Ligand-activated ion channels may share common gating mechanisms with the Shaker potassium channel.
This paper proposes a detailed gating mechanism for the N-methyl-D-aspartate (NMDA) channel. In the NMDAR1 subunit, the signal of agonist binding may be carried from Y456 to W590 through an electron transport chain, including W480 which could be the glycine modulatory site. The channel's opening may arise from repulsion between negatively charged W590s, analogous to W435s of the Shaker K+ channel. The cyclic nucleotide-gated channels may be activated by a similar mechanism, but the opening of nicotinic acetylcholine receptor (nAChR) channels is likely to be initiated by the formation of tyrosine radicals. The role of disulfide-bonded cysteines in the redox modulation can also be explained.
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Chemical Dynamics Corporation, Guilderland, NY 12084.
D000595:Amino Acid Sequence; D000818:Animals; D004579:Electron Transport; D015640:Ion Channel Gating; D008969:Molecular Sequence Data; D010084:Oxidation-Reduction; D015221:Potassium Channels / Q000378:metabolism*; D017470:Receptors, Glutamate / Q000378:metabolism*; D016194:Receptors, N-Methyl-D-Aspartate / Q000378:metabolism*
D015221:Potassium Channels; D017470:Receptors, Glutamate; D016194:Receptors, N-Methyl-D-Aspartate