S-Glutathionylation Decreases Mg super(2+) Inhibition and S-Nitrosylation Enhances Ca super(2+) Activation of RyR1 Channels

• Published in: The Journal of biological chemistry 2003-10, Vol.278 (44), p.42927-42935
• Main Authors: Aracena, P, Sanchez, G, Donoso, P, Hamilton, S L, Hidalgo, C
• Format: Article
• Language: English
• ISSN: 0021-9258; 1083-351X
• DOI: 10.1074/jbc.M306969200

We have analyzed the effects of the endogenous redoxactive agents S-nitrosoglutathione and glutathione disulfide, and the NO donor NOR-3, on calcium release kinetics mediated by ryanodine receptor channels. Incubation of triad-enriched sarcoplasmic reticulum vesicles isolated from mammalian skeletal muscle with these three agents elicits different responses. Glutathione disulfide significantly reduces the inhibitory effect of Mg super(2+) without altering Ca super(2+) activation of release kinetics, whereas NOR-3 enhances Ca super(2+) activation of release kinetics without altering Mg super(2+) inhibition. Incubation with S-nitrosoglutathione produces both effects; it significantly enhances Ca super(2+) activation of release kinetics and diminishes the inhibitory effect of Mg super(2+) on this process. Triad incubation with [ super(35)S]nitrosoglutathione at pCa 5 promoted super(35)S incorporation into 2.5 cysteine residues per channel monomer; this incorporation decreased significantly at pCa 9. These findings indicate that S-nitrosoglutathione supports S-glutathionylation as well as the reported S-nitrosylation of ryanodine receptor channels (Sun, J., Xu, L., Eu, J. P., Stamler, J. S., and Meissner, G. (2003) J. Biol. Chem. 278, 8184-8189). The combined results suggest that S-glutathionylation of specific cysteine residues can modulate channel inhibition by Mg super(2+), whereas S-nitrosylation of different cysteines can modulate the activation of the channel by Ca super(2+). Possible physiological and pathological implications of the activation of skeletal Ca super(2+) release channels by endogenous redox species are discussed.