Sulfhydration of p66Shc at cysteine59 mediates the antioxidant effect of hydrogen sulfide.
OBJECTIVE
Mitochondrion is considered as the major source of intracellular reactive oxygen species (ROS). H2S has been reported to be an antioxidant, but its mechanism remains largely elusive. P66Shc is an upstream activator of mitochondrial redox signaling. The aim of this study was to explore whether the antioxidant effect of H2S is mediated by p66Shc.


RESULTS
Application of exogenous H2S with its donor, NaHS, or overexpression of its generating enzyme, cystathionine β-synthase, induced sulfhydration of p66Shc, but inhibited its phosphorylation caused by H2O2/D-galactose in SH-SY5Y cells or in the mice cortex. H2S also decreased mitochondrial ROS production and protected neuronal cells against stress-induced senescence. PKCβII and PP2A are the two key proteins to regulate p66Shc phosphorylation. Although H2S failed to affect the activities of these two proteins, it disrupted their association. Cysteine-59 resides in proximity to serine-36, the phosphorylation site of p66Shc. The C59S mutant attenuated the above-described biological function of H2S.


METHODS
We revealed a novel mechanism for the antioxidant effect of H2S and its role in oxidative stress-related diseases.


CONCLUSIONS
H2S inhibits mitochondrial ROS production via the sulfhydration of Cys-59 residue, which in turn, prevents the phosphorylation of p66Shc.
Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore , Singapore , Singapore.
Zhi-Zhong
ZZ
Xie
Mei-Mei
MM
Shi
Li
L
Xie
Zhi-Yuan
ZY
Wu
Guang
G
Li
Fei
F
Hua
Jin-Song
JS
Bian
D000818:Animals; D000975:Antioxidants / Q000378:metabolism*; D002460:Cell Line; D003545:Cysteine / Q000378:metabolism; D006801:Humans; D006862:Hydrogen Sulfide / Q000378:metabolism / Q000494:pharmacology*; D051379:Mice; D008928:Mitochondria / Q000187:drug effects / Q000378:metabolism; D009474:Neurons / Q000187:drug effects; D018384:Oxidative Stress / Q000187:drug effects*; D017382:Reactive Oxygen Species / Q000378:metabolism; D055765:Shc Signaling Adaptor Proteins / Q000378:metabolism*; D015398:Signal Transduction; D000071425:Src Homology 2 Domain-Containing, Transforming Protein 1
D000975:Antioxidants; D017382:Reactive Oxygen Species; C528024:SHC1 protein, human; D055765:Shc Signaling Adaptor Proteins; D000071425:Src Homology 2 Domain-Containing, Transforming Protein 1; D003545:Cysteine; D006862:Hydrogen Sulfide