S-Sulfhydration of ATP synthase by hydrogen sulfide stimulates mitochondrial bioenergetics

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• 作者：Katalin Mó ; dis^a ; ^b ; ^c ; YoungJun Ju^a ; Akbar Ahmad^c ; Ashley A. Untereiner^a ; ^c ; Zaid Altaany^a ; Lingyun Wu^e ; Csaba Szabo^c ; ^{szabocsaba@aol.com" class="auth_mail" title="E-mail the corresponding author} ; Rui Wang^a ; ^f ; ^{rui.wang@laurentian.ca" class="auth_mail" title="E-mail the corresponding author}
• 关键词：H2S ; Bioenergetics ; S-Sulfhydration ; Burn ; ATP synthase ; Cysteine ; Mitochondria ; Bioenergetics ; ATP synthase ; Hydrogen sulfide ; Burn injury
• 刊名：Pharmacological Research
• 出版年：2016
• 出版时间：November 2016
• 年：2016
• 卷：113
• 期：part_PA
• 页码：116-124
• 全文大小：2239 K

文摘

Mammalian cells can utilize hydrogen sulfide (H₂S) to support mitochondrial respiration. The aim of our study was to explore the potential role of S-sulfhydration (a H₂S-induced posttranslational modification, also known as S-persulfidation) of the mitochondrial inner membrane protein ATP synthase (F1F0 ATP synthase/Complex V) in the regulation of mitochondrial bioenergetics. Using a biotin switch assay, we have detected S-sulfhydration of the α subunit (ATP5A1) of ATP synthase in response to exposure to H₂S in vitro. The H₂S generator compound NaHS induced S-sulfhydration of ATP5A1 in HepG2 and HEK293 cell lysates in a concentration-dependent manner (50–300 μM). The activity of immunocaptured mitochondrial ATP synthase enzyme isolated from HepG2 and HEK293 cells was stimulated by NaHS at low concentrations (10–100 nM). Site-directed mutagenesis of ATP5A1 in HEK293 cells demonstrated that cysteine residues at positions 244 and 294 are subject to S-sulfhydration. The double mutant ATP synthase protein (C244S/C294S) showed a significantly reduced enzyme activity compared to control and the single-cysteine-mutated recombinant proteins (C244S or C294S). To determine whether endogenous H₂S plays a role in the basal S-sulfhydration of ATP synthase in vivo, we compared liver tissues harvested from wild-type mice and mice deficient in cystathionine-gamma-lyase (CSE, one of the three principal mammalian H₂S-producing enzymes). Significantly reduced S-sulfhydration of ATP5A1 was observed in liver homogenates of CSE^−/− mice, compared to wild-type mice, suggesting a physiological role for CSE-derived endogenous H₂S production in the S-sulfhydration of ATP synthase. Various forms of critical illness (including burn injury) upregulate H₂S-producing enzymes and stimulate H₂S biosynthesis. In liver tissues collected from mice subjected to burn injury, we detected an increased S-sulfhydration of ATP5A1 at the early time points post-burn. At later time points (when systemic H₂S levels decrease) S-sulfhydration of ATP5A1 decreased as well. In conclusion, H₂S induces S-sulfhydration of ATP5A1 at C244 and C294. This post-translational modification may be a physiological mechanism to maintain ATP synthase in a physiologically activated state, thereby supporting mitochondrial bioenergetics. The sulfhydration of ATP synthase may be a dynamic process, which may be regulated by endogenous H₂S levels under various pathophysiological conditions.