Publication of the Year 2006
J. Hoffmann, C. Villmann, M. Werner, and M. Hollmann (2006).
Investigation via ion pore transplantation of the putative relationship between glutamate receptors and K+ channels.
Molecular and Cellular Neuroscience 33(4): 358-370.
doi: 10.1016/j.mcn.2006.08.004
Abstract
Ionotropic glutamate receptors (GluRs) and potassium channels (K+ channels) show structural similarities in their ion pore regions, which are hairpin loops suspended between two transmembrane domains. Since both GluRs and K+ channels are modular proteins, functional modules can potentially be exchanged. We used this approach to test whether the intramolecular signal transduction mechanism that couples the gating signal to ion pore opening is conserved. We transplanted pore regions from various K+ channel subunits into GluR subtypes, and vice versa. Although the chimaeric proteins were expressed on the cell surface, only one of 45 different pore chimaeras analysed showed ion channel function: the kainate receptor subunit GluR6 carrying the pore region of the prokaryotic, glutamate-gated, K+-selective GluR0. This chimera adopted several electrophysiological properties of the donor pore upon pore transplantation. Our results suggest that, despite structural similarities, K+ channel pores cannot be gated by the GluR gating machinery, and vice versa, except for GluR0, which has a unique signal transduction mechanism.
