Signaling by hydrogen sulfide and cyanide through post-translational modification (original) (raw)

Hydrogen Sulfide Signaling in Plants: Emerging Roles of Protein Persulfidation

Frontiers in plant science, 2018

Hydrogen sulfide (HS) has been largely referred as a toxic gas and environmental hazard, but recent years, it has emerged as an important gas-signaling molecule with effects on multiple physiological processes in both animal and plant systems. The regulatory functions of HS in plants are involved in important processes such as the modulation of defense responses, plant growth and development, and the regulation of senescence and maturation. The main signaling pathway involving sulfide has been proven to be through protein persulfidation (alternatively called sulfhydration), in which the thiol group of cysteine (-SH) in proteins is modified into a persulfide group (-SSH). This modification may cause functional changes in protein activities, structures, and subcellular localizations of the target proteins. New shotgun proteomic approaches and bioinformatic analyses have revealed that persulfidated cysteines regulate important biological processes, highlighting their importance in cell...

The Modus Operandi of Hydrogen Sulfide(H2S)-Dependent Protein Persulfidation in Higher Plants

Antioxidants

Protein persulfidation is a post-translational modification (PTM) mediated by hydrogen sulfide (H2S), which affects the thiol group of cysteine residues from target proteins and can have a positive, negative or zero impact on protein function. Due to advances in proteomic techniques, the number of potential protein targets identified in higher plants, which are affected by this PTM, has increased considerably. However, its precise impact on biological function needs to be evaluated at the experimental level in purified proteins in order to identify the specific cysteine(s) residue(s) affected. It also needs to be evaluated at the cellular redox level given the potential interactions among different oxidative post-translational modifications (oxiPTMs), such as S-nitrosation, glutathionylation, sulfenylation, S-cyanylation and S-acylation, which also affect thiol groups. This review aims to provide an updated and comprehensive overview of the important physiological role exerted by pe...

Hydrogen sulfide signaling in plant adaptations to adverse conditions: molecular mechanisms

Journal of Experimental Botany, 2021

Hydrogen sulfide (H2S) is a signaling molecule that regulates critical processes and allows plants to adapt to adverse conditions. The molecular mechanism underlying H2S action relies on its chemical reactivity, and the most-well characterized mechanism is persulfidation, which involves the modification of protein thiol groups, resulting in the formation of persulfide groups. This modification causes a change of protein function, altering catalytic activity or intracellular location and inducing important physiological effects. H2S cannot react directly with thiols but instead can react with oxidized cysteine residues; therefore, H2O2 signaling through sulfenylation is required for persulfidation. A comparative study performed in this review reveals 82% identity between sulfenylome and persulfidome. With regard to abscisic acid (ABA) signaling, widespread evidence shows an interconnection between H2S and ABA in the plant response to environmental stress. Proteomic analyses have reve...

Signaling in the plant cytosol: cysteine or sulfide?

Amino acids, 2014

Cysteine (Cys) is the first organic compound containing reduced sulfur that is synthesized in the last stage of plant photosynthetic assimilation of sulfate. It is a very important metabolite not only because it is crucial for the structure, function and regulation of proteins but also because it is the precursor molecule of an enormous number of sulfur-containing metabolites essential for plant health and development. The biosynthesis of Cys is accomplished by the sequential reaction of serine acetyltransferase (SAT) and O-acetylserine(thiol)synthase (OASTL). In Arabidopsis thaliana, the analysis of specific mutants of members of the SAT and OASTL families has demonstrated that the cytosol is the compartment where the bulk of Cys synthesis takes place and that the cytosolic OASTL enzyme OAS-A1 is the responsible enzyme. Another member of the OASTL family is DES1, a novel L-cysteine desulfhydrase that catalyzes the desulfuration of Cys to produce sulfide, thus acting in a manner opp...

Hydrogen sulfide: A versatile gaseous molecule in plants

Plant Physiology and Biochemistry, 2021

Hydrogen sulfide (H 2 S) is a gasotransmitter and signaling molecule associated with seed germination, plant growth, organogenesis, photosynthesis, stomatal conductance, senescence, and post-harvesting. H 2 S is produced in plants via both enzymatic and non-enzymatic pathways in different subcellular compartments. Exogenous application of H 2 S facilitates versatile metabolic processes and antioxidant machinery in plants under normal and environmental stresses. This compound interacts with phytohormones like auxins, abscisic acid, gibberellins, ethylene, jasmonic acid, and salicylic acid. Furthermore, H 2 S participates in signal transductions of other signaling molecules like nitric oxide, carbon monoxide, calcium, methylglyoxal, and hydrogen peroxide. It also mediates post-translational modification, which is a protective mechanism against oxidative damage of proteins. This review summarizes the roles of H 2 S as intriguing molecule in plants.

Persulfidation proteome reveals the regulation of protein function by hydrogen sulfide in diverse biological processes in Arabidopsis

Journal of Experimental Botany, 2017

Hydrogen sulfide-mediated signaling pathways regulate many physiological and pathophysiological processes in mammalian and plant systems. The molecular mechanism by which hydrogen sulfide exerts its action involves the post-translational modification of cysteine residues to form a persulfidated thiol motif, a process called protein persulfidation. We have developed a comparative and quantitative proteomic analysis approach for the detection of endogenous persulfidated proteins in wild-type Arabidopsis and L-CYSTEINE DESULFHYDRASE 1 mutant leaves using the tag-switch method. The 2015 identified persulfidated proteins were isolated from plants grown under controlled conditions, and therefore, at least 5% of the entire Arabidopsis proteome may undergo persulfidation under baseline conditions. Bioinformatic analysis revealed that persulfidated cysteines participate in a wide range of biological functions, regulating important processes such as carbon metabolism, plant responses to abiotic and biotic stresses, plant growth and development, and RNA translation. Quantitative analysis in both genetic backgrounds reveals that protein persulfidation is mainly involved in primary metabolic pathways such as the tricarboxylic acid cycle, glycolysis, and the Calvin cycle, suggesting that this protein modification is a new regulatory component in these pathways.

The role of compartment-specific cysteine synthesis for sulfur homeostasis during H2S exposure in Arabidopsis

Plant & cell physiology, 2015

Sulfide is the end-product of assimilatory sulfate reduction in chloroplasts. It is then used by O-acetylserine(thiol)lyase (OAS-TL) to produce cysteine, the source of reduced sulfur in plants. While its formation in chloroplasts is essential for plant metabolism, sulfide is also a potent toxin mainly targeting respiration in mitochondria. Here, the application of sublethal concentrations of sulfide to Arabidopsis thaliana was used to by-pass assimilatory sulfate reduction, resulting in down-regulation of most genes of the pathway. The dualism of sulfide as substrate and toxin was investigated using knock-out mutants of the chloroplast-, mitochondrion- and cytosol-targeted OAS-TL isoforms. Surprisingly, growth retardation due to intoxication by sulfide was independent of the presence or absence of the three OAS-TL isoforms, indicating rapid exchange towards sulfur homoeostasis between the compartments. Cysteine, glutathione and sulfate, and less so S-sulfocysteine, were identified a...

Hydrogen Sulfide: A Novel Gaseous Molecule for Plant Adaptation to Stress

Journal of Plant Growth Regulation, 2021

Hydrogen sulfide (H 2 S) has emerged as a novel gaseous signal molecule with multifarious effects on seed germination, plant growth, development, and physiological processes. Due to its dominant role in plant stress tolerance and cross-adaptation, it is getting more attention nowadays, although it has been largely referred as toxic and environmental hazardous gas. In this review work, we are highlighting the importance of H 2 S as an essential gaseous molecule to help in signaling, metabolism, and stress tolerance in plants. Firstly, production of H 2 S from different natural and artificial sources were discussed with its transformation from sulfur (S) to sulfate (SO 4 2−) and then to sulfite (SO 3 2−). The importance of different kinds of transporters that helps to take SO 4 2− from the soil solution was presented. Mainly, these transporters are SULTRs (H + /SO 4 2− cotransporters) and multigene family encodes them. Furthermore, these SULTRs have LAST (Low affinity transport proteins), HAST (High affinity transport proteins), vacuole transporters, and plastid transporters. Since it is well known that there is strong relationship between SO 4 2− and synthesis of hydrogen sulfide or dihydrogen sulfide or sulfane in plant cells. Thus, cysteine (Cys) metabolism through which H 2 S could be generated in plant cell with the role of different enzymes has been presented. Furthermore, H 2 S in interaction with other molecules could help to mitigate biotic and abiotic stress. Based on this review work, it can be concluded that H 2 S has potential to induce cross-adaptation to biotic and abiotic stress; thus, it is recommended that it should be considered in future studies to answer the questions like what are the receptors of H 2 S in plant cell, where in plants the physiological concentration of H 2 S is high in response to multiple stress and how it induces cross-adaptation by interaction with other signal molecules.

Hydrogen Sulfide: A Robust Combatant against Abiotic Stresses in Plants

Hydrogen

Hydrogen sulfide (H2S) is predominantly considered as a gaseous transmitter or signaling molecule in plants. It has been known as a crucial player during various plant cellular and physiological processes and has been gaining unprecedented attention from researchers since decades. They regulate growth and plethora of plant developmental processes such as germination, senescence, defense, and maturation in plants. Owing to its gaseous state, they are effectively diffused towards different parts of the cell to counterbalance the antioxidant pools as well as providing sulfur to cells. H2S participates actively during abiotic stresses and enhances plant tolerance towards adverse conditions by regulation of the antioxidative defense system, oxidative stress signaling, metal transport, Na+/K+ homeostasis, etc. They also maintain H2S-Cys-cycle during abiotic stressed conditions followed by post-translational modifications of cysteine residues. Besides their role during abiotic stresses, cr...