Moykkynen, T., Coleman, S.K., Semenov, A. and Keinänen, K. 2014. The N-terminal domain modulates α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor desensitization. Journal of Biological Chemistry. 289 (19), pp. 13197-13205. https://doi.org/10.1074/jbc.M113.526301
| Title | The N-terminal domain modulates α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor desensitization |
|---|---|
| Authors | Moykkynen, T., Coleman, S.K., Semenov, A. and Keinänen, K. |
| Abstract | AMPA receptors are tetrameric glutamate-gated ion channels that mediate fast synaptic neurotransmission in mammalian brain. Their subunits contain a two-lobed N-terminal domain (NTD) that comprises over 40% of the mature polypeptide. The NTD is not obligatory for the assembly of tetrameric receptors, and its functional role is still unclear. By analyzing full-length and NTD-deleted GluA1-4 AMPA receptors expressed in HEK 293 cells, we found that the removal of the NTD leads to a significant reduction in receptor transport to the plasma membrane, a higher steady state-to-peak current ratio of glutamate responses, and strongly increased sensitivity to glutamate toxicity in cell culture. Further analyses showed that NTD-deleted receptors display both a slower onset of desensitization and a faster recovery from desensitization of agonist responses. Our results indicate that the NTD promotes the biosynthetic maturation of AMPA receptors and, for membrane-expressed channels, enhances the stability of the desensitized state. Moreover, these findings suggest that interactions of the NTD with extracellular/synaptic ligands may be able to fine-tune AMPA receptor-mediated responses, in analogy with the allosteric regulatory role demonstrated for the NTD of NMDA receptors. |
| Keywords | Allosteric Regulation; Ion Channels; Ionotropic Glutamate Receptors (AMPA, NMDA); Protein Domains; Receptor Desensitization; Receptor Structure-Function |
| Journal | Journal of Biological Chemistry |
| Journal citation | 289 (19), pp. 13197-13205 |
| ISSN | 1083-351X |
| Year | 2014 |
| Publisher | American Society for Biochemistry and Molecular Biology |
| Digital Object Identifier (DOI) | https://doi.org/10.1074/jbc.M113.526301 |
| Web address (URL) | http://www.jbc.org/content/289/19/13197.long |
| Publication dates | |
| Published | 20 Mar 2014 |