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Author

Romy Greiner

Bio: Romy Greiner is an academic researcher from German Cancer Research Center. The author has contributed to research in topics: Hydrogen sulfide & Sulfide. The author has an hindex of 3, co-authored 4 publications receiving 411 citations.
Topics: Hydrogen sulfide, Sulfide, Sulfur, Phosphatase, PTEN

Papers
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Journal ArticleDOI
TL;DR: This study suggests that the effects that have been attributed to H2S in previous reports may in fact have been mediated by polysulfides, and supports the notion that sulfane sulfur rather than sulfide is the actual in vivo agent of H 2S signaling.
Abstract: Aims: Hydrogen sulfide (H2S) is suggested to act as a gaseous signaling molecule in a variety of physiological processes. Its molecular mechanism of action was proposed to involve protein S-sulfhydration, that is, conversion of cysteinyl thiolates (Cys-S−) to persulfides (Cys-S-S−). A central and unresolved question is how H2S—that is, a molecule with sulfur in its lowest possible oxidation state (−2)—can lead to oxidative thiol modifications. Results: Using the lipid phosphatase PTEN as a model protein, we find that the “H2S donor” sodium hydrosulfide (NaHS) leads to very rapid reversible oxidation of the enzyme in vitro. We identify polysulfides formed in NaHS solutions as the oxidizing species, and present evidence that sulfane sulfur is added to the active site cysteine. Polysulfide-mediated oxidation of PTEN was induced by all “H2S donors” tested, including sodium sulfide (Na2S), gaseous H2S, and morpholin-4-ium 4-methoxyphenyl(morpholino) phosphinodithioate (GYY4137). Moreover, we show that...

385 citations

Journal ArticleDOI
TL;DR: It is shown that the protein tyrosine phosphatases PTP1B and the dual‐specificity phosphatase PTEN are preferentially reactivated by the thioredoxin system, and that inducible depletion of thiOREDoxin 1(TRX1) slows PTEN reactivation in intact living cells.
Abstract: The transient inactivation of protein phosphatases contributes to the efficiency and temporal control of kinase-dependent signal transduction. In particular, members of the protein tyrosine phosphatase family are known to undergo reversible oxidation of their active site cysteine. The thiol oxidation step requires activation of colocalized NADPH oxidases and is mediated by locally produced reactive oxygen species, in particular H2O2. How oxidized phosphatases are returned to the reduced active state is less well studied. Both major thiol reductive systems, the thioredoxin and the glutathione systems, have been implicated in the reactivation of phosphatases. Here, we show that the protein tyrosine phosphatase PTP1B and the dual-specificity phosphatase PTEN are preferentially reactivated by the thioredoxin system. We show that inducible depletion of thioredoxin 1(TRX1) slows PTEN reactivation in intact living cells. Finally, using a mechanism-based trapping approach, we demonstrate direct thiol disulphide exchange between the active sites of thioredoxin and either phosphatase. The application of thioredoxin trapping mutants represents a complementary approach to direct assays of PTP oxidation in elucidating the significance of redox regulation of PTP function in the control of cell signaling. Structured digital abstract TRX1 physically interacts with PTP1B by anti tag coimmunoprecipitation (1, 2)

92 citations

Book ChapterDOI
TL;DR: In vitro assays for the real-time monitoring of thiol redox states in two model proteins with oxidizable cysteines, PTEN, and roGFP2 are detailed and the role of intermediary sulfane sulfur species in H2S-induced protein thiol oxidation is revealed.
Abstract: Hydrogen sulfide (H2S) is known to induce persulfidation of protein thiols. However, the process of H2S-induced persulfidation is not fully understood as it requires an additional oxidant. There are several mechanistic possibilities and it is of interest to determine which pathway is kinetically most relevant. Here, we detail in vitro assays for the real-time monitoring of thiol redox states in two model proteins with oxidizable cysteines, PTEN, and roGFP2. These allow kinetic measurements of the response of defined protein thiols (or disulfides) to sulfide and sulfane sulfur species. The combination of these assays with cold cyanolysis reveals the role of intermediary sulfane sulfur species in H2S-induced protein thiol oxidation.

11 citations

Journal ArticleDOI
TL;DR: It is proposed that the different sulfide pools are dynamically regulated in vivo, which is an essential determining factor in the regulation of endogenous-sulfide-mediated biological functions and in avoiding sulfide-related toxic events.

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Journal ArticleDOI
TL;DR: Access to this growing chemical toolbox of new molecular probes for H2S and related RSS sets the stage for applying these developing technologies to probe reactive sulfur biology in living systems.
Abstract: Hydrogen sulfide (H2S), a gaseous species produced by both bacteria and higher eukaryotic organisms, including mammalian vertebrates, has attracted attention in recent years for its contributions to human health and disease. H2S has been proposed as a cytoprotectant and gasotransmitter in many tissue types, including mediating vascular tone in blood vessels as well as neuromodulation in the brain. The molecular mechanisms dictating how H2S affects cellular signaling and other physiological events remain insufficiently understood. Furthermore, the involvement of H2S in metal-binding interactions and formation of related RSS such as sulfane sulfur may contribute to other distinct signaling pathways. Owing to its widespread biological roles and unique chemical properties, H2S is an appealing target for chemical biology approaches to elucidate its production, trafficking, and downstream function. In this context, reaction-based fluorescent probes offer a versatile set of screening tools to visualize H2S pools in living systems. Three main strategies used in molecular probe development for H2S detection include azide and nitro group reduction, nucleophilic attack, and CuS precipitation. Each of these approaches exploits the strong nucleophilicity and reducing potency of H2S to achieve selectivity over other biothiols. In addition, a variety of methods have been developed for the detection of other reactive sulfur species (RSS), including sulfite and bisulfite, as well as sulfane sulfur species and related modifications such as S-nitrosothiols. Access to this growing chemical toolbox of new molecular probes for H2S and related RSS sets the stage for applying these developing technologies to probe reactive sulfur biology in living systems.

831 citations

Journal ArticleDOI
TL;DR: It is proposed that reactive Cys persulfides and S-polythiolation have critical regulatory functions in redox cell signaling and H2S may act primarily as a marker for the biologically active of persulfide species.
Abstract: Using methodology developed herein, it is found that reactive persulfides and polysulfides are formed endogenously from both small molecule species and proteins in high amounts in mammalian cells and tissues. These reactive sulfur species were biosynthesized by two major sulfurtransferases: cystathionine β-synthase and cystathionine γ-lyase. Quantitation of these species indicates that high concentrations of glutathione persulfide (perhydropersulfide >100 μM) and other cysteine persulfide and polysulfide derivatives in peptides/proteins were endogenously produced and maintained in the plasma, cells, and tissues of mammals (rodent and human). It is expected that persulfides are especially nucleophilic and reducing. This view was found to be the case, because they quickly react with H2O2 and a recently described biologically generated electrophile 8-nitroguanosine 3′,5′-cyclic monophosphate. These results indicate that persulfides are potentially important signaling/effector species, and because H2S can be generated from persulfide degradation, much of the reported biological activity associated with H2S may actually be that of persulfides. That is, H2S may act primarily as a marker for the biologically active of persulfide species.

688 citations

Journal ArticleDOI
TL;DR: The biologically relevant chemistry of H2S and the enzymatic routes for its production and oxidation are discussed and the roles ascribed to protein persulfidation in cell signaling pathways are discussed.
Abstract: Signaling by H2S is proposed to occur via persulfidation, a posttranslational modification of cysteine residues (RSH) to persulfides (RSSH). Persulfidation provides a framework for understanding the physiological and pharmacological effects of H2S. Due to the inherent instability of persulfides, their chemistry is understudied. In this review, we discuss the biologically relevant chemistry of H2S and the enzymatic routes for its production and oxidation. We cover the chemical biology of persulfides and the chemical probes for detecting them. We conclude by discussing the roles ascribed to protein persulfidation in cell signaling pathways.

590 citations

Journal ArticleDOI
TL;DR: It is posited that sulfide oxidation pathways mediate sulfide signaling and that sulfurtransferases ensure target specificity and that sulfides, polysulfides and thiosulfate generate a series of reactive sulfur species that could modify target proteins.
Abstract: Sulfide signaling is biologically important, but the identity and source of reactive sulfur species (RSS) remains unclear. An analysis of sulfur reactivity now suggests that oxidation pathways thought to dispose of sulfur may actually create RSS. The chemical species involved in H2S signaling remain elusive despite the profound and pleiotropic physiological effects elicited by this molecule. The dominant candidate mechanism for sulfide signaling is persulfidation of target proteins. However, the relatively poor reactivity of H2S toward oxidized thiols, such as disulfides, the low concentration of disulfides in the reducing milieu of the cell and the low steady-state concentration of H2S raise questions about the plausibility of persulfide formation via reaction between an oxidized thiol and a sulfide anion or a reduced thiol and oxidized hydrogen disulfide. In contrast, sulfide oxidation pathways, considered to be primarily mechanisms for disposing of excess sulfide, generate a series of reactive sulfur species, including persulfides, polysulfides and thiosulfate, that could modify target proteins. We posit that sulfide oxidation pathways mediate sulfide signaling and that sulfurtransferases ensure target specificity.

452 citations

Journal ArticleDOI
TL;DR: This feature article addresses the synthesis and design strategies for the development of fluorescent probes for H2S based on the reaction type between H2 S and the probes, and highlights fluorescent probe for other reactive sulfur species, such as sulfane sulfurs and SO2 derivatives.

368 citations