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You X, Chen X, Jiang Y, Chen H, Liu J, Wu Z, Sun W, Ni J. 6PPD-quinone affects the photosynthetic carbon fixation in cyanobacteria by extracting photosynthetic electrons. Innovation (N Y) 2024; 5:100630. [PMID: 38800352 PMCID: PMC11126802 DOI: 10.1016/j.xinn.2024.100630] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2023] [Accepted: 04/23/2024] [Indexed: 05/29/2024] Open
Abstract
Photosynthetic carbon fixation by cyanobacteria plays a pivotal role in the global carbon cycle but is threatened by environmental pollutants. To date, the impact of quinones, with electron shuttling properties, on cyanobacterial photosynthesis is unknown. Here, we present the first study investigating the effects of an emerging quinone pollutant, i.e., 6PPD-Q (N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine-quinone), on the cyanobacterium Synechocystis sp. over a 400-generation exposure period. Synechocystis sp. exhibited distinct sequential phases, including hormesis, toxicity, and eventual recovery, throughout this exposure. Extensive evidence, including results of thylakoid membrane morphological and photosynthetic responses, carbon fixation rate, and key gene/protein analyses, strongly indicates that 6PPD-Q is a potent disruptor of photosynthesis. 6PPD-Q accepts photosynthetic electrons at the plastoquinone QB site in photosystem II (PSII) and the phylloquinone A1 site in PSI, leading to a sustained decrease in the carbon fixation of cyanobacteria after an ephemeral increase. This work revealed the specific mechanism by which 6PPD-Q interferes with photosynthetic carbon fixation in cyanobacteria, which is highly important for the global carbon cycle.
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Affiliation(s)
- Xiuqi You
- Key Laboratory of Water and Sediment Sciences, Ministry of Education, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China
- State Environmental Protection Key Laboratory of All Material Fluxes in River Ecosystems, Beijing 100871, China
| | - Ximin Chen
- Key Laboratory of Water and Sediment Sciences, Ministry of Education, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China
- State Environmental Protection Key Laboratory of All Material Fluxes in River Ecosystems, Beijing 100871, China
| | - Yi Jiang
- Department of Civil and Environmental Engineering, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong 999077, China
| | - Huan Chen
- Department of Environmental Engineering and Earth Sciences, Clemson University, Clemson, SC 29634, USA
| | - Juan Liu
- Key Laboratory of Water and Sediment Sciences, Ministry of Education, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China
- State Environmental Protection Key Laboratory of All Material Fluxes in River Ecosystems, Beijing 100871, China
| | - Zhen Wu
- Key Laboratory of Water and Sediment Sciences, Ministry of Education, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China
- State Environmental Protection Key Laboratory of All Material Fluxes in River Ecosystems, Beijing 100871, China
| | - Weiling Sun
- Key Laboratory of Water and Sediment Sciences, Ministry of Education, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China
- State Environmental Protection Key Laboratory of All Material Fluxes in River Ecosystems, Beijing 100871, China
| | - Jinren Ni
- Key Laboratory of Water and Sediment Sciences, Ministry of Education, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China
- State Environmental Protection Key Laboratory of All Material Fluxes in River Ecosystems, Beijing 100871, China
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Yalcin YS, Aydin BN, Sitther V. Impact of Zero-Valent Iron Nanoparticles and Ampicillin on Adenosine Triphosphate and Lactate Metabolism in the Cyanobacterium Fremyella diplosiphon. Microorganisms 2024; 12:612. [PMID: 38543663 PMCID: PMC10975374 DOI: 10.3390/microorganisms12030612] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2023] [Revised: 02/14/2024] [Accepted: 02/22/2024] [Indexed: 04/01/2024] Open
Abstract
In cyanobacteria, the interplay of ATP and lactate dynamics underpins cellular energetics; their pronounced shifts in response to zero-valent iron (nZVI) nanoparticles and ampicillin highlight the nuanced metabolic adaptations to environmental challenges. In this study, we investigated the impact of nZVIs and ampicillin on Fremyella diplosiphon cellular energetics as determined by adenosine triphosphate (ATP) content, intracellular and extracellular lactate levels, and their impact on cell morphology as visualized by transmission electron microscopy. While a significant increase in ATP concentration was observed in 0.8 mg/L ampicillin-treated cells compared to the untreated control, a significant decline was noted in cells treated with 3.2 mg/L nZVIs. ATP levels in the combination regimen of 0.8 mg/L ampicillin and 3.2 mg/L nZVIs were significantly elevated (p < 0.05) compared to the 3.2 mg/L nZVI treatment. Intracellular and extracellular lactate levels were significantly higher in 0.8 mg/L ampicillin, 3.2 mg/L nZVIs, and the combination regimen compared to the untreated control; however, extracellular lactate levels were the highest in cells treated with 3.2 mg/L nZVIs. Visualization of morphological changes indicated increased thylakoid membrane stacks and inter-thylakoidal distances in 3.2 mg/L nZVI-treated cells. Our findings demonstrate a complex interplay of nanoparticle and antibiotic-induced responses, highlighting the differential impact of these stressors on F. diplosiphon metabolism and cellular integrity.
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Affiliation(s)
| | | | - Viji Sitther
- Department of Biology, Morgan State University, 1700 E. Cold Spring Lane, Baltimore, MD 21251, USA
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3
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Jiang HW, Wu HY, Wang CH, Yang CH, Ko JT, Ho HC, Tsai MD, Bryant DA, Li FW, Ho MC, Ho MY. A structure of the relict phycobilisome from a thylakoid-free cyanobacterium. Nat Commun 2023; 14:8009. [PMID: 38049400 PMCID: PMC10696076 DOI: 10.1038/s41467-023-43646-9] [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: 04/27/2023] [Accepted: 11/15/2023] [Indexed: 12/06/2023] Open
Abstract
Phycobilisomes (PBS) are antenna megacomplexes that transfer energy to photosystems II and I in thylakoids. PBS likely evolved from a basic, inefficient form into the predominant hemidiscoidal shape with radiating peripheral rods. However, it has been challenging to test this hypothesis because ancestral species are generally inaccessible. Here we use spectroscopy and cryo-electron microscopy to reveal a structure of a "paddle-shaped" PBS from a thylakoid-free cyanobacterium that likely retains ancestral traits. This PBS lacks rods and specialized ApcD and ApcF subunits, indicating relict characteristics. Other features include linkers connecting two chains of five phycocyanin hexamers (CpcN) and two core subdomains (ApcH), resulting in a paddle-shaped configuration. Energy transfer calculations demonstrate that chains are less efficient than rods. These features may nevertheless have increased light absorption by elongating PBS before multilayered thylakoids with hemidiscoidal PBS evolved. Our results provide insights into the evolution and diversification of light-harvesting strategies before the origin of thylakoids.
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Affiliation(s)
- Han-Wei Jiang
- Department of Life Science, National Taiwan University, Taipei, Taiwan
| | - Hsiang-Yi Wu
- Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan
| | - Chun-Hsiung Wang
- Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan
| | - Cheng-Han Yang
- Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan
| | - Jui-Tse Ko
- Department of Life Science, National Taiwan University, Taipei, Taiwan
| | - Han-Chen Ho
- Department of Anatomy, Tzu Chi University, Hualien, Taiwan
| | - Ming-Daw Tsai
- Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan
- Institute of Biochemical Sciences, National Taiwan University, Taipei, Taiwan
| | - Donald A Bryant
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA, USA
| | - Fay-Wei Li
- Boyce Thompson Institute, Ithaca, NY, USA
- Plant Biology Section, Cornell University, Ithaca, NY, USA
| | - Meng-Chiao Ho
- Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan.
- Institute of Biochemical Sciences, National Taiwan University, Taipei, Taiwan.
- Graduate Institute of Biochemistry and Molecular Biology, National Taiwan University, Taipei, Taiwan.
| | - Ming-Yang Ho
- Department of Life Science, National Taiwan University, Taipei, Taiwan.
- Institute of Plant Biology, National Taiwan University, Taipei, Taiwan.
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4
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Sengupta A, Bandyopadhyay A, Schubert MG, Church GM, Pakrasi HB. Antenna Modification in a Fast-Growing Cyanobacterium Synechococcus elongatus UTEX 2973 Leads to Improved Efficiency and Carbon-Neutral Productivity. Microbiol Spectr 2023; 11:e0050023. [PMID: 37318337 PMCID: PMC10433846 DOI: 10.1128/spectrum.00500-23] [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: 02/01/2023] [Accepted: 05/19/2023] [Indexed: 06/16/2023] Open
Abstract
Our planet is sustained by sunlight, the primary energy source made accessible to all life forms by photoautotrophs. Photoautotrophs are equipped with light-harvesting complexes (LHCs) that enable efficient capture of solar energy, particularly when light is limiting. However, under high light, LHCs can harvest photons in excess of the utilization capacity of cells, causing photodamage. This damaging effect is most evident when there is a disparity between the amount of light harvested and carbon available. Cells strive to circumvent this problem by dynamically adjusting the antenna structure in response to the changing light signals, a process known to be energetically expensive. Much emphasis has been laid on elucidating the relationship between antenna size and photosynthetic efficiency and identifying strategies to synthetically modify antennae for optimal light capture. Our study is an effort in this direction and investigates the possibility of modifying phycobilisomes, the LHCs present in cyanobacteria, the simplest of photoautotrophs. We systematically truncate the phycobilisomes of Synechococcus elongatus UTEX 2973, a widely studied, fast-growing model cyanobacterium and demonstrate that partial truncation of its antenna can lead to a growth advantage of up to 36% compared to the wild type and an increase in sucrose titer of up to 22%. In contrast, targeted deletion of the linker protein which connects the first phycocyanin rod to the core proved detrimental, indicating that the core alone is not enough, and it is essential to maintain a minimal rod-core structure for efficient light harvest and strain fitness. IMPORTANCE Light energy is essential for the existence of life on this planet, and only photosynthetic organisms, equipped with light-harvesting antenna protein complexes, can capture this energy, making it readily accessible to all other life forms. However, these light-harvesting antennae are not designed to function optimally under extreme high light, a condition which can cause photodamage and significantly reduce photosynthetic productivity. In this study, we attempt to assess the optimal antenna structure for a fast-growing, high-light tolerant photosynthetic microbe with the goal of improving its productivity. Our findings provide concrete evidence that although the antenna complex is essential, antenna modification is a viable strategy to maximize strain performance under controlled growth conditions. This understanding can also be translated into identifying avenues to improve light harvesting efficiency in higher photoautotrophs.
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Affiliation(s)
- Annesha Sengupta
- Department of Biology, Washington University, St. Louis, Missouri, USA
| | | | - Max G. Schubert
- Department of Genetics, Harvard Medical School, Boston, Massachusetts, USA
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, Massachusetts, USA
| | - George M. Church
- Department of Genetics, Harvard Medical School, Boston, Massachusetts, USA
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, Massachusetts, USA
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5
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Liu H. Cyanobacterial Phycobilisome Allostery as Revealed by Quantitative Mass Spectrometry. Biochemistry 2023; 62:1307-1320. [PMID: 36943676 DOI: 10.1021/acs.biochem.3c00047] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/23/2023]
Abstract
Phycobilisomes (PBSs) are the major photosynthetic light-harvesting complexes in cyanobacteria and red algae. PBS, a multisubunit protein complex, has two major interfaces that comprise intrinsically disordered regions (IDRs): rod-core and core-membrane. IDRs do not form regular, three-dimensional structures on their own. Their presence in the photosynthetic pigment-protein complexes portends their structural and functional importance. A recent model suggests that PB-loop, an IDR located on the PBS subunit ApcE and C-terminal extension (CTE) of the PBS subunit ApcG, forms a structural protrusion on the PBS core-membrane side, facing the thylakoid membrane. Here, the structural synergy between the rod-core region and the core-membrane region was investigated using quantitative mass spectrometry (MS). The AlphaFold-predicted CpcG-CTE structure was first modeled onto the PBS rod-core region, guided and justified by the isotopically encoded structural MS data. Quantitative cross-linking MS analysis revealed that the structural proximity of the PB-loop in ApcE and ApcG-CTE is significantly disturbed in the absence of six PBS rods, which are attached to PBS via CpcG-CTE, indicative of drastic conformational changes and decreased structural integrity. These results suggest that CpcG-rod attachment on the PBS rod-core side is essentially required for the PBS core-membrane structural assembly. The hypothesized long-range synergy between the rod-core interface (where the orange carotenoid protein also functions) and the terminal energy emitter of PBS must have important regulatory roles in PBS core assembly, light-harvesting, and excitation energy transmission. These data also lend strategies that genetic truncation of the light-harvesting antennas aimed for improved photosynthetic productivity must rely on an in-depth understanding of their global structural integrity.
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Affiliation(s)
- Haijun Liu
- Department of Biology, Washington University in St. Louis, St. Louis, Missouri 63130, United States
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6
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Tay JW, Cameron JC. Asymmetric survival in single-cell lineages of cyanobacteria in response to photodamage. PHOTOSYNTHESIS RESEARCH 2023; 155:289-297. [PMID: 36581718 DOI: 10.1007/s11120-022-00986-9] [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: 07/21/2022] [Accepted: 11/14/2022] [Indexed: 06/17/2023]
Abstract
Oxygenic photosynthesis is driven by the coupled action of the light-dependent pigment-protein complexes, photosystem I and II, located within the internal thylakoid membrane system. However, photosystem II is known to be prone to photooxidative damage. Thus, photosynthetic organisms have evolved a repair cycle to continuously replace the damaged proteins in photosystem II. However, it has remained difficult to deconvolute the damage and repair processes using traditional ensemble approaches. Here, we demonstrate an automated approach using time-lapse fluorescence microscopy and computational image analysis to study the dynamics and effects of photodamage in single cells at subcellular resolution in cyanobacteria. By growing cells in a two-dimensional layer, we avoid shading effects, thereby generating uniform and reproducible growth conditions. Using this platform, we analyzed the growth and physiology of multiple strains simultaneously under defined photoinhibitory conditions stimulated by UV-A light. Our results reveal an asymmetric cellular response to photodamage between sibling cells and the generation of an elusive subcellular structure, here named a 'photoendosome,' derived from the thylakoid which could indicate the presence of a previously unknown photoprotective mechanism. We anticipate these results to be a starting point for further studies to better understand photodamage and repair at the single-cell level.
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Affiliation(s)
- Jian Wei Tay
- BioFrontiers Institute, University of Colorado Boulder, 3415 Colorado Avenue, Boulder, CO, 80309, USA
| | - Jeffrey C Cameron
- Department of Biochemistry, University of Colorado, Boulder, CO, 80309, USA.
- Renewable and Sustainable Energy Institute, University of Colorado, Boulder, CO, 80309, USA.
- National Renewable Energy Laboratory, Golden, CO, 80401, USA.
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7
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Heller WT. Small-Angle Neutron Scattering for Studying Lipid Bilayer Membranes. Biomolecules 2022; 12:1591. [PMID: 36358941 PMCID: PMC9687511 DOI: 10.3390/biom12111591] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2022] [Revised: 10/18/2022] [Accepted: 10/26/2022] [Indexed: 09/23/2023] Open
Abstract
Small-angle neutron scattering (SANS) is a powerful tool for studying biological membranes and model lipid bilayer membranes. The length scales probed by SANS, being from 1 nm to over 100 nm, are well-matched to the relevant length scales of the bilayer, particularly when it is in the form of a vesicle. However, it is the ability of SANS to differentiate between isotopes of hydrogen as well as the availability of deuterium labeled lipids that truly enable SANS to reveal details of membranes that are not accessible with the use of other techniques, such as small-angle X-ray scattering. In this work, an overview of the use of SANS for studying unilamellar lipid bilayer vesicles is presented. The technique is briefly presented, and the power of selective deuteration and contrast variation methods is discussed. Approaches to modeling SANS data from unilamellar lipid bilayer vesicles are presented. Finally, recent examples are discussed. While the emphasis is on studies of unilamellar vesicles, examples of the use of SANS to study intact cells are also presented.
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Affiliation(s)
- William T Heller
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
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8
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Mills LA, Moreno-Cabezuelo JÁ, Włodarczyk A, Victoria AJ, Mejías R, Nenninger A, Moxon S, Bombelli P, Selão TT, McCormick AJ, Lea-Smith DJ. Development of a Biotechnology Platform for the Fast-Growing Cyanobacterium Synechococcus sp. PCC 11901. Biomolecules 2022; 12:biom12070872. [PMID: 35883428 PMCID: PMC9313322 DOI: 10.3390/biom12070872] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2022] [Revised: 06/21/2022] [Accepted: 06/21/2022] [Indexed: 02/07/2023] Open
Abstract
Synechococcus sp. PCC 11901 reportedly demonstrates the highest, most sustained growth of any known cyanobacterium under optimized conditions. Due to its recent discovery, our knowledge of its biology, including the factors underlying sustained, fast growth, is limited. Furthermore, tools specific for genetic manipulation of PCC 11901 are not established. Here, we demonstrate that PCC 11901 shows faster growth than other model cyanobacteria, including the fast-growing species Synechococcuselongatus UTEX 2973, under optimal growth conditions for UTEX 2973. Comparative genomics between PCC 11901 and Synechocystis sp. PCC 6803 reveal conservation of most metabolic pathways but PCC 11901 has a simplified electron transport chain and reduced light harvesting complex. This may underlie its superior light use, reduced photoinhibition, and higher photosynthetic and respiratory rates. To aid biotechnology applications, we developed a vitamin B12 auxotrophic mutant but were unable to generate unmarked knockouts using two negative selectable markers, suggesting that recombinase- or CRISPR-based approaches may be required for repeated genetic manipulation. Overall, this study establishes PCC 11901 as one of the most promising species currently available for cyanobacterial biotechnology and provides a useful set of bioinformatics tools and strains for advancing this field, in addition to insights into the factors underlying its fast growth phenotype.
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Affiliation(s)
- Lauren A. Mills
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, UK; (L.A.M.); (J.Á.M.-C.); (R.M.); (S.M.)
| | - José Ángel Moreno-Cabezuelo
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, UK; (L.A.M.); (J.Á.M.-C.); (R.M.); (S.M.)
| | - Artur Włodarczyk
- Bondi Bio Pty Ltd., c/o Climate Change Cluster, University of Technology Sydney, 745 Harris Street, Ultimo, NSW 2007, Australia;
| | - Angelo J. Victoria
- SynthSys and Institute of Molecular Plant Sciences, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3BF, UK; (A.J.V.); (A.N.); (A.J.M.)
| | - Rebeca Mejías
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, UK; (L.A.M.); (J.Á.M.-C.); (R.M.); (S.M.)
| | - Anja Nenninger
- SynthSys and Institute of Molecular Plant Sciences, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3BF, UK; (A.J.V.); (A.N.); (A.J.M.)
| | - Simon Moxon
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, UK; (L.A.M.); (J.Á.M.-C.); (R.M.); (S.M.)
| | - Paolo Bombelli
- Department of Biochemistry, University of Cambridge, Cambridge CB2 1QW, UK;
| | - Tiago T. Selão
- Department of Chemical and Environmental Engineering, University of Nottingham, Nottingham NG7 2RD, UK;
| | - Alistair J. McCormick
- SynthSys and Institute of Molecular Plant Sciences, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3BF, UK; (A.J.V.); (A.N.); (A.J.M.)
| | - David J. Lea-Smith
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, UK; (L.A.M.); (J.Á.M.-C.); (R.M.); (S.M.)
- Correspondence:
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9
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Nagy G, Garab G. Neutron scattering in photosynthesis research: recent advances and perspectives for testing crop plants. PHOTOSYNTHESIS RESEARCH 2021; 150:41-49. [PMID: 32488447 PMCID: PMC8556207 DOI: 10.1007/s11120-020-00763-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Accepted: 05/25/2020] [Indexed: 05/05/2023]
Abstract
The photosynthetic performance of crop plants under a variety of environmental factors and stress conditions, at the fundamental level, depends largely on the organization and structural flexibility of thylakoid membranes. These highly organized membranes accommodate virtually all protein complexes and additional compounds carrying out the light reactions of photosynthesis. Most regulatory mechanisms fine-tuning the photosynthetic functions affect the organization of thylakoid membranes at different levels of the structural complexity. In order to monitor these reorganizations, non-invasive techniques are of special value. On the mesoscopic scale, small-angle neutron scattering (SANS) has been shown to deliver statistically and spatially averaged information on the periodic organization of the thylakoid membranes in vivo and/or, in isolated thylakoids, under physiologically relevant conditions, without fixation or staining. More importantly, SANS investigations have revealed rapid reversible reorganizations on the timescale of several seconds and minutes. In this paper, we give a short introduction into the basics of SANS technique, advantages and limitations, and briefly overview recent advances and potential applications of this technique in the physiology and biotechnology of crop plants. We also discuss future perspectives of neutron crystallography and different neutron scattering techniques, which are anticipated to become more accessible and of more use in photosynthesis research at new facilities with higher fluxes and innovative instrumentation.
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Affiliation(s)
- Gergely Nagy
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37830, USA.
- Institute for Solid State Physics and Optics, Wigner Research Centre for Physics, POB 49, 1525, Budapest, Hungary.
| | - Győző Garab
- Institute of Plant Biology, Biological Research Centre, POB 521, 6701, Szeged, Hungary.
- Department of Physics, Faculty of Science, Ostrava University, Chittussiho 10, Ostrava - Slezská, 710 0, Ostrava, Czech Republic.
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10
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Jakubauskas D, Mortensen K, Jensen PE, Kirkensgaard JJK. Small-Angle X-Ray and Neutron Scattering on Photosynthetic Membranes. Front Chem 2021; 9:631370. [PMID: 33954157 PMCID: PMC8090863 DOI: 10.3389/fchem.2021.631370] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2020] [Accepted: 02/01/2021] [Indexed: 11/26/2022] Open
Abstract
Ultrastructural membrane arrangements in living cells and their dynamic remodeling in response to environmental changes remain an area of active research but are also subject to large uncertainty. The use of noninvasive methods such as X-ray and neutron scattering provides an attractive complimentary source of information to direct imaging because in vivo systems can be probed in near-natural conditions. However, without solid underlying structural modeling to properly interpret the indirect information extracted, scattering provides at best qualitative information and at worst direct misinterpretations. Here we review the current state of small-angle scattering applied to photosynthetic membrane systems with particular focus on data interpretation and modeling.
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Affiliation(s)
- Dainius Jakubauskas
- X-ray and Neutron Science, Niels Bohr Institute, University of Copenhagen, Copenhagen, Denmark
| | - Kell Mortensen
- X-ray and Neutron Science, Niels Bohr Institute, University of Copenhagen, Copenhagen, Denmark
| | - Poul Erik Jensen
- Department of Food Science, University of Copenhagen, Copenhagen, Denmark
| | - Jacob J. K. Kirkensgaard
- X-ray and Neutron Science, Niels Bohr Institute, University of Copenhagen, Copenhagen, Denmark
- Department of Food Science, University of Copenhagen, Copenhagen, Denmark
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11
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Qian S, Sharma VK, Clifton LA. Understanding the Structure and Dynamics of Complex Biomembrane Interactions by Neutron Scattering Techniques. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2020; 36:15189-15211. [PMID: 33300335 DOI: 10.1021/acs.langmuir.0c02516] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
The membrane is one of the key structural materials of biology at the cellular level. Composed predominantly of a bilayer of lipids with embedded and bound proteins, it defines the boundaries of the cell and many organelles essential to life and therefore is involved in almost all biological processes. Membrane-specific interactions, such as drug binding to a membrane receptor or the interactions of an antimicrobial compound with the lipid matrix of a pathogen membrane, are of interest across the scientific disciplines. Herein we present a review, aimed at nonexperts, of the major neutron scattering techniques used in membrane studies: small-angle neutron scattering, neutron membrane diffraction, neutron reflectometry, quasielastic neutron scattering, and neutron spin echo. Neutron scattering techniques are well suited to studying biological membranes. The nondestructive nature of cold neutrons means that samples can be measured for long periods without fear of beam damage from ultraviolet, electron, or X-ray radiation, and neutron beams are highly penetrating, thus offering flexibility in samples and sample environments. Most important is the strong difference in neutron scattering lengths between the two most abundant forms of hydrogen, protium and deuterium. Changing the relative amounts of protium/deuterium in a sample allows the production of a series of neutron scattering data sets, enabling the observation of differing components within complex membrane architectures. This approach can be as simple as using the naturally occurring neutron contrast between different biomolecules to study components in a complex by changing the solution H2O/D2O ratio or as complex as selectively labeling individual components with hydrogen isotopes. This review presents an overview of each experimental technique with the neutron instrument configuration, related sample preparation and sample environment, and data analysis, highlighted by a special emphasis on using prominent neutron contrast to understand structure and dynamics. This review gives researchers a practical introduction to the often enigmatic suite of neutron beamlines, thereby lowering the barrier to taking advantage of these large-facility techniques to achieve new understandings of membranes and their interactions with other molecules.
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Affiliation(s)
- Shuo Qian
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830, United States
| | - Veerendra Kumar Sharma
- Solid State Physics Division, Bhabha Atomic Research Centre, Mumbai 400085, India
- Homi Bhabha National Institute, Anushaktinagar, Mumbai 400094, India
| | - Luke A Clifton
- ISIS Neutron and Muon Source, Rutherford Appleton Laboratory, Harwell Campus, Didcot, Oxfordshire, U.K. OX11 0QX
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12
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Ünnep R, Paul S, Zsiros O, Kovács L, Székely NK, Steinbach G, Appavou MS, Porcar L, Holzwarth AR, Garab G, Nagy G. Thylakoid membrane reorganizations revealed by small-angle neutron scattering of Monstera deliciosa leaves associated with non-photochemical quenching. Open Biol 2020; 10:200144. [PMID: 32931722 PMCID: PMC7536078 DOI: 10.1098/rsob.200144] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Accepted: 08/14/2020] [Indexed: 12/14/2022] Open
Abstract
Non-photochemical quenching (NPQ) is an important photoprotective mechanism in plants and algae. Although the process is extensively studied, little is known about its relationship with ultrastructural changes of the thylakoid membranes. In order to better understand this relationship, we studied the effects of illumination on the organization of thylakoid membranes in Monstera deliciosa leaves. This evergreen species is known to exhibit very large NPQ and to possess giant grana with dozens of stacked thylakoids. It is thus ideally suited for small-angle neutron scattering measurements (SANS)-a non-invasive technique, which is capable of providing spatially and statistically averaged information on the periodicity of the thylakoid membranes and their rapid reorganizations in vivo. We show that NPQ-inducing illumination causes a strong decrease in the periodic order of granum thylakoid membranes. Development of NPQ and light-induced ultrastructural changes, as well as the relaxation processes, follow similar kinetic patterns. Surprisingly, whereas NPQ is suppressed by diuron, it impedes only the relaxation of the structural changes and not its formation, suggesting that structural changes do not cause but enable NPQ. We also demonstrate that the diminishment of SANS peak does not originate from light-induced redistribution and reorientation of chloroplasts inside the cells.
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Affiliation(s)
- Renáta Ünnep
- Neutron Spectroscopy Department, Centre for Energy Research, H-1121 Budapest, Konkoly-Thege Miklós út 29-33, Hungary
- Laboratory for Neutron Scattering and Imaging, Paul Scherrer Institute, CH-5232 Villigen PSI, Switzerland
| | - Suman Paul
- Max-Planck-Institute for Chemical Energy Conversion, Stiftstr. 34-36, 45470 Mülheim a.d. Ruhr, Germany
| | - Ottó Zsiros
- Biological Research Centre, Institute of Plant Biology, 6726 Szeged, Hungary
| | - László Kovács
- Biological Research Centre, Institute of Plant Biology, 6726 Szeged, Hungary
| | - Noémi K. Székely
- Forschungszentrum Jülich GmbH, Jülich Centre for Neutron Science at MLZ, 85748 Garching, Germany
| | - Gábor Steinbach
- Biological Research Centre, Institute of Biophysics, Temesvári körút 62, 6726 Szeged, Hungary
| | - Marie-Sousai Appavou
- Forschungszentrum Jülich GmbH, Jülich Centre for Neutron Science at MLZ, 85748 Garching, Germany
| | - Lionel Porcar
- Institut Laue-Langevin, BP 156, 38042 Grenoble Cedex 9, France
| | - Alfred R. Holzwarth
- Max-Planck-Institute for Chemical Energy Conversion, Stiftstr. 34-36, 45470 Mülheim a.d. Ruhr, Germany
| | - Győző Garab
- Biological Research Centre, Institute of Plant Biology, 6726 Szeged, Hungary
- Department of Physics, Faculty of Science, Ostrava University, Chittussiho 10, 710 00 Ostrava, Czech Republic
| | - Gergely Nagy
- Laboratory for Neutron Scattering and Imaging, Paul Scherrer Institute, CH-5232 Villigen PSI, Switzerland
- European Spallation Source ESS ERIC, PO Box 176, 221 00 Lund, Sweden
- Institute for Solid State Physics and Optics, Wigner Research Centre for Physics, 1121 Budapest, Hungary
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13
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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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14
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Siebenaller C, Junglas B, Lehmann A, Hellmann N, Schneider D. Proton Leakage Is Sensed by IM30 and Activates IM30-Triggered Membrane Fusion. Int J Mol Sci 2020; 21:E4530. [PMID: 32630559 PMCID: PMC7350238 DOI: 10.3390/ijms21124530] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Revised: 06/19/2020] [Accepted: 06/23/2020] [Indexed: 12/19/2022] Open
Abstract
The inner membrane-associated protein of 30 kDa (IM30) is crucial for the development and maintenance of the thylakoid membrane system in chloroplasts and cyanobacteria. While its exact physiological function still is under debate, it has recently been suggested that IM30 has (at least) a dual function, and the protein is involved in stabilization of the thylakoid membrane as well as in Mg2+-dependent membrane fusion. IM30 binds to negatively charged membrane lipids, preferentially at stressed membrane regions where protons potentially leak out from the thylakoid lumen into the chloroplast stroma or the cyanobacterial cytoplasm, respectively. Here we show in vitro that IM30 membrane binding, as well as membrane fusion, is strongly increased in acidic environments. This enhanced activity involves a rearrangement of the protein structure. We suggest that this acid-induced transition is part of a mechanism that allows IM30 to (i) sense sites of proton leakage at the thylakoid membrane, to (ii) preferentially bind there, and to (iii) seal leaky membrane regions via membrane fusion processes.
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Affiliation(s)
| | | | | | | | - Dirk Schneider
- Department of Chemistry, Biochemistry, Johannes Gutenberg University Mainz, 55128 Mainz, Germany; (C.S.); (B.J.); (A.L.); (N.H.)
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Betterle N, Hidalgo Martinez D, Melis A. Cyanobacterial Production of Biopharmaceutical and Biotherapeutic Proteins. FRONTIERS IN PLANT SCIENCE 2020; 11:237. [PMID: 32194609 PMCID: PMC7062967 DOI: 10.3389/fpls.2020.00237] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/24/2019] [Accepted: 02/14/2020] [Indexed: 06/10/2023]
Abstract
Efforts to express human therapeutic proteins in photosynthetic organisms have been described in the literature. Regarding microalgae, most of the research entailed a heterologous transformation of the chloroplast, but transformant cells failed to accumulate the desired recombinant proteins in high quantity. The present work provides methods and DNA construct formulations for over-expressing in photosynthetic cyanobacteria, at the protein level, human-origin bio-pharmaceutical and bio-therapeutic proteins. Proof-of-concept evidence is provided for the design and reduction to practice of "fusion constructs as protein overexpression vectors" for the generation of the bio-therapeutic protein interferon alpha-2 (IFN). IFN is a member of the Type I interferon cytokine family, well-known for its antiviral and anti-proliferative functions. Fusion construct formulations enabled accumulation of IFN up to 12% of total cellular protein in soluble form. In addition, the work reports on the isolation and purification of the fusion IFN protein and preliminary verification of its antiviral activity. Combining the expression and purification protocols developed here, it is possible to produce fairly large quantities of interferon in these photosynthetic microorganisms, generated from sunlight, CO2, and H2O.
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16
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Pérez AA, Chen Q, Hernández HP, Branco dos Santos F, Hellingwerf KJ. On the use of oxygenic photosynthesis for the sustainable production of commodity chemicals. PHYSIOLOGIA PLANTARUM 2019; 166:413-427. [PMID: 30829400 PMCID: PMC6850307 DOI: 10.1111/ppl.12946] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2018] [Revised: 02/15/2019] [Accepted: 02/18/2019] [Indexed: 05/13/2023]
Abstract
A sustainable society will have to largely refrain from the use of fossil carbon deposits. In such a regime, renewable electricity can be harvested as a primary source of energy. However, as for the synthesis of carbon-based materials from bulk chemicals, an alternative is required. A sustainable approach towards this is the synthesis of commodity chemicals from CO2 , water and sunlight. Multiple paths to achieve this have been designed and tested in the domains of chemistry and biology. In the latter, the use of both chemotrophic and phototrophic organisms has been advocated. 'Direct conversion' of CO2 and H2 O, catalyzed by an oxyphototroph, has excellent prospects to become the most economically competitive of these transformations, because of the relative ease of scale-up of this process. Significantly, for a wide range of energy and commodity products, a proof of principle via engineering of the corresponding production organism has been provided. In the optimization of a cyanobacterial production organism, a wide range of aspects has to be addressed. Of these, here we will put our focus on: (1) optimizing the (carbon) flux to the desired product; (2) increasing the genetic stability of the producing organism and (3) maximizing its energy conversion efficiency. Significant advances have been made on all these three aspects during the past 2 years and these will be discussed: (1) increasing the carbon partitioning to >50%; (2) aligning product formation with the growth of the cells and (3) expanding the photosynthetically active radiation region for oxygenic photosynthesis.
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Affiliation(s)
- Adam A. Pérez
- Molecular Microbial Physiology GroupSwammerdam Institute for Life Sciences, University of Amsterdam1098 XH AmsterdamThe Netherlands
- Photanol BVMatrix VAmsterdam, 1098 XHThe Netherlands
| | - Que Chen
- Molecular Microbial Physiology GroupSwammerdam Institute for Life Sciences, University of Amsterdam1098 XH AmsterdamThe Netherlands
| | - Hugo Pineda Hernández
- Molecular Microbial Physiology GroupSwammerdam Institute for Life Sciences, University of Amsterdam1098 XH AmsterdamThe Netherlands
| | - Filipe Branco dos Santos
- Molecular Microbial Physiology GroupSwammerdam Institute for Life Sciences, University of Amsterdam1098 XH AmsterdamThe Netherlands
| | - Klaas J. Hellingwerf
- Molecular Microbial Physiology GroupSwammerdam Institute for Life Sciences, University of Amsterdam1098 XH AmsterdamThe Netherlands
- Photanol BVMatrix VAmsterdam, 1098 XHThe Netherlands
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17
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Kirst H, Shen Y, Vamvaka E, Betterle N, Xu D, Warek U, Strickland JA, Melis A. Downregulation of the CpSRP43 gene expression confers a truncated light-harvesting antenna (TLA) and enhances biomass and leaf-to-stem ratio in Nicotiana tabacum canopies. PLANTA 2018; 248:139-154. [PMID: 29623472 DOI: 10.1007/s00425-018-2889-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2018] [Accepted: 03/29/2018] [Indexed: 05/13/2023]
Abstract
MAIN CONCLUSION Downregulation in the expression of the signal recognition particle 43 (SRP43) gene in tobacco conferred a truncated photosynthetic light-harvesting antenna (TLA property), and resulted in plants with a greater leaf-to-stem ratio, improved photosynthetic productivity and canopy biomass accumulation under high-density cultivation conditions. Evolution of sizable arrays of light-harvesting antennae in all photosynthetic systems confers a survival advantage for the organism in the wild, where sunlight is often the growth-limiting factor. In crop monocultures, however, this property is strongly counterproductive, when growth takes place under direct and excess sunlight. The large arrays of light-harvesting antennae in crop plants cause the surface of the canopies to over-absorb solar irradiance, far in excess of what is needed to saturate photosynthesis and forcing them to engage in wasteful dissipation of the excess energy. Evidence in this work showed that downregulation by RNA-interference approaches of the Nicotiana tabacum signal recognition particle 43 (SRP43), a nuclear gene encoding a chloroplast-localized component of the photosynthetic light-harvesting assembly pathway, caused a decrease in the light-harvesting antenna size of the photosystems, a corresponding increase in the photosynthetic productivity of chlorophyll in the leaves, and improved tobacco plant canopy biomass accumulation under high-density cultivation conditions. Importantly, the resulting TLA transgenic plants had a substantially greater leaf-to-stem biomass ratio, compared to those of the wild type, grown under identical agronomic conditions. The results are discussed in terms of the potential benefit that could accrue to agriculture upon application of the TLA-technology to crop plants, entailing higher density planting with plants having a greater biomass and leaf-to-stem ratio, translating into greater crop yields per plant with canopies in a novel agronomic configuration.
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Affiliation(s)
- Henning Kirst
- Department of Plant and Microbial Biology, University of California, Berkeley, CA, 94720-3102, USA
| | - Yanxin Shen
- Biotechnology Division, Altria Client Services, Richmond, VA, 23219, USA
| | - Evangelia Vamvaka
- Department of Plant and Microbial Biology, University of California, Berkeley, CA, 94720-3102, USA
| | - Nico Betterle
- Department of Plant and Microbial Biology, University of California, Berkeley, CA, 94720-3102, USA
| | - Dongmei Xu
- Biotechnology Division, Altria Client Services, Richmond, VA, 23219, USA
| | - Ujwala Warek
- Biotechnology Division, Altria Client Services, Richmond, VA, 23219, USA
| | - James A Strickland
- Biotechnology Division, Altria Client Services, Richmond, VA, 23219, USA
| | - Anastasios Melis
- Department of Plant and Microbial Biology, University of California, Berkeley, CA, 94720-3102, USA.
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18
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Liberton M, Chrisler WB, Nicora CD, Moore RJ, Smith RD, Koppenaal DW, Pakrasi HB, Jacobs JM. Phycobilisome truncation causes widespread proteome changes in Synechocystis sp. PCC 6803. PLoS One 2017; 12:e0173251. [PMID: 28253354 PMCID: PMC5333879 DOI: 10.1371/journal.pone.0173251] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2016] [Accepted: 02/17/2017] [Indexed: 11/18/2022] Open
Abstract
In cyanobacteria such as Synechocystis sp. PCC 6803, large antenna complexes called phycobilisomes (PBS) harvest light and transfer the energy to the photosynthetic reaction centers. Modification of the light harvesting machinery in cyanobacteria has widespread consequences, causing changes in cell morphology and physiology. In the current study, we investigated the effects of PBS truncation on the proteomes of three Synechocystis 6803 PBS antenna mutants. These range from the progressive truncation of phycocyanin rods in the CB and CK strains, to full removal of PBS in the PAL mutant. Comparative quantitative protein results revealed surprising changes in protein abundances in the mutant strains. Our results showed that PBS truncation in Synechocystis 6803 broadly impacted core cellular mechanisms beyond light harvesting and photosynthesis. Specifically, we observed dramatic alterations in membrane transport mechanisms, where the most severe PBS truncation in the PAL strain appeared to suppress the cellular utilization and regulation of bicarbonate and iron. These changes point to the role of PBS as a component critical to cell function, and demonstrate the continuing need to assess systems-wide protein based abundances to understand potential indirect phenotypic effects.
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Affiliation(s)
- Michelle Liberton
- Department of Biology, Washington University, St. Louis, Missouri, United States of America
| | - William B. Chrisler
- Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, Washington, United States of America
| | - Carrie D. Nicora
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, Washington, United States of America
| | - Ronald J. Moore
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, Washington, United States of America
| | - Richard D. Smith
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, Washington, United States of America
| | - David W. Koppenaal
- Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, Washington, United States of America
| | - Himadri B. Pakrasi
- Department of Biology, Washington University, St. Louis, Missouri, United States of America
| | - Jon M. Jacobs
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, Washington, United States of America
- * E-mail:
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19
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Steinbach G, Schubert F, Kaňa R. Cryo-imaging of photosystems and phycobilisomes in Anabaena sp. PCC 7120 cells. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2015; 152:395-9. [DOI: 10.1016/j.jphotobiol.2015.10.003] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/29/2015] [Revised: 10/02/2015] [Accepted: 10/05/2015] [Indexed: 01/03/2023]
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20
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Heberle FA, Myles DAA, Katsaras J. Biomembranes research using thermal and cold neutrons. Chem Phys Lipids 2015; 192:41-50. [PMID: 26241882 DOI: 10.1016/j.chemphyslip.2015.07.020] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2015] [Revised: 07/25/2015] [Accepted: 07/27/2015] [Indexed: 01/26/2023]
Abstract
In 1932 James Chadwick discovered the neutron using a polonium source and a beryllium target (Chadwick, 1932). In a letter to Niels Bohr dated February 24, 1932, Chadwick wrote: "whatever the radiation from Be may be, it has most remarkable properties." Where it concerns hydrogen-rich biological materials, the "most remarkable" property is the neutron's differential sensitivity for hydrogen and its isotope deuterium. Such differential sensitivity is unique to neutron scattering, which unlike X-ray scattering, arises from nuclear forces. Consequently, the coherent neutron scattering length can experience a dramatic change in magnitude and phase as a result of resonance scattering, imparting sensitivity to both light and heavy atoms, and in favorable cases to their isotopic variants. This article describes recent biomembranes research using a variety of neutron scattering techniques.
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Affiliation(s)
- F A Heberle
- Biology and Soft Matter Division, Neutron Sciences Directorate, Oak Ridge, TN, 37831, United States; Joint Institute for Neutron Sciences, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, United States
| | - D A A Myles
- Biology and Soft Matter Division, Neutron Sciences Directorate, Oak Ridge, TN, 37831, United States
| | - J Katsaras
- Biology and Soft Matter Division, Neutron Sciences Directorate, Oak Ridge, TN, 37831, United States; Joint Institute for Neutron Sciences, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, United States; Department of Physics and Astronomy, University of Tennessee, Knoxville, TN, 37996, United States.
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21
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Consequences of Decreased Light Harvesting Capability on Photosystem II Function in Synechocystis sp. PCC 6803. Life (Basel) 2014; 4:903-14. [PMID: 25513759 PMCID: PMC4284473 DOI: 10.3390/life4040903] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2014] [Revised: 11/24/2014] [Accepted: 12/04/2014] [Indexed: 01/08/2023] Open
Abstract
Cyanobacteria use large pigment-protein complexes called phycobilisomes to harvest light energy primarily for photosystem II (PSII). We used a series of mutants with partial to complete reduction of phycobilisomes to examine the effects of antenna truncation on photosystem function in Synechocystis sp. PCC 6803. The antenna mutants CB, CK, and PAL expressed increasing levels of functional PSII centers to compensate for the loss of phycobilisomes, with a concomitant decrease in photosystem I (PSI). This increased PSII titer led to progressively higher oxygen evolution rates on a per chlorophyll basis. The mutants also exhibited impaired S-state transition profiles for oxygen evolution. Additionally, P700+ re-reduction rates were impacted by antenna reduction. Thus, a decrease in antenna size resulted in overall physiological changes in light harvesting and delivery to PSII as well as changes in downstream electron transfer to PSI.
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22
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Unnep R, Nagy G, Markó M, Garab G. Monitoring thylakoid ultrastructural changes in vivo using small-angle neutron scattering. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2014; 81:197-207. [PMID: 24629664 DOI: 10.1016/j.plaphy.2014.02.005] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/17/2013] [Accepted: 02/08/2014] [Indexed: 05/01/2023]
Abstract
The light reactions of oxygenic photosynthesis take place in the thylakoid membranes, flattened vesicles, which contain the two photosystems and also embed the cytochrome b6f complex and the ATP synthase. In general, the thylakoid membranes are assembled into multilamellar membrane systems, which warrant an optimal light capturing efficiency. In nature, they show astounding variations, primarily due to large variations in their protein composition, which is controlled by multilevel regulatory mechanisms during long-term acclimation and short-term adaptation processes and also influenced by biotic or abiotic stresses - indicating a substantial degree of flexibility in the membrane ultrastructure. The better understanding of the dynamic features of this membrane system requires the use of non-invasive techniques, such as small angle neutron scattering (SANS), which is capable of providing accurate, statistically and spatially averaged information on the repeat distances of periodically organized thylakoid membranes under physiologically relevant conditions with time resolutions of seconds and minutes. In this review, after a short section on the basic properties of neutrons, we outline the fundamental principles of SANS measurements, its strengths and weaknesses in comparison to complementary structure investigation techniques. Then we overview recent results on isolated plant thylakoid membranes, and on living cyanobacterial and algal cells as well as on whole leaves. Special attention is paid to light-induced reversible ultrastructural changes in vivo, which, in cyanobacterial and diatom cells, were uncovered with the aid of SANS measurements; we also discuss the role of membrane reorganizations in light adaptation and photoprotection mechanisms.
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Affiliation(s)
- Renáta Unnep
- Institute for Solid State Physics and Optics, Wigner Research Centre for Physics, Hungarian Academy of Sciences, POB 49, H-1525 Budapest, Hungary
| | - Gergely Nagy
- Institute for Solid State Physics and Optics, Wigner Research Centre for Physics, Hungarian Academy of Sciences, POB 49, H-1525 Budapest, Hungary; Laboratory for Neutron Scattering, Paul Scherrer Institute, 5232 Villigen PSI, Switzerland
| | - Márton Markó
- Institute for Solid State Physics and Optics, Wigner Research Centre for Physics, Hungarian Academy of Sciences, POB 49, H-1525 Budapest, Hungary; Laboratory for Neutron Scattering, Paul Scherrer Institute, 5232 Villigen PSI, Switzerland
| | - Győző Garab
- Institute of Plant Biology, Biological Research Centre, Hungarian Academy of Sciences, POB 521, H-6701 Szeged, Hungary.
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23
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Kirst H, Formighieri C, Melis A. Maximizing photosynthetic efficiency and culture productivity in cyanobacteria upon minimizing the phycobilisome light-harvesting antenna size. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2014; 1837:1653-64. [PMID: 25046143 DOI: 10.1016/j.bbabio.2014.07.009] [Citation(s) in RCA: 115] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 04/14/2014] [Revised: 07/03/2014] [Accepted: 07/10/2014] [Indexed: 12/25/2022]
Abstract
A phycocyanin-deletion mutant of Synechocystis (cyanobacteria) was generated upon replacement of the CPC-operon with a kanamycin resistance cassette. The Δcpc transformant strains (Δcpc) exhibited a green phenotype, compared to the blue-green of the wild type (WT), lacked the distinct phycocyanin absorbance at 625nm, and had a lower Chl per cell content and a lower PSI/PSII reaction center ratio compared to the WT. Molecular and genetic analyses showed replacement of all WT copies of the Synechocystis DNA with the transgenic version, thereby achieving genomic DNA homoplasmy. Biochemical analyses showed the absence of the phycocyanin α- and β-subunits, and the overexpression of the kanamycin resistance NPTI protein in the Δcpc. Physiological analyses revealed a higher, by a factor of about 2, intensity for the saturation of photosynthesis in the Δcpc compared to the WT. Under limiting intensities of illumination, growth of the Δcpc was slower than that of the WT. This difference in the rate of cell duplication diminished gradually as growth irradiance increased. Identical rates of cell duplication of about 13h for both WT and Δcpc were observed at about 800μmolphotonsm(-2)s(-1) or greater. Culture productivity analyses under simulated bright sunlight and high cell-density conditions showed that biomass accumulation by the Δcpc was 1.57-times greater than that achieved by the WT. Thus, the work provides first-time direct evidence of the applicability of the Truncated Light-harvesting Antenna (TLA)-concept in cyanobacteria, entailing substantial improvements in the photosynthetic efficiency and productivity of mass cultures upon minimizing the phycobilisome light-harvesting antenna size.
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Affiliation(s)
- Henning Kirst
- Department of Plant & Microbial Biology, University of California, Berkeley, CA 94720-3102, USA
| | - Cinzia Formighieri
- Department of Plant & Microbial Biology, University of California, Berkeley, CA 94720-3102, USA
| | - Anastasios Melis
- Department of Plant & Microbial Biology, University of California, Berkeley, CA 94720-3102, USA.
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24
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Heller WT, Urban VS, Lynn GW, Weiss KL, O'Neill HM, Pingali SV, Qian S, Littrell KC, Melnichenko YB, Buchanan MV, Selby DL, Wignall GD, Butler PD, Myles DA. The Bio-SANS instrument at the High Flux Isotope Reactor of Oak Ridge National Laboratory. J Appl Crystallogr 2014. [DOI: 10.1107/s1600576714011285] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Small-angle neutron scattering (SANS) is a powerful tool for characterizing complex disordered materials, including biological materials. The Bio-SANS instrument of the High Flux Isotope Reactor of Oak Ridge National Laboratory (ORNL) is a high-flux low-background SANS instrument that is, uniquely among SANS instruments, dedicated to serving the needs of the structural biology and biomaterials communities as an open-access user facility. Here, the technical specifications and performance of the Bio-SANS are presented. Sample environments developed to address the needs of the user program of the instrument are also presented. Further, the isotopic labeling and sample preparation capabilities available in the Bio-Deuteration Laboratory for users of the Bio-SANS and other neutron scattering instruments at ORNL are described. Finally, a brief survey of research performed using the Bio-SANS is presented, which demonstrates the breadth of the research that the instrument's user community engages in.
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25
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Janssen PJD, Lambreva MD, Plumeré N, Bartolucci C, Antonacci A, Buonasera K, Frese RN, Scognamiglio V, Rea G. Photosynthesis at the forefront of a sustainable life. Front Chem 2014; 2:36. [PMID: 24971306 PMCID: PMC4054791 DOI: 10.3389/fchem.2014.00036] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2014] [Accepted: 05/25/2014] [Indexed: 11/13/2022] Open
Abstract
The development of a sustainable bio-based economy has drawn much attention in recent years, and research to find smart solutions to the many inherent challenges has intensified. In nature, perhaps the best example of an authentic sustainable system is oxygenic photosynthesis. The biochemistry of this intricate process is empowered by solar radiation influx and performed by hierarchically organized complexes composed by photoreceptors, inorganic catalysts, and enzymes which define specific niches for optimizing light-to-energy conversion. The success of this process relies on its capability to exploit the almost inexhaustible reservoirs of sunlight, water, and carbon dioxide to transform photonic energy into chemical energy such as stored in adenosine triphosphate. Oxygenic photosynthesis is responsible for most of the oxygen, fossil fuels, and biomass on our planet. So, even after a few billion years of evolution, this process unceasingly supports life on earth, and probably soon also in outer-space, and inspires the development of enabling technologies for a sustainable global economy and ecosystem. The following review covers some of the major milestones reached in photosynthesis research, each reflecting lasting routes of innovation in agriculture, environmental protection, and clean energy production.
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Affiliation(s)
- Paul J. D. Janssen
- Molecular and Cellular Biology - Unit of Microbiology, Institute for Environment, Health and Safety, Belgian Nuclear Research Centre SCK•CENMol, Belgium
| | - Maya D. Lambreva
- Institute of Crystallography, National Research Council of ItalyRome, Italy
| | - Nicolas Plumeré
- Center for Electrochemical Sciences-CES, Ruhr-Universität BochumBochum, Germany
| | - Cecilia Bartolucci
- Institute of Crystallography, National Research Council of ItalyRome, Italy
| | - Amina Antonacci
- Institute of Crystallography, National Research Council of ItalyRome, Italy
| | - Katia Buonasera
- Institute of Crystallography, National Research Council of ItalyRome, Italy
| | - Raoul N. Frese
- Division of Physics and Astronomy, Department of Biophysics, VU University AmsterdamAmsterdam, Netherlands
| | | | - Giuseppina Rea
- Institute of Crystallography, National Research Council of ItalyRome, Italy
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