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Sarasa-Buisan C, Nieves-Morión M, Arévalo S, Helm RF, Sevilla E, Luque I, Fillat MF. FurC (PerR) contributes to the regulation of peptidoglycan remodeling and intercellular molecular transfer in the cyanobacterium Anabaena sp. strain PCC 7120. mBio 2024; 15:e0323123. [PMID: 38334377 PMCID: PMC10936207 DOI: 10.1128/mbio.03231-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2023] [Accepted: 01/09/2024] [Indexed: 02/10/2024] Open
Abstract
Microbial extracellular proteins and metabolites provide valuable information concerning how microbes adapt to changing environments. In cyanobacteria, dynamic acclimation strategies involve a variety of regulatory mechanisms, being ferric uptake regulator proteins as key players in this process. In the nitrogen-fixing cyanobacterium Anabaena sp. strain PCC 7120, FurC (PerR) is a global regulator that modulates the peroxide response and several genes involved in photosynthesis and nitrogen metabolism. To investigate the possible role of FurC in shaping the extracellular environment of Anabaena, the analysis of the extracellular metabolites and proteins of a furC-overexpressing variant was compared to that of the wild-type strain. There were 96 differentially abundant proteins, 78 of which were found for the first time in the extracellular fraction of Anabaena. While these proteins belong to different functional categories, most of them are predicted to be secreted or have a peripheral location. Several stress-related proteins, including PrxA, flavodoxin, and the Dps homolog All1173, accumulated in the exoproteome of furC-overexpressing cells, while decreased levels of FurA and a subset of membrane proteins, including several export proteins and amiC gene products, responsible for nanopore formation, were detected. Direct repression by FurC of some of those genes, including amiC1 and amiC2, could account for odd septal nanopore formation and impaired intercellular molecular transfer observed in the furC-overexpressing variant. Assessment of the exometabolome from both strains revealed the release of two peptidoglycan fragments in furC-overexpressing cells, namely 1,6-anhydro-N-acetyl-β-D-muramic acid (anhydroMurNAc) and its associated disaccharide (β-D-GlcNAc-(1-4)-anhydroMurNAc), suggesting alterations in peptidoglycan breakdown and recycling.IMPORTANCECyanobacteria are ubiquitous photosynthetic prokaryotes that can adapt to environmental stresses by modulating their extracellular contents. Measurements of the organization and composition of the extracellular milieu provide useful information about cyanobacterial adaptive processes, which can potentially lead to biomimetic approaches to stabilizing biological systems to adverse conditions. Anabaena sp. strain PCC 7120 is a multicellular, nitrogen-fixing cyanobacterium whose intercellular molecular exchange is mediated by septal junctions that traverse the septal peptidoglycan through nanopores. FurC (PerR) is an essential transcriptional regulator in Anabaena, which modulates the response to several stresses. Here, we show that furC-overexpressing cells result in a modified exoproteome and the release of peptidoglycan fragments. Phenotypically, important alterations in nanopore formation and cell-to-cell communication were observed. Our results expand the roles of FurC to the modulation of cell-wall biogenesis and recycling, as well as in intercellular molecular transfer.
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Affiliation(s)
- Cristina Sarasa-Buisan
- Departamento de Bioquímica y Biología Molecular y Celular, Facultad de Ciencias e Instituto de Biocomputación y Física de Sistemas Complejos. Universidad de Zaragoza, Zaragoza, Spain
- Instituto de Bioquímica Vegetal y Fotosíntesis, CSIC and Universidad de Sevilla, Sevilla, Spain
| | - Mercedes Nieves-Morión
- Instituto de Bioquímica Vegetal y Fotosíntesis, CSIC and Universidad de Sevilla, Sevilla, Spain
| | - Sergio Arévalo
- Instituto de Bioquímica Vegetal y Fotosíntesis, CSIC and Universidad de Sevilla, Sevilla, Spain
| | - Richard F. Helm
- Department of Biochemistry, Virginia Tech, Blacksburg, Virginia, USA
| | - Emma Sevilla
- Departamento de Bioquímica y Biología Molecular y Celular, Facultad de Ciencias e Instituto de Biocomputación y Física de Sistemas Complejos. Universidad de Zaragoza, Zaragoza, Spain
| | - Ignacio Luque
- Instituto de Bioquímica Vegetal y Fotosíntesis, CSIC and Universidad de Sevilla, Sevilla, Spain
| | - María F. Fillat
- Departamento de Bioquímica y Biología Molecular y Celular, Facultad de Ciencias e Instituto de Biocomputación y Física de Sistemas Complejos. Universidad de Zaragoza, Zaragoza, Spain
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2
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Cao X, van Putten JP, Wösten MM. Campylobacter jejuni benefits from the bile salt deoxycholate under low-oxygen condition in a PldA dependent manner. Gut Microbes 2023; 15:2262592. [PMID: 37768138 PMCID: PMC10540661 DOI: 10.1080/19490976.2023.2262592] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/07/2023] [Accepted: 09/20/2023] [Indexed: 09/29/2023] Open
Abstract
Enteric bacteria need to adapt to endure the antibacterial activities of bile salts in the gut. Phospholipase A (PldA) is a key enzyme in the maintenance of bacterial membrane homeostasis. Bacteria respond to stress by modulating their membrane composition. Campylobacter jejuni is the most common cause of human worldwide. However, the mechanism by which C. jejuni adapts and survives in the gut environment is not fully understood. In this study, we investigated the roles of PldA, bile salt sodium deoxycholate (DOC), and oxygen availability in C. jejuni biology, mimicking an in vivo situation. Growth curves were used to determine the adaptation of C. jejuni to bile salts. RNA-seq and functional assays were employed to investigate the PldA-dependent and DOC-induced changes in gene expression that influence bacterial physiology. Survival studies were performed to address oxidative stress defense in C. jejuni. Here, we discovered that PldA of C. jejuni is required for optimal growth in the presence of bile salt DOC. Under high oxygen conditions, DOC is toxic to C. jejuni, but under low oxygen conditions, as is present in the lumen of the gut, C. jejuni benefits from DOC. C. jejuni PldA seems to enable the use of iron needed for optimal growth in the presence of DOC but makes the bacterium more vulnerable to oxidative stress. In conclusion, DOC stimulates C. jejuni growth under low oxygen conditions and alters colony morphology in a PldA-dependent manner. C. jejuni benefits from DOC by upregulating iron metabolism in a PldA-dependent manner.
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Affiliation(s)
- Xuefeng Cao
- Department Biomolecular Health Sciences, Utrecht University, Utrecht, The Netherlands
| | - Jos P.M. van Putten
- Department Biomolecular Health Sciences, Utrecht University, Utrecht, The Netherlands
| | - Marc M.S.M. Wösten
- Department Biomolecular Health Sciences, Utrecht University, Utrecht, The Netherlands
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3
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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: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [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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4
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Sarasa-Buisan C, Guio J, Broset E, Peleato ML, Fillat MF, Sevilla E. FurC (PerR) from Anabaena sp. PCC7120: a versatile transcriptional regulator engaged in the regulatory network of heterocyst development and nitrogen fixation. Environ Microbiol 2021; 24:566-582. [PMID: 33938105 DOI: 10.1111/1462-2920.15552] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Revised: 04/19/2021] [Accepted: 04/30/2021] [Indexed: 11/29/2022]
Abstract
FurC (PerR) from Anabaena sp. PCC7120 was previously described as a key transcriptional regulator involved in setting off the oxidative stress response. In the last years, the cross-talk between oxidative stress, iron homeostasis and nitrogen metabolism is becoming more and more evident. In this work, the transcriptome of a furC-overexpressing strain was compared with that of a wild-type strain under both standard and nitrogen-deficiency conditions. The results showed that the overexpression of furC deregulates genes involved in several categories standing out photosynthesis, iron transport and nitrogen metabolism. The novel FurC-direct targets included some regulatory elements that control heterocyst development (hetZ and asr1734), genes directly involved in the heterocyst envelope formation (devBCA and hepC) and genes which participate in the nitrogen fixation process (nifHDK and nifH2, rbrA rubrerythrin and xisHI excisionase). Likewise, furC overexpression notably impacts the mRNA levels of patA encoding a key protein in the heterocyst pattern formation. The relevance of FurC in these processes is bringing out by the fact that the overexpression of furC impairs heterocyst development and cell growth under nitrogen step-down conditions. In summary, this work reveals a new player in the complex regulatory network of heterocyst formation and nitrogen fixation.
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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, Pedro Cerbuna 12, Zaragoza, 50009, Spain
| | - Jorge Guio
- Departamento de Bioquímica y Biología Molecular y Celular and Institute for Biocomputation and Physics of Complex Systems, Universidad de Zaragoza, Pedro Cerbuna 12, Zaragoza, 50009, Spain
| | - Esther Broset
- Departamento de Bioquímica y Biología Molecular y Celular and Institute for Biocomputation and Physics of Complex Systems, Universidad de Zaragoza, Pedro Cerbuna 12, Zaragoza, 50009, Spain
| | - M Luisa Peleato
- Departamento de Bioquímica y Biología Molecular y Celular and Institute for Biocomputation and Physics of Complex Systems, Universidad de Zaragoza, Pedro Cerbuna 12, Zaragoza, 50009, Spain
| | - María F Fillat
- Departamento de Bioquímica y Biología Molecular y Celular and Institute for Biocomputation and Physics of Complex Systems, Universidad de Zaragoza, Pedro Cerbuna 12, Zaragoza, 50009, Spain
| | - Emma Sevilla
- Departamento de Bioquímica y Biología Molecular y Celular and Institute for Biocomputation and Physics of Complex Systems, Universidad de Zaragoza, Pedro Cerbuna 12, Zaragoza, 50009, Spain
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Shafiee RT, Snow JT, Hester S, Zhang Q, Rickaby REM. Proteomic response of the marine ammonia-oxidising archaeon Nitrosopumilus maritimus to iron limitation reveals strategies to compensate for nutrient scarcity. Environ Microbiol 2021; 24:835-849. [PMID: 33876540 DOI: 10.1111/1462-2920.15491] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2020] [Accepted: 03/25/2021] [Indexed: 11/26/2022]
Abstract
Dissolved iron (Fe) is vanishingly low in the oceans, with ecological success conferred to microorganisms that can restructure their biochemistry to maintain high growth rates during Fe scarcity. Chemolithoautotrophic ammonia-oxidising archaea (AOA) are highly abundant in the oceans, constituting ~30% of cells below the photic zone. Here we examine the proteomic response of the AOA isolate Nitrosopumilus maritimus to growth-limiting Fe concentrations. Under Fe limitation, we observed a significant reduction in the intensity of Fe-dense ferredoxins associated with respiratory complex I whilst complex III and IV proteins with more central roles in the electron transport chain remain unchanged. We concomitantly observed an increase in the intensity of Fe-free functional alternatives such as flavodoxin and plastocyanin, thioredoxin and alkyl hydroperoxide which are known to mediate electron transport and reactive oxygen species detoxification, respectively. Under Fe limitation, we found a marked increase in the intensity of the ABC phosphonate transport system (Phn), highlighting an intriguing link between Fe and P cycling in N. maritimus. We hypothesise that an elevated uptake of exogenous phosphonates under Fe limitation may either supplement N. maritimus' endogenous methylphosphonate biosynthesis pathway - which requires Fe - or enhance the production of phosphonate-containing exopolysaccharides known to efficiently bind environmental Fe.
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Affiliation(s)
- Roxana T Shafiee
- Department of Earth Sciences, South Parks Road, University of Oxford, Oxfordshire, OX1 3AN, UK
| | - Joseph T Snow
- Department of Earth Sciences, South Parks Road, University of Oxford, Oxfordshire, OX1 3AN, UK
| | - Svenja Hester
- Department of Biochemistry, South Parks Road, University of Oxford, Oxfordshire, OX1 3QU, UK
| | - Qiong Zhang
- Department of Earth Sciences, South Parks Road, University of Oxford, Oxfordshire, OX1 3AN, UK
| | - Rosalind E M Rickaby
- Department of Earth Sciences, South Parks Road, University of Oxford, Oxfordshire, OX1 3AN, UK
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Zhan J, Steglich C, Scholz I, Hess WR, Kirilovsky D. Inverse regulation of light harvesting and photoprotection is mediated by a 3'-end-derived sRNA in cyanobacteria. THE PLANT CELL 2021; 33:358-380. [PMID: 33793852 PMCID: PMC8136909 DOI: 10.1093/plcell/koaa030] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Accepted: 12/01/2020] [Indexed: 06/12/2023]
Abstract
Phycobilisomes (PBSs), the principal cyanobacterial antenna, are among the most efficient macromolecular structures in nature, and are used for both light harvesting and directed energy transfer to the photosynthetic reaction center. However, under unfavorable conditions, excess excitation energy needs to be rapidly dissipated to avoid photodamage. The orange carotenoid protein (OCP) senses light intensity and induces thermal energy dissipation under stress conditions. Hence, its expression must be tightly controlled; however, the molecular mechanism of this regulation remains to be elucidated. Here, we describe the discovery of a posttranscriptional regulatory mechanism in Synechocystis sp. PCC 6803 in which the expression of the operon encoding the allophycocyanin subunits of the PBS is directly and in an inverse fashion linked to the expression of OCP. This regulation is mediated by ApcZ, a small regulatory RNA that is derived from the 3'-end of the tetracistronic apcABC-apcZ operon. ApcZ inhibits ocp translation under stress-free conditions. Under most stress conditions, apc operon transcription decreases and ocp translation increases. Thus, a key operon involved in the collection of light energy is functionally connected to the expression of a protein involved in energy dissipation. Our findings support the view that regulatory RNA networks in bacteria evolve through the functionalization of mRNA 3'-UTRs.
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Affiliation(s)
- Jiao Zhan
- Université Paris-Saclay, Commissariat à l’Énergie Atomiques et aux Énergies Alternatives, Centre National de la Recherche Scientifique (CEA, CNRS), Institute for Integrative Biology of the Cell (I2BC), 91198 Gif sur Yvette, France
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
| | - Claudia Steglich
- Faculty of Biology, Institute of Biology III, University of Freiburg, D-79104 Freiburg im Breisgau, Germany
| | - Ingeborg Scholz
- Faculty of Biology, Institute of Biology III, University of Freiburg, D-79104 Freiburg im Breisgau, Germany
| | - Wolfgang R Hess
- Faculty of Biology, Institute of Biology III, University of Freiburg, D-79104 Freiburg im Breisgau, Germany
| | - Diana Kirilovsky
- Université Paris-Saclay, Commissariat à l’Énergie Atomiques et aux Énergies Alternatives, Centre National de la Recherche Scientifique (CEA, CNRS), Institute for Integrative Biology of the Cell (I2BC), 91198 Gif sur Yvette, France
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7
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Sevilla E, Bes MT, Peleato ML, Fillat MF. Fur-like proteins: Beyond the ferric uptake regulator (Fur) paralog. Arch Biochem Biophys 2021; 701:108770. [PMID: 33524404 DOI: 10.1016/j.abb.2021.108770] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Revised: 01/12/2021] [Accepted: 01/17/2021] [Indexed: 10/22/2022]
Abstract
Proteins belonging to the FUR (ferric uptake regulator) family are the cornerstone of metalloregulation in most prokaryotes. Although numerous reviews have been devoted to these proteins, these reports are mainly focused on the Fur paralog that gives name to the family. In the last years, the increasing knowledge on the other, less ubiquitous members of this family has evidenced their importance in bacterial metabolism. As the Fur paralog, the major regulator of iron homeostasis, Zur, Irr, BosR and PerR are tightly related to stress defenses and host-pathogen interaction being in many cases essential for virulence. Furthermore, the Nur and Mur paralogs largely contribute to control nickel and manganese homeostasis, which are cofactors of pivotal proteins for host colonization and bacterial redox homeostasis. The present review highlights the main features of FUR proteins that differ to the canonical Fur paralog either in the coregulatory metal, such as Zur, Nur and Mur, or in the action mechanism to control target genes, such as PerR, Irr and BosR.
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Affiliation(s)
- Emma Sevilla
- Departamento de Bioquímica y Biología Molecular y Celular, Facultad de Ciencias, Instituto de Biocomputación y Física de Sistemas Complejos (GBsC-CSIC and BIFI-IQFR Joint Units), Universidad de Zaragoza, Zaragoza, Spain
| | - M Teresa Bes
- Departamento de Bioquímica y Biología Molecular y Celular, Facultad de Ciencias, Instituto de Biocomputación y Física de Sistemas Complejos (GBsC-CSIC and BIFI-IQFR Joint Units), Universidad de Zaragoza, Zaragoza, Spain
| | - M Luisa Peleato
- Departamento de Bioquímica y Biología Molecular y Celular, Facultad de Ciencias, Instituto de Biocomputación y Física de Sistemas Complejos (GBsC-CSIC and BIFI-IQFR Joint Units), Universidad de Zaragoza, Zaragoza, Spain
| | - María F Fillat
- Departamento de Bioquímica y Biología Molecular y Celular, Facultad de Ciencias, Instituto de Biocomputación y Física de Sistemas Complejos (GBsC-CSIC and BIFI-IQFR Joint Units), Universidad de Zaragoza, Zaragoza, Spain.
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8
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Rachedi R, Foglino M, Latifi A. Stress Signaling in Cyanobacteria: A Mechanistic Overview. Life (Basel) 2020; 10:life10120312. [PMID: 33256109 PMCID: PMC7760821 DOI: 10.3390/life10120312] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2020] [Revised: 11/22/2020] [Accepted: 11/25/2020] [Indexed: 12/22/2022] Open
Abstract
Cyanobacteria are highly diverse, widely distributed photosynthetic bacteria inhabiting various environments ranging from deserts to the cryosphere. Throughout this range of niches, they have to cope with various stresses and kinds of deprivation which threaten their growth and viability. In order to adapt to these stresses and survive, they have developed several global adaptive responses which modulate the patterns of gene expression and the cellular functions at work. Sigma factors, two-component systems, transcriptional regulators and small regulatory RNAs acting either separately or collectively, for example, induce appropriate cyanobacterial stress responses. The aim of this review is to summarize our current knowledge about the diversity of the sensors and regulators involved in the perception and transduction of light, oxidative and thermal stresses, and nutrient starvation responses. The studies discussed here point to the fact that various stresses affecting the photosynthetic capacity are transduced by common mechanisms.
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9
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Molecular organizations and function of iron-stress-induced-A protein family in Anabaena sp. PCC 7120. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2020; 1862:148327. [PMID: 33069682 DOI: 10.1016/j.bbabio.2020.148327] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 08/06/2020] [Revised: 09/29/2020] [Accepted: 10/13/2020] [Indexed: 11/22/2022]
Abstract
Iron-stress-induced-A proteins (IsiAs) are expressed in cyanobacteria under iron-deficient conditions, and surround photosystem I (PSI) trimer with a ring formation. A cyanobacterium Anabaena sp. PCC 7120 has four isiA genes; however, it is unknown how the IsiAs are associated with PSI. Here we report on molecular organizations and function of the IsiAs in this cyanobacterium. A deletion mutant of the isiA1 gene was constructed, and the four types of thylakoids were prepared from the wild-type (WT) and ΔisiA1 cells under iron-replete (+Fe) and iron-deficient (-Fe) conditions. Immunoblotting analysis exhibits a clear expression of the IsiA1 in the WT-Fe. The PSI-IsiA1 supercomplex is found in the WT-Fe, and excitation-energy transfer from IsiA1 to PSI is verified by time-resolved fluorescence analyses. Instead of the IsiA1, both IsiA2 and IsiA3 are bound to PSI monomer in the ΔisiA1-Fe. These findings provide insights into multiple-expression system of the IsiA family in this cyanobacterium.
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Iron limitation – A perspective on a growth-restricted cultivation strategy for a H2 production system using the diazotrophic cyanobacterium Nostoc PCC 7120 ΔhupW. ACTA ACUST UNITED AC 2020. [DOI: 10.1016/j.biteb.2020.100508] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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Lambrecht SJ, Steglich C, Hess WR. A minimum set of regulators to thrive in the ocean. FEMS Microbiol Rev 2020; 44:232-252. [DOI: 10.1093/femsre/fuaa005] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2019] [Accepted: 02/19/2020] [Indexed: 12/25/2022] Open
Abstract
ABSTRACT
Marine cyanobacteria of the genus Prochlorococcus thrive in high cell numbers throughout the euphotic zones of the world's subtropical and tropical oligotrophic oceans, making them some of the most ecologically relevant photosynthetic microorganisms on Earth. The ecological success of these free-living phototrophs suggests that they are equipped with a regulatory system competent to address many different stress situations. However, Prochlorococcus genomes are compact and streamlined, with the majority encoding only five different sigma factors, five to six two-component systems and eight types of other transcriptional regulators. Here, we summarize the existing information about the functions of these protein regulators, about transcriptomic responses to defined stress conditions, and discuss the current knowledge about riboswitches, RNA-based regulation and the roles of certain metabolites as co-regulators. We focus on the best-studied isolate, Prochlorococcus MED4, but extend to other strains and ecotypes when appropriate, and we include some information gained from metagenomic and metatranscriptomic analyses.
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Affiliation(s)
- S Joke Lambrecht
- Genetics and Experimental Bioinformatics, Institute of Biology III, Faculty of Biology, University of Freiburg, Schänzlestr. 1, D-79104 Freiburg, Germany
| | - Claudia Steglich
- Genetics and Experimental Bioinformatics, Institute of Biology III, Faculty of Biology, University of Freiburg, Schänzlestr. 1, D-79104 Freiburg, Germany
| | - Wolfgang R Hess
- Genetics and Experimental Bioinformatics, Institute of Biology III, Faculty of Biology, University of Freiburg, Schänzlestr. 1, D-79104 Freiburg, Germany
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Roumezi B, Xu X, Risoul V, Fan Y, Lebrun R, Latifi A. The Pkn22 Kinase of Nostoc PCC 7120 Is Required for Cell Differentiation via the Phosphorylation of HetR on a Residue Highly Conserved in Genomes of Heterocyst-Forming Cyanobacteria. Front Microbiol 2020; 10:3140. [PMID: 32038573 PMCID: PMC6985446 DOI: 10.3389/fmicb.2019.03140] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2019] [Accepted: 12/27/2019] [Indexed: 11/13/2022] Open
Abstract
Hanks-type kinases encoding genes are present in most cyanobacterial genomes. Despite their widespread pattern of conservation, little is known so far about their role because their substrates and the conditions triggering their activation are poorly known. Here we report that under diazotrophic conditions, normal heterocyst differentiation and growth of the filamentous cyanobacterium Nostoc PCC 7120 require the presence of the Pkn22 kinase, which is induced under combined nitrogen starvation conditions. By analyzing the phenotype of pkn22 mutant overexpressing genes belonging to the regulatory cascade initiating the development program, an epistatic relationship was found to exist between this kinase and the master regulator of differentiation, HetR. The results obtained using a bacterial two hybrid approach indicated that Pkn22 and HetR interact, and the use of a genetic screen inducing the loss of this interaction showed that residues of HetR which are essential for this interaction to occur are also crucial to HetR activity both in vitro and in vivo. Mass spectrometry showed that HetR co-produced with the Pkn22 kinase in Escherichia coli is phosphorylated on Serine 130 residue. Phosphoablative substitution of this residue impaired the ability of the strain to undergo cell differentiation, while its phosphomimetic substitution increased the number of heterocysts formed. The Serine 130 residue is part of a highly conserved sequence in filamentous cyanobacterial strains differentiating heterocysts. Heterologous complementation assays showed that the presence of this domain is necessary for heterocyst induction. We propose that the phosphorylation of HetR might have been acquired to control heterocyst differentiation.
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Affiliation(s)
- Baptiste Roumezi
- Laboratoire de Chimie Bactérienne, CNRS, Aix-Marseille Université, Marseille, France
| | - Xiaomei Xu
- Laboratoire de Chimie Bactérienne, CNRS, Aix-Marseille Université, Marseille, France
| | - Véronique Risoul
- Laboratoire de Chimie Bactérienne, CNRS, Aix-Marseille Université, Marseille, France
| | - Yingping Fan
- Laboratoire de Chimie Bactérienne, CNRS, Aix-Marseille Université, Marseille, France
| | - Régine Lebrun
- Proteomic Platform, Marseille Protéomique IBiSA Labelled, CNRS, IMM, Aix-Marseille Université, Marseille, France
| | - Amel Latifi
- Laboratoire de Chimie Bactérienne, CNRS, Aix-Marseille Université, Marseille, France
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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 PHYSIOLOGY 2019; 60:1778-1789. [PMID: 31111929 DOI: 10.1093/pcp/pcz094] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [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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Willcocks SJ, Stabler RA, Atkins HS, Oyston PF, Wren BW. High-throughput analysis of Yersinia pseudotuberculosis gene essentiality in optimised in vitro conditions, and implications for the speciation of Yersinia pestis. BMC Microbiol 2018; 18:46. [PMID: 29855259 PMCID: PMC5984423 DOI: 10.1186/s12866-018-1189-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2017] [Accepted: 05/18/2018] [Indexed: 12/12/2022] Open
Abstract
Background Yersinia pseudotuberculosis is a zoonotic pathogen, causing mild gastrointestinal infection in humans. From this comparatively benign pathogenic species emerged the highly virulent plague bacillus, Yersinia pestis, which has experienced significant genetic divergence in a relatively short time span. Much of our knowledge of Yersinia spp. evolution stems from genomic comparison and gene expression studies. Here we apply transposon-directed insertion site sequencing (TraDIS) to describe the essential gene set of Y. pseudotuberculosis IP32953 in optimised in vitro growth conditions, and contrast these with the published essential genes of Y. pestis. Results The essential genes of an organism are the core genetic elements required for basic survival processes in a given growth condition, and are therefore attractive targets for antimicrobials. One such gene we identified is yptb3665, which encodes a peptide deformylase, and here we report for the first time, the sensitivity of Y. pseudotuberculosis to actinonin, a deformylase inhibitor. Comparison of the essential genes of Y. pseudotuberculosis with those of Y. pestis revealed the genes whose importance are shared by both species, as well as genes that were differentially required for growth. In particular, we find that the two species uniquely rely upon different iron acquisition and respiratory metabolic pathways under similar in vitro conditions. Conclusions The discovery of uniquely essential genes between the closely related Yersinia spp. represent some of the fundamental, species-defining points of divergence that arose during the evolution of Y. pestis from its ancestor. Furthermore, the shared essential genes represent ideal candidates for the development of novel antimicrobials against both species. Electronic supplementary material The online version of this article (10.1186/s12866-018-1189-5) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Samuel J Willcocks
- Department of Pathogen Molecular Biology, London School of Hygiene and Tropical Medicine, Keppel Street, London, WC1E 7HT, UK
| | - Richard A Stabler
- Department of Pathogen Molecular Biology, London School of Hygiene and Tropical Medicine, Keppel Street, London, WC1E 7HT, UK
| | - Helen S Atkins
- Microbiology, CBR Division, DSTL Porton Down, Salisbury, SP4 0JQ, UK
| | - Petra F Oyston
- Microbiology, CBR Division, DSTL Porton Down, Salisbury, SP4 0JQ, UK
| | - Brendan W Wren
- Department of Pathogen Molecular Biology, London School of Hygiene and Tropical Medicine, Keppel Street, London, WC1E 7HT, UK.
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15
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Molecular basis for the integration of environmental signals by FurB from Anabaena sp. PCC 7120. Biochem J 2018; 475:151-168. [DOI: 10.1042/bcj20170692] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2017] [Revised: 11/22/2017] [Accepted: 12/04/2017] [Indexed: 12/29/2022]
Abstract
FUR (Ferric uptake regulator) proteins are among the most important families of transcriptional regulators in prokaryotes, often behaving as global regulators. In the cyanobacterium Anabaena PCC 7120, FurB (Zur, Zinc uptake regulator) controls zinc and redox homeostasis through the repression of target genes in a zinc-dependent manner. In vitro, non-specific binding of FurB to DNA elicits protection against oxidative damage and avoids cleavage by deoxyribonuclease I. The present study provides, for the first time, evidence of the influence of redox environment in the interaction of FurB with regulatory zinc and its consequences in FurB–DNA-binding affinity. Calorimetry studies showed that, in addition to one structural Zn(II), FurB is able to bind two additional Zn(II) per monomer and demonstrated the implication of cysteine C93 in regulatory Zn(II) coordination. The interaction of FurB with the second regulatory zinc occurred only under reducing conditions. While non-specific FurB–DNA interaction is Zn(II)-independent, the optimal binding of FurB to target promoters required loading of two regulatory zinc ions. Those results combined with site-directed mutagenesis and gel-shift assays evidenced that the redox state of cysteine C93 conditions the binding of the second regulatory Zn(II) and, in turn, modulates the affinity for a specific DNA target. Furthermore, differential spectroscopy studies showed that cysteine C93 could also be involved in heme coordination by FurB, either as a direct ligand or being located near the binding site. The results indicate that besides controlling zinc homeostasis, FurB could work as a redox-sensing protein probably modifying its zinc and DNA-binding abilities depending upon environmental conditions.
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Ishaq SL, Johnson SP, Miller ZJ, Lehnhoff EA, Olivo S, Yeoman CJ, Menalled FD. Impact of Cropping Systems, Soil Inoculum, and Plant Species Identity on Soil Bacterial Community Structure. MICROBIAL ECOLOGY 2017; 73:417-434. [PMID: 27677892 DOI: 10.1007/s00248-016-0861-2] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2016] [Accepted: 09/13/2016] [Indexed: 06/06/2023]
Abstract
Farming practices affect the soil microbial community, which in turn impacts crop growth and crop-weed interactions. This study assessed the modification of soil bacterial community structure by organic or conventional cropping systems, weed species identity [Amaranthus retroflexus L. (redroot pigweed) or Avena fatua L. (wild oat)], and living or sterilized inoculum. Soil from eight paired USDA-certified organic and conventional farms in north-central Montana was used as living or autoclave-sterilized inoculant into steam-pasteurized potting soil, planted with Am. retroflexus or Av. fatua and grown for two consecutive 8-week periods to condition soil nutrients and biota. Subsequently, the V3-V4 regions of the microbial 16S rRNA gene were sequenced by Illumina MiSeq. Treatments clustered significantly, with living or sterilized inoculum being the strongest delineating factor, followed by organic or conventional cropping system, then individual farm. Living inoculum-treated soil had greater species richness and was more diverse than sterile inoculum-treated soil (observed OTUs, Chao, inverse Simpson, Shannon, P < 0.001) and had more discriminant taxa delineating groups (linear discriminant analysis). Living inoculum soil contained more Chloroflexi and Acidobacteria, while the sterile inoculum soil had more Bacteroidetes, Firmicutes, Gemmatimonadetes, and Verrucomicrobia. Organically farmed inoculum-treated soil had greater species richness, more diversity (observed OTUs, Chao, Shannon, P < 0.05), and more discriminant taxa than conventionally farmed inoculum-treated soil. Cyanobacteria were higher in pots growing Am. retroflexus, regardless of inoculum type, for three of the four organic farms. Results highlight the potential of cropping systems and species identity to modify soil bacterial communities, subsequently modifying plant growth and crop-weed competition.
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Affiliation(s)
- Suzanne L Ishaq
- Department of Animal and Range Sciences, Montana State University, P.O. Box 172900, Bozeman, MT, 59717, USA
- Department of Land Resources and Environmental Sciences, Montana State University, P.O. Box 173120, Bozeman, MT, 59717, USA
| | - Stephen P Johnson
- Department of Land Resources and Environmental Sciences, Montana State University, P.O. Box 173120, Bozeman, MT, 59717, USA
| | - Zach J Miller
- Western Agriculture Research Center, Montana State University, Bozeman, MT, USA
| | - Erik A Lehnhoff
- Department of Entomology, Plant Pathology and Weed Science, New Mexico State University, Las Cruces, NM, USA
| | - Sarah Olivo
- Department of Animal and Range Sciences, Montana State University, P.O. Box 172900, Bozeman, MT, 59717, USA
| | - Carl J Yeoman
- Department of Animal and Range Sciences, Montana State University, P.O. Box 172900, Bozeman, MT, 59717, USA.
| | - Fabian D Menalled
- Department of Land Resources and Environmental Sciences, Montana State University, P.O. Box 173120, Bozeman, MT, 59717, USA.
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Physiological and Proteomic Responses of Continuous Cultures of Microcystis aeruginosa PCC 7806 to Changes in Iron Bioavailability and Growth Rate. Appl Environ Microbiol 2016; 82:5918-29. [PMID: 27474713 DOI: 10.1128/aem.01207-16] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2016] [Accepted: 07/24/2016] [Indexed: 11/20/2022] Open
Abstract
UNLABELLED The hepatotoxin microcystin (MCYST) is produced by a variety of freshwater cyanobacterial species, including Microcystis aeruginosa Interestingly, MCYST-producing M. aeruginosa strains have been shown to outcompete their nontoxic counterparts under iron-limiting conditions. However, the reasons for this are unclear. Here we examined the proteomic response of M. aeruginosa PCC 7806 continuous cultures under different iron and growth regimes. Iron limitation was correlated with a global reduction in levels of proteins associated with energy metabolism and photosynthesis. These proteomic changes were consistent with physiological observations, including reduced chlorophyll a content and reduced cell size. While levels of MCYST biosynthesis proteins did not fluctuate during the study period, both intra- and extracellular toxin quotas were significantly higher under iron-limiting conditions. Our results support the hypothesis that intracellular MCYST plays a role in protecting the cell against oxidative stress. Further, we propose that extracellular MCYST may act as a signaling molecule, stimulating MCYST production under conditions of iron limitation and enhancing the fitness of bloom populations. IMPORTANCE Microcystin production in water supply reservoirs is a global public health problem. Understanding the ecophysiology of hepatotoxic cyanobacteria, including their responses to the presence of key micronutrient metals such as iron, is central to managing harmful blooms. To our knowledge, this was the first study to examine proteomic and physiological changes occurring in M. aeruginosa continuous cultures under conditions of iron limitation at different growth rates.
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Sánchez-Riego AM, Mata-Cabana A, Galmozzi CV, Florencio FJ. NADPH-Thioredoxin Reductase C Mediates the Response to Oxidative Stress and Thermotolerance in the Cyanobacterium Anabaena sp. PCC7120. Front Microbiol 2016; 7:1283. [PMID: 27588019 PMCID: PMC4988983 DOI: 10.3389/fmicb.2016.01283] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2016] [Accepted: 08/04/2016] [Indexed: 12/30/2022] Open
Abstract
NADPH-thioredoxin reductase C (NTRC) is a bimodular enzyme composed of an NADPH-thioredoxin reductase and a thiioredoxin domain extension in the same protein. In plants, NTRC has been described to be involved in the protection of the chloroplast against oxidative stress damage through reduction of the 2-Cys peroxiredoxin (2-Cys Prx) as well as through other functions related to redox enzyme regulation. In cyanobacteria, the Anabaena NTRC has been characterized in vitro, however, nothing was known about its in vivo function. In order to study that, we have generated the first knockout mutant strain (ΔntrC), apart from the previously described in Arabidopsis. Detailed characterization of this strain reveals a differential sensitivity to oxidative stress treatments with respect to the wild-type Anabaena strain, including a higher level of ROS (reactive oxygen species) in normal growth conditions. In the mutant strain, different oxidative stress treatments such as hydrogen peroxide, methyl-viologen or high light irradiance provoke an increase in the expression of genes related to ROS detoxification, including AnNTRC and peroxiredoxin genes, with a concomitant increase in the amount of AnNTRC and 2-Cys Prx. Moreover, the role of AnNTRC in the antioxidant response is confirmed by the observation of a pronounced overoxidation of the 2-Cys Prx and a time-delay recovery of the reduced form of this protein upon oxidative stress treatments. Our results suggest the participation of this enzyme in the peroxide detoxification in Anabaena. In addition, we describe the role of Anabaena NTRC in thermotolerance, by the appearance of high molecular mass AnNTRC complexes, showing that the mutant strain is more sensitive to high temperature treatments.
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Affiliation(s)
- Ana M Sánchez-Riego
- Instituto de Bioquímica Vegetal y Fotosíntesis, Universidad de Sevilla-Consejo Superior de Investigaciones Científicas Seville, Spain
| | - Alejandro Mata-Cabana
- Instituto de Bioquímica Vegetal y Fotosíntesis, Universidad de Sevilla-Consejo Superior de Investigaciones Científicas Seville, Spain
| | - Carla V Galmozzi
- Instituto de Bioquímica Vegetal y Fotosíntesis, Universidad de Sevilla-Consejo Superior de Investigaciones Científicas Seville, Spain
| | - Francisco J Florencio
- Instituto de Bioquímica Vegetal y Fotosíntesis, Universidad de Sevilla-Consejo Superior de Investigaciones Científicas Seville, Spain
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Expanding the Role of FurA as Essential Global Regulator in Cyanobacteria. PLoS One 2016; 11:e0151384. [PMID: 26967347 PMCID: PMC4788461 DOI: 10.1371/journal.pone.0151384] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2015] [Accepted: 02/26/2016] [Indexed: 01/03/2023] Open
Abstract
In the nitrogen-fixing heterocyst-forming cyanobacterium Anabaena sp. PCC 7120, the ferric uptake regulator FurA plays a global regulatory role. Failures to eliminate wild-type copies of furA gene from the polyploid genome suggest essential functions. In the present study, we developed a selectively regulated furA expression system by the replacement of furA promoter in the Anabaena sp. chromosomes with the Co2+/Zn2+ inducible coaT promoter from Synechocystis sp. PCC 6803. By removing Co2+ and Zn2+ from the medium and shutting off furA expression, we showed that FurA was absolutely required for cyanobacterial growth. RNA-seq based comparative transcriptome analyses of the furA-turning off strain and its parental wild-type in conjunction with subsequent electrophoretic mobility shift assays and semi-quantitative RT-PCR were carried out in order to identify direct transcriptional targets and unravel new biological roles of FurA. The results of such approaches led us to identify 15 novel direct iron-dependent transcriptional targets belonging to different functional categories including detoxification and defences against oxidative stress, phycobilisome degradation, chlorophyll catabolism and programmed cell death, light sensing and response, heterocyst differentiation, exopolysaccharide biosynthesis, among others. Our analyses evidence novel interactions in the complex regulatory network orchestrated by FurA in cyanobacteria.
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20
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Kaushik MS, Singh P, Tiwari B, Mishra AK. Ferric Uptake Regulator (FUR) protein: properties and implications in cyanobacteria. ANN MICROBIOL 2015. [DOI: 10.1007/s13213-015-1134-x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
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21
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Yingping F, Lemeille S, González A, Risoul V, Denis Y, Richaud P, Lamrabet O, Fillat MF, Zhang CC, Latifi A. The Pkn22 Ser/Thr kinase in Nostoc PCC 7120: role of FurA and NtcA regulators and transcript profiling under nitrogen starvation and oxidative stress. BMC Genomics 2015. [PMID: 26220092 PMCID: PMC4518582 DOI: 10.1186/s12864-015-1703-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Background The filamentous cyanobacterium Nostoc sp. strain PCC 7120 can fix N2 when combined nitrogen is not available. Furthermore, it has to cope with reactive oxygen species generated as byproducts of photosynthesis and respiration. We have previously demonstrated the synthesis of Ser/Thr kinase Pkn22 as an important survival response of Nostoc to oxidative damage. In this study we wished to investigate the possible involvement of this kinase in signalling peroxide stress and nitrogen deprivation. Results Quantitative RT-PCR experiments revealed that the pkn22 gene is induced in response to peroxide stress and to combined nitrogen starvation. Electrophoretic motility assays indicated that the pkn22 promoter is recognized by the global transcriptional regulators FurA and NtcA. Transcriptomic analysis comparing a pkn22-insertion mutant and the wild type strain indicated that this kinase regulates genes involved in important cellular functions such as photosynthesis, carbon metabolism and iron acquisition. Since metabolic changes may lead to oxidative stress, we investigated whether this is the case with nitrogen starvation. Our results rather invalidate this hypothesis thereby suggesting that the function of Pkn22 under nitrogen starvation is independent of its role in response to peroxide stress. Conclusions Our analyses have permitted a more complete functional description of Ser/Thr kinase in Nostoc. We have decrypted the transcriptional regulation of the pkn22 gene, and analysed the whole set of genes under the control of this kinase in response to the two environmental changes often encountered by cyanobacteria in their natural habitat: oxidative stress and nitrogen deprivation. Electronic supplementary material The online version of this article (doi:10.1186/s12864-015-1703-1) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Fan Yingping
- Aix-Marseille University and CNRS, Laboratoire de Chimie Bactérienne - UMR7283, IMM, 31 Chemin Joseph Aiguier, 13402, Marseille cedex 20, France.
| | - Sylvain Lemeille
- Department of Microbiology and Molecular Medicine, CMU, Medical Faculty, University of Geneva, Genève, 1211, Switzerland.
| | - Andrés González
- Departamento de Bioquímica y Biología Molecular y Celular, Universidad de Zaragoza, 50009, Zaragoza, Spain.
| | - Véronique Risoul
- Aix-Marseille University and CNRS, Laboratoire de Chimie Bactérienne - UMR7283, IMM, 31 Chemin Joseph Aiguier, 13402, Marseille cedex 20, France.
| | - Yann Denis
- Plate-forme Transcriptome FR3479, IMM-CNRS, Marseille, France.
| | - Pierre Richaud
- CEA, DSV, IBEB, SBVME, Saint-Paul-lez-Durance, F-13108, France. .,CNRS, UMR 7265 Biol Veget & Microbiol Environ, Saint-Paul-lez-Durance, F-13108, France. .,Aix Marseille Université, BVME UMR7265, Marseille, F-13284, France.
| | - Otmane Lamrabet
- Aix-Marseille University and CNRS, Laboratoire de Chimie Bactérienne - UMR7283, IMM, 31 Chemin Joseph Aiguier, 13402, Marseille cedex 20, France.
| | - Maria F Fillat
- Departamento de Bioquímica y Biología Molecular y Celular, Universidad de Zaragoza, 50009, Zaragoza, Spain.
| | - Cheng-Cai Zhang
- Aix-Marseille University and CNRS, Laboratoire de Chimie Bactérienne - UMR7283, IMM, 31 Chemin Joseph Aiguier, 13402, Marseille cedex 20, France.
| | - Amel Latifi
- Aix-Marseille University and CNRS, Laboratoire de Chimie Bactérienne - UMR7283, IMM, 31 Chemin Joseph Aiguier, 13402, Marseille cedex 20, France.
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22
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Oxalic acid and sclerotial differentiation of Polyporus umbellatus. Sci Rep 2015; 5:10759. [PMID: 26030006 PMCID: PMC5377064 DOI: 10.1038/srep10759] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2015] [Accepted: 04/28/2015] [Indexed: 01/02/2023] Open
Abstract
The present investigation aimed to uncover the effects of exogenous oxalic acid during the sclerotial formation of Polyporus umbellatus, with an emphasis on determining the content of the endogenic oxalic acid in the fungus. To this end, the oxalic acid content of the vegetative mycelia, sclerotia, culture mediums and sclerotial exudate were measured using High Performance Liquid Chromatography (HPLC). Furthermore, the lipid peroxidation was estimated by detecting thiobarbituric bituric acid reactive substances (TBARS). The results showed that the exogenous oxalic acid caused a delay in sclerotial differentiation (of up to 9 or more days), suppressed the sclerotial biomass and decreased the lipid peroxidation significantly in a concentration-dependent manner. Oxalic acid was found at very low levels in the mycelia and the maltose medium, whereas it was found at high levels in the mycelia and sucrose medium. After sclerotial differentiation, oxalic acid accumulated at high levels in both the sclerotia and the sclerotial exudate. Oxalic acid was therefore found to inhibit P. umbellatus sclerotial formation.
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Sein-Echaluce VC, González A, Napolitano M, Luque I, Barja F, Peleato ML, Fillat MF. Zur (FurB) is a key factor in the control of the oxidative stress response inAnabaenasp. PCC 7120. Environ Microbiol 2014; 17:2006-17. [DOI: 10.1111/1462-2920.12628] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2014] [Revised: 09/05/2014] [Accepted: 09/09/2014] [Indexed: 01/08/2023]
Affiliation(s)
- Violeta C. Sein-Echaluce
- Departamento de Bioquímica y Biología Molecular y Celular; Instituto de Biocomputación y Física de Sistemas Complejos; Universidad de Zaragoza; Zaragoza 50009 Spain
| | - Andrés González
- Departamento de Bioquímica y Biología Molecular y Celular; Instituto de Biocomputación y Física de Sistemas Complejos; Universidad de Zaragoza; Zaragoza 50009 Spain
| | - Mauro Napolitano
- Instituto de Bioquímica Vegetal y Fotosíntesis; CSIC-Universidad de Sevilla; Sevilla E-41092 Spain
| | - Ignacio Luque
- Instituto de Bioquímica Vegetal y Fotosíntesis; CSIC-Universidad de Sevilla; Sevilla E-41092 Spain
| | - Francisco Barja
- Microbiology Unit; Botany and Plant Biology Department; University of Geneva; Ch. Des Embrouchis 10 Jussy-Geneva CH-1254 Switzerland
| | - M. Luisa Peleato
- Departamento de Bioquímica y Biología Molecular y Celular; Instituto de Biocomputación y Física de Sistemas Complejos; Universidad de Zaragoza; Zaragoza 50009 Spain
| | - María F. Fillat
- Departamento de Bioquímica y Biología Molecular y Celular; Instituto de Biocomputación y Física de Sistemas Complejos; Universidad de Zaragoza; Zaragoza 50009 Spain
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