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Choudhary AK, Singh S, Khatri N, Gupta R. Hydrogen sulphide: an emerging regulator of plant defence signalling. PLANT BIOLOGY (STUTTGART, GERMANY) 2022; 24:532-539. [PMID: 34904345 DOI: 10.1111/plb.13376] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2021] [Accepted: 11/21/2021] [Indexed: 06/14/2023]
Abstract
Hydrogen sulphide (H2 S), a gaseous signalling molecule in plants, has gained considerable attention in recent years because of its emerging roles in the regulation of plant growth and development and responses to abiotic stressors. Although the involvement of H2 S in biotic stress is not well documented in the literature, a growing body of evidence indicates its potential role in plant defence, particularly against bacterial and fungal pathogens. Recent reports have suggested that H2 S participates in plant defence signalling potentially by (1) regulating glutathione metabolism, (2) inducing expression of pathogenesis-related (PR) and other defence-related genes, (3) modulating enzyme activity through post-translational modifications, and (4) interacting with phytohormones such as jasmonic acid, ethylene and auxin. In this review, we discuss the biosynthesis, metabolism and interaction of H2 S with phytohormones, and highlight evidence gathered so far to support the emerging roles of H2 S in plant defence against invading pathogens.
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Affiliation(s)
- A K Choudhary
- Department of Botany, University of Delhi, New Delhi, India
| | - S Singh
- Department of Biotechnology, TERI School of Advanced Studies, Vasant Kunj, New Delhi, India
| | - N Khatri
- Department of Botany, Dyal Singh College, New Delhi, India
| | - R Gupta
- College of General Education, Kookmin University, Seoul, South Korea
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Benoni R, Beck CM, Garza-Sánchez F, Bettati S, Mozzarelli A, Hayes CS, Campanini B. Activation of an anti-bacterial toxin by the biosynthetic enzyme CysK: mechanism of binding, interaction specificity and competition with cysteine synthase. Sci Rep 2017; 7:8817. [PMID: 28821763 PMCID: PMC5562914 DOI: 10.1038/s41598-017-09022-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2017] [Accepted: 07/20/2017] [Indexed: 12/20/2022] Open
Abstract
Contact-dependent growth inhibition (CDI) is a wide-spread mechanism of inter-bacterial competition. CDI+ bacteria deliver CdiA-CT toxins into neighboring bacteria and produce specific immunity proteins that protect against self-intoxication. The CdiA-CT toxin from uropathogenic Escherichia coli 536 is a latent tRNase that is only active when bound to the cysteine biosynthetic enzyme CysK. Remarkably, the CysK:CdiA-CT binding interaction mimics the ‘cysteine synthase’ complex of CysK:CysE. The C-terminal tails of CysE and CdiA-CT each insert into the CysK active-site cleft to anchor the respective complexes. The dissociation constant for CysK:CdiA-CT (Kd ~ 11 nM) is comparable to that of the E. coli cysteine synthase complex (Kd ~ 6 nM), and both complexes bind through a two-step mechanism with a slow isomerization phase after the initial encounter. However, the second-order rate constant for CysK:CdiA-CT binding is two orders of magnitude slower than that of the cysteine synthase complex, suggesting that CysE should outcompete the toxin for CysK occupancy. However, we find that CdiA-CT can effectively displace CysE from pre-formed cysteine synthase complexes, enabling toxin activation even in the presence of excess competing CysE. This adventitious binding, coupled with the very slow rate of CysK:CdiA-CT dissociation, ensures robust nuclease activity in target bacteria.
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Affiliation(s)
- Roberto Benoni
- Dipartimento di Medicina e Chirurgia, Università di Parma, Parma, Italy.,Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Praha, Czech Republic
| | - Christina M Beck
- Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, Santa Barbara, CA, USA.,Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Fernando Garza-Sánchez
- Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, Santa Barbara, CA, USA
| | - Stefano Bettati
- Dipartimento di Medicina e Chirurgia, Università di Parma, Parma, Italy.,Istituto Nazionale Biostrutture e Biosistemi, Rome, Italy
| | - Andrea Mozzarelli
- Istituto Nazionale Biostrutture e Biosistemi, Rome, Italy.,Dipartimento di Scienze degli Alimenti e del Farmaco, Università di Parma, Parma, Italy
| | - Christopher S Hayes
- Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, Santa Barbara, CA, USA. .,Biomolecular Science and Engineering Program, University of California, Santa Barbara, Santa Barbara, CA, USA.
| | - Barbara Campanini
- Dipartimento di Scienze degli Alimenti e del Farmaco, Università di Parma, Parma, Italy.
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Physiological Implications of Hydrogen Sulfide in Plants: Pleasant Exploration behind Its Unpleasant Odour. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2015; 2015:397502. [PMID: 26078806 PMCID: PMC4442293 DOI: 10.1155/2015/397502] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/27/2014] [Accepted: 02/16/2015] [Indexed: 11/20/2022]
Abstract
Recently, overwhelming evidence has proven that hydrogen sulfide (H2S), which was identified as a gasotransmitter in animals, plays important roles in diverse physiological processes in plants as well. With the discovery and systematic classification of the enzymes producing H2S in vivo, a better understanding of the mechanisms by which H2S influences plant responses to various stimuli was reached. There are many functions of H2S, including the modulation of defense responses and plant growth and development, as well as the regulation of senescence and maturation. Additionally, mounting evidence indicates that H2S signaling interacts with plant hormones, hydrogen peroxide, nitric oxide, carbon monoxide, and other molecules in signaling pathways.
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Controlling reaction specificity in pyridoxal phosphate enzymes. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2011; 1814:1407-18. [PMID: 21664990 DOI: 10.1016/j.bbapap.2011.05.019] [Citation(s) in RCA: 125] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2011] [Revised: 05/18/2011] [Accepted: 05/25/2011] [Indexed: 11/20/2022]
Abstract
Pyridoxal 5'-phosphate enzymes are ubiquitous in the nitrogen metabolism of all organisms. They catalyze a wide variety of reactions including racemization, transamination, decarboxylation, elimination, retro-aldol cleavage, Claisen condensation, and others on substrates containing an amino group, most commonly α-amino acids. The wide variety of reactions catalyzed by PLP enzymes is enabled by the ability of the covalent aldimine intermediate formed between substrate and PLP to stabilize carbanionic intermediates at Cα of the substrate. This review attempts to summarize the mechanisms by which reaction specificity can be achieved in PLP enzymes by focusing on three aspects of these reactions: stereoelectronic effects, protonation state of the external aldimine intermediate, and interaction of the carbanionic intermediate with the protein side chains present in the active site. This article is part of a Special Issue entitled: Pyridoxal Phosphate Enzymology.
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Campanini B, Speroni F, Salsi E, Cook PF, Roderick SL, Huang B, Bettati S, Mozzarelli A. Interaction of serine acetyltransferase with O-acetylserine sulfhydrylase active site: evidence from fluorescence spectroscopy. Protein Sci 2005; 14:2115-24. [PMID: 15987896 PMCID: PMC2279323 DOI: 10.1110/ps.051492805] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2005] [Revised: 05/09/2005] [Accepted: 05/09/2005] [Indexed: 10/25/2022]
Abstract
Serine acetyltransferase is a key enzyme in the sulfur assimilation pathway of bacteria and plants, and is known to form a bienzyme complex with O-acetylserine sulfhydrylase, the last enzyme in the cysteine biosynthetic pathway. The biological function of the complex and the mechanism of reciprocal regulation of the constituent enzymes are still poorly understood. In this work the effect of complex formation on the O-acetylserine sulfhydrylase active site has been investigated exploiting the fluorescence properties of pyridoxal 5'-phosphate, which are sensitive to the cofactor microenvironment and to conformational changes within the protein matrix. The results indicate that both serine acetyltransferase and its C-terminal decapeptide bind to the alpha-carboxyl subsite of O-acetylserine sulfhydrylase, triggering a transition from an open to a closed conformation. This finding suggests that serine acetyltransferase can inhibit O-acetylserine sulfhydrylase catalytic activity with a double mechanism, the competition with O-acetylserine for binding to the enzyme active site and the stabilization of a closed conformation that is less accessible to the natural substrate.
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Affiliation(s)
- Barbara Campanini
- Department of Biochemistry and Molecular Biology, Univeristy of Parma, 43100 Parma, Italy
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