Measurement of Conformational Changes accompanying Desensitization in an Ionotropic Glutamate Receptor.Armstrong, N., Jasti, J., Beich-Frandsen, M., Gouaux, E.
(2006) Cell 127: 85-97
- PubMed: 17018279
- DOI: 10.1016/j.cell.2006.08.037
- Primary Citation of Related Structures:
- PubMed Abstract:
- Probing the ligand binding domain of the GluR2 receptor by proteolysis and deletion mutagenesis defines
domain boundaries and yields a crystallizable construct
Chen, G.Q., Sun, Y., Jin, R., Gouaux, E.
(1998) Protein Sci 7: 2623
The canonical conformational states occupied by most ligand-gated ion channels, and many cell-surface receptors, are the resting, activated, and desensitized states. While the resting and activated states of multiple receptors are well characterized, ...
The canonical conformational states occupied by most ligand-gated ion channels, and many cell-surface receptors, are the resting, activated, and desensitized states. While the resting and activated states of multiple receptors are well characterized, elaboration of the structural properties of the desensitized state, a state that is by definition inactive, has proven difficult. Here we use electrical, chemical, and crystallographic experiments on the AMPA-sensitive GluR2 receptor, defining the conformational rearrangements of the agonist binding cores that occur upon desensitization of this ligand-gated ion channel. These studies demonstrate that desensitization involves the rupture of an extensive interface between domain 1 of 2-fold related glutamate-binding core subunits, compensating for the ca. 21 degrees of domain closure induced by glutamate binding. The rupture of the domain 1 interface allows the ion channel to close and thereby provides a simple explanation to the long-standing question of how agonist binding is decoupled from ion channel gating upon receptor desensitization.
Department of Biochemistry and Molecular Biophysics, Columbia University, 650 West 168th Street, New York, NY 10032 USA.