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Rachedi R, Risoul V, Foglino M, Aoudache Y, Lang K, Champ S, Kaplan E, Orelle C, Douzi B, Jault JM, Latifi A. Unravelling HetC as a peptidase-based ABC exporter driving functional cell differentiation in the cyanobacterium Nostoc PCC 7120. Microbiol Spectr 2024; 12:e0405823. [PMID: 38358282 DOI: 10.1128/spectrum.04058-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2023] [Accepted: 01/30/2024] [Indexed: 02/16/2024] Open
Abstract
The export of peptides or proteins is essential for a variety of important functions in bacteria. Among the diverse protein-translocation systems, peptidase-containing ABC transporters (PCAT) are involved in the maturation and export of quorum-sensing or antimicrobial peptides in Gram-positive bacteria and of toxins in Gram-negative organisms. In the multicellular and diazotrophic cyanobacterium Nostoc PCC 7120, the protein HetC is essential for the differentiation of functional heterocysts, which are micro-oxic and non-dividing cells specialized in atmospheric nitrogen fixation. HetC shows similarities to PCAT systems, but whether it actually acts as a peptidase-based exporter remains to be established. In this study, we show that the N-terminal part of HetC, encompassing the peptidase domain, displays a cysteine-type protease activity. The conserved catalytic residues conserved in this family of proteases are essential for the proteolytic activity of HetC and the differentiation of heterocysts. Furthermore, we show that the catalytic residue of the ATPase domain of HetC is also essential for cell differentiation. Interestingly, HetC has a cyclic nucleotide-binding domain at its N-terminus which can bind ppGpp in vitro and which is required for its function in vivo. Our results indicate that HetC is a peculiar PCAT that might be regulated by ppGpp to potentially facilitate the export of a signaling peptide essential for cell differentiation, thereby broadening the scope of PCAT role in Gram-negative bacteria.IMPORTANCEBacteria have a great capacity to adapt to various environmental and physiological conditions; it is widely accepted that their ability to produce extracellular molecules contributes greatly to their fitness. Exported molecules are used for a variety of purposes ranging from communication to adjust cellular physiology, to the production of toxins that bacteria secrete to fight for their ecological niche. They use export machineries for this purpose, the most common of which energize transport by hydrolysis of adenosine triphosphate. Here, we demonstrate that such a mechanism is involved in cell differentiation in the filamentous cyanobacterium Nostoc PCC 7120. The HetC protein belongs to the ATP-binding cassette transporter superfamily and presumably ensures the maturation of a yet unknown substrate during export. These results open interesting perspectives on cellular signaling pathways involving the export of regulatory peptides, which will broaden our knowledge of how these bacteria use two cell types to conciliate photosynthesis and nitrogen fixation.
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Affiliation(s)
- Raphaël Rachedi
- Aix-Marseille Université, CNRS, Laboratoire de Chimie Bactérienne LCB, IMM, Marseille, France
| | - Véronique Risoul
- Aix-Marseille Université, CNRS, Laboratoire de Chimie Bactérienne LCB, IMM, Marseille, France
| | - Maryline Foglino
- Aix-Marseille Université, CNRS, Laboratoire de Chimie Bactérienne LCB, IMM, Marseille, France
| | | | - Kevin Lang
- Microbiologie Moléculaire et Biochimie Structurale, UMR5086 Université de Lyon/CNRS, IBCP, Lyon, France
| | - Stéphanie Champ
- Aix-Marseille Université, CNRS, Laboratoire de Chimie Bactérienne LCB, IMM, Marseille, France
| | - Elise Kaplan
- Microbiologie Moléculaire et Biochimie Structurale, UMR5086 Université de Lyon/CNRS, IBCP, Lyon, France
| | - Cédric Orelle
- Microbiologie Moléculaire et Biochimie Structurale, UMR5086 Université de Lyon/CNRS, IBCP, Lyon, France
| | | | - Jean-Michel Jault
- Microbiologie Moléculaire et Biochimie Structurale, UMR5086 Université de Lyon/CNRS, IBCP, Lyon, France
| | - Amel Latifi
- Aix-Marseille Université, CNRS, Laboratoire de Chimie Bactérienne LCB, IMM, Marseille, France
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Sklyar J, Wilson A, Kirilovsky D, Adir N. Insights into energy quenching mechanisms and carotenoid uptake by orange carotenoid protein homologs: HCP4 and CTDH. Int J Biol Macromol 2024; 265:131028. [PMID: 38521321 DOI: 10.1016/j.ijbiomac.2024.131028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2024] [Revised: 03/09/2024] [Accepted: 03/19/2024] [Indexed: 03/25/2024]
Abstract
Photodamage to the photosynthetic apparatus by excessive light radiation has led to the evolution of a variety of energy dissipation mechanisms. A mechanism that exists in some cyanobacterial species, enables non-photochemical quenching of excitation energy within the phycobilisome (PBS) antenna complex by the Orange Carotenoid Protein (OCP). The OCP contains an active N-terminal domain (NTD) and a regulatory C-terminal domain (CTD). Some cyanobacteria also have genes encoding for homologs to both the CTD (CTDH) and the NTD (referred to as helical carotenoid proteins, HCP). The CTDH facilitates uptake of carotenoids from the thylakoid membranes to be transferred to the HCPs. Holo-HCPs exhibit diverse functionalities such as carotenoid carriers, singlet oxygen quenchers, and in the case of HCP4, constitutive OCP-like energy quenching. Here, we present the first crystal structure of the holo-HCP4 binding canthaxanthin molecule and an improved structure of the apo-CTDH from Anabaena sp. PCC 7120. We propose here models of the binding of the HCP4 to the PBS and the associated energy quenching mechanism. Our results show that the presence of the carotenoid is essential for fluorescence quenching. We also examined interactions within OCP-like species, including HCP4 and CTDH, providing the basis for mechanisms of carotenoid transfer from CTDH to HCPs.
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Affiliation(s)
- Jenia Sklyar
- Schulich Faculty of Chemistry, Technion, Haifa 3200003, Israel
| | - Adjélé Wilson
- Université Paris-Saclay, CNRS, CEA, Institute for Integrative Biology of the Cell (I2BC), 91198 Gif sur Yvette, France
| | - Diana Kirilovsky
- Université Paris-Saclay, CNRS, CEA, Institute for Integrative Biology of the Cell (I2BC), 91198 Gif sur Yvette, France.
| | - Noam Adir
- Schulich Faculty of Chemistry, Technion, Haifa 3200003, Israel.
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Sarasa-Buisan C, Ochoa de Alda JAG, Velázquez-Suárez C, Rubio MÁ, Gómez-Baena G, Fillat MF, Luque I. An ancient bacterial zinc acquisition system identified from a cyanobacterial exoproteome. PLoS Biol 2024; 22:e3002546. [PMID: 38466754 PMCID: PMC10957091 DOI: 10.1371/journal.pbio.3002546] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2023] [Revised: 03/21/2024] [Accepted: 02/12/2024] [Indexed: 03/13/2024] Open
Abstract
Bacteria have developed fine-tuned responses to cope with potential zinc limitation. The Zur protein is a key player in coordinating this response in most species. Comparative proteomics conducted on the cyanobacterium Anabaena highlighted the more abundant proteins in a zur mutant compared to the wild type. Experimental evidence showed that the exoprotein ZepA mediates zinc uptake. Genomic context of the zepA gene and protein structure prediction provided additional insights on the regulation and putative function of ZepA homologs. Phylogenetic analysis suggests that ZepA represents a primordial system for zinc acquisition that has been conserved for billions of years in a handful of species from distant bacterial lineages. Furthermore, these results show that Zur may have been one of the first regulators of the FUR family to evolve, consistent with the scarcity of zinc in the ecosystems of the Archean eon.
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Affiliation(s)
- Cristina Sarasa-Buisan
- Departamento de Bioquímica y Biología Molecular y Celular e Instituto de Biocomputación y Física de Sistemas Complejos (Bifi), Universidad de Zaragoza, Zaragoza, Spain
| | - Jesús A. G. Ochoa de Alda
- Didáctica de las Ciencias Experimentales y la Matemáticas, Universidad de Extremadura, Cáceres, Spain
| | | | - Miguel Ángel Rubio
- Instituto de Bioquímica Vegetal y Fotosíntesis, CSIC and Universidad de Sevilla, Seville, Spain
| | - Guadalupe Gómez-Baena
- Departamento de Bioquímica y Biología Molecular, Universidad de Córdoba, Córdoba, Spain
| | - María F. Fillat
- Departamento de Bioquímica y Biología Molecular y Celular e Instituto de Biocomputación y Física de Sistemas Complejos (Bifi), Universidad de Zaragoza, Zaragoza, Spain
| | - Ignacio Luque
- Instituto de Bioquímica Vegetal y Fotosíntesis, CSIC and Universidad de Sevilla, Seville, Spain
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Bhakat S, Mondal A, Mandal S, Rath J. Role of exopolysaccharides of Anabaena sp. in desiccation tolerance and biodeterioration of ancient terracotta monuments of Bishnupur. Arch Microbiol 2024; 206:105. [PMID: 38363385 DOI: 10.1007/s00203-024-03841-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2023] [Revised: 12/23/2023] [Accepted: 01/08/2024] [Indexed: 02/17/2024]
Abstract
Colonization of the cyanobacteria in the Bishnupur terracotta temples, one of the heritage sites of West Bengal, India is in an alarming state of deterioration now. Among the cyanobacteria Anabaena sp. (VBCCA 052002) has been isolated from most of the crust samples of terracotta monuments of Bishnupur. The identification was done using micromorphological characters and confirmed by 16S rRNA gene sequencing. The isolated strain produces enormous exopolysaccharides, which are extracted, hydrolyzed, and analyzed by HPLC. We have studied desiccation tolerance in this cyanobacterium and found biosynthesis of trehalose with an increase in durations of desiccation. The in vitro experiment shows that Chlorophyll-a and carotenoid content increase with fourteen days of desiccation, and cellular carbohydrates increase continuously. However, cellular protein decreases with desiccation. To gain insights into the survival strategies and biodeterioration mechanisms of Anabaena sp. in the desiccated conditions of the Bishnupur monuments, the present study focuses on the physiological aspects of the cyanobacteria under controlled in vitro conditions. Our study indicates that in desiccation conditions, trehalose biosynthesis takes place in Anabaena sp. As a result of the excessive sugar and polysaccharide produced, it adheres to the surface of the terracotta structure. The continuous contraction and expansion of these polysaccharides contribute to the biodeterioration of these monuments.
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Affiliation(s)
- Shailen Bhakat
- Department of Botany, Sambhu Nath College, Labpur, Birbhum, West Bengal, 731303, India
| | - Arka Mondal
- Department of Botany, Visva-Bharati (Central University), Santiniketan, West Bengal, 731235, India
| | - Sikha Mandal
- Department of Botany, Sree Chaitanya College, Habra, West Bengal, 743268, India.
| | - Jnanendra Rath
- Department of Botany, Visva-Bharati (Central University), Santiniketan, West Bengal, 731235, India
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Ghosh J, Haraguchi Y, Asahi T, Nakao Y, Shimizu T. Muscle cell proliferation using water-soluble extract from nitrogen-fixing cyanobacteria Anabaena sp. PCC 7120 for sustainable cultured meat production. Biochem Biophys Res Commun 2023; 682:316-324. [PMID: 37837752 DOI: 10.1016/j.bbrc.2023.10.018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2023] [Revised: 09/16/2023] [Accepted: 10/04/2023] [Indexed: 10/16/2023]
Abstract
Muscle cell cultivation, specifically the culture of artificial meat from livestock-derived cells in serum-free media is an emerging technology and has attracted much attention. However, till now, the high cost of production and environmental load have been significant deterrents. This study aims to provide an alternate growth-promoting substance that is free from animal derivatives and lowers nitrogen pollution. We have extracted water-soluble compounds from the filamentous nitrogen-fixing cyanobacteria Anabaena sp. PCC 7120 by the ultrasonication method. The heat-inactivated and molecular weight separation experiments were conducted to identify the bioactive compound present in the extract. Finally, the compounds soluble in water (CW) containing the water-soluble pigment protein, phycocyanin as a bioactive compound, was added as a growth supplement to cultivate muscle cells such as C2C12 muscle cells and quail muscle clone 7 (QM7) cells to analyze the effectiveness of the extract. The results indicated that CW had a positive role in muscle cell proliferation. A three-dimensional (3-D) cell-dense structure was fabricated by culturing QM7 cells using the extract. Furthermore, the nitrogen-fixing cyanobacterial extract has vast potential for cultured meat production without animal sera in the near future.
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Affiliation(s)
- Jayeesha Ghosh
- Department of Chemistry and Biochemistry, School of Advanced Science and Engineering, Waseda University, Tokyo, Japan; Institute of Advanced Biomedical Engineering and Science, TWIns, Tokyo Women's Medical University, Tokyo, Japan
| | - Yuji Haraguchi
- Institute of Advanced Biomedical Engineering and Science, TWIns, Tokyo Women's Medical University, Tokyo, Japan
| | - Toru Asahi
- Department of Life Science and Medical Bioscience, School of Advanced Science and Engineering, Waseda University, Tokyo, Japan
| | - Yoichi Nakao
- Department of Chemistry and Biochemistry, School of Advanced Science and Engineering, Waseda University, Tokyo, Japan
| | - Tatsuya Shimizu
- Institute of Advanced Biomedical Engineering and Science, TWIns, Tokyo Women's Medical University, Tokyo, Japan.
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Shimizu S, Ogawa H, Tsuboshita N, Suzuki T, Kato K, Nakajima Y, Dohmae N, Shen JR, Nagao R. Tight association of CpcL with photosystem I in Anabaena sp. PCC 7120 grown under iron-deficient conditions. Biochim Biophys Acta Bioenerg 2023; 1864:148993. [PMID: 37321385 DOI: 10.1016/j.bbabio.2023.148993] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2023] [Revised: 05/23/2023] [Accepted: 06/09/2023] [Indexed: 06/17/2023]
Abstract
Phycobilisomes (PBSs), which are huge pigment-protein complexes displaying distinctive color variations, bind to photosystem cores for excitation-energy transfer. It is known that isolation of supercomplexes consisting of PBSs and photosystem I (PSI) or PBSs and photosystem II is challenging due to weak interactions between PBSs and the photosystem cores. In this study, we succeeded in purifying PSI-monomer-PBS and PSI-dimer-PBS supercomplexes from the cyanobacterium Anabaena sp. PCC 7120 grown under iron-deficient conditions by anion-exchange chromatography, followed by trehalose density gradient centrifugation. The absorption spectra of the two types of supercomplexes showed apparent bands originating from PBSs, and their fluorescence-emission spectra exhibited characteristic peaks of PBSs. Two-dimensional blue-native (BN)/SDS-PAGE of the two samples showed a band of CpcL, which is a linker protein of PBS, in addition to PsaA/B. Since interactions of PBSs with PSI are easily dissociated during BN-PAGE using thylakoids from this cyanobacterium grown under iron-replete conditions, it is suggested that iron deficiency for Anabaena induces tight association of CpcL with PSI, resulting in the formation of PSI-monomer-PBS and PSI-dimer-PBS supercomplexes. Based on these findings, we discuss interactions of PBSs with PSI in Anabaena.
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Affiliation(s)
- Shota Shimizu
- Research Institute for Interdisciplinary Science and Graduate School of Natural Science and Technology, Okayama University, Okayama 700-8530, Japan
| | - Haruya Ogawa
- Research Institute for Interdisciplinary Science and Graduate School of Natural Science and Technology, Okayama University, Okayama 700-8530, Japan
| | - Naoki Tsuboshita
- Research Institute for Interdisciplinary Science and Graduate School of Natural Science and Technology, Okayama University, Okayama 700-8530, Japan
| | - Takehiro Suzuki
- Biomolecular Characterization Unit, RIKEN Center for Sustainable Resource Science, Saitama 351-0198, Japan
| | - Koji Kato
- Research Institute for Interdisciplinary Science and Graduate School of Natural Science and Technology, Okayama University, Okayama 700-8530, Japan
| | - Yoshiki Nakajima
- Research Institute for Interdisciplinary Science and Graduate School of Natural Science and Technology, Okayama University, Okayama 700-8530, Japan
| | - Naoshi Dohmae
- Biomolecular Characterization Unit, RIKEN Center for Sustainable Resource Science, Saitama 351-0198, Japan
| | - Jian-Ren Shen
- Research Institute for Interdisciplinary Science and Graduate School of Natural Science and Technology, Okayama University, Okayama 700-8530, Japan
| | - Ryo Nagao
- Faculty of Agriculture, Shizuoka University, Shizuoka 422-8529, Japan.
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7
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Olivan-Muro I, Sarasa-Buisan C, Guio J, Arenas J, Sevilla E, Fillat MF. Unbalancing Zur (FurB)-mediated homeostasis in Anabaena sp. PCC7120: Consequences on metal trafficking, heterocyst development and biofilm formation. Environ Microbiol 2023; 25:2142-2162. [PMID: 37315963 DOI: 10.1111/1462-2920.16434] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2023] [Accepted: 05/22/2023] [Indexed: 06/16/2023]
Abstract
Zinc is required for the activity of many enzymes and plays an essential role in gene regulation and redox homeostasis. In Anabaena (Nostoc) sp. PCC7120, the genes involved in zinc uptake and transport are controlled by the metalloregulator Zur (FurB). Comparative transcriptomics of a zur mutant (Δzur) with the parent strain unveiled unexpected links between zinc homeostasis and other metabolic pathways. A notable increase in the transcription of numerous desiccation tolerance-related genes, including genes involved in the synthesis of trehalose and the transference of saccharide moieties, among many others, was detected. Biofilm formation analysis under static conditions revealed a reduced capacity of Δzur filaments to form biofilms compared to the parent strain, and such capacity was enhanced when Zur was overexpressed. Furthermore, microscopy analysis revealed that zur expression is required for the correct formation of the envelope polysaccharide layer in the heterocyst, as Δzur cells showed reduced staining with alcian blue compared to Anabaena sp. PCC7120. We suggest that Zur is an important regulator of the enzymes involved in the synthesis and transport of the envelope polysaccharide layer, influencing heterocyst development and biofilm formation, both relevant processes for cell division and interaction with substrates in its ecological niche.
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Affiliation(s)
- Irene Olivan-Muro
- Department of Biochemistry and Molecular and Cellular Biology, Faculty of Sciences and Institute of Bioinformatics and Physical of Complex Systems, University of Zaragoza, Zaragoza, Spain
| | - Cristina Sarasa-Buisan
- Department of Biochemistry and Molecular and Cellular Biology, Faculty of Sciences and Institute of Bioinformatics and Physical of Complex Systems, University of Zaragoza, Zaragoza, Spain
| | - Jorge Guio
- Department of Biochemistry and Molecular and Cellular Biology, Faculty of Sciences and Institute of Bioinformatics and Physical of Complex Systems, University of Zaragoza, Zaragoza, Spain
| | - Jesús Arenas
- Department of Animal Pathology, Unit of Microbiology and Immunology, Faculty of Veterinary, University of Zaragoza, Zaragoza, Spain
| | - Emma Sevilla
- Department of Biochemistry and Molecular and Cellular Biology, Faculty of Sciences and Institute of Bioinformatics and Physical of Complex Systems, University of Zaragoza, Zaragoza, Spain
| | - Maria F Fillat
- Department of Biochemistry and Molecular and Cellular Biology, Faculty of Sciences and Institute of Bioinformatics and Physical of Complex Systems, University of Zaragoza, Zaragoza, Spain
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Velázquez-Suárez C, Springstein BL, Nieves-Morión M, Helbig AO, Kieninger AK, Maldener I, Nürnberg DJ, Stucken K, Luque I, Dagan T, Herrero A. SepT, a novel protein specific to multicellular cyanobacteria, influences peptidoglycan growth and septal nanopore formation in Anabaena sp. PCC 7120. mBio 2023; 14:e0098323. [PMID: 37650636 PMCID: PMC10653889 DOI: 10.1128/mbio.00983-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2023] [Accepted: 06/27/2023] [Indexed: 09/01/2023] Open
Abstract
IMPORTANCE Multicellular organization is a requirement for the development of complex organisms, and filamentous cyanobacteria such as Anabaena represent a paradigmatic case of bacterial multicellularity. The Anabaena filament can include hundreds of communicated cells that exchange nutrients and regulators and, depending on environmental conditions, can include different cell types specialized in distinct biological functions. Hence, the specific features of the Anabaena filament and how they are propagated during cell division represent outstanding biological issues. Here, we studied SepT, a novel coiled-coil-rich protein of Anabaena that is located in the intercellular septa and influences the formation of the septal specialized structures that allow communication between neighboring cells along the filament, a fundamental trait for the performance of Anabaena as a multicellular organism.
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Affiliation(s)
| | | | - Mercedes Nieves-Morión
- Instituto de Bioquímica Vegetal y Fotosíntesis, CSIC and Universidad de Sevilla, Seville, Spain
| | - Andreas O. Helbig
- AG Proteomics & Bioanalytics, Institute for Experimental Medicine, Christian-Albrechts-Universität zu Kiel, Kiel, Germany
| | - Ann-Katrin Kieninger
- Department of Microbiology/Organismic Interactions, University of Tübingen, Tübingen, Germany
| | - Iris Maldener
- Department of Microbiology/Organismic Interactions, University of Tübingen, Tübingen, Germany
| | - Dennis J. Nürnberg
- Institute of Experimental Physics and Dahlem Centre of Plant Sciences, Free University of Berlin, Berlin, Germany
| | - Karina Stucken
- Department of Food Engineering, Universidad de La Serena, La Serena, Chile
| | - Ignacio Luque
- Instituto de Bioquímica Vegetal y Fotosíntesis, CSIC and Universidad de Sevilla, Seville, Spain
| | - Tal Dagan
- Institute of General Microbiology, Kiel University, Kiel, Germany
| | - Antonia Herrero
- Instituto de Bioquímica Vegetal y Fotosíntesis, CSIC and Universidad de Sevilla, Seville, Spain
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Wang X, Zhang J, Li Q, Jia R, Qiao M, Cui W. In Situ Observation of Cellular Structure Changes in and Chain Segregations of Anabaena sp. PCC 7120 on TiO 2 Films under a Photocatalytic Device. Molecules 2023; 28:7200. [PMID: 37894679 PMCID: PMC10609019 DOI: 10.3390/molecules28207200] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2023] [Revised: 10/17/2023] [Accepted: 10/17/2023] [Indexed: 10/29/2023] Open
Abstract
Cyanobacteria outbreaks are serious water pollution events, causing water crises around the world. Photocatalytic disinfection, as an effective approach, has been widely used to inhibit blue algae growth. In this study, a tiny reaction room containing a TiO2 film was designed to fulfill in situ optical observation of the destruction process of a one-dimensional multicellular microorganism, Anabaena sp. PCC 7120, which is also a typical bacterial strain causing water blooms. It was found that the fragment number increased exponentially with the activation time. The fracture mechanics of the algae chains were hypothesized to be the combining functions of increased local tensile stress originated from the cell contracting as well as the oxidative attacks coming from reactive oxygen species (ROSs). It was assumed that the oxidative species were the root cause of cellular structure changes in and chain fractures of Anabaena sp. PCC 7120 in the photocatalytic inactivation activity.
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Affiliation(s)
- Xiaoxin Wang
- College of Physics and Electronics, Dezhou University, Dezhou 253000, China; (R.J.); (M.Q.)
- Shandong Provincial Key Laboratory of Biophysics, Dezhou University, Dezhou 253000, China;
- Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China; (J.Z.); (Q.L.)
| | - Jingtao Zhang
- Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China; (J.Z.); (Q.L.)
- College of Tobacco Science and Engineering, Zhengzhou University of Light Industry, Zhengzhou 450002, China
| | - Qi Li
- Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China; (J.Z.); (Q.L.)
- Key Laboratory of Advanced Technologies of Materials (Ministry of Education), School of Materials Science and Engineering, Southwest Jiaotong University, Chengdu 610031, China
| | - Ran Jia
- College of Physics and Electronics, Dezhou University, Dezhou 253000, China; (R.J.); (M.Q.)
| | - Mei Qiao
- College of Physics and Electronics, Dezhou University, Dezhou 253000, China; (R.J.); (M.Q.)
| | - Wanling Cui
- Shandong Provincial Key Laboratory of Biophysics, Dezhou University, Dezhou 253000, China;
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Mandhata CP, Bishoyi AK, Sahoo CR, Maharana S, Padhy RN. Insight to biotechnological utility of phycochemicals from cyanobacterium Anabaena sp.: An overview. Fitoterapia 2023; 169:105594. [PMID: 37343687 DOI: 10.1016/j.fitote.2023.105594] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2023] [Revised: 06/12/2023] [Accepted: 06/17/2023] [Indexed: 06/23/2023]
Abstract
Cyanobacteria (blue-green algae) are well-known for the ability to excrete extra-cellular products, as a variety of cyanochemicals (phycocompounds) of curio with several extensive therapeutic applications. Among these phycocompound, the cyanotoxins from certain water-bloom forming taxa are toxic to biota, including crocodiles. Failure of current non-renewable source compounds in producing sustainable and non-toxic therapeutics led the urgency of discovering products from natural sources. Particularly, compounds of the filamentous N2-fixing Anabaena sp. have effective antibacterial, antifungal, antioxidant, and anticancer properties. Today, such newer compounds are the potential targets for the possible novel chemical scaffolds, suitable for mainstream-drug development cascades. Bioactive compounds of Anabaena sp. such as, anatoxins, hassallidins and phycobiliproteins have proven their inherent antibacterial, antifungal, and antineoplastic activities, respectively. Herein, the available details of the biomass production and the inherent phyco-constituents namely, alkaloids, lipids, phenols, peptides, proteins, polysaccharides, terpenoids and cyanotoxins are considered, along with geographical distributions and morphological characteristics of the cyanobacterium. The acquisitions of cyanochemicals in recent years have newly addressed several pharmaceutical aliments, and the understanding of the associated molecular interactions of phycochemicals have been considered, for plausible use in drug developments in future.
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Affiliation(s)
- Chinmayee Priyadarsani Mandhata
- Central Research Laboratory, Institute of Medical Science & SUM Hospital, Siksha O Anusandhan Deemed to be University, Bhubaneswar, 751003, Odisha, India
| | - Ajit Kumar Bishoyi
- Central Research Laboratory, Institute of Medical Science & SUM Hospital, Siksha O Anusandhan Deemed to be University, Bhubaneswar, 751003, Odisha, India
| | - Chita Ranjan Sahoo
- Central Research Laboratory, Institute of Medical Science & SUM Hospital, Siksha O Anusandhan Deemed to be University, Bhubaneswar, 751003, Odisha, India.
| | | | - Rabindra Nath Padhy
- Central Research Laboratory, Institute of Medical Science & SUM Hospital, Siksha O Anusandhan Deemed to be University, Bhubaneswar, 751003, Odisha, India.
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Sarasa-Buisan C, Guío J, Peleato ML, Fillat MF, Sevilla E. Expanding the FurC (PerR) regulon in Anabaena (Nostoc) sp. PCC 7120: Genome-wide identification of novel direct targets uncovers FurC participation in central carbon metabolism regulation. PLoS One 2023; 18:e0289761. [PMID: 37549165 PMCID: PMC10406281 DOI: 10.1371/journal.pone.0289761] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2023] [Accepted: 07/25/2023] [Indexed: 08/09/2023] Open
Abstract
FurC (PerR, Peroxide Response Regulator) from Anabaena sp. PCC 7120 (also known as Nostoc sp. PCC 7120) is a master regulator engaged in the modulation of relevant processes including the response to oxidative stress, photosynthesis and nitrogen fixation. Previous differential gene expression analysis of a furC-overexpressing strain (EB2770FurC) allowed the inference of a putative FurC DNA-binding consensus sequence. In the present work, more data concerning the regulon of the FurC protein were obtained through the searching of the putative FurC-box in the whole Anabaena sp. PCC 7120 genome. The total amount of novel FurC-DNA binding sites found in the promoter regions of genes with known function was validated by electrophoretic mobility shift assays (EMSA) identifying 22 new FurC targets. Some of these identified targets display relevant roles in nitrogen fixation (hetR and hgdC) and carbon assimilation processes (cmpR, glgP1 and opcA), suggesting that FurC could be an additional player for the harmonization of carbon and nitrogen metabolisms. Moreover, differential gene expression of a selection of newly identified FurC targets was measured by Real Time RT-PCR in the furC-overexpressing strain (EB2770FurC) comparing to Anabaena sp. PCC 7120 revealing that in most of these cases FurC could act as a transcriptional activator.
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Affiliation(s)
- Cristina Sarasa-Buisan
- Departamento de Bioquímica y Biología Molecular y Celular and Institute for Biocomputation and Physics of Complex Systems, Universidad de Zaragoza, Zaragoza, Spain
| | - Jorge Guío
- Departamento de Bioquímica y Biología Molecular y Celular and Institute for Biocomputation and Physics of Complex Systems, Universidad de Zaragoza, Zaragoza, Spain
| | - M. Luisa Peleato
- Departamento de Bioquímica y Biología Molecular y Celular and Institute for Biocomputation and Physics of Complex Systems, Universidad de Zaragoza, Zaragoza, Spain
| | - María F. Fillat
- Departamento de Bioquímica y Biología Molecular y Celular and Institute for Biocomputation and Physics of Complex Systems, Universidad de Zaragoza, Zaragoza, Spain
| | - Emma Sevilla
- Departamento de Bioquímica y Biología Molecular y Celular and Institute for Biocomputation and Physics of Complex Systems, Universidad de Zaragoza, Zaragoza, Spain
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12
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Wang ZQ, Yang Y, Zhang JY, Zeng X, Zhang CC. Global translational control by the transcriptional repressor TrcR in the filamentous cyanobacterium Anabaena sp. PCC 7120. Commun Biol 2023; 6:643. [PMID: 37322092 PMCID: PMC10272220 DOI: 10.1038/s42003-023-05012-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2023] [Accepted: 06/02/2023] [Indexed: 06/17/2023] Open
Abstract
Transcriptional and translational regulations are important mechanisms for cell adaptation to environmental conditions. In addition to house-keeping tRNAs, the genome of the filamentous cyanobacterium Anabaena sp. strain PCC 7120 (Anabaena) has a long tRNA operon (trn operon) consisting of 26 genes present on a megaplasmid. The trn operon is repressed under standard culture conditions, but is activated under translational stress in the presence of antibiotics targeting translation. Using the toxic amino acid analog β-N-methylamino-L-alanine (BMAA) as a tool, we isolated and characterized several BMAA-resistance mutants from Anabaena, and identified one gene of unknown function, all0854, named as trcR, encoding a transcription factor belonging to the ribbon-helix-helix (RHH) family. We provide evidence that TrcR represses the expression of the trn operon and is thus the missing link between the trn operon and translational stress response. TrcR represses the expression of several other genes involved in translational control, and is required for maintaining translational fidelity. TrcR, as well as its binding sites, are highly conserved in cyanobacteria, and its functions represent an important mechanism for the coupling of the transcriptional and translational regulations in cyanobacteria.
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Affiliation(s)
- Zi-Qian Wang
- State Key Laboratory of Freshwater Ecology and Biotechnology and Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, Hubei, 430072, People's Republic of China.
- University of Chinese Academy of Sciences, Beijing, 100049, People's Republic of China.
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China.
| | - Yiling Yang
- State Key Laboratory of Freshwater Ecology and Biotechnology and Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, Hubei, 430072, People's Republic of China
| | - Ju-Yuan Zhang
- State Key Laboratory of Freshwater Ecology and Biotechnology and Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, Hubei, 430072, People's Republic of China
| | - Xiaoli Zeng
- State Key Laboratory of Freshwater Ecology and Biotechnology and Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, Hubei, 430072, People's Republic of China
| | - Cheng-Cai Zhang
- State Key Laboratory of Freshwater Ecology and Biotechnology and Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, Hubei, 430072, People's Republic of China.
- Institute AMU-WUT, Aix-Marseille Université and Wuhan University of Technology, Wuhan, Hubei, People's Republic of China.
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13
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Kaleem M, Mumtaz AS, Hashmi MZ, Saeed A, Inam F, Waqar R, Jabeen A. Myco- and phyco-remediation of polychlorinated biphenyls in the environment: a review. Environ Sci Pollut Res Int 2023; 30:13994-14007. [PMID: 36550253 DOI: 10.1007/s11356-022-24902-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Accepted: 12/17/2022] [Indexed: 06/17/2023]
Abstract
Polychlorinated biphenyls (PCBs) are toxic organic compounds and pose serious threats to environment and public health. PCBs still exist in different environments such as air, water, soil, and sediments even on ban. This review summarizes the phyco- and myco-remediation technologies developed to detoxify the PCB-polluted sites. It was found that algae mostly use bioaccumulation to biodegradation strategies to reclaim the environment. As bio-accumulator, Ulva rigida C. Agardh has been best at 25 ng/g dry wt to remove PCBs. Evidently, Anabaena PD-1 is the only known PCB degrading alga and efficiently degrade Aroclor 1254 and dioxin-like PCBs up to 84.4% and 37.4% to 68.4%, respectively. The review suggested that factors such as choice of algal strains, response of microalgae, biomass, the rate of growth, and cost-effective cultivation conditions significantly influence the remediation of PCBs. Furthermore, the Anabaena sp. linA gene of Pseudomonas paucimobilis Holmes UT26 showed enhanced efficiency. Pleurotus ostreatus (Jacq.) P. Kumm is the most efficient PCB degrading fungus, degrading up to 98.4% and 99.6% of PCB in complex and mineral media, respectively. Combine metabolic activities of bacteria and yeast led to the higher detoxification of PCBs. Fungi-algae consortia would be a promising approach in remediation of PCBs. A critical analysis on potentials and limits of PCB treatment through fungal and algal biosystems have been reviewed, and thus, new insights have emerged for possible bioremediation, bioaccumulation, and biodegradation of PCBs.
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Affiliation(s)
- Muhammad Kaleem
- Department of Plant Sciences, Quaid-I-Azam University, Islamabad, Pakistan
| | - Abdul Samad Mumtaz
- Department of Plant Sciences, Quaid-I-Azam University, Islamabad, Pakistan
| | | | - Aamer Saeed
- Department of Chemistry, Quaid-I-Azam University, Islamabad, Pakistan
| | - Farooq Inam
- Department of Plant Sciences, Quaid-I-Azam University, Islamabad, Pakistan
| | - Rooma Waqar
- Department of Plant Sciences, Quaid-I-Azam University, Islamabad, Pakistan
| | - Amber Jabeen
- Department of Plant Sciences, Quaid-I-Azam University, Islamabad, Pakistan
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14
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Srivastava A, Kumar A, Biswas S, Kumar R, Srivastava V, Rajaram H, Mishra Y. Gamma (γ)-radiation stress response of the cyanobacterium Anabaena sp. PCC7120: Regulatory role of LexA and photophysiological changes. Plant Sci 2023; 326:111529. [PMID: 36332765 DOI: 10.1016/j.plantsci.2022.111529] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2022] [Revised: 10/28/2022] [Accepted: 10/30/2022] [Indexed: 06/16/2023]
Abstract
High radioresistance of the cyanobacterium, Anabaena sp. PCC7120 has been attributed to efficient DNA repair, protein recycling, and oxidative stress management. However, the regulatory network involved in these batteries of responses remains unexplored. In the present study, the role of a global regulator, LexA in modulating gamma (γ)-radiation stress response of Anabaena was investigated. Comparison of the cytosolic proteome profiles upon γ-radiation in recombinant Anabaena strains, AnpAM (vector-control) and AnlexA+ (LexA-overexpressing), revealed 41 differentially accumulated proteins, corresponding to 29 distinct proteins. LexA was found to be involved in the regulation of 27 of the corresponding genes based on the presence of AnLexA-Box, EMSA, and/or qRT-PCR studies. The majority of the regulated genes were found to be involved in C-assimilation either through photosynthesis or C-catabolism and oxidative stress alleviation. Photosynthesis, measured in terms of PSII photophysiological parameters and thylakoid membrane proteome was found to be affected by γ-radiation in both AnpAM and AnlexA+ cells, with LexA affecting them even under control growth conditions. Thus, LexA functioned as one of the transcriptional regulators involved in modulating γ-radiation stress response in Anabaena. This study could pave the way for a deeper understanding of the regulation of γ-radiation-responsive genes in cyanobacteria at large.
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Affiliation(s)
- Akanksha Srivastava
- Department of Botany, Centre of Advanced Study in Botany, Institute of Science, Banaras Hindu University, Varanasi 221005, India
| | - Arvind Kumar
- Molecular Biology Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085, India
| | - Subhankar Biswas
- Department of Botany, Centre of Advanced Study in Botany, Institute of Science, Banaras Hindu University, Varanasi 221005, India
| | - Rajender Kumar
- Division of Glycoscience, Department of Chemistry, School of Engineering Sciences in Chemistry, Biotechnology and Health, Royal Institute of Technology (KTH), AlbaNova University Centre, Stockholm 10691, Sweden
| | - Vaibhav Srivastava
- Division of Glycoscience, Department of Chemistry, School of Engineering Sciences in Chemistry, Biotechnology and Health, Royal Institute of Technology (KTH), AlbaNova University Centre, Stockholm 10691, Sweden
| | - Hema Rajaram
- Molecular Biology Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085, India; Homi Bhabha National Institute, Anushakti Nagar, Mumbai 400094, India.
| | - Yogesh Mishra
- Department of Botany, Centre of Advanced Study in Botany, Institute of Science, Banaras Hindu University, Varanasi 221005, India.
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15
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Chakraborty S, Bhattacharjee S, Tiwari B, Jaishwal T, Singh SS, Mishra AK. Deciphering the mechanisms of zinc tolerance in the cyanobacterium Anabaena sphaerica and its zinc bioremediation potential. Environ Sci Pollut Res Int 2023; 30:9591-9608. [PMID: 36057058 DOI: 10.1007/s11356-022-22388-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2022] [Accepted: 07/29/2022] [Indexed: 06/15/2023]
Abstract
Cyanobacteria adopt a variety of changes at proteomic and metabolic levels for surviving under harmful environmental conditions including heavy metal stress. The current study investigates the impact of zinc stress on the proteome of Anabaena sphaerica to get an insight into its molecular mechanisms of zinc tolerance. The study revealed three different aspects that were associated with the zinc tolerance in A. sphaerica: (i) the reduced expression of photosynthesis, nitrogen fixation, energy metabolism, respiratory, and transcriptional/translational proteins probably to conserve energy and utilizing it to sustain growth; (ii) the enhanced expression of metallothionein and ferritin domain protein All 3940 to chelate free zinc ions whereas upregulation of antioxidative proteins for detoxifying reactive oxygen species; and (iii) the expression of large numbers of hypothetical proteins to maintain the important cellular functions. Furthermore, over expressions of sulfate adenylyl transferase and cystathionine beta synthase along with the increased synthesis of peptidases and thiolated antioxidant proteins were also noticed which denoted cysteine synthesis under sulfur deprivation possibly by mobilizing the sulfur from dead cells and its channelization towards the production of thiolated antioxidants. Besides tolerating excess amount of zinc, A. sphaerica exhibited high zinc biosorption efficiency which confirmed its outstanding zinc bioremediation potential.
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Affiliation(s)
- Sindhunath Chakraborty
- Laboratory of Microbial Genetics, Department of Botany, Banaras Hindu University, Varanasi, 221005, India
| | - Samujjal Bhattacharjee
- Laboratory of Microbial Genetics, Department of Botany, Banaras Hindu University, Varanasi, 221005, India
| | - Balkrishna Tiwari
- Laboratory of Microbial Genetics, Department of Botany, Banaras Hindu University, Varanasi, 221005, India
| | - Tameshwar Jaishwal
- Laboratory of Microbial Genetics, Department of Botany, Banaras Hindu University, Varanasi, 221005, India
- Laboratory of Cyanobacterial Systematics and Stress Biology, Department of Botany, Banaras Hindu University, Varanasi, 221005, India
| | - Satya Shila Singh
- Laboratory of Cyanobacterial Systematics and Stress Biology, Department of Botany, Banaras Hindu University, Varanasi, 221005, India
| | - Arun Kumar Mishra
- Laboratory of Microbial Genetics, Department of Botany, Banaras Hindu University, Varanasi, 221005, India.
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16
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Santana‐Sánchez A, Nikkanen L, Werner E, Tóth G, Ermakova M, Kosourov S, Walter J, He M, Aro E, Allahverdiyeva Y. Flv3A facilitates O 2 photoreduction and affects H 2 photoproduction independently of Flv1A in diazotrophic Anabaena filaments. New Phytol 2023; 237:126-139. [PMID: 36128660 PMCID: PMC10092803 DOI: 10.1111/nph.18506] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2022] [Accepted: 09/10/2022] [Indexed: 05/23/2023]
Abstract
The model heterocyst-forming filamentous cyanobacterium Anabaena sp. PCC 7120 (Anabaena) is a typical example of a multicellular organism capable of simultaneously performing oxygenic photosynthesis in vegetative cells and O2 -sensitive N2 -fixation inside heterocysts. The flavodiiron proteins have been shown to participate in photoprotection of photosynthesis by driving excess electrons to O2 (a Mehler-like reaction). Here, we performed a phenotypic and biophysical characterization of Anabaena mutants impaired in vegetative-specific Flv1A and Flv3A in order to address their physiological relevance in the bioenergetic processes occurring in diazotrophic Anabaena under variable CO2 conditions. We demonstrate that both Flv1A and Flv3A are required for proper induction of the Mehler-like reaction upon a sudden increase in light intensity, which is likely important for the activation of carbon-concentrating mechanisms and CO2 fixation. Under ambient CO2 diazotrophic conditions, Flv3A is responsible for moderate O2 photoreduction, independently of Flv1A, but only in the presence of Flv2 and Flv4. Strikingly, the lack of Flv3A resulted in strong downregulation of the heterocyst-specific uptake hydrogenase, which led to enhanced H2 photoproduction under both oxic and micro-oxic conditions. These results reveal a novel regulatory network between the Mehler-like reaction and the diazotrophic metabolism, which is of great interest for future biotechnological applications.
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Affiliation(s)
- Anita Santana‐Sánchez
- Molecular Plant Biology, Department of Life TechnologiesUniversity of TurkuTurkuFI‐20014Finland
| | - Lauri Nikkanen
- Molecular Plant Biology, Department of Life TechnologiesUniversity of TurkuTurkuFI‐20014Finland
| | - Elisa Werner
- Molecular Plant Biology, Department of Life TechnologiesUniversity of TurkuTurkuFI‐20014Finland
| | - Gábor Tóth
- Molecular Plant Biology, Department of Life TechnologiesUniversity of TurkuTurkuFI‐20014Finland
| | - Maria Ermakova
- Molecular Plant Biology, Department of Life TechnologiesUniversity of TurkuTurkuFI‐20014Finland
| | - Sergey Kosourov
- Molecular Plant Biology, Department of Life TechnologiesUniversity of TurkuTurkuFI‐20014Finland
| | - Julia Walter
- Molecular Plant Biology, Department of Life TechnologiesUniversity of TurkuTurkuFI‐20014Finland
| | - Meilin He
- Molecular Plant Biology, Department of Life TechnologiesUniversity of TurkuTurkuFI‐20014Finland
| | - Eva‐Mari Aro
- Molecular Plant Biology, Department of Life TechnologiesUniversity of TurkuTurkuFI‐20014Finland
| | - Yagut Allahverdiyeva
- Molecular Plant Biology, Department of Life TechnologiesUniversity of TurkuTurkuFI‐20014Finland
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17
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Sarasa-Buisan C, Emonot E, Martínez-Júlvez M, Sevilla E, Velázquez-Campoy A, Crouzy S, Bes MT, Michaud-Soret I, Fillat MF. Metal binding and oligomerization properties of FurC (PerR) from Anabaena sp. PCC7120: an additional layer of regulation? Metallomics 2022; 14:6750011. [PMID: 36201459 DOI: 10.1093/mtomcs/mfac077] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Accepted: 10/03/2022] [Indexed: 11/12/2022]
Abstract
Metal and redox homeostasis in cyanobacteria is tightly controlled to preserve the photosynthetic machinery from mismetallation and minimize cell damage. This control is mainly taken by FUR (ferric uptake regulation) proteins. FurC works as the PerR (peroxide response) paralog in Anabaena sp. PCC7120. Despite its importance, this regulator remained poorly characterized. Although FurC lacks the typical CXXC motifs present in FUR proteins, it contains a tightly bound zinc per subunit. FurC:Zn stoichiometrically binds zinc and manganese in a second site, being manganese more efficient in the binding of FurC:Zn to its DNA target PprxA. Oligomerization analyses of FurC:Zn evidence the occurrence of different aggregates ranging from dimers to octamers. Notably, intermolecular disulfide bonds are not involved in FurC:Zn dimerization, being the dimer the most reduced form of the protein. Oligomerization of dimers occurs upon oxidation of thiols by H2O2 or diamide and can be reversed by DTT. Irreversible inactivation of the regulator occurs by metal catalyzed oxidation promoted by ferrous iron. However, inactivation upon oxidation with H2O2 in the absence of iron was reverted by addition of DTT. Comparison of models for FurC:Zn dimers and tetramers obtained using AlphaFold Colab and SWISS-MODEL allowed to infer the residues forming both metal-binding sites and to propose the involvement of Cys86 in reversible tetramer formation. Our results decipher the existence of two levels of inactivation of FurC:Zn of Anabaena sp. PCC7120, a reversible one through disulfide-formed FurC:Zn tetramers and the irreversible metal catalyzed oxidation. This additional reversible regulation may be specific of cyanobacteria.
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Affiliation(s)
- Cristina Sarasa-Buisan
- Departamento de Bioquímica y Biología Molecular y Celular e Instituto de Biocomputación y Física de Sistemas Complejos (Bifi), Universidad de Zaragoza, 50009-Zaragoza, Spain
| | - Etienne Emonot
- Université Grenoble Alpes, CNRS CEA, IRIG-LCBM, 38000 Grenoble, France
| | - Marta Martínez-Júlvez
- Departamento de Bioquímica y Biología Molecular y Celular e Instituto de Biocomputación y Física de Sistemas Complejos (Bifi), Universidad de Zaragoza, 50009-Zaragoza, Spain
| | - Emma Sevilla
- Departamento de Bioquímica y Biología Molecular y Celular e Instituto de Biocomputación y Física de Sistemas Complejos (Bifi), Universidad de Zaragoza, 50009-Zaragoza, Spain
| | - Adrián Velázquez-Campoy
- Departamento de Bioquímica y Biología Molecular y Celular e Instituto de Biocomputación y Física de Sistemas Complejos (Bifi), Universidad de Zaragoza, 50009-Zaragoza, Spain
| | - Serge Crouzy
- Université Grenoble Alpes, CNRS CEA, IRIG-LCBM, 38000 Grenoble, France
| | - M Teresa Bes
- Departamento de Bioquímica y Biología Molecular y Celular e Instituto de Biocomputación y Física de Sistemas Complejos (Bifi), Universidad de Zaragoza, 50009-Zaragoza, Spain
| | | | - María F Fillat
- Departamento de Bioquímica y Biología Molecular y Celular e Instituto de Biocomputación y Física de Sistemas Complejos (Bifi), Universidad de Zaragoza, 50009-Zaragoza, Spain
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18
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Kalwani P, Rath D, Ballal A. Loss of 2-Cys-Prx affects cellular ultrastructure, disturbs redox poise and impairs photosynthesis in cyanobacteria. Plant Cell Environ 2022; 45:2972-2986. [PMID: 35909079 DOI: 10.1111/pce.14412] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/10/2022] [Revised: 07/19/2022] [Accepted: 07/27/2022] [Indexed: 06/15/2023]
Abstract
In a striking similarity to plant chloroplasts, the cyanobacterium Anabaena displays very low catalase activity, but expresses several peroxiredoxins (Prxs), including the typical 2-Cys-Prx (annotated as Alr4641), that detoxify H2 O2 . Due to the presence of multiple Prxs, the precise contribution of Alr4641 to the oxidative stress response of Anabaena is not well-defined. To unambiguously assess its in vivo function, the Alr4641 protein was knocked down using the CRISPRi approach in Anabaena PCC 7120. The knockdown strain (An-KD4641), which showed over 85% decrease in the content of Alr4641, was viable, but grew slower than the control strain (An-dCas9). An-KD4641 showed elevated levels of reactive oxygen species and the expression of several redox-responsive genes was analogous to that of An-dCas9 subjected to oxidative stress. The knockdown strain displayed reduced filament size, altered thylakoid ultrastructure, a marked drop in the ratio of phycocyanin to chlorophyll a and decreased photosynthetic parameters compared to An-dCas9. In comparison to the control strain, exposure to H2 O2 had a more severe effect on the photosynthetic parameters or survival of An-KD4641. Thus, in the absence of adequate catalase activity, 2-Cys-Prx appears to be the principal Prx responsible for maintaining redox homoeostasis in diverse photosynthetic systems ranging from chloroplasts to cyanobacteria.
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Affiliation(s)
- Prakash Kalwani
- Molecular Biology Division, Bhabha Atomic Research Centre, Trombay, Mumbai, India
- Homi Bhabha National Institute, Anushaktinagar, Mumbai, India
| | - Devashish Rath
- Applied Genomics Section, Bhabha Atomic Research Centre, Trombay, Mumbai, India
- Homi Bhabha National Institute, Anushaktinagar, Mumbai, India
| | - Anand Ballal
- Molecular Biology Division, Bhabha Atomic Research Centre, Trombay, Mumbai, India
- Homi Bhabha National Institute, Anushaktinagar, Mumbai, India
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19
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Sukkasam N, Incharoensakdi A, Monshupanee T. Chemicals Affecting Cyanobacterial Poly(3-hydroxybutyrate) Accumulation: 2-Phenylethanol Treatment Combined with Nitrogen Deprivation Synergistically Enhanced Poly(3-hydroxybutyrate) Storage in Synechocystis sp. PCC6803 and Anabaena sp. TISTR8076. Plant Cell Physiol 2022; 63:1253-1272. [PMID: 35818829 DOI: 10.1093/pcp/pcac100] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/06/2022] [Revised: 07/04/2022] [Accepted: 07/11/2022] [Indexed: 06/15/2023]
Abstract
Various photoautotrophic cyanobacteria increase the accumulation of bioplastic poly(3-hydroxybutyrate) (PHB) under nitrogen deprivation (-N) for energy storage. Several metabolic engineering enhanced cyanobacterial PHB accumulation, but these strategies are not applicable in non-gene-transformable strains. Alternatively, stimulating PHB levels by chemical exposure is desirable because it might be applied to various cyanobacterial strains. However, the study of such chemicals is still limited. Here, 19 compounds previously reported to affect bacterial cellular processes were evaluated for their effect on PHB accumulation in Synechocystis sp. PCC6803, where 3-(3,4-dichlorophenyl)-1,1-dimethylurea, methyl viologen, arsenite, phenoxyethanol and 2-phenylethanol were found to increase PHB accumulation. When cultivated with optimal nitrate supply, Synechocystis contained less than 0.5% [w/w dry weight (DW)] PHB, while cultivation under -N conditions increased the PHB content to 7% (w/w DW). Interestingly, the -N cultivation combined with 2-phenylethanol exposure reduced the Synechocystis protein content by 27% (w/w DW) but significantly increased PHB levels up to 33% (w/w DW), the highest ever reported photoautotrophic cyanobacterial PHB accumulation in a wild-type strain. Results from transcriptomic and metabolomic analysis suggested that under 2-phenylethanol treatment, Synechocystis proteins were degraded to amino acids, which might be subsequently utilized as the source of carbon and energy for PHB biosynthesis. 2-Phenylethanol treatment also increased the levels of metabolites required for Synechocystis PHB synthesis (acetyl-CoA, acetoacetyl-CoA, 3-hydroxybutyryl-CoA and NADPH). Additionally, under -N, the exposure to phenoxyethanol and 2-phenylethanol increased the PHB levels of Anabaena sp. from 0.4% to 4.1% and 6.6% (w/w DW), respectively. The chemicals identified in this study might be applicable for enhancing PHB accumulation in other cyanobacteria.
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Affiliation(s)
- Nannaphat Sukkasam
- Department of Biochemistry, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand
- Program in Biotechnology, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand
| | - Aran Incharoensakdi
- Department of Biochemistry, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand
- Academy of Science, Royal Society of Thailand, Bangkok 10300, Thailand
| | - Tanakarn Monshupanee
- Department of Biochemistry, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand
- Program in Biotechnology, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand
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20
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Casanova-Ferrer P, Ares S, Muñoz-García J. Terminal heterocyst differentiation in the Anabaena patA mutant as a result of post-transcriptional modifications and molecular leakage. PLoS Comput Biol 2022; 18:e1010359. [PMID: 35969646 PMCID: PMC9410556 DOI: 10.1371/journal.pcbi.1010359] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2022] [Revised: 08/25/2022] [Accepted: 07/05/2022] [Indexed: 12/27/2022] Open
Abstract
The Anabaena genus is a model organism of filamentous cyanobacteria whose vegetative cells can differentiate under nitrogen-limited conditions into a type of cell called heterocyst. These heterocysts lose the possibility to divide and are necessary for the colony because they can fix and share environmental nitrogen. In order to distribute the nitrogen efficiently, heterocysts are arranged to form a quasi-regular pattern whose features are maintained as the filament grows. Recent efforts have allowed advances in the understanding of the interactions and genetic mechanisms underlying this dynamic pattern. However, the main role of the patA and hetF genes are yet to be clarified; in particular, the patA mutant forms heterocysts almost exclusively in the terminal cells of the filament. In this work, we investigate the function of these genes and provide a theoretical model that explains how they interact within the broader genetic network, reproducing their knock-out phenotypes in several genetic backgrounds, including a nearly uniform concentration of HetR along the filament for the patA mutant. Our results suggest a role of hetF and patA in a post-transcriptional modification of HetR which is essential for its regulatory function. In addition, the existence of molecular leakage out of the filament in its boundary cells is enough to explain the preferential appearance of terminal heterocysts, without any need for a distinct regulatory pathway. Understanding multicellular pattern formation is key for the study of both natural and synthetic developmental processes. Arguably one of the simplest model systems for this is the filamentous cyanobacterium Anabaena, that in conditions of nitrogen deprivation undergoes a dynamical differentiation process that differentiates roughly one in every ten cells into nitrogen-fixing heterocysts, in a quasi-regular pattern that is maintained as the filament keeps growing. One of the most characteristic mutations affecting this process forms heterocysts mostly constrained to the terminal cells of the filament. We have used experimental observations to propose a mathematical model of heterocyst differentiation able to reproduce this striking phenotype. The model extends our understanding of the regulations in this pattern-forming system and makes several predictions on molecular interactions. Importantly, a key aspect is the boundary condition at the filament’s ends: inhibitors of differentiation should be able to leak out of the filament, or otherwise the terminal cells would not differentiate. This highlights, in a very clear example, the importance of considering physical constraints in developmental processes.
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Affiliation(s)
- Pau Casanova-Ferrer
- Grupo Interdisciplinar de Sistemas Complejos (GISC) and Departamento de Matemáticas, Universidad Carlos III de Madrid, Leganés, Spain
- Centro Nacional de Biotecnologia (CNB), CSIC, Madrid, Spain
| | - Saúl Ares
- Grupo Interdisciplinar de Sistemas Complejos (GISC) and Departamento de Matemáticas, Universidad Carlos III de Madrid, Leganés, Spain
- Centro Nacional de Biotecnologia (CNB), CSIC, Madrid, Spain
- * E-mail: (SA); (JM-G)
| | - Javier Muñoz-García
- Grupo Interdisciplinar de Sistemas Complejos (GISC) and Departamento de Matemáticas, Universidad Carlos III de Madrid, Leganés, Spain
- * E-mail: (SA); (JM-G)
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Doppler P, Kriechbaum R, Spadiut O. High-throughput characterization of the filamentous cyanobacterium Anabaena sp. using flow cytometry. J Microbiol Methods 2022; 199:106510. [PMID: 35697185 DOI: 10.1016/j.mimet.2022.106510] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2022] [Revised: 06/06/2022] [Accepted: 06/06/2022] [Indexed: 12/27/2022]
Abstract
In stirred-tank photobioreactors agitation causes fragmentation of filamentous cyanobacteria. Here, we introduce a flow cytometric approach for high-throughput measurements of trichome dimensions, heterocysts and metabolic activity of Anabaena sp. cultures. The longest characterized trichome had 1135 μm chain length. This technology could potentially be used for monitoring and control purposes.
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Affiliation(s)
- Philipp Doppler
- Research Division Biochemical Engineering, Institute of Chemical, Environmental and Bioscience Engineering, Technische Universität Wien, Gumpendorfer Strasse 1a, 1060 Vienna, Austria.
| | - Ricarda Kriechbaum
- Research Division Biochemical Engineering, Institute of Chemical, Environmental and Bioscience Engineering, Technische Universität Wien, Gumpendorfer Strasse 1a, 1060 Vienna, Austria.
| | - Oliver Spadiut
- Research Division Biochemical Engineering, Institute of Chemical, Environmental and Bioscience Engineering, Technische Universität Wien, Gumpendorfer Strasse 1a, 1060 Vienna, Austria.
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Abstract
Short-range protein electron transfer (ET) is crucially important in light-induced biological processes such as in photoenzymes and photoreceptors and often occurs on time scales similar to those of environment fluctuations, leading to a coupled dynamic process. Herein, we use semiquinone Anabaena flavodoxin to characterize the ultrafast photoinduced redox cycle of the wild type and seven mutants by ultrafast spectroscopy. We have found that the forward and backward ET dynamics show stretched behaviors in a few picoseconds (1-5 ps), indicating a coupling with the local protein fluctuations. By comparison with the results from semiquinone D. vulgaris flavodoxin, we find that the electronic coupling is crucial to the ET rates. With our new nonergodic model, we obtain smaller values of the outer reorganization energy (λoγ) of environment fluctuations and the reaction free energy force (ΔGγ), a signature of nonequilibrium ET dynamics.
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Affiliation(s)
- Jie Yang
- Center for Ultrafast Science and Technology, School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Yifei Zhang
- Center for Ultrafast Science and Technology, School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Yangyi Lu
- Department of Physics, Department of Chemistry and Biochemistry, Programs of Biophysics, Chemical Physics, and Biochemistry, The Ohio State University, Columbus, Ohio 43210, United States
- Center for Ultrafast Science and Technology, School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Lijuan Wang
- Department of Physics, Department of Chemistry and Biochemistry, Programs of Biophysics, Chemical Physics, and Biochemistry, The Ohio State University, Columbus, Ohio 43210, United States
| | - Faming Lu
- Center for Ultrafast Science and Technology, School of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Dongping Zhong
- Center for Ultrafast Science and Technology, School of Chemistry and Chemical Engineering, School of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240, China
- Department of Physics, Department of Chemistry and Biochemistry, Programs of Biophysics, Chemical Physics, and Biochemistry, The Ohio State University, Columbus, Ohio 43210, United States
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Wang ZQ, Zhang CC. A tRNA t 6A modification system contributes to the sensitivity towards the toxin β-N-methylamino-L-alanine (BMAA) in the cyanobacterium Anabaena sp. PCC 7120. Aquat Toxicol 2022; 245:106121. [PMID: 35180454 DOI: 10.1016/j.aquatox.2022.106121] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Revised: 01/24/2022] [Accepted: 02/12/2022] [Indexed: 06/14/2023]
Abstract
Cyanobacteria are oxygen-evolving photosynthetic autotrophs essential for nutrient cycling in the environment. They possess multiple control mechanisms for their cellular activities in order to adapt to the environment. While protein translation is essential for cell survival and adaptation, the regulation and the flexibility of this process are poorly understood in cyanobacteria. β-N-methylamino-L-alanine (BMAA), an amino acid analog proposed as an environmental neurotoxin, is highly toxic to the filamentous diazotrophic cyanobacterium Anabaena PCC 7120. In this study, through genetic analysis of BMAA-resistant mutants, we demonstrate that the system responsible for modification of ANN-decoding tRNAs with N(6)-threonylcarbamoyl adenosine (t6A) is involved in BMAA sensitivity through the control of translation. Both BMAA and inactivation of the t6A biosynthesis pathway affect translational fidelity and ribosome assembly. However, the two factors display either additive effects on translational elongation, or attenuate each other over translational fidelity or the resistance/sensitivity to antibiotics that inhibit different steps of the translational process. BMAA has a broad effect on translation and transcription, and once BMAA enters the cells, the presence of the t6A biosynthesis pathway increases the sensitivity of the cells towards this toxin. BMAA-resistant mutants screening is an effective method for getting insight into the toxic mechanisms of BMAA. In addition, BMAA is a useful tool for probing translational flexibility of cyanobacteria, and the characterization of the corresponding resistant mutants should help us to reveal translational mechanism allowing cyanobacteria to adapt to changing environments.
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Affiliation(s)
- Zi-Qian Wang
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, Hubei, People's Republic of China; University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China
| | - Cheng-Cai Zhang
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, Hubei, People's Republic of China; Institute WUT-AMU, Aix-Marseille University and Wuhan University of Technology, Wuhan, Hubei, People's Republic of China.
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Chanu NK, Mandal MK, Srivastava A, Chaurasia N. Proteomics analysis reveals several metabolic alterations in cyanobacterium Anabaena sp. NC-K1 in response to alpha-cypermethrin exposure. Environ Sci Pollut Res Int 2022; 29:19762-19777. [PMID: 34718975 DOI: 10.1007/s11356-021-16611-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2021] [Accepted: 09/14/2021] [Indexed: 06/13/2023]
Abstract
In the current study, the effect of the EC50 and LC90 concentrations of pyrethroid insecticide alpha-cypermethrin to cyanobacteria Anabaena sp. NC-K1 was investigated at different time exposures (1st day, 4th day and 7th day) with reference to growth, photosynthetic pigments, oxidative damage and antioxidant defence system. Superoxide dismutase (1.38-fold), peroxidase (5.04) and proline content (2.27-fold) were enhanced compared to the control. After performing 2D gel electrophoresis at 1st day EC50 exposure, where appropriate differences in the biochemical and physiological parameters were observed, 22 differentially accumulated proteins (20 upregulated and 2 downregulated) were selected for mass spectrometry. Out of 42 proteins identified, 20 upregulated protein spots were classified into twelve categories according to their metabolic functions. Proteins related to photosynthesis (phycobilisome rod-core linker polypeptide, rubisco), stress responses (Hsp70, Hsp40, catalase family peroxidase), translation (elongation factor Tu) and amino acid biosynthesis and metabolism (3-phosphoshikimate 1-carboxyvinyl transferase) were significantly upregulated. Additionally, proteins involved in transcription and DNA repair (Snf-2 histone linker phd ring helicase, RNA polymerase sigma factor RpoD and Holliday junction ATP-dependent DNA helicase RuvA) were considerably upregulated. Upregulation of these proteins against pesticide stress presumably maintained the photosynthesis, energy metabolism, carbohydrate metabolism, transport and signalling proteins, transcription, translation and DNA repair. Additionally, these proteins might involve in sufficient detoxification of ROS and play a crucial role in damage removal and repair of oxidized proteins, lipids and nucleic acids. Taken together, Anabaena sp. NC-K1 responded towards alpha-cypermethrin stress via modulating its proteome to maintain its cellular metabolism and homeostasis.
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Affiliation(s)
- Ng Kunjarani Chanu
- Environmental Biotechnology Laboratory, Department of Biotechnology and Bioinformatics, North-Eastern Hill University, Shillong, Meghalaya, 793022, India
| | - Madan Kumar Mandal
- Environmental Biotechnology Laboratory, Department of Biotechnology and Bioinformatics, North-Eastern Hill University, Shillong, Meghalaya, 793022, India
| | - Akanksha Srivastava
- Department of Botany, Centre of Advanced Study in Botany, Institute of Science, Banaras Hindu University, Varanasi, 221005, India
| | - Neha Chaurasia
- Environmental Biotechnology Laboratory, Department of Biotechnology and Bioinformatics, North-Eastern Hill University, Shillong, Meghalaya, 793022, India.
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Abstract
Anabaena sp. PCC7120 (hereafter Anabaena 7120) is a nitrogen-fixing, filamentous cyanobacterium. Given its diverse metabolism, it serves as an excellent model organism, particularly for studying cell differentiation, nitrogen fixation, photosynthesis, production of high-value chemicals, and synthetic biology. Gene knockout is a common approach to assess the function of gene products through assessing phenotypic loss of function. In the method described here, a double crossover approach is used to inactivate a target gene or target genes in Anabaena 7120. This method involves replicating the gene(s) from the wild-type genomic DNA and inserting them into an integrative plasmid vector. An internal portion of the genes may be removed and replaced with a GFP-Spectinomycin (gfp-sp) cassette. The plasmid is then introduced into Anabaena 7120 where a double crossover event occurs between the wild-type chromosome and the cargo plasmid, effectively replacing the wild-type gene with the disrupted gene from the plasmid. The gfp-sp cassette combined with the sacB gene serve as positive selection to identify double crossover mutants (Cai and Wolk (1990), 172(6):3138-3145, J. Bacteriol). Finally, the functional genes are cloned into another replicating plasmid vector to produce a cargo plasmid, which is conjugatively introduced into the mutant for a complementation test. By comparing the phenotypes among the wild-type, mutant, and complement, one should see a loss of function in the mutant which is recovered in the complement, thereby defining the function of the target gene. The double crossover approach described here for Anabaena PCC 7120 may be broadly applicable to the study of gene function in cyanobacteria and other prokaryotic organisms.
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Affiliation(s)
- Jaimie Gibbons
- Department of Biology and Microbiology, South Dakota State University, Brookings, SD, USA
| | - Liping Gu
- Department of Biology and Microbiology, South Dakota State University, Brookings, SD, USA
| | - Ruanbao Zhou
- Department of Biology and Microbiology, South Dakota State University, Brookings, SD, USA.
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26
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Gibbons J, Gu L, Qiu Y, Zhou R. Single Crossover to Inactivate Target Gene in Cyanobacteria. Methods Mol Biol 2022; 2489:289-298. [PMID: 35524056 DOI: 10.1007/978-1-0716-2273-5_15] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Anabaena sp. PCC 7120 (hereafter Anabaena 7120) is a model cyanobacterium for studying pathways such as photosynthesis and nitrogen fixation along with many other metabolic pathways common to plants. In addition, since Anabaena 7120 forms specialized N2-fixing cells, called heterocysts, to perform uniquely solar-powered, oxic nitrogen fixation under fixed-nitrogen depleted conditions, this cyanobacterium provides the unique opportunity to study cellular differentiation in bacteria. Since more than 155,810 sequenced prokaryotic genomes are currently available (Zhang et al., Microbiome 8(1):134, 2020), target gene inactivation, combined with analyses of the corresponding mutant's phenotype, has become a powerful tool to assess gene function through detecting a loss-of-function in the knockout mutant. In the method described here, a single crossover approach is used to knockout a target gene in Anabaena 7120. The method requires inserting an internal fragment of the target gene into the cyanobacterial integration vector pZR606 to create a knockout plasmid, and then is introduced to Anabaena 7120 via conjugative transformation. A single crossover, occurring via homologous recombination, disrupts the target gene, creating 3'- and 5'-deleted fragments (Fig. 1). The mutant containing the inactivated gene can then be studied to determine any loss of function, thereby defining the gene's function. This gene inactivation approach is based on an integrative vector pZR606 (Chen et al., Appl Microbiol Biotechnol 99:1779-1793, 2015), which may be broadly applied to gene inactivation in other cyanobacterial species as well as other prokaryotic organisms.
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Affiliation(s)
- Jaimie Gibbons
- Department of Biology and Microbiology, South Dakota State University, Brookings, SD, USA
| | - Liping Gu
- Department of Biology and Microbiology, South Dakota State University, Brookings, SD, USA
| | - Yeyan Qiu
- Department of Biology and Microbiology, South Dakota State University, Brookings, SD, USA
| | - Ruanbao Zhou
- Department of Biology and Microbiology, South Dakota State University, Brookings, SD, USA.
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27
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Swapnil P, Meena M, Rai AK. Molecular interaction of nitrate transporter proteins with recombinant glycinebetaine results in efficient nitrate uptake in the cyanobacterium Anabaena PCC 7120. PLoS One 2021; 16:e0257870. [PMID: 34793479 PMCID: PMC8601584 DOI: 10.1371/journal.pone.0257870] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2020] [Accepted: 09/14/2021] [Indexed: 11/18/2022] Open
Abstract
Nitrate transport in cyanobacteria is mediated by ABC-transporter, which consists of a highly conserved ATP binding cassette (ABC) and a less conserved transmembrane domain (TMD). Under salt stress, recombinant glycinebetaine (GB) not only protected the rate of nitrate transport in transgenic Anabaena PCC 7120, rather stimulated the rate by interacting with the ABC-transporter proteins. In silico analyses revealed that nrtA protein consisted of 427 amino acids, the majority of which were hydrophobic and contained a Tat (twin-arginine translocation) signal profile of 34 amino acids (1-34). The nrtC subunit of 657 amino acids contained two hydrophobic distinct domains; the N-terminal (5-228 amino acids), which was 59% identical to nrtD (the ATP-binding subunit) and the C-terminal (268-591), 28.2% identical to nrtA, suggesting C-terminal as a solute binding domain and N-terminal as ATP binding domain. Subunit nrtD consisted of 277 amino acids and its N-terminal (21-254) was an ATP binding motif. Phylogenetic analysis revealed that nitrate-ABC-transporter proteins are highly conserved among the cyanobacterial species, though variation existed in sequences resulting in several subclades. Nostoc PCC 7120 was very close to Anabaena variabilis ATCC 29413, Anabaena sp. 4-3 and Anabaena sp. CA = ATCC 33047. On the other, Nostoc spp. NIES-3756 and PCC 7524 were often found in the same subclade suggesting more work before referring it to Anabaena PCC 7120 or Nostoc PCC 7120. The molecular interaction of nitrate with nrtA was hydrophilic, while hydrophobic with nrtC and nrtD. GB interaction with nrtACD was hydrophobic and showed higher affinity compared to nitrate.
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Affiliation(s)
- Prashant Swapnil
- Centre of Advanced Study in Botany, Institute of Science, Banaras Hindu University, Varanasi, India
- Department of Botany, University of Delhi, New Delhi, India
| | - Mukesh Meena
- Laboratory of Phytopathology and Microbial Biotechnology, Department of Botany, Mohanlal Sukhadia University, Udaipur, Rajasthan, India
| | - Ashwani K. Rai
- Centre of Advanced Study in Botany, Institute of Science, Banaras Hindu University, Varanasi, India
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Hou X, Qiu Z, Xian Q, Kala S, Jing J, Wong KF, Zhu J, Guo J, Zhu T, Yang M, Sun L. Precise Ultrasound Neuromodulation in a Deep Brain Region Using Nano Gas Vesicles as Actuators. Adv Sci (Weinh) 2021; 8:e2101934. [PMID: 34546652 PMCID: PMC8564444 DOI: 10.1002/advs.202101934] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Revised: 08/12/2021] [Indexed: 05/02/2023]
Abstract
Ultrasound is a promising new modality for non-invasive neuromodulation. Applied transcranially, it can be focused down to the millimeter or centimeter range. The ability to improve the treatment's spatial resolution to a targeted brain region could help to improve its effectiveness, depending upon the application. The present paper details a neurostimulation scheme using gas-filled nanostructures, gas vesicles (GVs), as actuators for improving the efficacy and precision of ultrasound stimuli. Sonicated primary neurons display dose-dependent, repeatable Ca2+ responses, closely synced to stimuli, and increased nuclear expression of the activation marker c-Fos in the presence of GVs. GV-mediated ultrasound triggered rapid and reversible Ca2+ responses in vivo and could selectively evoke neuronal activation in a deep-seated brain region. Further investigation indicate that mechanosensitive ion channels are important mediators of this effect. GVs themselves and the treatment scheme are also found not to induce significant cytotoxicity, apoptosis, or membrane poration in treated cells. Altogether, this study demonstrates a simple and effective method to achieve enhanced and better-targeted neurostimulation with non-invasive low-intensity ultrasound.
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Affiliation(s)
- Xuandi Hou
- Department of Biomedical EngineeringThe Hong Kong Polytechnic UniversityHung HomHong Kong SAR999077P. R. China
| | - Zhihai Qiu
- Department of Biomedical EngineeringThe Hong Kong Polytechnic UniversityHung HomHong Kong SAR999077P. R. China
| | - Quanxiang Xian
- Department of Biomedical EngineeringThe Hong Kong Polytechnic UniversityHung HomHong Kong SAR999077P. R. China
| | - Shashwati Kala
- Department of Biomedical EngineeringThe Hong Kong Polytechnic UniversityHung HomHong Kong SAR999077P. R. China
| | - Jianing Jing
- Department of Biomedical EngineeringThe Hong Kong Polytechnic UniversityHung HomHong Kong SAR999077P. R. China
| | - Kin Fung Wong
- Department of Biomedical EngineeringThe Hong Kong Polytechnic UniversityHung HomHong Kong SAR999077P. R. China
| | - Jiejun Zhu
- Department of Biomedical EngineeringThe Hong Kong Polytechnic UniversityHung HomHong Kong SAR999077P. R. China
| | - Jinghui Guo
- Department of Biomedical EngineeringThe Hong Kong Polytechnic UniversityHung HomHong Kong SAR999077P. R. China
| | - Ting Zhu
- Department of Biomedical EngineeringThe Hong Kong Polytechnic UniversityHung HomHong Kong SAR999077P. R. China
| | - Minyi Yang
- Department of Biomedical EngineeringThe Hong Kong Polytechnic UniversityHung HomHong Kong SAR999077P. R. China
| | - Lei Sun
- Department of Biomedical EngineeringThe Hong Kong Polytechnic UniversityHung HomHong Kong SAR999077P. R. China
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Patel A, Tiwari S, Prasad SM. Arsenate and arsenite-induced inhibition and recovery in two diazotrophic cyanobacteria Nostoc muscorum and Anabaena sp.: study on time-dependent toxicity regulation. Environ Sci Pollut Res Int 2021; 28:51088-51104. [PMID: 33974205 DOI: 10.1007/s11356-021-13800-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/04/2020] [Accepted: 03/31/2021] [Indexed: 06/12/2023]
Abstract
Exposure time, metal bio-accumulation, and upregulation of ascorbate-glutathione (AsA-GSH) cycle are the key factor that provide tolerance against heavy metal stress. Thus, the current study is an endeavor to prove our hypothesis that regulation of arsenate (AsV: 50, 100, and 150 mM) and arsenite (AsIII: 50, 100, and 150 μM) toxicity is time dependent (48-96 h) due to modulation in bio-accumulation pattern, AsA-GSH cycle, and non-enzymatic antioxidants in two paddy field cyanobacteria Nostoc muscorum ATCC27893 and Anabaena sp. PCC7120. After 48 h, reduction in growth associated with increased sensitivity index, As bio-accumulation, and oxidative stress was observed which further intensified after 96 h but the degree of damage was lesser than 48 h. It denotes a significant recovery in growth after 96 h which is correlated with decreased As bio-accumulation and oxidative stress due to increased efficiency of AsA-GSH cycle and non-enzymatic antioxidants. Both the species of As caused significant rise in oxidative biomarkers as evident by in -vitro analysis of O2·-, H2O2, and MDA equivalent contents despite appreciable rise in the activity antioxidative enzymes APX, DHAR, and GR. The study concludes that among both forms of arsenic, AsIII induced more toxic effect on growth by over-accumulating the ROS as evident by weak induction of AsA-GSH cycle to overcome the stress as compared to AsV. Further, with increasing the time exposure, apparent recovery was noticed with the lower doses of AsV, i.e., 50 and 100 mM and AsIII, i.e., 50 and 100 μM; however, the toxicity further aggravated with higher dose of both AsV and AsIII. Study proposes the deleterious impact of AsV and AsIII on cyanobacteria N. muscorum and Anabaena sp. but the toxicity was overcome by time-dependent recovery.
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Affiliation(s)
- Anuradha Patel
- Ranjan Plant Physiology and Biochemistry Laboratory, Department of Botany, University of Allahabad, Prayagraj, 211002, India
| | - Sanjesh Tiwari
- Ranjan Plant Physiology and Biochemistry Laboratory, Department of Botany, University of Allahabad, Prayagraj, 211002, India
| | - Sheo Mohan Prasad
- Ranjan Plant Physiology and Biochemistry Laboratory, Department of Botany, University of Allahabad, Prayagraj, 211002, India.
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Banerjee M, Kalwani P, Chakravarty D, Singh B, Ballal A. Functional and mechanistic insights into the differential effect of the toxicant 'Se(IV)' in the cyanobacterium Anabaena PCC 7120. Aquat Toxicol 2021; 236:105839. [PMID: 34015754 DOI: 10.1016/j.aquatox.2021.105839] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/13/2020] [Revised: 04/07/2021] [Accepted: 04/12/2021] [Indexed: 06/12/2023]
Abstract
Selenium, an essential trace element for animals, poses a threat to all forms of life above a threshold concentration. The ubiquitously present cyanobacteria, a major photosynthetic biotic component of aquatic and other ecosystems, are excellent systems to study the effects of environmental toxicants. The molecular changes that led to beneficial or detrimental effects in response to different doses of selenium oxyanion Se(IV) were analyzed in the filamentous cyanobacterium Anabaena PCC 7120. This organism showed no inhibition in growth up to 15 mg/L sodium selenite, but above this dose i.e. 20-100 mg/L of Se(IV), both growth and photosynthesis were substantially inhibited. Along with the increased accumulation of non-protein thiols, a consistent reduction in levels of ROS was observed at 10 mg/mL dose of Se(IV). High dose of Se(IV) (above 20 mg/L) enhanced endogenous reactive oxygen species (ROS)/lipid peroxidation, and decreased photosynthetic capability. Treatment with 100 mg/L Se(IV) downregulated transcription of several photosynthesis pathways-related genes such as those encoding photosystem I and II proteins, phycobilisome rod-core linker protein, phycocyanobilin, phycoerythrocyanin-associated proteins etc. Interestingly, at a dose range of 10-15 mg/L Se(IV), Anabaena showed an increase in PSII photosynthetic yield and electron transport rate (at PSII), suggesting improved photosynthesis. Se was incorporated into the Anabaena cells, and Se-enriched thylakoid membranes showed higher redox conductivity than the thylakoid membranes from untreated cells. Overall, the data supports that modulation of photosynthetic machinery is one of the crucial mechanisms responsible for the dose-dependent contrasting effect of Se(IV) observed in Anabaena.
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Affiliation(s)
- Manisha Banerjee
- Molecular Biology Division; Bhabha Atomic Research Centre, Mumbai 400085, India; Homi Bhabha National Institute, Anushaktinagar, Mumbai 400094, India.
| | - Prakash Kalwani
- Molecular Biology Division; Bhabha Atomic Research Centre, Mumbai 400085, India; Homi Bhabha National Institute, Anushaktinagar, Mumbai 400094, India
| | - Dhiman Chakravarty
- Molecular Biology Division; Bhabha Atomic Research Centre, Mumbai 400085, India; Homi Bhabha National Institute, Anushaktinagar, Mumbai 400094, India
| | - Beena Singh
- Radiation and Photo Chemistry Division; Bhabha Atomic Research Centre, Mumbai 400085, India; Homi Bhabha National Institute, Anushaktinagar, Mumbai 400094, India
| | - Anand Ballal
- Molecular Biology Division; Bhabha Atomic Research Centre, Mumbai 400085, India; Homi Bhabha National Institute, Anushaktinagar, Mumbai 400094, India.
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31
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Dhuldhaj UP, Pandya UV. Physicochemical behavioral changes in consort with nitrogen metabolism of cyanobacterium Anabaena PCC 7120 under arsenite regimes. Arch Microbiol 2021; 203:4367-4383. [PMID: 34120198 DOI: 10.1007/s00203-021-02405-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2020] [Revised: 05/20/2021] [Accepted: 05/22/2021] [Indexed: 11/25/2022]
Abstract
The present study was undertaken to investigate the arsenite (As III)-induced changes in the diazotrophic cyanobacterium Anabaena PCC 7120. It was observed that the growth of cyanobacterial decreased with increase in As (III) concentration. The cells exposed to As (III) showed morphological variation (deformity) due to the formation of deeper constrictions in vegetative cells. Strain showed increased heterocyst differentiation (1.6-fold higher) whereas decreased nitrogenase activity at the concentration of 40 ppm As (III). The activities of NR, NiR, urease and GS decreased with increase in As (III) concentrations and attained their minimum levels at 40 ppm of As (III). The Ca2+-dependent ATPase activity increased with increase in As (III) concentration and attained its about 2.72-fold higher level at 40 ppm of As (III). In contrast, sharp decline in Mg2+-dependent ATPase activity (28%) was recorded at 1 ppm of As (III) over untreated control. The rates of photosynthetic O2 evolution and respiration decreased with increase in As (III) concentration and attained its minimal level at 40 ppm of As (III). Therefore, this study highlighted arsenite regimes efficiently correlated with behavioral changes in consort with strain.
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Affiliation(s)
- Umesh Pravin Dhuldhaj
- School of Life Sciences, Swami Ramanand Teerth Marathwada University, Nanded, 431606, Maharashtra, India
| | - Urja Vinodray Pandya
- Department of Microbiology, Gujarat Vidyapith, Sadra, Gandhinagar, 382320, Gujarat, India.
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Srivastava A, Biswas S, Yadav S, Kumar S, Srivastava V, Mishra Y. Acute cadmium toxicity and post-stress recovery: Insights into coordinated and integrated response/recovery strategies of Anabaena sp. PCC 7120. J Hazard Mater 2021; 411:124822. [PMID: 33858073 DOI: 10.1016/j.jhazmat.2020.124822] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/03/2020] [Revised: 12/01/2020] [Accepted: 12/08/2020] [Indexed: 06/12/2023]
Abstract
Cyanobacteria, the first photoautotrophs have remarkable adaptive capabilities against most abiotic stresses, including Cd. A model cyanobacterium, Anabaena sp. PCC 7120 has been commonly used to understand cyanobacterial plasticity under different environmental stresses. However, very few studies have focused on the acute Cd toxicity. In this context, Anabaena was subjected to 100 μM Cd for 48 h (acute Cd stress, ACdS) and then transferred into the fresh medium for post-stress recovery (PSR). We further investigated the dynamics of morpho-ultrastructure, physiology, cytosolic proteome, thylakoidal complexes, chelators, and transporters after ACdS, as well as during early (ER), mid (MR), and late (LR) phases of PSR. The findings revealed that ACdS induced intracellular Cd accumulation and ROS production, altered morpho-ultrastructure, reduced photosynthetic pigments, and affected the structural organization of PSII, which subsequently hindered photosynthetic efficiency. Anabaena responded to ACdS and recovered during PSR by reprogramming the expression pattern of proteins/genes involved in cellular defense and repair; CO2 access, Calvin-Benson cycle, glycolysis, and pentose phosphate pathway; protein biosynthesis, folding, and degradation; regulatory functions; PSI-based cyclic electron flow; Cd chelation; and efflux. These modulations occurred in an integrated and coordinated manner that facilitated Anabaena to detoxify Cd and repair ACdS-induced cellular damage.
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Affiliation(s)
- Akanksha Srivastava
- Department of Botany, Centre of Advanced Study in Botany, Institute of Science, Banaras Hindu University, Varanasi 221005, India
| | - Subhankar Biswas
- Department of Botany, Centre of Advanced Study in Botany, Institute of Science, Banaras Hindu University, Varanasi 221005, India
| | - Sandhya Yadav
- Department of Botany, Centre of Advanced Study in Botany, Institute of Science, Banaras Hindu University, Varanasi 221005, India
| | - Sanjiv Kumar
- Division of Glycoscience, Department of Chemistry, School of Engineering Sciences in Chemistry, Biotechnology and Health, Royal Institute of Technology (KTH), AlbaNova University Centre, Stockholm 10691, Sweden
| | - Vaibhav Srivastava
- Division of Glycoscience, Department of Chemistry, School of Engineering Sciences in Chemistry, Biotechnology and Health, Royal Institute of Technology (KTH), AlbaNova University Centre, Stockholm 10691, Sweden
| | - Yogesh Mishra
- Department of Botany, Centre of Advanced Study in Botany, Institute of Science, Banaras Hindu University, Varanasi 221005, India.
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Perin G, Fletcher T, Sagi-Kiss V, Gaboriau DCA, Carey MR, Bundy JG, Jones PR. Calm on the surface, dynamic on the inside. Molecular homeostasis of Anabaena sp. PCC 7120 nitrogen metabolism. Plant Cell Environ 2021; 44:1885-1907. [PMID: 33608943 DOI: 10.1111/pce.14034] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Revised: 02/12/2021] [Accepted: 02/13/2021] [Indexed: 06/12/2023]
Abstract
Nitrogen sources are all converted into ammonium/ia as a first step of assimilation. It is reasonable to expect that molecular components involved in the transport of ammonium/ia across biological membranes connect with the regulation of both nitrogen and central metabolism. We applied both genetic (i.e., Δamt mutation) and environmental treatments to a target biological system, the cyanobacterium Anabaena sp PCC 7120. The aim was to both perturb nitrogen metabolism and induce multiple inner nitrogen states, respectively, followed by targeted quantification of key proteins, metabolites and enzyme activities. The absence of AMT transporters triggered a substantial whole-system response, affecting enzyme activities and quantity of proteins and metabolites, spanning nitrogen and carbon metabolisms. Moreover, the Δamt strain displayed a molecular fingerprint indicating nitrogen deficiency even under nitrogen replete conditions. Contrasting with such dynamic adaptations was the striking near-complete lack of an externally measurable altered phenotype. We conclude that this species evolved a highly robust and adaptable molecular network to maintain homeostasis, resulting in substantial internal but minimal external perturbations. This analysis provides evidence for a potential role of AMT transporters in the regulatory/signalling network of nitrogen metabolism and the existence of a novel fourth regulatory mechanism controlling glutamine synthetase activity.
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Affiliation(s)
- Giorgio Perin
- Department of Life Sciences, Imperial College London, London, UK
| | - Tyler Fletcher
- Complex Carbohydrate Research Center and Department of Chemistry, University of Georgia, Athens, Georgia, USA
| | - Virag Sagi-Kiss
- Department of Metabolism, Digestion and Reproduction, Imperial College London, London, UK
| | - David C A Gaboriau
- Facility for Imaging by Light Microscopy, NHLI, Imperial College London, London, UK
| | - Mathew R Carey
- Department of Metabolism, Digestion and Reproduction, Imperial College London, London, UK
| | - Jacob G Bundy
- Department of Metabolism, Digestion and Reproduction, Imperial College London, London, UK
| | - Patrik R Jones
- Department of Life Sciences, Imperial College London, London, UK
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He H, Miao R, Huang L, Jiang H, Cheng Y. Vegetative cells may perform nitrogen fixation function under nitrogen deprivation in Anabaena sp. strain PCC 7120 based on genome-wide differential expression analysis. PLoS One 2021; 16:e0248155. [PMID: 33662009 PMCID: PMC7932525 DOI: 10.1371/journal.pone.0248155] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Accepted: 02/20/2021] [Indexed: 11/25/2022] Open
Abstract
Nitrogen assimilation is strictly regulated in cyanobacteria. In an inorganic nitrogen-deficient environment, some vegetative cells of the cyanobacterium Anabaena differentiate into heterocysts. We assessed the photosynthesis and nitrogen-fixing capacities of heterocysts and vegetative cells, respectively, at the transcriptome level. RNA extracted from nitrogen-replete vegetative cells (NVs), nitrogen-deprived vegetative cells (NDVs), and nitrogen-deprived heterocysts (NDHs) in Anabaena sp. strain PCC 7120 was evaluated by transcriptome sequencing. Paired comparisons of NVs vs. NDHs, NVs vs. NDVs, and NDVs vs. NDHs revealed 2,044 differentially expressed genes (DEGs). Kyoto Encyclopedia of Genes and Genomes enrichment analysis of the DEGs showed that carbon fixation in photosynthetic organisms and several nitrogen metabolism-related pathways were significantly enriched. Synthesis of Gvp (Gas vesicle synthesis protein gene) in NVs was blocked by nitrogen deprivation, which may cause Anabaena cells to sink and promote nitrogen fixation under anaerobic conditions; in contrast, heterocysts may perform photosynthesis under nitrogen deprivation conditions, whereas the nitrogen fixation capability of vegetative cells was promoted by nitrogen deprivation. Immunofluorescence analysis of nitrogenase iron protein suggested that the nitrogen fixation capability of vegetative cells was promoted by nitrogen deprivation. Our findings provide insight into the molecular mechanisms underlying nitrogen fixation and photosynthesis in vegetative cells and heterocysts at the transcriptome level. This study provides a foundation for further functional verification of heterocyst growth, differentiation, and water bloom control.
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Affiliation(s)
- Hongli He
- Jilin Provincial Key Laboratory of Plant Resource Science and Green Production, Jilin Normal University, Siping, Jilin Province, China
| | - Runyu Miao
- Jilin Provincial Key Laboratory of Plant Resource Science and Green Production, Jilin Normal University, Siping, Jilin Province, China
| | - Lilong Huang
- Jilin Provincial Key Laboratory of Plant Resource Science and Green Production, Jilin Normal University, Siping, Jilin Province, China
| | - Hongshan Jiang
- Jilin Provincial Key Laboratory of Plant Resource Science and Green Production, Jilin Normal University, Siping, Jilin Province, China
| | - Yunqing Cheng
- Jilin Provincial Key Laboratory of Plant Resource Science and Green Production, Jilin Normal University, Siping, Jilin Province, China
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Mitra R, Gadkari VV, Meinen BA, van Mierlo CPM, Ruotolo BT, Bardwell JCA. Mechanism of the small ATP-independent chaperone Spy is substrate specific. Nat Commun 2021; 12:851. [PMID: 33558474 PMCID: PMC7870927 DOI: 10.1038/s41467-021-21120-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2020] [Accepted: 01/08/2021] [Indexed: 11/17/2022] Open
Abstract
ATP-independent chaperones are usually considered to be holdases that rapidly bind to non-native states of substrate proteins and prevent their aggregation. These chaperones are thought to release their substrate proteins prior to their folding. Spy is an ATP-independent chaperone that acts as an aggregation inhibiting holdase but does so by allowing its substrate proteins to fold while they remain continuously chaperone bound, thus acting as a foldase as well. The attributes that allow such dual chaperoning behavior are unclear. Here, we used the topologically complex protein apoflavodoxin to show that the outcome of Spy's action is substrate specific and depends on its relative affinity for different folding states. Tighter binding of Spy to partially unfolded states of apoflavodoxin limits the possibility of folding while bound, converting Spy to a holdase chaperone. Our results highlight the central role of the substrate in determining the mechanism of chaperone action.
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Affiliation(s)
- Rishav Mitra
- Howard Hughes Medical Institute, University of Michigan, Ann Arbor, MI, USA
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI, USA
| | - Varun V Gadkari
- Department of Chemistry, University of Michigan, Ann Arbor, MI, USA
| | - Ben A Meinen
- Howard Hughes Medical Institute, University of Michigan, Ann Arbor, MI, USA
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI, USA
| | | | | | - James C A Bardwell
- Howard Hughes Medical Institute, University of Michigan, Ann Arbor, MI, USA.
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI, USA.
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36
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Verma N, Prasad SM. Regulation of redox homeostasis in cadmium stressed rice field cyanobacteria by exogenous hydrogen peroxide and nitric oxide. Sci Rep 2021; 11:2893. [PMID: 33536576 PMCID: PMC7858583 DOI: 10.1038/s41598-021-82397-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Accepted: 01/15/2021] [Indexed: 01/24/2023] Open
Abstract
In the present study, defensive strategies of H2O2 mediated NO signaling were analyzed in Cd stressed Nostoc muscorum and Anabaena sp. Exogenously supplied SNP (10 µM) and H2O2 (1 µM) lessen the toxicity of Cd (6 µM) but without NO; H2O2 was unable to release the stress from cyanobacterial cells potentially. The reduced contents of exopolysaccharide, protein content, endogenous NO and enzymatic antioxidants (SOD, POD, CAT, and GST) due to Cd toxicity, were found increased significantly after exogenous application of H2O2 and SNP thereafter, cyanobacterial calls flourished much better after releasing toxic level of Cd. Moreover, increased level of ROS due to Cd stress also normalized under exogenous application of H2O2 and SNP. However, chelation of NO hindered the signaling mechanism of H2O2 that diminished its potential against Cd stress while signaling of NO has not been hindered by chelation of H2O2 and NO potentially released the Cd stress from cyanobacterial cells. In conclusion, current findings demonstrated the synergistic signaling between H2O2 and NO towards the improvement of cyanobacterial tolerance to Cd stress, thereby enhancing the growth and antioxidant defense system of test cyanobacteria that improved fertility and productivity of soil even under the situation of metal contamination.
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Affiliation(s)
- Nidhi Verma
- Ranjan Plant Physiology and Biochemistry Laboratory, Department of Botany, University of Allahabad, Prayagraj, 211002, India
| | - Sheo Mohan Prasad
- Ranjan Plant Physiology and Biochemistry Laboratory, Department of Botany, University of Allahabad, Prayagraj, 211002, India.
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Akhtar P, Biswas A, Petrova N, Zakar T, van Stokkum IHM, Lambrev PH. Time-resolved fluorescence study of excitation energy transfer in the cyanobacterium Anabaena PCC 7120. Photosynth Res 2020; 144:247-259. [PMID: 32076913 PMCID: PMC7203587 DOI: 10.1007/s11120-020-00719-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/28/2019] [Accepted: 02/07/2020] [Indexed: 05/28/2023]
Abstract
Excitation energy transfer (EET) and trapping in Anabaena variabilis (PCC 7120) intact cells, isolated phycobilisomes (PBS) and photosystem I (PSI) complexes have been studied by picosecond time-resolved fluorescence spectroscopy at room temperature. Global analysis of the time-resolved fluorescence kinetics revealed two lifetimes of spectral equilibration in the isolated PBS, 30-35 ps and 110-130 ps, assigned primarily to energy transfer within the rods and between the rods and the allophycocyanin core, respectively. An additional intrinsic kinetic component with a lifetime of 500-700 ps was found, representing non-radiative decay or energy transfer in the core. Isolated tetrameric PSI complexes exhibited biexponential fluorescence decay kinetics with lifetimes of about 10 ps and 40 ps, representing equilibration between the bulk antenna chlorophylls with low-energy "red" states and trapping of the equilibrated excitations, respectively. The cascade of EET in the PBS and in PSI could be resolved in intact filaments as well. Virtually all energy absorbed by the PBS was transferred to the photosystems on a timescale of 180-190 ps.
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Affiliation(s)
- Parveen Akhtar
- Biological Research Centre, Szeged, Temesvári krt. 62, Szeged, 6726, Hungary
- ELI-ALPS, ELI-HU Nonprofit Ltd., Wolfgang Sandner u. 3, Szeged, 6728, Hungary
| | - Avratanu Biswas
- Biological Research Centre, Szeged, Temesvári krt. 62, Szeged, 6726, Hungary
- Doctoral School of Biology, University of Szeged, Közép Fasor 52, Szeged, 6726, Hungary
- Department of Physics and Astronomy and LaserLaB, Faculty of Science, Vrije Universiteit Amsterdam, De Boelelaan 1081, 1081 HV, Amsterdam, The Netherlands
| | - Nia Petrova
- Institute of Biophysics and Biomedical Engineering, Bulgarian Academy of Sciences, Acad G. Bontchev Str., Bl. 21, 1113, Sofia, Bulgaria
| | - Tomas Zakar
- Biological Research Centre, Szeged, Temesvári krt. 62, Szeged, 6726, Hungary
| | - Ivo H M van Stokkum
- Department of Physics and Astronomy and LaserLaB, Faculty of Science, Vrije Universiteit Amsterdam, De Boelelaan 1081, 1081 HV, Amsterdam, The Netherlands
| | - Petar H Lambrev
- Biological Research Centre, Szeged, Temesvári krt. 62, Szeged, 6726, Hungary.
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Lee H, Rhee S. Structural and mutational analyses of the bifunctional arginine dihydrolase and ornithine cyclodeaminase AgrE from the cyanobacterium Anabaena. J Biol Chem 2020; 295:5751-5760. [PMID: 32198136 PMCID: PMC7186175 DOI: 10.1074/jbc.ra120.012768] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2020] [Revised: 03/17/2020] [Indexed: 01/07/2023] Open
Abstract
In cyanobacteria, metabolic pathways that use the nitrogen-rich amino acid arginine play a pivotal role in nitrogen storage and mobilization. The N-terminal domains of two recently identified bacterial enzymes: ArgZ from Synechocystis and AgrE from Anabaena, have been found to contain an arginine dihydrolase. This enzyme provides catabolic activity that converts arginine to ornithine, resulting in concomitant release of CO2 and ammonia. In Synechocystis, the ArgZ-mediated ornithine-ammonia cycle plays a central role in nitrogen storage and remobilization. The C-terminal domain of AgrE contains an ornithine cyclodeaminase responsible for the formation of proline from ornithine and ammonia production, indicating that AgrE is a bifunctional enzyme catalyzing two sequential reactions in arginine catabolism. Here, the crystal structures of AgrE in three different ligation states revealed that it has a tetrameric conformation, possesses a binding site for the arginine dihydrolase substrate l-arginine and product l-ornithine, and contains a binding site for the coenzyme NAD(H) required for ornithine cyclodeaminase activity. Structure-function analyses indicated that the structure and catalytic mechanism of arginine dihydrolase in AgrE are highly homologous with those of a known bacterial arginine hydrolase. We found that in addition to other active-site residues, Asn-71 is essential for AgrE's dihydrolase activity. Further analysis suggested the presence of a passage for substrate channeling between the two distinct AgrE active sites, which are situated ∼45 Å apart. These results provide structural and functional insights into the bifunctional arginine dihydrolase-ornithine cyclodeaminase enzyme AgrE required for arginine catabolism in Anabaena.
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Affiliation(s)
- Haehee Lee
- Department of Agricultural Biotechnology, Seoul National University, Seoul 151-921, Korea
| | - Sangkee Rhee
- Department of Agricultural Biotechnology, Seoul National University, Seoul 151-921, Korea; Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul 151-921, Korea.
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Österholm J, Popin RV, Fewer DP, Sivonen K. Phylogenomic Analysis of Secondary Metabolism in the Toxic Cyanobacterial Genera Anabaena, Dolichospermum and Aphanizomenon. Toxins (Basel) 2020; 12:E248. [PMID: 32290496 PMCID: PMC7232259 DOI: 10.3390/toxins12040248] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2020] [Revised: 04/08/2020] [Accepted: 04/09/2020] [Indexed: 01/20/2023] Open
Abstract
Cyanobacteria produce an array of toxins that pose serious health risks to humans and animals. The closely related diazotrophic genera, Anabaena, Dolichospermum, and Aphanizomenon, frequently form poisonous blooms in lakes and brackish waters around the world. These genera form a complex now termed the Anabaena, Dolichospermum, and Aphanizomenon (ADA) clade and produce a greater array of toxins than any other cyanobacteria group. However, taxonomic confusion masks the distribution of toxin biosynthetic pathways in cyanobacteria. Here we obtained 11 new draft genomes to improve the understanding of toxin production in these genera. Comparison of secondary metabolite pathways in all available 31 genomes for these three genera suggests that the ability to produce microcystin, anatoxin-a, and saxitoxin is associated with specific subgroups. Each toxin gene cluster was concentrated or even limited to a certain subgroup within the ADA clade. Our results indicate that members of the ADA clade encode a variety of secondary metabolites following the phylogenetic clustering of constituent species. The newly sequenced members of the ADA clade show that phylogenetic separation of planktonic Dolichospermum and benthic Anabaena is not complete. This underscores the importance of taxonomic revision of Anabaena, Dolichospermum, and Aphanizomenon genera to reflect current phylogenomic understanding.
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Affiliation(s)
| | | | | | - Kaarina Sivonen
- Department of Microbiology, University of Helsinki, Viikinkaari 9, FI-00014 Helsinki, Finland; (J.Ö.); (R.V.P.); (D.P.F.)
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Mihara S, Sugiura K, Yoshida K, Hisabori T. Thioredoxin targets are regulated in heterocysts of cyanobacterium Anabaena sp. PCC 7120 in a light-independent manner. J Exp Bot 2020; 71:2018-2027. [PMID: 31863668 PMCID: PMC7242069 DOI: 10.1093/jxb/erz561] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/22/2019] [Accepted: 12/18/2019] [Indexed: 05/22/2023]
Abstract
In the nitrogen-fixing cyanobacterium Anabaena sp. PCC 7120, glucose 6-phosphate dehydrogenase (G6PDH) plays an important role in producing the power for reducing nitrogenase under light conditions. Our previous study showed that thioredoxin suppresses G6PDH by reducing its activator protein OpcA, implying that G6PDH is inactivated under light conditions because thioredoxins are reduced by the photosynthetic electron transport system in cyanobacteria. To address how Anabaena sp. PCC 7120 maintains G6PDH activity even under light conditions when nitrogen fixation occurs, we investigated the redox regulation system in vegetative cells and specific nitrogen-fixing cells named heterocysts, individually. We found that thioredoxin target proteins were more oxidized in heterocysts than in vegetative cells under light conditions. Alterations in the redox regulation mechanism of heterocysts may affect the redox states of thioredoxin target proteins, including OpcA, so that G6PDH is activated in heterocysts even under light conditions.
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Affiliation(s)
- Shoko Mihara
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, Nagatsuta-cho, Midori-ku, Yokohama, Japan
| | - Kazunori Sugiura
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, Nagatsuta-cho, Midori-ku, Yokohama, Japan
- School of Life Science and Technology, Tokyo Institute of Technology, Nagatsuta-cho, Midori-ku, Yokohama, Japan
- Present address: The Institute of Scientific and Industrial Research, Osaka University, Ibaraki, Osaka 567-0047, Japan
| | - Keisuke Yoshida
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, Nagatsuta-cho, Midori-ku, Yokohama, Japan
- School of Life Science and Technology, Tokyo Institute of Technology, Nagatsuta-cho, Midori-ku, Yokohama, Japan
| | - Toru Hisabori
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, Nagatsuta-cho, Midori-ku, Yokohama, Japan
- School of Life Science and Technology, Tokyo Institute of Technology, Nagatsuta-cho, Midori-ku, Yokohama, Japan
- Correspondence:
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41
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Chen M, Perez-Boerema A, Zhang L, Li Y, Yang M, Li S, Amunts A. Distinct structural modulation of photosystem I and lipid environment stabilizes its tetrameric assembly. Nat Plants 2020; 6:314-320. [PMID: 32170279 DOI: 10.1038/s41477-020-0610-x] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2019] [Accepted: 01/30/2020] [Indexed: 05/19/2023]
Abstract
Photosystem I (PSI) is able to form different oligomeric states across various species. To reveal the structural basis for PSI dimerization and tetramerization, we structurally investigated PSI from the cyanobacterium Anabaena. This revealed a disrupted trimerization domain due to lack of the terminal residues of PsaL in the lumen, which resulted in PSI dimers with loose connections between monomers and weaker energy-coupled chlorophylls than in the trimer. At the dimer surface, specific phospholipids, cofactors and interactions in combination facilitated recruitment of another dimer to form a tetramer. Taken together, the relaxed luminal connections and lipid specificity at the dimer interface account for membrane curvature. PSI tetramer assembly appears to increase the surface area of the thylakoid membrane, which would contribute to PSI crowding.
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Affiliation(s)
- Ming Chen
- Beijing Engineering Research Center for Biofuels, Institute of Nuclear and New, Energy Technology, Tsinghua University, Beijing, P. R. China
| | - Annemarie Perez-Boerema
- Science for Life Laboratory, Department of Biochemistry and Biophysics, Stockholm University, Solna, Sweden
- Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
| | - Laixing Zhang
- Ministry of Education Key Laboratory of Protein Science, Tsinghua-Peking Joint, Center for Life Sciences, Beijing Advanced Innovation Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing, P. R. China
| | - Yanxue Li
- Beijing Engineering Research Center for Biofuels, Institute of Nuclear and New, Energy Technology, Tsinghua University, Beijing, P. R. China
| | - Maojun Yang
- Ministry of Education Key Laboratory of Protein Science, Tsinghua-Peking Joint, Center for Life Sciences, Beijing Advanced Innovation Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing, P. R. China
| | - Shizhong Li
- Beijing Engineering Research Center for Biofuels, Institute of Nuclear and New, Energy Technology, Tsinghua University, Beijing, P. R. China.
| | - Alexey Amunts
- Science for Life Laboratory, Department of Biochemistry and Biophysics, Stockholm University, Solna, Sweden.
- Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden.
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González-Pleiter M, Cirés S, Wörmer L, Agha R, Pulido-Reyes G, Martín-Betancor K, Rico A, Leganés F, Quesada A, Fernández-Piñas F. Ecotoxicity assessment of microcystins from freshwater samples using a bioluminescent cyanobacterial bioassay. Chemosphere 2020; 240:124966. [PMID: 31726608 DOI: 10.1016/j.chemosphere.2019.124966] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Revised: 09/03/2019] [Accepted: 09/24/2019] [Indexed: 06/10/2023]
Abstract
The hepatotoxic cyanotoxins microcystins (MCs) are emerging contaminants naturally produced by cyanobacteria. Yet their ecological role remains unsolved, previous research suggests that MCs have allelopathic effects on competing photosynthetic microorganisms, even eliciting toxic effects on other freshwater cyanobacteria. In this context, the bioluminescent recombinant cyanobacterium Anabaena sp. PCC7120 CPB4337 (hereinafter Anabaena) was exposed to extracts of MCs. These were obtained from eight natural samples from freshwater reservoirs that contained MCs with a concentration range of 0.04-11.9 μg MCs L-1. MCs extracts included the three most common MCs variants (MC-LR, MC-RR, MC-YR) in different proportions (MC-LR: 100-0%; MC-RR: 100-0%; MC-YR: 14.2-0%). The Anabaena bioassay based on bioluminescence inhibition has been successfully used to test the toxicity of many emerging contaminants (e.g., pharmaceuticals) but never for cyanotoxins prior to this study. Exposure of Anabaena to MCs extracts induced a decrease in its bioluminescence with effective concentration decreasing bioluminescence by 50% ranging from 0.4 to 50.5 μg MC L-1 in the different samples. Bioluminescence responses suggested an interaction between MCs variants which was analyzed via the Additive Index method (AI), indicating an antagonistic effect (AI < 0) of MC-LR and MC-RR present in the samples. Additionally, MC extracts exposure triggered an increase of intracellular free Ca2+ in Anabaena. In short, this study supports the use of the Anabaena bioassay as a sensitive tool to assess the presence of MCs at environmentally relevant concentrations and opens interesting avenues regarding the interactions between MCs variants and the possible implication of Ca2+ in the mode of action of MCs towards cyanobacteria.
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Affiliation(s)
- Miguel González-Pleiter
- Departamento de Biología, C/Darwin, 2, Universidad Autónoma de Madrid, 28049, Madrid, Spain.
| | - Samuel Cirés
- Departamento de Biología, C/Darwin, 2, Universidad Autónoma de Madrid, 28049, Madrid, Spain
| | - Lars Wörmer
- Organic Geochemistry Group, MARUM-Center for Marine Environmental Sciences, University of Bremen, Leobener Str. 8, 28359, Bremen, Germany
| | - Ramsy Agha
- Department of Ecosystem Research, Leibniz-Institute of Freshwater Ecology and Inland Fisheries (IGB), Müggelseedamm 301, Berlin, 12587, Germany
| | - Gerardo Pulido-Reyes
- Departamento de Biología, C/Darwin, 2, Universidad Autónoma de Madrid, 28049, Madrid, Spain
| | - Keila Martín-Betancor
- Departamento de Biología, C/Darwin, 2, Universidad Autónoma de Madrid, 28049, Madrid, Spain
| | - Andreu Rico
- IMDEA Water Institute, Science and Technology Campus of the University of Alcalá, Avenida Punto Com 2, 28805, Alcalá de Henares, Madrid, Spain
| | - Francisco Leganés
- Departamento de Biología, C/Darwin, 2, Universidad Autónoma de Madrid, 28049, Madrid, Spain
| | - Antonio Quesada
- Departamento de Biología, C/Darwin, 2, Universidad Autónoma de Madrid, 28049, Madrid, Spain
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Kato K, Nagao R, Jiang TY, Ueno Y, Yokono M, Chan SK, Watanabe M, Ikeuchi M, Shen JR, Akimoto S, Miyazaki N, Akita F. Structure of a cyanobacterial photosystem I tetramer revealed by cryo-electron microscopy. Nat Commun 2019; 10:4929. [PMID: 31666526 PMCID: PMC6821847 DOI: 10.1038/s41467-019-12942-8] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2019] [Accepted: 10/04/2019] [Indexed: 11/17/2022] Open
Abstract
Photosystem I (PSI) functions to harvest light energy for conversion into chemical energy. The organisation of PSI is variable depending on the species of organism. Here we report the structure of a tetrameric PSI core isolated from a cyanobacterium, Anabaena sp. PCC 7120, analysed by single-particle cryo-electron microscopy (cryo-EM) at 3.3 Å resolution. The PSI tetramer has a C2 symmetry and is organised in a dimer of dimers form. The structure reveals interactions at the dimer-dimer interface and the existence of characteristic pigment orientations and inter-pigment distances within the dimer units that are important for unique excitation energy transfer. In particular, characteristic residues of PsaL are identified to be responsible for the formation of the tetramer. Time-resolved fluorescence analyses showed that the PSI tetramer has an enhanced excitation-energy quenching. These structural and spectroscopic findings provide insights into the physiological significance of the PSI tetramer and evolutionary changes of the PSI organisations.
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Affiliation(s)
- Koji Kato
- Research Institute for Interdisciplinary Science and Graduate School of Natural Science and Technology, Okayama University, Okayama, 700-8530, Japan
| | - Ryo Nagao
- Research Institute for Interdisciplinary Science and Graduate School of Natural Science and Technology, Okayama University, Okayama, 700-8530, Japan
| | - Tian-Yi Jiang
- Research Institute for Interdisciplinary Science and Graduate School of Natural Science and Technology, Okayama University, Okayama, 700-8530, Japan
| | - Yoshifumi Ueno
- Graduate School of Science, Kobe University, Hyogo, 657-8501, Japan
| | - Makio Yokono
- Nippon Flour Mills Co., Ltd., Innovation Center, Kanagawa, 243-0041, Japan
| | - Siu Kit Chan
- Research Institute for Interdisciplinary Science and Graduate School of Natural Science and Technology, Okayama University, Okayama, 700-8530, Japan
| | - Mai Watanabe
- Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, Tokyo, 153-8902, Japan
| | - Masahiko Ikeuchi
- Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, Tokyo, 153-8902, Japan
| | - Jian-Ren Shen
- Research Institute for Interdisciplinary Science and Graduate School of Natural Science and Technology, Okayama University, Okayama, 700-8530, Japan.
| | - Seiji Akimoto
- Graduate School of Science, Kobe University, Hyogo, 657-8501, Japan.
| | - Naoyuki Miyazaki
- Life Science Center for Survival Dynamics, Tsukuba Advanced Research Alliance (TARA), University of Tsukuba, Tsukuba, Japan.
- Institute for Protein Research, Laboratory of Protein Synthesis and Expression, Osaka University, Osaka, 565-0871, Japan.
| | - Fusamichi Akita
- Research Institute for Interdisciplinary Science and Graduate School of Natural Science and Technology, Okayama University, Okayama, 700-8530, Japan.
- Japan Science and Technology Agency, PRESTO, Saitama, 332-0012, Japan.
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Zheng L, Li Y, Li X, Zhong Q, Li N, Zhang K, Zhang Y, Chu H, Ma C, Li G, Zhao J, Gao N. Structural and functional insights into the tetrameric photosystem I from heterocyst-forming cyanobacteria. Nat Plants 2019; 5:1087-1097. [PMID: 31595062 DOI: 10.1038/s41477-019-0525-6] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2019] [Accepted: 09/05/2019] [Indexed: 05/05/2023]
Abstract
Two large protein-cofactor complexes, photosystem I and photosystem II, are the central components of photosynthesis in the thylakoid membranes. Here, we report the 2.37-Å structure of a tetrameric photosystem I complex from a heterocyst-forming cyanobacterium Anabaena sp. PCC 7120. Four photosystem I monomers, organized in a dimer of dimer, form two distinct interfaces that are largely mediated by specifically orientated polar lipids, such as sulfoquinovosyl diacylglycerol. The structure depicts a more closely connected network of chlorophylls across monomer interfaces than those seen in trimeric PSI from thermophilic cyanobacteria, possibly allowing a more efficient energy transfer between monomers. Our physiological data also revealed a functional link of photosystem I oligomerization to cyclic electron flow and thylakoid membrane organization.
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Affiliation(s)
- Lvqin Zheng
- State Key Laboratory of Membrane Biology, Peking-Tsinghua Center for Life Sciences, Academy for Advanced Interdisciplinary Studies, School of Life Sciences, Peking University, Beijing, China
| | - Yanbing Li
- State Key Laboratory of Protein and Plant Genetic Engineering, School of Life Sciences, Peking University, Beijing, China
| | - Xiying Li
- State Key Laboratory of Protein and Plant Genetic Engineering, School of Life Sciences, Peking University, Beijing, China
| | - Qinglu Zhong
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, China
| | - Ningning Li
- State Key Laboratory of Membrane Biology, Peking-Tsinghua Center for Life Sciences, Academy for Advanced Interdisciplinary Studies, School of Life Sciences, Peking University, Beijing, China
| | - Kun Zhang
- State Key Laboratory of Protein and Plant Genetic Engineering, School of Life Sciences, Peking University, Beijing, China
| | - Yuebin Zhang
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, China
| | - Huiying Chu
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, China
| | - Chengying Ma
- State Key Laboratory of Membrane Biology, Peking-Tsinghua Center for Life Sciences, Academy for Advanced Interdisciplinary Studies, School of Life Sciences, Peking University, Beijing, China
| | - Guohui Li
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, China.
| | - Jindong Zhao
- State Key Laboratory of Protein and Plant Genetic Engineering, School of Life Sciences, Peking University, Beijing, China.
- Chinese Academy of Sciences Key Laboratory of Phycological Research, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, Hubei, China.
| | - Ning Gao
- State Key Laboratory of Membrane Biology, Peking-Tsinghua Center for Life Sciences, Academy for Advanced Interdisciplinary Studies, School of Life Sciences, Peking University, Beijing, China.
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Olmedo-Verd E, Brenes-Álvarez M, Vioque A, Muro-Pastor AM. A Heterocyst-Specific Antisense RNA Contributes to Metabolic Reprogramming in Nostoc sp. PCC 7120. Plant Cell Physiol 2019; 60:1646-1655. [PMID: 31093664 DOI: 10.1093/pcp/pcz087] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Accepted: 04/28/2019] [Indexed: 06/09/2023]
Abstract
Upon nitrogen deficiency, some filamentous cyanobacteria differentiate specialized cells, called heterocysts, devoted to N2 fixation. Heterocysts appear regularly spaced along the filaments and exhibit structural and metabolic adaptations, such as loss of photosynthetic CO2 fixation or increased respiration, to provide a proper microaerobic environment for its specialized function. Heterocyst development is under transcriptional control of the global nitrogen regulator NtcA and the specific regulator HetR. Transcription of a large number of genes is induced or repressed upon nitrogen deficiency specifically in cells undergoing differentiation. In recent years, the HetR regulon has been described to include heterocyst-specific trans-acting small RNAs and antisense RNAs (asRNAs), suggesting that there is an additional layer of post-transcriptional regulation involved in heterocyst development. Here, we characterize in the cyanobacterium Nostoc (Anabaena) sp. PCC 7120 an asRNA, that we call as_glpX, transcribed within the glpX gene encoding the Calvin cycle bifunctional enzyme sedoheptulose-1,7-bisphosphatase/fructose-1,6-bisphosphatase (SBPase). Transcription of as_glpX is restricted to heterocysts and is induced very early during the process of differentiation. Expression of as_glpX RNA promotes the cleavage of the glpX mRNA by RNase III, resulting in a reduced amount of SBPase. Therefore, the early expression of this asRNA could contribute to the quick shut-down of CO2 fixation in those cells in the filament that are undergoing differentiation into heterocysts. In summary, as_glpX is the first naturally occurring asRNA shown to rapidly and dynamically regulate metabolic transformation in Nostoc heterocysts. The use of antisense transcripts to manipulate gene expression specifically in heterocysts could became a useful tool for metabolic engineering in cyanobacteria.
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Affiliation(s)
- Elvira Olmedo-Verd
- Instituto de Bioquímica Vegetal y Fotosíntesis, Universidad de Sevilla and CSIC, Américo Vespucio 49, 41092 Sevilla, Spain
| | - Manuel Brenes-Álvarez
- Instituto de Bioquímica Vegetal y Fotosíntesis, Universidad de Sevilla and CSIC, Américo Vespucio 49, 41092 Sevilla, Spain
| | - Agustín Vioque
- Instituto de Bioquímica Vegetal y Fotosíntesis, Universidad de Sevilla and CSIC, Américo Vespucio 49, 41092 Sevilla, Spain
| | - Alicia M Muro-Pastor
- Instituto de Bioquímica Vegetal y Fotosíntesis, Universidad de Sevilla and CSIC, Américo Vespucio 49, 41092 Sevilla, Spain
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46
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Sevilla E, Sarasa-Buisan C, González A, Cases R, Kufryk G, Peleato ML, Fillat MF. Regulation by FurC in Anabaena Links the Oxidative Stress Response to Photosynthetic Metabolism. Plant Cell Physiol 2019; 60:1778-1789. [PMID: 31111929 DOI: 10.1093/pcp/pcz094] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2019] [Accepted: 05/10/2019] [Indexed: 06/09/2023]
Abstract
The FUR (Ferric Uptake Regulator) family in Anabaena sp. PCC 7120 consists of three paralogs named FurA (Fur), FurB (Zur) and FurC (PerR). furC seems to be an essential gene in the filamentous nitrogen-fixing strain Anabaena sp. PCC 7120, suggesting that it plays a fundamental role in this organism. In order to better understand the functions of FurC in Anabaena, the phenotype of a derivative strain that overexpresses this regulator (EB2770FurC) has been characterized. The furC-overexpressing variant presented alterations in growth rate, morphology and ultrastructure, as well as higher sensitivity to peroxide than Anabaena sp. PCC 7120. Interestingly, the overexpression of furC led to reduced photosynthetic O2 evolution, increased respiratory activity, and had a significant influence in the composition and efficiency of both photosystems. Comparative transcriptional analyses, together with electrophoretic mobility shift assays allowed the identification of different genes directly controlled by FurC, and involved in processes not previously related to PerR proteins, such as the cell division gene ftsZ and the major thylakoid membrane protease ftsH. The rise in the transcription of ftsH in EB2770FurC cells correlated with reduced levels of the D1 protein, which is involved in the PSII repair cycle. Deregulation of the oxidative stress response in EB2770FurC cells led to the identification of novel FurC targets involved in the response to H2O2 through different mechanisms. These results, together with the effect of furC overexpression on the composition, stability and efficiency of the photosynthetic machinery of Anabaena, disclose novel links between PerR proteins, cell division and photosynthesis in filamentous cyanobacteria.
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Affiliation(s)
- Emma Sevilla
- Departamento de Bioquímica y Biología Molecular y Celular, Universidad de Zaragoza, Pedro Cerbuna 12, Zaragoza, Spain
- Institute for Biocomputation and Physics of Complex Systems, Universidad de Zaragoza, Pedro Cerbuna 12, Zaragoza, Spain
| | - Cristina Sarasa-Buisan
- Departamento de Bioquímica y Biología Molecular y Celular, Universidad de Zaragoza, Pedro Cerbuna 12, Zaragoza, Spain
- Institute for Biocomputation and Physics of Complex Systems, Universidad de Zaragoza, Pedro Cerbuna 12, Zaragoza, Spain
| | - Andrés González
- Departamento de Bioquímica y Biología Molecular y Celular, Universidad de Zaragoza, Pedro Cerbuna 12, Zaragoza, Spain
- Institute for Biocomputation and Physics of Complex Systems, Universidad de Zaragoza, Pedro Cerbuna 12, Zaragoza, Spain
- Aragon Institute for Health Research (IIS Aragón), Zaragoza, Spain
| | - Rafael Cases
- Instituto de Ciencia de Materiales de Aragón, Universidad de Zaragoza-CSIC, Zaragoza, Spain
- Departamento de Física de la Materia Condensada, Facultad de Ciencias, Universidad de Zaragoza-CSIC, Zaragoza, Spain
| | - Galyna Kufryk
- College of Science, Engineering and Technology, Grand Canyon University, 3300 W. Camelback Rd, Phoenix, AZ, USA
| | - M Luisa Peleato
- Departamento de Bioquímica y Biología Molecular y Celular, Universidad de Zaragoza, Pedro Cerbuna 12, Zaragoza, Spain
- Institute for Biocomputation and Physics of Complex Systems, Universidad de Zaragoza, Pedro Cerbuna 12, Zaragoza, Spain
| | - María F Fillat
- Departamento de Bioquímica y Biología Molecular y Celular, Universidad de Zaragoza, Pedro Cerbuna 12, Zaragoza, Spain
- Institute for Biocomputation and Physics of Complex Systems, Universidad de Zaragoza, Pedro Cerbuna 12, Zaragoza, Spain
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47
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Hamed SM, Hassan SH, Selim S, Kumar A, Khalaf SMH, Wadaan MAM, Hozzein WN, AbdElgawad H. Physiological and biochemical responses to aluminum-induced oxidative stress in two cyanobacterial species. Environ Pollut 2019; 251:961-969. [PMID: 31234263 DOI: 10.1016/j.envpol.2019.05.036] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2018] [Revised: 04/23/2019] [Accepted: 05/08/2019] [Indexed: 06/09/2023]
Abstract
Phycoremediation technologies significantly contribute to solving serious problems induced by heavy metals accumulation in the aquatic systems. Here we studied the mechanisms underlying Al stress tolerance in two diazotrophic cyanobacterial species, to identify suitable species for Al phycoremediation. Al uptake as well as the physiological and biochemical responses of Anabaena laxa and Nostoc muscorum to 7 days Al exposure at two different concentrations i.e., mild (100 μM) and high dose (200 μM), were investigated. Our results revealed that A. laxa accumulated more Al, and it could acclimatize to long-term exposure of Al stress. Al induced a dose-dependent decrease in photosynthesis and its related parameters e.g., chlorophyll content (Chl a), phosphoenolpyruvate carboxylase (PEPC) and Ribulose‒1,5‒bisphosphate carboxylase/oxygenase (RuBisCo) activities. The affect was less pronounced in A. laxa than N. muscorum. Moreover, Al stress significantly increased cellular membrane damage as indicated by induced H2O2, lipid peroxidation, protein oxidation, and NADPH oxidase activity. However, these increases were lower in A. laxa compared to N. muscorum. To mitigate the impact of Al stress, A. laxa induced its antioxidant defense system by increasing polyphenols, flavonoids, tocopherols and glutathione levels as well as peroxidase (POX), catalase (CAT), glutathione reductase (GR) and glutathione peroxidase (GPX) enzymes activities. On the other hand, the antioxidant increases in N. muscorum were only limited to ascorbate (ASC) cycle. Overall, high biosorption/uptake capacity and efficient antioxidant defense system of A. laxa recommend its feasibility in the treatment of Al contaminated waters/soils.
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Affiliation(s)
- Seham M Hamed
- Soil Microbiology Department, Soils, Water and Environment Research Institute, Agricultural Research Center, Giza, P.O. 175, El‒Orman, Egypt.
| | - Sherif H Hassan
- Department of Clinical Laboratory Sciences, College of Applied Medical Sciences, Jouf University, Sakaka, P.O, 2014, Saudi Arabia; Botany and Microbiology Department, Faculty of Science, Beni‒Suef University, Beni‒Suef, 62521, Egypt
| | - Samy Selim
- Department of Clinical Laboratory Sciences, College of Applied Medical Sciences, Jouf University, Sakaka, P.O, 2014, Saudi Arabia; Microbiology and Botany Department, Faculty of Science, Suez Canal University, Ismailia, P.O.Box, 41522, Egypt
| | - Amit Kumar
- Centre for Climate Change Studies, Sathyabama Institute of Science and Technology, Chennai, 600119, India
| | - Sameh M H Khalaf
- Bioproducts Research Chair, Zoology Department, College of Science, King Saud University, Riyadh, 11451, Saudi Arabia
| | - Mohammed A M Wadaan
- Bioproducts Research Chair, Zoology Department, College of Science, King Saud University, Riyadh, 11451, Saudi Arabia
| | - Wael N Hozzein
- Bioproducts Research Chair, Zoology Department, College of Science, King Saud University, Riyadh, 11451, Saudi Arabia; Botany and Microbiology Department, Faculty of Science, Beni‒Suef University, Beni‒Suef, 62521, Egypt
| | - Hamada AbdElgawad
- Botany and Microbiology Department, Faculty of Science, Beni‒Suef University, Beni‒Suef, 62521, Egypt; Integrated Molecular Plant Physiology Research, Department of Biology, University of Antwerp, Antwerp, Belgium
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48
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Chakravarty D, Bihani SC, Banerjee M, Ballal A. Novel molecular insights into the anti-oxidative stress response and structure-function of a salt-inducible cyanobacterial Mn-catalase. Plant Cell Environ 2019; 42:2508-2521. [PMID: 30993731 DOI: 10.1111/pce.13563] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2019] [Accepted: 04/07/2019] [Indexed: 06/09/2023]
Abstract
KatB, a salt-inducible Mn-catalase, protects the cyanobacterium Anabaena from salinity/oxidative stress. In this report, we provide distinctive insights into the biological-biochemical function of KatB at the molecular level. Anabaena overexpressing the wild-type KatB protein (KatBWT) detoxified H2 O2 efficiently, showing reduced burden of reactive oxygen species compared with the strain overproducing KatBF2V (wherein F-2 is replaced by V). Correspondingly, the KatBWT protein also displayed several folds more activity than KatBF2V. Interestingly, the KatB variants with large hydrophobic amino acids (F/W/Y) were more compact, showed enhanced activity, and were resistant to thermal/chemical denaturation than variants with smaller residues (G/A/V) at the second position. X-ray crystallography-based analysis showed that F-2 was required for appropriate interactions between two subunits. These contacts provided stability to the hexamer, making it more compact. F-2, through its interaction with F-66 and W-43, formed the proper hydrophobic pocket that held the active site together. Consequently, only residues that supported activity (i.e., F/Y/W) were selected at the second position in Mn-catalases during evolution. This study (a) demonstrates that modification of nonactive site residues can alter the response of catalases to environmental stress and (b) has expanded the scope of amino acids that can be targeted for rational protein engineering in plants.
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Affiliation(s)
- Dhiman Chakravarty
- Molecular Biology Division, Bhabha Atomic Research Centre, Trombay, Mumbai, 400085, India
- Homi Bhabha National Institute, Anushakti Nagar, Mumbai, 400094, India
| | - Subhash C Bihani
- Radiation Biology & Health Sciences Division, Bhabha Atomic Research Centre, Trombay, Mumbai, 400085, India
| | - Manisha Banerjee
- Molecular Biology Division, Bhabha Atomic Research Centre, Trombay, Mumbai, 400085, India
- Homi Bhabha National Institute, Anushakti Nagar, Mumbai, 400094, India
| | - Anand Ballal
- Molecular Biology Division, Bhabha Atomic Research Centre, Trombay, Mumbai, 400085, India
- Homi Bhabha National Institute, Anushakti Nagar, Mumbai, 400094, India
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49
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Deschoenmaeker FDR, Mihara S, Niwa T, Taguchi H, Nomata J, Wakabayashi KI, Hisabori T. Disruption of the Gene trx-m1 Impedes the Growth of Anabaena sp. PCC 7120 under Nitrogen Starvation. Plant Cell Physiol 2019; 60:1504-1513. [PMID: 31038682 DOI: 10.1093/pcp/pcz056] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2018] [Accepted: 03/31/2019] [Indexed: 06/09/2023]
Abstract
Cyanobacteria possess a sophisticated photosynthesis-based metabolism with admirable plasticity. This plasticity is possible via the deep regulation network, the thiol-redox regulations operated by thioredoxin (hereafter, Trx). In this context, we characterized the Trx-m1-deficient mutant strain of Anabaena sp., PCC 7120 (shortly named A.7120), cultivated under nitrogen limitation. Trx-m1 appears to coordinate the nitrogen response and its absence induces large changes in the proteome. Our data clearly indicate that Trx-m1 is crucial for the diazotrophic growth of A.7120. The lack of Trx-m1 resulted in a large differentiation of heterocysts (>20% of total cells), which were barely functional probably due to a weak expression of nitrogenase. In addition, heterocysts of the mutant strain did not display the usual cellular structure of nitrogen-fixative cells. This unveiled why the mutant strain was not able to grow under nitrogen starvation.
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Affiliation(s)
- Frï Dï Ric Deschoenmaeker
- Laboratory for Chemistry and Life Science, Institute for Innovative Research, Tokyo Institute of Technology, Nagatsuta-cho 4259-R1-8, Midori-ku, Yokohama, Japan
| | - Shoko Mihara
- Laboratory for Chemistry and Life Science, Institute for Innovative Research, Tokyo Institute of Technology, Nagatsuta-cho 4259-R1-8, Midori-ku, Yokohama, Japan
- Department of Life Science, Tokyo Institute of Technology, Nagatsuta-cho, Midori-ku, Yokohama, Japan
| | - Tatsuya Niwa
- Cell Biology Center, Tokyo Institute of Technology, Nagatsuta-cho, 4259-S2-19 Midori-ku Yokohama, Japan
| | - Hideki Taguchi
- Cell Biology Center, Tokyo Institute of Technology, Nagatsuta-cho, 4259-S2-19 Midori-ku Yokohama, Japan
| | - Jiro Nomata
- Laboratory for Chemistry and Life Science, Institute for Innovative Research, Tokyo Institute of Technology, Nagatsuta-cho 4259-R1-8, Midori-ku, Yokohama, Japan
- Department of Life Science, Tokyo Institute of Technology, Nagatsuta-cho, Midori-ku, Yokohama, Japan
| | - Ken-Ichi Wakabayashi
- Laboratory for Chemistry and Life Science, Institute for Innovative Research, Tokyo Institute of Technology, Nagatsuta-cho 4259-R1-8, Midori-ku, Yokohama, Japan
- Department of Life Science, Tokyo Institute of Technology, Nagatsuta-cho, Midori-ku, Yokohama, Japan
| | - Toru Hisabori
- Laboratory for Chemistry and Life Science, Institute for Innovative Research, Tokyo Institute of Technology, Nagatsuta-cho 4259-R1-8, Midori-ku, Yokohama, Japan
- Department of Life Science, Tokyo Institute of Technology, Nagatsuta-cho, Midori-ku, Yokohama, Japan
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50
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Kaushik MS, Mishra AK. Iron deficiency influences NtcA-dependent regulation of fatty acid desaturation and heterocyte envelop formation in Anabaena sp. PCC 7120. Physiol Plant 2019; 166:570-584. [PMID: 30035317 DOI: 10.1111/ppl.12806] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2018] [Revised: 07/09/2018] [Accepted: 07/12/2018] [Indexed: 06/08/2023]
Abstract
In Anabaena sp. PCC 7120, iron is an essential trace element and its availability determines proper functioning of several kinds of metabolisms. Iron deficiency leads to several unavoidable consequences including membrane damage. In the present study, we dealt with the impact of iron deficiency on NtcA (global nitrogen regulator)-dependent regulation of two important processes, i.e. fatty acid desaturation and heterocyte envelop formation in cyanobacterium Anabaena sp. PCC 7120. In Anabaena sp. PCC 7120, NtcA regulates fatty acid desaturation by regulating enzyme fatty acid desaturases. The NtcA-based regulation of fatty acid desaturation may be direct or indirect. Furthermore, the expression of genes involved in the heterocyte envelope polysaccharide (HEP) layer formation (hepABCK) and heterocyte-specific glycolipids (HGLs) synthesis (devH, hglEA , prpJ and devB) were also under the control of NtcA and reduced under iron deficiency background. The enhanced expression of furA and early downregulation of ntcA under iron deficiency is responsible for reduction in fatty acid desaturation as well as decrease in the expression of genes involved in HEP layer formation and HGL synthesis. Overall results confirmed that iron deficiency influences the NtcA-based regulation of fatty acid desaturation and heterocyte envelop formation in Anabaena sp. PCC 7120.
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Affiliation(s)
- Manish S Kaushik
- Laboratory of Microbial Genetics, Department of Botany, Banaras Hindu University, Varanasi, 221005, India
| | - Arun K Mishra
- Laboratory of Microbial Genetics, Department of Botany, Banaras Hindu University, Varanasi, 221005, India
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