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Kim KH, Kim JM, Baek JH, Jeong SE, Kim H, Yoon HS, Jeon CO. Metabolic relationships between marine red algae and algae-associated bacteria. MARINE LIFE SCIENCE & TECHNOLOGY 2024; 6:298-314. [PMID: 38827136 PMCID: PMC11136935 DOI: 10.1007/s42995-024-00227-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/27/2023] [Accepted: 12/28/2023] [Indexed: 06/04/2024]
Abstract
Mutualistic interactions between marine phototrophs and associated bacteria are an important strategy for their successful survival in the ocean, but little is known about their metabolic relationships. Here, bacterial communities in the algal sphere (AS) and bulk solution (BS) of nine marine red algal cultures were analyzed, and Roseibium and Phycisphaera were identified significantly more abundantly in AS than in BS. The metabolic features of Roseibium RMAR6-6 (isolated and genome-sequenced), Phycisphaera MAG 12 (obtained by metagenomic sequencing), and a marine red alga, Porphyridium purpureum CCMP1328 (from GenBank), were analyzed bioinformatically. RMAR6-6 has the genetic capability to fix nitrogen and produce B vitamins (B1, B2, B5, B6, B9, and B12), bacterioferritin, dimethylsulfoniopropionate (DMSP), and phenylacetate that may enhance algal growth, whereas MAG 12 may have a limited metabolic capability, not producing vitamins B9 and B12, DMSP, phenylacetate, and siderophores, but with the ability to produce bacitracin, possibly modulating algal microbiome. P. purpureum CCMP1328 lacks the genetic capability to fix nitrogen and produce vitamin B12, DMSP, phenylacetate, and siderophore. It was shown that the nitrogen-fixing ability of RMAR6-6 promoted the growth of P. purpureum, and DMSP reduced the oxidative stress of P. purpureum. The metabolic interactions between strain RMAR6-6 and P. purpureum CCMP1328 were also investigated by the transcriptomic analyses of their monoculture and co-culture. Taken together, potential metabolic relationships between Roseibium and P. purpureum were proposed. This study provides a better understanding of the metabolic relationships between marine algae and algae-associated bacteria for successful growth. Supplementary Information The online version contains supplementary material available at 10.1007/s42995-024-00227-z.
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Affiliation(s)
- Kyung Hyun Kim
- Department of Biological Sciences and Biotechnology, Hannam University, Daejon, 34054 Republic of Korea
| | - Jeong Min Kim
- Department of Life Science, Chung-Ang University, Seoul, 06974 Republic of Korea
| | - Ju Hye Baek
- Department of Life Science, Chung-Ang University, Seoul, 06974 Republic of Korea
| | - Sang Eun Jeong
- Department of Life Science, Chung-Ang University, Seoul, 06974 Republic of Korea
| | - Hocheol Kim
- Department of Biological Sciences, Sungkyunkwan University, Suwon, 16419 Republic of Korea
| | - Hwan Su Yoon
- Department of Biological Sciences, Sungkyunkwan University, Suwon, 16419 Republic of Korea
| | - Che Ok Jeon
- Department of Life Science, Chung-Ang University, Seoul, 06974 Republic of Korea
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2
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Mijovilovich A, Cloetens P, Lanzirotti A, Newville M, Wellenreuther G, Kumari P, Katsaros C, Carrano CJ, Küpper H, Küpper FC. Synchrotron X-rays reveal the modes of Fe binding and trace metal storage in the brown algae Laminaria digitata and Ectocarpus siliculosus. Metallomics 2023; 15:mfad058. [PMID: 37740572 PMCID: PMC10588612 DOI: 10.1093/mtomcs/mfad058] [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: 03/01/2023] [Accepted: 09/21/2023] [Indexed: 09/24/2023]
Abstract
Iron is accumulated symplastically in kelp in a non-ferritin core that seems to be a general feature of brown algae. Microprobe studies show that Fe binding depends on tissue type. The sea is generally an iron-poor environment and brown algae were recognized in recent years for having a unique, ferritin-free iron storage system. Kelp (Laminaria digitata) and the filamentous brown alga Ectocarpus siliculosus were investigated using X-ray microprobe imaging and nanoprobe X-ray fluorescence tomography to explore the localization of iron, arsenic, strontium, and zinc, and micro-X-ray absorption near-edge structure (μXANES) to study Fe binding. Fe distribution in frozen hydrated environmental samples of both algae shows higher accumulation in the cortex with symplastic subcellular localization. This should be seen in the context of recent ultrastructural insight by cryofixation-freeze substitution that found a new type of cisternae that may have a storage function but differs from the apoplastic Fe accumulation found by conventional chemical fixation. Zn distribution co-localizes with Fe in E. siliculosus, whereas it is chiefly located in the L. digitata medulla, which is similar to As and Sr. Both As and Sr are mostly found at the cell wall of both algae. XANES spectra indicate that Fe in L. digitata is stored in a mineral non-ferritin core, due to the lack of ferritin-encoding genes. We show that the L. digitata cortex contains mostly a ferritin-like mineral, while the meristoderm may include an additional component.
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Affiliation(s)
- Ana Mijovilovich
- Czech Academy of Sciences, Biology Centre, Institute of Plant Molecular Biology, Laboratory of Plant Biophysics and Biochemistry, Branišovska 1160/31, 370 05 Česke Budějovice, Czech Republic
| | - Peter Cloetens
- ESRF—The European Synchrotron Radiation Facility, Beamline ID16A, 71, avenue des Martyrs CS 40220 38043 Grenoble Cedex 9, France
| | - Antonio Lanzirotti
- Argonne National Laboratory, The University of Chicago, Building 434A, 9700 South Cass Avenue, Lemont, IL 60439, USA
| | - Matt Newville
- Argonne National Laboratory, The University of Chicago, Building 434A, 9700 South Cass Avenue, Lemont, IL 60439, USA
| | | | - Puja Kumari
- School of Biological Sciences, University of Aberdeen, Cruickshank Building, St Machar Drive, Aberdeen AB24 3UU, UK
| | - Christos Katsaros
- Department of Biology, National and Kapodistrian University of Athens, Panepistimiopolis, Athens 157 84, Hellas, Greece
| | - Carl J Carrano
- Department of Chemistry and Biochemistry, San Diego State University, CA 92182-1030,USA
| | - Hendrik Küpper
- Czech Academy of Sciences, Biology Centre, Institute of Plant Molecular Biology, Laboratory of Plant Biophysics and Biochemistry, Branišovska 1160/31, 370 05 Česke Budějovice, Czech Republic
- Department of Experimental Plant Biology, University of South Bohemia, Branišovská 31/1160, 370 05 České Budějovice, Czech Republic
| | - Frithjof C Küpper
- School of Biological Sciences, University of Aberdeen, Cruickshank Building, St Machar Drive, Aberdeen AB24 3UU, UK
- Department of Chemistry and Biochemistry, San Diego State University, CA 92182-1030,USA
- Marine Biodiscovery Centre, Department of Chemistry, University of Aberdeen, Aberdeen AB24 3UE, UK
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3
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Cruz-López R, Carrano CJ. Iron uptake, transport and storage in marine brown algae. Biometals 2023; 36:371-383. [PMID: 36930341 DOI: 10.1007/s10534-023-00489-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2021] [Accepted: 01/10/2023] [Indexed: 03/18/2023]
Abstract
Iron is a vital although biologically inaccessible trace nutrient for nearly all forms of life but "free" iron can be deleterious to cells and thus iron uptake and storage must be carefully controlled. The marine environment is particularly iron poor making mechanisms for its uptake and storage even more imperative. In this brief review we explore the known and potential iron uptake and storage pathways for the biologically and economically important marine brown macroalgae (seaweeds/kelps).
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Affiliation(s)
- Ricardo Cruz-López
- Instituto de Investigaciones Oceanológicas (IIO), Universidad Autónoma de Baja California (UABC), Ensenada, Baja California, México.
| | - Carl J Carrano
- Department of Chemistry and Biochemistry, San Diego State University, San Diego, CA, 92182-1030, USA
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Yang Q, Liu Y, Wang L, Zhou Q, Cheng M, Zhou J, Huang X. Cerium exposure in Lake Taihu water aggravates microcystin pollution via enhancing endocytosis of Microcystis aeruginosa. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2022; 292:118308. [PMID: 34626705 DOI: 10.1016/j.envpol.2021.118308] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2021] [Revised: 10/03/2021] [Accepted: 10/05/2021] [Indexed: 06/13/2023]
Abstract
Aggravating the pollution of microcystins (MCs) in freshwater environments is detrimental to aquatic living organisms and humans, and thus threatens the stability of ecosystems. Some environmental factors have been verified to promote the production of MCs in Microcystis aeruginosa, thereby aggravating the pollution of MCs. However, the effects of cerium (Ce), the most abundant rare earth element in global water environments, on the production of MCs in M. aeruginosa are unknown. Here, Lake Taihu water was selected as a representative of freshwater environments. By using interdisciplinary methods, it was found that: (1) the exposure level of Ce [Ce(III) and Ce(IV)] in Lake Taihu water is in the range of 0.271-0.282 μg/L; (2) Ce exposure in Lake Taihu water promoted the contents of three main MCs (MC-LR, MC-LW and MC-YR) in M. aeruginosa and water; (3) a cellular mechanism of Ce promoting the production of MCs in M. aeruginosa in Lake Taihu water was suggested: Ce enhanced endocytosis in cells of M. aeruginosa to promote the essential element uptake by M. aeruginosa for MC synthesis. Thus, Ce exposure in Lake Taihu water aggravates the pollution of MCs via enhancing endocytosis in cells of M. aeruginosa. The results provide reference for assessing the environmental risk of Ce in water environments, investigating the mechanism of the pollution of MCs induced by environmental factors, and developing strategies aimed at preventing and controlling the pollution of MCs.
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Affiliation(s)
- Qing Yang
- National and Local Joint Engineering Research Center of Biomedical Functional Materials, Jiangsu Collaborative Innovation Center of Biomedical Functional Materials, School of Chemistry and Materials Science, School of Life Sciences, Nanjing Normal University, Nanjing, 210023, China
| | - Yongqiang Liu
- National and Local Joint Engineering Research Center of Biomedical Functional Materials, Jiangsu Collaborative Innovation Center of Biomedical Functional Materials, School of Chemistry and Materials Science, School of Life Sciences, Nanjing Normal University, Nanjing, 210023, China
| | - Lihong Wang
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, 214122, China
| | - Qing Zhou
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, 214122, China; Jiangsu Cooperative Innovation Center of Water Treatment Technology and Materials, Suzhou University of Science and Technology, Suzhou, 215009, China
| | - Mengzhu Cheng
- National and Local Joint Engineering Research Center of Biomedical Functional Materials, Jiangsu Collaborative Innovation Center of Biomedical Functional Materials, School of Chemistry and Materials Science, School of Life Sciences, Nanjing Normal University, Nanjing, 210023, China; Center for Plant Cell Biology, Institute of Integrative Genome Biology, And Department of Botany and Plant Sciences, University of California, Riverside, CA, 92521, USA
| | - Jiahong Zhou
- National and Local Joint Engineering Research Center of Biomedical Functional Materials, Jiangsu Collaborative Innovation Center of Biomedical Functional Materials, School of Chemistry and Materials Science, School of Life Sciences, Nanjing Normal University, Nanjing, 210023, China
| | - Xiaohua Huang
- National and Local Joint Engineering Research Center of Biomedical Functional Materials, Jiangsu Collaborative Innovation Center of Biomedical Functional Materials, School of Chemistry and Materials Science, School of Life Sciences, Nanjing Normal University, Nanjing, 210023, China.
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Ulagesan S, Choi JW, Nam TJ, Choi YH. Characterization of recombinant protein ferritin from Pyropia yezoensis (rPyFer) and its biological activities. Food Sci Biotechnol 2020; 29:1501-1509. [PMID: 33088599 DOI: 10.1007/s10068-020-00821-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2020] [Revised: 08/09/2020] [Accepted: 08/31/2020] [Indexed: 11/29/2022] Open
Abstract
Ferritins are iron-binding proteins that are basically participated in iron storage, detoxification, and immune response. In the present study, ferritin gene from the marine red algae Pyropia yezoensis was cloned into a pET21d expression vector. High-efficiency transformation was performed in Escherichia coli BL21, the recombinant protein was expressed by induction with 0.1 mM isopropyl-β-D-thiogalactoside and purified via ammonium sulfate precipitation, anion exchange and size exclusion chromatography. The purified recombinant ferritin from P. yezoensis (rPyFer) was characterized and analyzed for its antimicrobial activity against both Gram-negative and Gram-positive bacterial cultures and exhibited significant antibacterial activity against Gram-positive cultures. The recombinant protein was also analyzed for its iron-uptake and radical-scavenging activities; rPyFer exhibited significant iron-uptake activity at low concentrations, and its radical-scavenging activity increased in a dose-dependent manner. This research will contribute to the development of new therapeutic proteins from marine algae.
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Affiliation(s)
- Selvakumari Ulagesan
- Institute of Fisheries Sciences, Pukyong National University, Busan, 46041 Republic of Korea
| | - Jeong-Wook Choi
- Institute of Fisheries Sciences, Pukyong National University, Busan, 46041 Republic of Korea
| | - Taek-Jeong Nam
- Institute of Fisheries Sciences, Pukyong National University, Busan, 46041 Republic of Korea
| | - Youn-Hee Choi
- Institute of Fisheries Sciences, Pukyong National University, Busan, 46041 Republic of Korea.,Department of Marine Bio-materials and Aquaculture, Pukyong National University, 45, Yongso-ro, Nam-Gu, Busan, 48513 Republic of Korea
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6
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Savvidou MG, Boli E, Logothetis D, Lymperopoulou T, Ferraro A, Louli V, Mamma D, Kekos D, Magoulas K, Kolisis FN. A Study on the Effect of Macro- and Micro- Nutrients on Nannochloropsis oceanica Growth, Fatty Acid Composition and Magnetic Harvesting Efficiency. PLANTS (BASEL, SWITZERLAND) 2020; 9:E660. [PMID: 32456121 PMCID: PMC7284572 DOI: 10.3390/plants9050660] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/02/2020] [Revised: 05/19/2020] [Accepted: 05/21/2020] [Indexed: 12/13/2022]
Abstract
The effect of iron, manganese, phosphorus and nitrogen on growth and lipid synthesis of the microalgae Nannochloropsis oceanica CCMP1779, as well as their impact on the magnetic harvesting efficiency, are examined under their depriving cell culture conditions. Herein, it is demonstrated that nitrogen and manganese depletion primarily reduced cell growth while phosphorus and iron restriction led to higher dry biomass. Subsequently, the role of those nutrients on fatty acids profile was examined. Phosphorus and nitrogen restriction resulted in lower and higher lipid content, respectively. High amounts of polyunsaturated fatty acids like eicosapentaenoic acid are produced under iron and manganese depletion. Phosphorus deprivation favors monounsaturated fatty acids such as C18:1 and C16:1, while nitrogen restriction favors saturated fatty acid production like C14:0, C16:0 and C18:0. Since the presence/absence of macro- and micro-elements may affect the overall electrostatic charges on the outmost microalgae surface, it was also analyzed how these elements affect the magnetic harvesting efficiency. Results showed that phosphorus deprivation led to the best magnetic harvesting efficiency of N. oceanica cells (93%) as compared to other nutrient starvation as well as standard medium.
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Affiliation(s)
- Maria G. Savvidou
- Biotechnology Laboratory, School of Chemical Engineering, National Technical University of Athens, 9 Iroon Polytechniou Str, Zografou Campus, 15780 Athens, Greece; (M.G.S.); (A.F.); (D.M.); (D.K.)
| | - Elenitsa Boli
- Laboratory of Thermodynamics and Transport Phenomena, School of Chemical Engineering, National Technical University of Athens, 9 Iroon Polytechniou Str, Zografou Campus, 15780 Athens, Greece; (E.B.); (D.L.); (V.L.); (K.M.)
| | - Dimitrios Logothetis
- Laboratory of Thermodynamics and Transport Phenomena, School of Chemical Engineering, National Technical University of Athens, 9 Iroon Polytechniou Str, Zografou Campus, 15780 Athens, Greece; (E.B.); (D.L.); (V.L.); (K.M.)
| | - Theopisti Lymperopoulou
- Environment and Quality of Life Center, School of Chemical Engineering, National Technical University of Athens, 9 Iroon Polytechniou Str, Zografou Campus, 15780 Athens, Greece;
| | - Angelo Ferraro
- Biotechnology Laboratory, School of Chemical Engineering, National Technical University of Athens, 9 Iroon Polytechniou Str, Zografou Campus, 15780 Athens, Greece; (M.G.S.); (A.F.); (D.M.); (D.K.)
| | - Vasiliki Louli
- Laboratory of Thermodynamics and Transport Phenomena, School of Chemical Engineering, National Technical University of Athens, 9 Iroon Polytechniou Str, Zografou Campus, 15780 Athens, Greece; (E.B.); (D.L.); (V.L.); (K.M.)
| | - Diomi Mamma
- Biotechnology Laboratory, School of Chemical Engineering, National Technical University of Athens, 9 Iroon Polytechniou Str, Zografou Campus, 15780 Athens, Greece; (M.G.S.); (A.F.); (D.M.); (D.K.)
| | - Dimitris Kekos
- Biotechnology Laboratory, School of Chemical Engineering, National Technical University of Athens, 9 Iroon Polytechniou Str, Zografou Campus, 15780 Athens, Greece; (M.G.S.); (A.F.); (D.M.); (D.K.)
| | - Kostis Magoulas
- Laboratory of Thermodynamics and Transport Phenomena, School of Chemical Engineering, National Technical University of Athens, 9 Iroon Polytechniou Str, Zografou Campus, 15780 Athens, Greece; (E.B.); (D.L.); (V.L.); (K.M.)
| | - Fragiskos N. Kolisis
- Biotechnology Laboratory, School of Chemical Engineering, National Technical University of Athens, 9 Iroon Polytechniou Str, Zografou Campus, 15780 Athens, Greece; (M.G.S.); (A.F.); (D.M.); (D.K.)
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7
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Küpper FC, Miller EP, Andrews SJ, Hughes C, Carpenter LJ, Meyer-Klaucke W, Toyama C, Muramatsu Y, Feiters MC, Carrano CJ. Emission of volatile halogenated compounds, speciation and localization of bromine and iodine in the brown algal genome model Ectocarpus siliculosus. J Biol Inorg Chem 2018; 23:1119-1128. [PMID: 29523971 DOI: 10.1007/s00775-018-1539-7] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2017] [Accepted: 01/28/2018] [Indexed: 11/25/2022]
Abstract
This study explores key features of bromine and iodine metabolism in the filamentous brown alga and genomics model Ectocarpus siliculosus. Both elements are accumulated in Ectocarpus, albeit at much lower concentration factors (2-3 orders of magnitude for iodine, and < 1 order of magnitude for bromine) than e.g. in the kelp Laminaria digitata. Iodide competitively reduces the accumulation of bromide. Both iodide and bromide are accumulated in the cell wall (apoplast) of Ectocarpus, with minor amounts of bromine also detectable in the cytosol. Ectocarpus emits a range of volatile halogenated compounds, the most prominent of which by far is methyl iodide. Interestingly, biosynthesis of this compound cannot be accounted for by vanadium haloperoxidase since the latter have not been found to catalyze direct halogenation of an unactivated methyl group or hydrocarbon so a methyl halide transferase-type production mechanism is proposed.
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Affiliation(s)
- Frithjof C Küpper
- Oceanlab, University of Aberdeen, Main Street, Newburgh, AB41 6AA, Scotland, UK.
- Dunstaffnage Marine Laboratory, Scottish Association for Marine Science, Oban, Argyll, PA37 1QA, Scotland, UK.
| | - Eric P Miller
- Department of Chemistry and Biochemistry, San Diego State University, San Diego, CA, 92182-1030, USA
| | - Stephen J Andrews
- Wolfson Atmospheric Chemistry Laboratories, Department of Chemistry, University of York, York, YO10 5DD, UK
| | - Claire Hughes
- Environment Department, University of York, York, YO10 5NG, UK
| | - Lucy J Carpenter
- Wolfson Atmospheric Chemistry Laboratories, Department of Chemistry, University of York, York, YO10 5DD, UK
| | - Wolfram Meyer-Klaucke
- Department of Chemistry - Inorganic Chemistry, Faculty of Science, University of Paderborn, Warburger Strasse 100, 33098, Paderborn, Germany
| | - Chiaki Toyama
- Geological Survey of Japan, The National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki, 305-8567, Japan
| | - Yasuyuki Muramatsu
- Department of Chemistry, Faculty of Science, Gakushuin University, Toshima-Ku, Tokyo, 171-8588, Japan
| | - Martin C Feiters
- Department of Organic Chemistry, Institute for Molecules and Materials, Radboud University Nijmegen, Heyendaalseweg 135, 6525 AJ, Nijmegen, The Netherlands
| | - Carl J Carrano
- Department of Chemistry and Biochemistry, San Diego State University, San Diego, CA, 92182-1030, USA
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Yarimizu K, Cruz-López R, Auerbach H, Heimann L, Schünemann V, Carrano CJ. Iron uptake and storage in the HAB dinoflagellate Lingulodinium polyedrum. Biometals 2017; 30:945-953. [PMID: 29067573 DOI: 10.1007/s10534-017-0061-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2017] [Accepted: 10/17/2017] [Indexed: 10/18/2022]
Abstract
The iron uptake and storage systems of terrestrial/higher plants are now reasonably well understood with two basic strategies being distinguished: Strategy I involves the induction of an Fe(III)-chelate reductase (ferrireductase) along with Fe(II) or Fe(III) transporter proteins while strategy II plants have evolved sophisticated systems based on high-affinity, iron specific, binding compounds called phytosiderophores. In contrast, there is little knowledge about the corresponding systems in marine, plant-like lineages. Herein we report a study of the iron uptake and storage mechanisms in the harmful algal bloom dinoflagellate Lingulodinium polyedrum. L. polyedrum is an armored dinoflagellate with a mixotrophic lifestyle and one of the most common bloom species on Southern California coast widely noted for its bioluminescent properties and as a producer of yessotoxins. Short term radio-iron uptake studies indicate that iron is taken up by L. polyedrum in a time dependent manner consistent with an active transport process. Based on inhibitor and other studies it appears that a reductive-oxidative pathway such as that found in yeast and the green alga Chlamydomonas reinhardtii is likely. Of the various iron sources tested vibrioferrin, a photoactive and relatively weak siderophore produced by potentially mutualistic Marinobacter bacterial species, was the most efficient. Other more stable and non-photoactive siderophores such as ferrioxamine E were ineffective. Several pieces of data including long term exposure to 57Fe using Mössbauer spectroscopy suggest that L. polyedrum does not possess an iron storage system but rather presumably relies on an efficient iron uptake system, perhaps mediated by mutualistic interactions with bacteria.
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Affiliation(s)
- Kyoko Yarimizu
- Department of Chemistry and Biochemistry, San Diego State University, San Diego, CA, 92182-1030, USA
| | - Ricardo Cruz-López
- Department of Biological Oceanography, Centro de Investigación Científica y de Educación Superior deEnsenada, Ensenada, BC, Mexico
| | - Hendrik Auerbach
- Department of Physics, University of Kaiserslautern, 67663, Kaiserslautern, Germany
| | - Larissa Heimann
- Department of Physics, University of Kaiserslautern, 67663, Kaiserslautern, Germany
| | - Volker Schünemann
- Department of Physics, University of Kaiserslautern, 67663, Kaiserslautern, Germany
| | - Carl J Carrano
- Department of Chemistry and Biochemistry, San Diego State University, San Diego, CA, 92182-1030, USA.
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Auerbach H, Giammanco GE, Schünemann V, Ostrowski AD, Carrano CJ. Mössbauer Spectroscopic Characterization of Iron(III)–Polysaccharide Coordination Complexes: Photochemistry, Biological, and Photoresponsive Materials Implications. Inorg Chem 2017; 56:11524-11531. [DOI: 10.1021/acs.inorgchem.7b00686] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Affiliation(s)
- Hendrik Auerbach
- Department of Physics, University of Kaiserslautern, 67663 Kaiserslautern, Germany
| | - Giuseppe E. Giammanco
- Department of Chemistry, Bowling Green State University, Bowling
Green, Ohio 43403 United States
| | - Volker Schünemann
- Department of Physics, University of Kaiserslautern, 67663 Kaiserslautern, Germany
| | - Alexis D. Ostrowski
- Department of Chemistry, Bowling Green State University, Bowling
Green, Ohio 43403 United States
| | - Carl J. Carrano
- Department of Chemistry and Biochemistry, San Diego State University, San Diego, California 92182-1030, United States
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Iron incorporation in biosilica of the marine diatom Stephanopyxis turris: dispersed or clustered? Biometals 2017; 30:71-82. [PMID: 28064420 DOI: 10.1007/s10534-016-9987-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2016] [Accepted: 12/21/2016] [Indexed: 01/08/2023]
Abstract
Iron incorporation into diatom biosilica was investigated for the species Stephanopyxis turris. It is known that several "foreign" elements (e.g., germanium, titanium, aluminum, zinc, iron) can be incorporated into the siliceous cell walls of diatoms in addition to silicon dioxide (SiO2). In order to examine the amount and form of iron incorporation, the iron content in the growth medium was varied during cultivation. Fe:Si ratios of isolated cell walls were measured by ICP-OES. SEM studies were performed to examine of a possible influence of excess iron during diatom growth upon cell wall formation. The chemical state of biosilica-attached iron was characterized by a combination of infrared, 29Si MAS NMR, and EPR spectroscopy. For comparison, synthetic silicagels of variable iron content were studied. Our investigations show that iron incorporation in biosilica is limited. More than 95% of biosilica-attached iron is found in the form of iron clusters/nanoparticles. In contrast, iron is preferentially dispersedly incorporated within the silica framework in synthetic silicagels leading to Si-O-Fe bond formation.
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Abstract
Iron is an essential cofactor for many basic metabolic pathways in pathogenic microbes and their hosts. It is also dangerous as it can catalyse the production of reactive free radicals. This dual character makes the host can either limit iron availability to invading microbes or exploit iron to induce toxicity to pathogens. Successful pathogens, including Leishmania species, must possess mechanisms to circumvent host's iron limitation and iron-induced toxicity in order to survive. In this review, we discuss the regulation of iron metabolism in the setting of infection and delineate the iron acquisition strategies used by Leishmania parasites and their subversions to host iron metabolism to overcome host's iron-related defences.
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Miller EP, Auerbach H, Schünemann V, Tymon T, Carrano CJ. Surface binding, localization and storage of iron in the giant kelp Macrocystis pyrifera. Metallomics 2016; 8:403-11. [PMID: 27009567 DOI: 10.1039/c6mt00027d] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2024]
Abstract
Iron is an essential element for all living organisms due to its ubiquitous role in redox and other enzymes, especially in the context of respiration and photosynthesis. Although the iron uptake and storage mechanisms of terrestrial/higher plants have been well-studied, the corresponding systems in marine algae have received far less attention. While the iron many marine algae take up from the environment, irrespective of its detailed internalization mechanism, arrives at the cell surface by diffusion, there is growing evidence for more "active" means of concentrating this element prior to uptake. It has been well established in both laboratory and environmentally derived samples, that a large amount of iron can be "non-specifically" adsorbed to the surface of marine algae. While this phenomenon is widely recognized and has prompted the development of experimental protocols to eliminate its contribution to iron uptake studies, its potential biological significance as a concentrated iron storage source for marine algae is only now being recognized. In this study, using an interdisciplinary array of techniques, we show that the giant kelp Macrocystis pyrifera also displays significant cell surface bound iron although less than that seen with the related brown alga Ectocarpus siliculosus. The iron on the surface is likely bound to carboxylate groups and once inside the iron is found to localize differently depending on cell type. Iron appears to be stored in an as yet undefined mineral phase.
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Affiliation(s)
- Eric P Miller
- Department of Chemistry and Biochemistry, San Diego State University, San Diego, CA 92182-1030, USA.
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13
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Diversity and Evolutionary History of Iron Metabolism Genes in Diatoms. PLoS One 2015; 10:e0129081. [PMID: 26052941 PMCID: PMC4460010 DOI: 10.1371/journal.pone.0129081] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2015] [Accepted: 05/05/2015] [Indexed: 01/04/2023] Open
Abstract
Ferroproteins arose early in Earth’s history, prior to the emergence of oxygenic photosynthesis and the subsequent reduction of bioavailable iron. Today, iron availability limits primary productivity in about 30% of the world’s oceans. Diatoms, responsible for nearly half of oceanic primary production, have evolved molecular strategies for coping with variable iron concentrations. Our understanding of the evolutionary breadth of these strategies has been restricted by the limited number of species for which molecular sequence data is available. To uncover the diversity of strategies marine diatoms employ to meet cellular iron demands, we analyzed 367 newly released marine microbial eukaryotic transcriptomes, which include 47 diatom species. We focused on genes encoding proteins previously identified as having a role in iron management: iron uptake (high-affinity ferric reductase, multi-copper oxidase, and Fe(III) permease); iron storage (ferritin); iron-induced protein substitutions (flavodoxin/ferredoxin, and plastocyanin/cytochrome c6) and defense against reactive oxygen species (superoxide dismutases). Homologs encoding the high-affinity iron uptake system components were detected across the four diatom Classes suggesting an ancient origin for this pathway. Ferritin transcripts were also detected in all Classes, revealing a more widespread utilization of ferritin throughout diatoms than previously recognized. Flavodoxin and plastocyanin transcripts indicate possible alternative redox metal strategies. Predicted localization signals for ferredoxin identify multiple examples of gene transfer from the plastid to the nuclear genome. Transcripts encoding four superoxide dismutase metalloforms were detected, including a putative nickel-coordinating isozyme. Taken together, our results suggest that the majority of iron metabolism genes in diatoms appear to be vertically inherited with functional diversity achieved via possible neofunctionalization of paralogs. This refined view of iron use strategies in diatoms elucidates the history of these adaptations, and provides potential molecular markers for determining the iron nutritional status of different diatom species in environmental samples.
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14
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Folgosa F, Camacho I, Penas D, Guilherme M, Fróis J, Ribeiro PA, Tavares P, Pereira AS. UV radiation effects on a DNA repair enzyme: conversion of a [4Fe-4S](2+) cluster into a [2Fe-2S] (2+). RADIATION AND ENVIRONMENTAL BIOPHYSICS 2015; 54:111-121. [PMID: 25249071 DOI: 10.1007/s00411-014-0569-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2014] [Accepted: 09/17/2014] [Indexed: 06/03/2023]
Abstract
Organisms are often exposed to different types of ionizing radiation that, directly or not, will promote damage to DNA molecules and/or other cellular structures. Because of that, organisms developed a wide range of response mechanisms to deal with these threats. Endonuclease III is one of the enzymes responsible to detect and repair oxidized pyrimidine base lesions. However, the effect of radiation on the structure/function of these enzymes is not clear yet. Here, we demonstrate the effect of UV-C radiation on E. coli endonuclease III through several techniques, namely UV-visible, fluorescence and Mössbauer spectroscopies, as well as SDS-PAGE and electrophoretic mobility shift assay. We demonstrate that irradiation with a UV-C source has dramatic consequences on the absorption, fluorescence, structure and functionality of the protein, affecting its [4Fe-4S] cluster and its DNA-binding ability, which results in its inactivation. An UV-C radiation-induced conversion of the [4Fe-4S](2+) into a [2Fe-2S](2+) was observed for the first time and proven by Mössbauer and UV-visible analysis. This work also shows that the DNA-binding capability of endonuclease III is highly dependent of the nuclearity of the endogenous iron-sulfur cluster. Thus, from our point of view, in a cellular context, these results strengthen the argument that cellular sensitivity to radiation can also be due to loss of radiation-induced damage repair ability.
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Affiliation(s)
- Filipe Folgosa
- REQUIMTE/CQFB, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516, Caparica, Portugal
- CEFITEC, Departamento de Física, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516, Caparica, Portugal
| | - Inês Camacho
- REQUIMTE/CQFB, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516, Caparica, Portugal
| | - Daniela Penas
- REQUIMTE/CQFB, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516, Caparica, Portugal
| | - Márcia Guilherme
- REQUIMTE/CQFB, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516, Caparica, Portugal
| | - João Fróis
- REQUIMTE/CQFB, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516, Caparica, Portugal
| | - Paulo A Ribeiro
- CEFITEC, Departamento de Física, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516, Caparica, Portugal
| | - Pedro Tavares
- REQUIMTE/CQFB, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516, Caparica, Portugal
| | - Alice S Pereira
- REQUIMTE/CQFB, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516, Caparica, Portugal.
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15
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Masuda T, Yamamoto A, Toyohara H. The iron content and ferritin contribution in fresh, dried, and toasted nori, Pyropia yezoensis. Biosci Biotechnol Biochem 2014; 79:74-81. [PMID: 25315337 DOI: 10.1080/09168451.2014.968087] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
Iron is one of the essential trace elements for humans. In this study, the iron contents in fresh, dried, and toasted nori (Pyropia yezoensis) were analyzed. The mean iron content of fresh, dried, and toasted nori were 19.0, 22.6, and 26.2 mg/100 g (dry weight), respectively. These values were superior to other food of plant origin. Furthermore, most of the iron in nori was maintained during processing, such as washing, drying, and toasting. Then, the form of iron in fresh, dried, and toasted nori was analyzed. As a result, an iron storage protein ferritin contributed to iron storage in raw and dried nori, although the precise rate of its contribution is yet to be determined, while ferritin protein cage was degraded in the toasted nori. It is the first report that verified the ferritin contribution to iron storage in such edible macroalgae with commercial importance.
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Affiliation(s)
- Taro Masuda
- a Laboratory of Food Quality Design and Development, Division of Agronomy and Horticultural Science, Graduate School of Agriculture , Kyoto University , Kyoto , Japan
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16
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Küpper FC, Leblanc C, Meyer-Klaucke W, Potin P, Feiters MC. Different speciation for bromine in brown and red algae, revealed by in vivo X-ray absorption spectroscopic studies. JOURNAL OF PHYCOLOGY 2014; 50:652-664. [PMID: 26988449 DOI: 10.1111/jpy.12199] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/2013] [Accepted: 03/22/2014] [Indexed: 06/05/2023]
Abstract
Members of various algal lineages are known to be strong producers of atmospherically relevant halogen emissions, that is a consequence of their capability to store and metabolize halogens. This study uses a noninvasive, synchrotron-based technique, X-ray absorption spectroscopy, for addressing in vivo bromine speciation in the brown algae Ectocarpus siliculosus, Ascophyllum nodosum, and Fucus serratus, the red algae Gracilaria dura, G. gracilis, Chondrus crispus, Osmundea pinnatifida, Asparagopsis armata, Polysiphonia elongata, and Corallina officinalis, the diatom Thalassiosira rotula, the dinoflagellate Lingulodinium polyedrum and a natural phytoplankton sample. The results highlight a diversity of fundamentally different bromine storage modes: while most of the stramenopile representatives and the dinoflagellate store mostly bromide, there is evidence for Br incorporated in nonaromatic hydrocarbons in Thalassiosira. Red algae operate various organic bromine stores - including a possible precursor (by the haloform reaction) for bromoform in Asparagopsis and aromatically bound Br in Polysiphonia and Corallina. Large fractions of the bromine in the red algae G. dura and C. crispus and the brown alga F. serratus are present as Br(-) defects in solid KCl, similar to what was reported earlier for Laminaria parts. These results are discussed according to different defensive strategies that are used within algal taxa to cope with biotic or abiotic stresses.
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Affiliation(s)
- Frithjof C Küpper
- Oceanlab, University of Aberdeen, Main Street, Newburgh, AB41 6 AA, UK
- Scottish Association for Marine Science, Dunstaffnage Marine Laboratory, Argyll, Oban, PA37 1QA, UK
| | - Catherine Leblanc
- Integrative Biology of Marine Models, Centre National de la Recherche Scientifique, Station Biologique, Roscoff, F-29680, France
- Marine Plants and Biomolecules Laboratory, Université Pierre et Marie Curie, Université Paris 6, Station Biologique, Roscoff, F-29680, France
| | - Wolfram Meyer-Klaucke
- European Molecular Biology Laboratory (EMBL), Hamburg Unit, c/o DESY, Notkestrasse 85, Hamburg, D-22607, Germany
| | - Philippe Potin
- Integrative Biology of Marine Models, Centre National de la Recherche Scientifique, Station Biologique, Roscoff, F-29680, France
- Marine Plants and Biomolecules Laboratory, Université Pierre et Marie Curie, Université Paris 6, Station Biologique, Roscoff, F-29680, France
| | - Martin C Feiters
- Department of Organic Chemistry, Institute for Molecules and Materials, Radboud University Nijmegen, Heyendaalseweg 135, Nijmegen, NL-6525 AJ, The Netherlands
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Carmel N, Tel-Or E, Chen Y, Pick U. Iron uptake mechanism in the chrysophyte microalga Dinobryon. JOURNAL OF PLANT PHYSIOLOGY 2014; 171:993-997. [PMID: 24974325 DOI: 10.1016/j.jplph.2014.03.014] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/12/2013] [Revised: 03/29/2014] [Accepted: 03/31/2014] [Indexed: 06/03/2023]
Abstract
The mechanism of iron uptake in the chrysophyte microalga Dinobryon was studied. Previous studies have shown that iron is the dominant limiting elements for growth of Dinobryon in the Eshkol reservoir in northern Israel, which control its burst of bloom. It is demonstrated that Dinobryon has a light-stimulated ferrireductase activity, which is sensitive to the photosynthetic electron transport inhibitor DCMU and to the uncoupler CCCP. Iron uptake is also light-dependent, is inhibited by DCMU and by CCCP and also by the ferrous iron chelator BPDS. These results suggest that ferric iron reduction by ferrireductase is involved in iron uptake in Dinobryon and that photosynthesis provides the major reducing power to energize iron acquisition. Iron deprivation does not enhance but rather inhibits iron uptake contrary to observations in other algae.
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Affiliation(s)
- Nava Carmel
- Department of Agricultural Botany, The Robert H. Smith Institute of Plant Sciences and Genetics in Agriculture, The Hebrew University of Jerusalem, 76100 Rehovot, Israel
| | - Elisha Tel-Or
- Department of Agricultural Botany, The Robert H. Smith Institute of Plant Sciences and Genetics in Agriculture, The Hebrew University of Jerusalem, 76100 Rehovot, Israel.
| | - Yona Chen
- Department of Soil and Water Sciences, The Robert H. Smith Institute of Plant Sciences and Genetics in Agriculture, The Hebrew University of Jerusalem, 76100 Rehovot, Israel
| | - Uri Pick
- Department of Biological Chemistry, The Weizmann Institute of Science, Rehovot 76100, Israel.
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Miller EP, Böttger LH, Weerasinghe AJ, Crumbliss AL, Matzanke BF, Meyer-Klaucke W, Küpper FC, Carrano CJ. Surface-bound iron: a metal ion buffer in the marine brown alga Ectocarpus siliculosus? JOURNAL OF EXPERIMENTAL BOTANY 2014; 65:585-94. [PMID: 24368501 PMCID: PMC3904714 DOI: 10.1093/jxb/ert406] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Although the iron uptake and storage mechanisms of terrestrial/higher plants have been well studied, the corresponding systems in marine algae have received far less attention. Studies have shown that while some species of unicellular algae utilize unique mechanisms of iron uptake, many acquire iron through the same general mechanisms as higher plants. In contrast, the iron acquisition strategies of the multicellular macroalgae remain largely unknown. This is especially surprising since many of these organisms represent important ecological and evolutionary niches in the coastal marine environment. It has been well established in both laboratory and environmentally derived samples, that a large amount of iron can be 'non-specifically' adsorbed to the surface of marine algae. While this phenomenon is widely recognized and has prompted the development of experimental protocols to eliminate its contribution to iron uptake studies, its potential biological significance as a concentrated iron source for marine algae is only now being recognized. This study used an interdisciplinary array of techniques to explore the nature of the extensive and powerful iron binding on the surface of both laboratory and environmental samples of the marine brown alga Ectocarpus siliculosus and shows that some of this surface-bound iron is eventually internalized. It is proposed that the surface-binding properties of E. siliculosus allow it to function as a quasibiological metal ion 'buffer', allowing iron uptake under the widely varying external iron concentrations found in coastal marine environments.
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Affiliation(s)
- Eric P. Miller
- Department of Chemistry and Biochemistry, San Diego State University, San Diego, CA 92182-1030, USA
| | - Lars H. Böttger
- Section Natural Sciences, Isotopes Laboratory, University of Lübeck, Ratzeburger Allee 160, D-23538 Lübeck, Germany
- * Present address: Department of Chemistry, Stanford University, Stanford, CA 94305-5080, USA
| | | | | | - Berthold F. Matzanke
- Section Natural Sciences, Isotopes Laboratory, University of Lübeck, Ratzeburger Allee 160, D-23538 Lübeck, Germany
| | - Wolfram Meyer-Klaucke
- European Molecular Biology Laboratory (EMBL), Hamburg Unit, c/o DESY, Notkestrasse 85, D-22607 Hamburg, Germany
| | - Frithjof C. Küpper
- Oceanlab, University of Aberdeen, Main Street, Newburgh AB41 6AA, Scotland, UK
| | - Carl J. Carrano
- Department of Chemistry and Biochemistry, San Diego State University, San Diego, CA 92182-1030, USA
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Flannery AR, Renberg RL, Andrews NW. Pathways of iron acquisition and utilization in Leishmania. Curr Opin Microbiol 2013; 16:716-21. [PMID: 23962817 DOI: 10.1016/j.mib.2013.07.018] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2013] [Revised: 07/24/2013] [Accepted: 07/25/2013] [Indexed: 11/16/2022]
Abstract
Iron is essential for many metabolic pathways, but is toxic in excess. Recent identification of the ferric iron reductase LFR1, the ferrous iron transporter LIT1, and the heme transporter LHR1 greatly advanced our understanding of how Leishmania parasites acquire iron and regulate its uptake. LFR1 and LIT1 have close orthologs in plants, and are required for Leishmania virulence. Consistent with the lack of heme biosynthesis in trypanosomatids, LHR1 and LABCG5, a protein involved in heme salvage from hemoglobin, seem essential for Leishmania survival. LFR1, LIT1 and LHR1 are upregulated under low iron availability, in agreement with the need to prevent excessive iron uptake. Future studies should clarify how Leishmania interacts with the iron homeostasis machinery of its host cell, the macrophage.
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Affiliation(s)
- Andrew R Flannery
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD, USA
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Hartnett A, Böttger LH, Matzanke BF, Carrano CJ. Iron transport and storage in the coccolithophore: Emiliania huxleyi. Metallomics 2012; 4:1160-6. [PMID: 23011578 DOI: 10.1039/c2mt20144e] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Iron is an essential element for all living organisms due to its ubiquitous role in redox and other enzymes, especially in the context of respiration and photosynthesis. The iron uptake and storage systems of terrestrial/higher plants are now reasonably well understood with two basic strategies for iron uptake being distinguished: strategy I plants use a mechanism involving soil acidification and induction of Fe(III)-chelate reductase (ferrireductase) and Fe(II) transporter proteins while strategy II plants have evolved sophisticated systems based on high-affinity, iron specific, binding compounds called phytosiderophores. In contrast, there is little knowledge about the corresponding systems in marine plant-like lineages. Herein we report a study of the iron uptake and storage mechanisms in the coccolithophore Emiliania huxleyi. Short term radio-iron uptake studies indicate that iron is taken up by Emiliania in a time and concentration dependent manner consistent with an active transport process. Based on inhibitor studies it appears that iron is taken up directly as Fe(iii). However if a reductive step is involved the Fe(II) must not be accessible to the external environment. Upon long term exposure to (57)Fe we have been able, using a combination of Mössbauer and XAS spectroscopies, to identify a single metabolite which displays spectral features similar to the phosphorus-rich mineral core of bacterial and plant ferritins.
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Affiliation(s)
- Andrej Hartnett
- Department of Chemistry and Biochemistry, San Diego State University, San Diego CA, 92182-1030, USA
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