Molecule of the Month: AMPA Receptor
Receptors for the neurotransmitter glutamate in our brain come in several shapes and sizes.
Learning and Memory
Layers of Complexity
Exploring the Structure
This structure (PDB entry 4u5c) shows how things can go wrong. Some cone snails make a small protein toxin that they use to paralyze their prey. It binds in the middle of the glutamate-binding portion of the receptor, corrupting its action. To explore this structure in more detail, click on the image for an interactive JSmol. As you look at this structure, notice that there is a mismatch of symmetry between the different parts: the ion channel forms a typical four-fold structure, but the glutamate-binding portions are two side-by-side dimers.
Topics for Further Discussion
- Ionotropic glutamate receptors are quite flexible--as you look at these structures, notice the many different arrangements of the transmembrane domains relative to the glutamate-binding domains.
- These structures are all missing portions of the receptors, which are not observed because they are so flexible. You can use the Protein Feature View to determine which portions of the protein chain are included in the structure entries.
Related PDB-101 Resources
- Browse Drugs and the Brain
- Browse Cellular Signaling
- Chen, S., Gouaux, E. (2019) Structure and mechanism of AMPA receptor -- auxiliary protein complexes. Current Opinion in Structural Biology 54: 104-111.
- Zhu, S., Gouaux, E. (2017) Structure and symmetry inform gating principles of ionotropic glutamate receptors. Neuropharmacology 112: 11-15.
- 5weo: Twomey, E.C., Yelshanskaya, M.V., Grassucci, R.A., Frank, J., Sobolevsky, A.I. (2017) Channel opening and gating mechanism in AMPA-subtype glutamate receptors. Nature 549: 60-65.
- 5kuf: Meyerson, J.R., Chittori, S., Merk, A., Rao, P., Han, T.H., Serpe, M., Mayer, M.L., Subramaniam, S. (2016) Structural basis of kainate subtype glutamate receptor desensitization. Nature 537: 567-571.
- 4u5c: Chen, L., Durr, K.L., Gouaux, E. (2014) X-ray structures of AMPA receptor-cone snail toxin complexes illuminate activation mechanism. Science 345: 1021-1026.
- 4pe5: Karakas, E., Furukawa, H. (2014) Crystal structure of a heterotetrameric NMDA receptor ion channel. Science 344: 992-997.
- Yokoi, N., Fukata, M., Fukata, Y. (2012) Synaptic plasticity regulated by protein-protein interactions and posttranslational modifications. International Review of Cell and Molecular Biology 297:1-43.
- 3kg2: Sobolevsky, A.I., Rosconi, M.P., Gouaux, E. (2009) X-ray structure, symmetry and mechanism of an AMPA-subtype glutamate receptor. Nature 462: 745-756.
July 2019, David Goodselldoi:10.2210/rcsb_pdb/mom_2019_7