized by subtype composition. Although subunit composition of AMPA receptors varies, they must contain at least one edited GluR2 subunit to be calcium impermeable. The critical residue controlling calcium permeability is in the pore loop region. In GluR1, GluR3, and GluR4, this positionis occupied by a Gln residue. In GluR2, it is occupied by an Arg residue. It has been shown experimentally that the presence of Arg in this position blocks CA2+ ion permeability, while a Gln does not. Relative calcium permeability in AMPA receptor channels may be significant in pathological neurotoxic damage and long term changes in nervous system responses.