Interaction proteomics of the AMPA receptor: towards identification of receptor sub-complexes

AMPA receptors (AMPAR) are the main ligand-gated ion channels responsible for the fast excitatory synaptic transmission in the mammalian brain. Whereas a number of proteins that interact with AMPAR are known to be involved in the trafficking and localization of the receptor and/or the regulation of receptor channel properties, the protein composition of the AMPAR supra-complexes are largely unclear. Recent interaction proteomics report the presence of up to 34 proteins as high-confidence constituents of the AMPAR. It was proposed that the inner core of the receptor complex consists of the GluA tetramer and four auxiliary proteins comprising transmembrane AMPA receptor regulatory proteins and/or cornichons. The other AMPAR interactors, present in lower amount, may form the outer shell of the AMPAR with a range in size and variability.