Forum 10/20/2005

“Structure of AMPA Subtype of Glutamate Receptors”

Teru Nakagawa – UCSD Chemistry Department

Glutamate receptors are ligand-gated ion channels that regulate the excitability of the membrane in excitatory synapses.  AMPA subtype of ionotropic glutamate receptors contribute to the majority of post synaptic excitatory currents in the brain. Furthermore, modulation of AMPA receptors are believed to be involved in the basic mechanisms of information processing in the brain such as seen in learning and memory. Compared to our knowledge on the electrophysiology and the phenotypes of the mutant mice, very little is known about the structure of the intact AMPA receptors. To fully understand the molecular mechanism of AMPA receptor signaling, it is important to study the structure of the intact tetrameric receptor channel. In our recent study, we characterized using single particle EM, the structure and conformational changes of the native AMPA receptor complexes purified from rat brain. In this talk, I will present these data and discuss about the approaches we are taking to obtain higher resolution structure of intact AMPA receptors.