S-Glutathionylation of Ion Channels: Insights into the Regulation of Channel Functions, Thiol Modification Crosstalk, and Mechanosensing

Significance: Ion channels control membrane potential, cellular excitability, and Ca++ signaling, all of which play essential roles in cellular functions. The regulation of ion channels enables cells to respond to changing environments, and post-translational modification (PTM) is one major regulation mechanism. Recent Advances: Many PTMs (e.g., S-glutathionylation, S-nitrosylation, S-palmitoylation, S-sulfhydration, etc.) targeting the thiol group of cysteine residues have emerged to be essential for ion channels regulation under physiological and pathological conditions. Critical Issues: Under oxidative stress, S-glutathionylation could be a critical PTM that regulates many molecules. In this review, we discuss S-glutathionylation-mediated structural and functional changes of ion channels. Criteria for testing S-glutathionylation, methods and reagents used in ion channel S-glutathionylation studies, and thiol modification crosstalk, are also covered. Mechanotransduction, and S-glutathionylation of the mechanosensitive K-ATP channel, are discussed. Future Directions: Further investigation of the ion channel S-glutathionylation, especially the physiological significance of S-glutathionylation and thiol modification crosstalk, could lead to a better understanding of the thiol modifications in general and the ramifications of such modifications on cellular functions and related diseases. Antioxid. Redox Signal. 20, 937-951.