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Fake It 'Till You Make It-The Pursuit of Suitable Membrane Mimetics for Membrane Protein Biophysics. Int J Mol Sci 2020; 22:ijms22010050. [PMID: 33374526 PMCID: PMC7793082 DOI: 10.3390/ijms22010050] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2020] [Revised: 12/17/2020] [Accepted: 12/19/2020] [Indexed: 12/13/2022] Open
Abstract
Membrane proteins evolved to reside in the hydrophobic lipid bilayers of cellular membranes. Therefore, membrane proteins bridge the different aqueous compartments separated by the membrane, and furthermore, dynamically interact with their surrounding lipid environment. The latter not only stabilizes membrane proteins, but directly impacts their folding, structure and function. In order to be characterized with biophysical and structural biological methods, membrane proteins are typically extracted and subsequently purified from their native lipid environment. This approach requires that lipid membranes are replaced by suitable surrogates, which ideally closely mimic the native bilayer, in order to maintain the membrane proteins structural and functional integrity. In this review, we survey the currently available membrane mimetic environments ranging from detergent micelles to bicelles, nanodiscs, lipidic-cubic phase (LCP), liposomes, and polymersomes. We discuss their respective advantages and disadvantages as well as their suitability for downstream biophysical and structural characterization. Finally, we take a look at ongoing methodological developments, which aim for direct in-situ characterization of membrane proteins within native membranes instead of relying on membrane mimetics.
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2
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Croce R. Beyond 'seeing is believing': the antenna size of the photosystems in vivo. THE NEW PHYTOLOGIST 2020; 228:1214-1218. [PMID: 32562266 PMCID: PMC7689736 DOI: 10.1111/nph.16758] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2020] [Accepted: 06/04/2020] [Indexed: 05/03/2023]
Abstract
Photosystems I and II are the central components of the solar energy conversion machinery in oxygenic photosynthesis. They are large functional units embedded in the photosynthetic membranes, where they harvest light and use its energy to drive electrons from water to NADPH. Their composition and organization change in response to different environmental conditions, making these complexes dynamic units. Some of the interactions between subunits survive purification, resulting in the well-defined structures that were recently resolved by cryo-electron microscopy. Other interactions instead are weak, preventing the possibility of isolating and thus studying these complexes in vitro. This review focuses on these supercomplexes of vascular plants, which at the moment cannot be 'seen' but that represent functional units in vivo.
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Affiliation(s)
- Roberta Croce
- Biophysics of PhotosynthesisDepartment of Physics and AstronomyFaculty of ScienceVrije Universiteit AmsterdamDe Boelelaan 1083Amsterdam1081 HVthe Netherlands
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3
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Abstract
Photosynthetic membranes are typically densely packed with proteins, and this is crucial for their function in efficient trapping of light energy. Despite being crowded with protein, the membranes are fluid systems in which proteins and smaller molecules can diffuse. Fluidity is also crucial for photosynthetic function, as it is essential for biogenesis, electron transport, and protein redistribution for functional regulation. All photosynthetic membranes seem to maintain a delicate balance between crowding, order, and fluidity. How does this work in phototrophic bacteria? In this review, we focus on two types of intensively studied bacterial photosynthetic membranes: the chromatophore membranes of purple bacteria and the thylakoid membranes of cyanobacteria. Both systems are distinct from the plasma membrane, and both have a distinctive protein composition that reflects their specialized roles. Chromatophores are formed from plasma membrane invaginations, while thylakoid membranes appear to be an independent intracellular membrane system. We discuss the techniques that can be applied to study the organization and dynamics of these membrane systems, including electron microscopy techniques, atomic force microscopy, and many variants of fluorescence microscopy. We go on to discuss the insights that havebeen acquired from these techniques, and the role of membrane dynamics in the physiology of photosynthetic membranes. Membrane dynamics on multiple timescales are crucial for membrane function, from electron transport on timescales of microseconds to milliseconds to regulation and biogenesis on timescales of minutes to hours. We emphasize the open questions that remain in the field.
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Affiliation(s)
- Conrad W. Mullineaux
- School of Biological and Chemical Sciences, Queen Mary University of London, London E1 4NS, United Kingdom
| | - Lu-Ning Liu
- Institute of Integrative Biology, University of Liverpool, Liverpool L69 7ZB, United Kingdom
- College of Marine Life Sciences, and Frontiers Science Center for Deep Ocean Multispheres and Earth System, Ocean University of China, Qingdao 266003, China
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4
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Yoo YJ, Kim W, Ko JH, Kim YJ, Lee Y, Stanciu SG, Lee J, Kim S, Oh J, Song YM. Large-Area Virus Coated Ultrathin Colorimetric Sensors with a Highly Lossy Resonant Promoter for Enhanced Chromaticity. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2020; 7:2000978. [PMID: 32999838 PMCID: PMC7509654 DOI: 10.1002/advs.202000978] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/17/2020] [Revised: 05/07/2020] [Indexed: 05/28/2023]
Abstract
Acclimatable colors in response to environmental stimuli, which are naturally endowed with some living things, can provide an opportunity for humans to recognize hazardous substances without taking empirical risks. Despite efforts to create artificial responsive colors, realistic applications in everyday life require an immediate/distinct colorimetric realization with wide chromatic selectivity. A dynamically responsive virus (M-13 phage)-based changeable coloring strategy is presented with a highly lossy resonant promoter (HLRP). An ultrathin M-13 phage layer for rapid response to external stimuli displays colorimetric behavior, even in its subtle swelling with strong resonances on HLRP, which is modeled using the complex effective refractive index. Optimal designs of HLRP for several material combinations allow selective chromatic responsivity from the corresponding wide color palette without modification of the dynamic responsive layer. As a practical demonstration, the spatially designed colorimetric indicator, which is insensitive/sensitive to external stimuli, provides an intuitive perception of environmental changes with hidden/revealed patterns. Furthermore, the proposed colorimetric sensor is tested by exposure to various volatile organic chemicals and endocrine disrupting chemicals for versatile detectability, and is fabricated in a wafer-scale sample for large-area scalability.
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Affiliation(s)
- Young Jin Yoo
- School of Electrical Engineering and Computer ScienceGwangju Institute of Science and TechnologyGwangju61005Republic of Korea
| | - Won‐Geun Kim
- Department of Nano Fusion TechnologyPusan National UniversityBusan46241Republic of Korea
| | - Joo Hwan Ko
- School of Electrical Engineering and Computer ScienceGwangju Institute of Science and TechnologyGwangju61005Republic of Korea
| | - Yeong Jae Kim
- School of Electrical Engineering and Computer ScienceGwangju Institute of Science and TechnologyGwangju61005Republic of Korea
| | - Yujin Lee
- Department of Nano Fusion TechnologyPusan National UniversityBusan46241Republic of Korea
| | - Stefan G. Stanciu
- Center for Microscopy‐Microanalysis and Information ProcessingPolitehnica University BucharestBucharest060042Romania
| | - Jong‐Min Lee
- Research Center for Energy Convergence and TechnologyPusan National UniversityBusan46241Republic of Korea
| | - Seungchul Kim
- Department of Optics and Mechatronics EngineeringPusan National UniversityBusan46241Republic of Korea
| | - Jin‐Woo Oh
- Department of Nano Fusion TechnologyPusan National UniversityBusan46241Republic of Korea
- Department of Nanoenergy EngineeringPusan National UniversityBusan46241Republic of Korea
- BK21 PLUS Nanoconvergence Technology DivisionPusan National UniversityBusan46241Republic of Korea
| | - Young Min Song
- School of Electrical Engineering and Computer ScienceGwangju Institute of Science and TechnologyGwangju61005Republic of Korea
- Anti‐Viral Research CenterGwangju Institute of Science and TechnologyGwangju61005Republic of Korea
- AI Graduate SchoolGwangju Institute of Science and TechnologyGwangju61005Republic of Korea
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5
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Tokano T, Kato Y, Sugiyama S, Uchihashi T, Noguchi T. Structural Dynamics of a Protein Domain Relevant to the Water-Oxidizing Complex in Photosystem II as Visualized by High-Speed Atomic Force Microscopy. J Phys Chem B 2020; 124:5847-5857. [PMID: 32551630 DOI: 10.1021/acs.jpcb.0c03892] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Photosystem II (PSII) is a multiprotein complex that has a function of light-driven water oxidation. The catalytic site of water oxidation is the Mn4CaO5 cluster, which is bound to the lumenal side of PSII through amino acid residues from the D1 and CP43 proteins and is further surrounded by the extrinsic proteins. In this study, we have for the first time visualized the structural dynamics of the lumenal region of a PSII core complex using high-speed atomic force microscopy (HS-AFM). The HS-AFM images of a PSII membrane fragment showed stepwise dissociation of the PsbP and PsbO extrinsic proteins. Upon subsequent destruction of the Mn4CaO5 cluster, the lumenal domain of CP43 was found to undergo a conformational fluctuation. The observed structural flexibility and conformational fluctuation of the CP43 lumenal domain are suggested to play important roles in the biogenesis of PSII and the photoassembly of the Mn4CaO5 cluster.
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Affiliation(s)
- Takaya Tokano
- Division of Material Science, Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8602, Japan
| | - Yuki Kato
- Division of Material Science, Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8602, Japan
| | - Shogo Sugiyama
- Division of Material Science, Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8602, Japan
| | - Takayuki Uchihashi
- Division of Material Science, Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8602, Japan
| | - Takumi Noguchi
- Division of Material Science, Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8602, Japan
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6
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Wood WHJ, Johnson MP. Modeling the Role of LHCII-LHCII, PSII-LHCII, and PSI-LHCII Interactions in State Transitions. Biophys J 2020; 119:287-299. [PMID: 32621865 DOI: 10.1016/j.bpj.2020.05.034] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2019] [Revised: 03/28/2020] [Accepted: 05/04/2020] [Indexed: 02/08/2023] Open
Abstract
The light-dependent reactions of photosynthesis take place in the plant chloroplast thylakoid membrane, a complex three-dimensional structure divided into the stacked grana and unstacked stromal lamellae domains. Plants regulate the macro-organization of photosynthetic complexes within the thylakoid membrane to adapt to changing environmental conditions and avoid oxidative stress. One such mechanism is the state transition that regulates photosynthetic light harvesting and electron transfer. State transitions are driven by changes in the phosphorylation of light harvesting complex II (LHCII), which cause a decrease in grana diameter and stacking, a decrease in energetic connectivity between photosystem II (PSII) reaction centers, and an increase in the relative LHCII antenna size of photosystem I (PSI) compared to PSII. Phosphorylation is believed to drive these changes by weakening the intramembrane lateral PSII-LHCII and LHCII-LHCII interactions and the intermembrane stacking interactions between these complexes, while simultaneously increasing the affinity of LHCII for PSI. We investigated the relative roles and contributions of these three types of interaction to state transitions using a lattice-based model of the thylakoid membrane based on existing structural data, developing a novel algorithm to simulate protein complex dynamics. Monte Carlo simulations revealed that state transitions are unlikely to lead to a large-scale migration of LHCII from the grana to the stromal lamellae. Instead, the increased light harvesting capacity of PSI is largely due to the more efficient recruitment of LHCII already residing in the stromal lamellae into PSI-LHCII supercomplexes upon its phosphorylation. Likewise, the increased light harvesting capacity of PSII upon dephosphorylation was found to be driven by a more efficient recruitment of LHCII already residing in the grana into functional PSII-LHCII clusters, primarily driven by lateral interactions.
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Affiliation(s)
- William H J Wood
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, United Kingdom
| | - Matthew P Johnson
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, United Kingdom.
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7
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Lattice Models for Protein Organization throughout Thylakoid Membrane Stacks. Biophys J 2020; 118:2680-2693. [PMID: 32413311 DOI: 10.1016/j.bpj.2020.03.036] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2019] [Revised: 03/14/2020] [Accepted: 03/24/2020] [Indexed: 11/21/2022] Open
Abstract
Proteins in photosynthetic membranes can organize into patterned arrays that span the membrane's lateral size. Attractions between proteins in different layers of a membrane stack can play a key role in this ordering, as was suggested by microscopy and fluorescence spectroscopy and demonstrated by computer simulations of a coarse-grained model. The architecture of thylakoid membranes, however, also provides opportunities for interlayer interactions that instead disfavor the high protein densities of ordered arrangements. Here, we explore the interplay between these opposing driving forces and, in particular, the phase transitions that emerge in the periodic geometry of stacked thylakoid membrane disks. We propose a lattice model that roughly accounts for proteins' attraction within a layer and across the stromal gap, steric repulsion across the lumenal gap, and regulation of protein density by exchange with the stroma lamellae. Mean-field analysis and computer simulation reveal rich phase behavior for this simple model, featuring a broken-symmetry striped phase that is disrupted at both high and low extremes of chemical potential. The resulting sensitivity of microscopic protein arrangement to the thylakoid's mesoscale vertical structure raises intriguing possibilities for regulation of photosynthetic function.
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8
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Onoa B, Fukuda S, Iwai M, Bustamante C, Niyogi KK. Atomic Force Microscopy Visualizes Mobility of Photosynthetic Proteins in Grana Thylakoid Membranes. Biophys J 2020; 118:1876-1886. [PMID: 32224302 PMCID: PMC7175462 DOI: 10.1016/j.bpj.2020.02.029] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2019] [Revised: 02/10/2020] [Accepted: 02/28/2020] [Indexed: 12/19/2022] Open
Abstract
Thylakoid membranes in chloroplasts contain photosynthetic protein complexes that convert light energy into chemical energy. Photosynthetic protein complexes are considered to undergo structural reorganization to maintain the efficiency of photochemical reactions. A detailed description of the mobility of photosynthetic complexes in real time is necessary to understand how macromolecular organization of the membrane is altered by environmental fluctuations. Here, we used high-speed atomic force microscopy to visualize and characterize the in situ mobility of individual protein complexes in grana thylakoid membranes isolated from Spinacia oleracea. Our observations reveal that these membranes can harbor complexes with at least two distinctive classes of mobility. A large fraction of grana membranes contained proteins with quasistatic mobility exhibiting molecular displacements smaller than 10 nm2. In the remaining fraction, the protein mobility is variable with molecular displacements of up to 100 nm2. This visualization at high spatiotemporal resolution enabled us to estimate an average diffusion coefficient of ∼1 nm2 s-1. Interestingly, both confined and Brownian diffusion models could describe the protein mobility of the second group of membranes. We also provide the first direct evidence, to our knowledge, of rotational diffusion of photosynthetic complexes. The rotational diffusion of photosynthetic complexes could be an adaptive response to the high protein density in the membrane to guarantee the efficiency of electron transfer reactions. This characterization of the mobility of individual photosynthetic complexes in grana membranes establishes a foundation that could be adapted to study the dynamics of the complexes inside intact and photosynthetically functional thylakoid membranes to be able to understand its structural responses to diverse environmental fluctuations.
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Affiliation(s)
- Bibiana Onoa
- Howard Hughes Medical Institute, University of California, Berkeley, California.
| | - Shingo Fukuda
- Howard Hughes Medical Institute, University of California, Berkeley, California
| | - Masakazu Iwai
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, California; Department of Plant and Microbial Biology, University of California, Berkeley, California
| | - Carlos Bustamante
- Howard Hughes Medical Institute, University of California, Berkeley, California; Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, California; Jason L. Choy Laboratory of Single Molecule Biophysics, University of California, Berkeley, California; Department of Molecular and Cell Biology, University of California, Berkeley, California; Department of Physics, University of California, Berkeley, California; Kavli Energy NanoScience Institute, Lawrence Berkeley National Laboratory, University of California, Berkeley, California
| | - Krishna K Niyogi
- Howard Hughes Medical Institute, University of California, Berkeley, California; Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, California; Department of Plant and Microbial Biology, University of California, Berkeley, California.
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9
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Liu N, Zhang H, Zhao J, Xu Y, Ge F. Mechanisms of cetyltrimethyl ammonium chloride-induced toxicity to photosystem II oxygen evolution complex of Chlorella vulgaris F1068. JOURNAL OF HAZARDOUS MATERIALS 2020; 383:121063. [PMID: 31539660 DOI: 10.1016/j.jhazmat.2019.121063] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/10/2019] [Revised: 08/05/2019] [Accepted: 08/20/2019] [Indexed: 06/10/2023]
Abstract
Microalgae photosynthesis is sensitive to coexisted contaminates in aquatic environment, thereby causes adverse effect on algal growth and nutrients uptake. Here, we investigated the photosynthetic toxicity mechanism of cetyltrimethyl ammonium chloride (CTAC)-induced on a green microalga Chlorella vulgaris F1068 (C. vulgaris F1068). Results showed that CTAC reduced the algal growth rate, nutrients removal efficiency and weakened the photosynthetic performance. Meanwhile, the efficiency of oxygen evolution complex (OEC) and oxygen evolvement rates stressed by CTAC were significantly declined to 90.48% and 58.48% of the control (without CTAC), respectively. In addition, atomic force microscopy (AFM) detected the damage of PSII-OEC morphology and structure by CTAC. Furthermore, proteomic analysis showed that 41% of proteins were in the chloroplast thylakoid membranes which function in photosynthesis. The activity of oxygen-evolving enhancer protein 2 (OEE2 or PsbP) involved in electron transfer was significantly inhibited by CTAC, which down-regulated 15.14-fold in the presence of 0.6 mg/L CTAC. These results indicated that photosynthetic inhibition of CTAC mainly occurred in the PSII-OEC. This study provided a new perspective of the photosynthetic response in evaluation of environmental bioimpacts of surfactants on microalgae.
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Affiliation(s)
- Na Liu
- College of Environment and Resource, Xiangtan University, Xiangtan, 411105, PR China
| | - Han Zhang
- College of Environment and Resource, Xiangtan University, Xiangtan, 411105, PR China
| | - Jinfeng Zhao
- College of Environment and Resource, Xiangtan University, Xiangtan, 411105, PR China
| | - Yin Xu
- College of Environment and Resource, Xiangtan University, Xiangtan, 411105, PR China
| | - Fei Ge
- College of Environment and Resource, Xiangtan University, Xiangtan, 411105, PR China.
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10
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Pollastri S, Jorba I, Hawkins TJ, Llusià J, Michelozzi M, Navajas D, Peñuelas J, Hussey PJ, Knight MR, Loreto F. Leaves of isoprene-emitting tobacco plants maintain PSII stability at high temperatures. THE NEW PHYTOLOGIST 2019; 223:1307-1318. [PMID: 30980545 DOI: 10.1111/nph.15847] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2019] [Accepted: 04/07/2019] [Indexed: 05/13/2023]
Abstract
At high temperatures, isoprene-emitting plants display a higher photosynthetic rate and a lower nonphotochemical quenching (NPQ) compared with nonemitting plants. The mechanism of this phenomenon, which may be very important under current climate warming, is still elusive. NPQ was dissected into its components, and chlorophyll fluorescence lifetime imaging microscopy (FLIM) was used to analyse the dynamics of excited chlorophyll relaxation in isoprene-emitting and nonemitting plants. Thylakoid membrane stiffness was also measured using atomic force microscope (AFM) to identify a possible mode of action of isoprene in improving photochemical efficiency and photosynthetic stability. We show that, when compared with nonemitters, isoprene-emitting tobacco plants exposed at high temperatures display a reduced increase of the NPQ energy-dependent component (qE) and stable (1) chlorophyll fluorescence lifetime; (2) amplitude of the fluorescence decay components; and (3) thylakoid membrane stiffness. Our study shows for the first time that isoprene maintains PSII stability at high temperatures by preventing the modifications of the surrounding environment, namely providing a more steady and homogeneous distribution of the light-absorbing centres and a stable thylakoid membrane stiffness. Isoprene photoprotects leaves with a mechanism alternative to NPQ, enabling plants to maintain a high photosynthetic rate at rising temperatures.
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Affiliation(s)
- Susanna Pollastri
- Institute for Sustainable Plant Protection, National Research Council of Italy, Via Madonna del Piano 10, Sesto Fiorentino, 50019, Florence, Italy
- Department of Biosciences, Durham University, South Road, DH1 3LE, Durham, UK
| | - Ignasi Jorba
- University of Barcelona and Institute for Bioengineering of Catalonia - The Barcelona Institute of Science and Technology, Barcelona, Spain
| | - Timothy J Hawkins
- Department of Biosciences, Durham University, South Road, DH1 3LE, Durham, UK
| | - Joan Llusià
- CSIC, Global Ecology Unit CREAF-CSIC-Universitat Autònoma de Barcelona, Bellaterra, 08193, Catalonia, Spain
- CREAF, Cerdanyola del Vallès, 08193, Catalonia, Spain
| | - Marco Michelozzi
- Institute of Biosciences and Bioresources, National Research Council of Italy, Via Madonna del Piano 10, Sesto Fiorentino, 50019, Florence, Italy
| | - Daniel Navajas
- University of Barcelona and Institute for Bioengineering of Catalonia - The Barcelona Institute of Science and Technology, Barcelona, Spain
| | - Josep Peñuelas
- CSIC, Global Ecology Unit CREAF-CSIC-Universitat Autònoma de Barcelona, Bellaterra, 08193, Catalonia, Spain
- CREAF, Cerdanyola del Vallès, 08193, Catalonia, Spain
| | - Patrick J Hussey
- Department of Biosciences, Durham University, South Road, DH1 3LE, Durham, UK
| | - Marc R Knight
- Department of Biosciences, Durham University, South Road, DH1 3LE, Durham, UK
| | - Francesco Loreto
- Department of Biology, Agriculture and Food Sciences, National Research Council of Italy, Piazzale Aldo Moro 7, 00185, Rome, Italy
- Department of Biology, University of Naples Federico II, via Cinthia, 80126, Naples, Italy
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11
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MacGregor-Chatwin C, Jackson PJ, Sener M, Chidgey JW, Hitchcock A, Qian P, Mayneord GE, Johnson MP, Luthey-Schulten Z, Dickman MJ, Scanlan DJ, Hunter CN. Membrane organization of photosystem I complexes in the most abundant phototroph on Earth. NATURE PLANTS 2019; 5:879-889. [PMID: 31332310 PMCID: PMC6699766 DOI: 10.1038/s41477-019-0475-z] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/19/2018] [Accepted: 06/13/2019] [Indexed: 05/20/2023]
Abstract
Prochlorococcus is a major contributor to primary production, and globally the most abundant photosynthetic genus of picocyanobacteria because it can adapt to highly stratified low-nutrient conditions that are characteristic of the surface ocean. Here, we examine the structural adaptations of the photosynthetic thylakoid membrane that enable different Prochlorococcus ecotypes to occupy high-light, low-light and nutrient-poor ecological niches. We used atomic force microscopy to image the different photosystem I (PSI) membrane architectures of the MED4 (high-light) Prochlorococcus ecotype grown under high-light and low-light conditions in addition to the MIT9313 (low-light) and SS120 (low-light) Prochlorococcus ecotypes grown under low-light conditions. Mass spectrometry quantified the relative abundance of PSI, photosystem II (PSII) and cytochrome b6f complexes and the various Pcb proteins in the thylakoid membrane. Atomic force microscopy topographs and structural modelling revealed a series of specialized PSI configurations, each adapted to the environmental niche occupied by a particular ecotype. MED4 PSI domains were loosely packed in the thylakoid membrane, whereas PSI in the low-light MIT9313 is organized into a tightly packed pseudo-hexagonal lattice that maximizes harvesting and trapping of light. There are approximately equal levels of PSI and PSII in MED4 and MIT9313, but nearly twofold more PSII than PSI in SS120, which also has a lower content of cytochrome b6f complexes. SS120 has a different tactic to cope with low-light levels, and SS120 thylakoids contained hundreds of closely packed Pcb-PSI supercomplexes that economize on the extra iron and nitrogen required to assemble PSI-only domains. Thus, the abundance and widespread distribution of Prochlorococcus reflect the strategies that various ecotypes employ for adapting to limitations in light and nutrient levels.
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Affiliation(s)
- C MacGregor-Chatwin
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, UK
| | - P J Jackson
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, UK
- ChELSI Institute, Department of Chemical and Biological Engineering, University of Sheffield, Sheffield, UK
| | - M Sener
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
- Department of Physics, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - J W Chidgey
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, UK
| | - A Hitchcock
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, UK
| | - P Qian
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, UK
| | - G E Mayneord
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, UK
| | - M P Johnson
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, UK
| | - Z Luthey-Schulten
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
- Department of Physics, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - M J Dickman
- ChELSI Institute, Department of Chemical and Biological Engineering, University of Sheffield, Sheffield, UK
| | - D J Scanlan
- School of Life Sciences, University of Warwick, Coventry, UK
| | - C N Hunter
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, UK.
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12
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Johnson MP, Wientjes E. The relevance of dynamic thylakoid organisation to photosynthetic regulation. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2019; 1861:148039. [PMID: 31228404 DOI: 10.1016/j.bbabio.2019.06.011] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2019] [Revised: 06/14/2019] [Accepted: 06/15/2019] [Indexed: 12/11/2022]
Abstract
The higher plant chloroplast thylakoid membrane system performs the light-dependent reactions of photosynthesis. These provide the ATP and NADPH required for the fixation of CO2 into biomass by the Calvin-Benson cycle and a range of other metabolic reactions in the stroma. Land plants are frequently challenged by fluctuations in their environment, such as light, nutrient and water availability, which can create a mismatch between the amounts of ATP and NADPH produced and the amounts required by the downstream metabolism. Left unchecked, such imbalances can lead to the production of reactive oxygen species that damage the plant and harm productivity. Fortunately, plants have evolved a complex range of regulatory processes to avoid or minimize such deleterious effects by controlling the efficiency of light harvesting and electron transfer in the thylakoid membrane. Generally the regulation of the light reactions has been studied and conceptualised at the microscopic level of protein-protein and protein-ligand interactions, however in recent years dynamic changes in the thylakoid macrostructure itself have been recognised to play a significant role in regulating light harvesting and electron transfer. Here we review the evidence for the involvement of macrostructural changes in photosynthetic regulation and review the techniques that brought this evidence to light.
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Affiliation(s)
- Matthew P Johnson
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield S10 2TN, United Kingdom.
| | - Emilie Wientjes
- Laboratory of Biophysics, Wageningen University, Stippeneng 4, 6708 WE Wageningen, the Netherlands
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13
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Adams PG, Vasilev C, Hunter CN, Johnson MP. Correlated fluorescence quenching and topographic mapping of Light-Harvesting Complex II within surface-assembled aggregates and lipid bilayers. BIOCHIMICA ET BIOPHYSICA ACTA. BIOENERGETICS 2018; 1859:1075-1085. [PMID: 29928860 PMCID: PMC6135645 DOI: 10.1016/j.bbabio.2018.06.011] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/27/2018] [Revised: 06/11/2018] [Accepted: 06/15/2018] [Indexed: 01/30/2023]
Abstract
Light-Harvesting Complex II (LHCII) is a chlorophyll-protein antenna complex that efficiently absorbs solar energy and transfers electronic excited states to photosystems I and II. Under excess light intensity LHCII can adopt a photoprotective state in which excitation energy is safely dissipated as heat, a process known as Non-Photochemical Quenching (NPQ). In vivo NPQ is triggered by combinatorial factors including transmembrane ΔpH, PsbS protein and LHCII-bound zeaxanthin, leading to dramatically shortened LHCII fluorescence lifetimes. In vitro, LHCII in detergent solution or in proteoliposomes can reversibly adopt an NPQ-like state, via manipulation of detergent/protein ratio, lipid/protein ratio, pH or pressure. Previous spectroscopic investigations revealed changes in exciton dynamics and protein conformation that accompany quenching, however, LHCII-LHCII interactions have not been extensively studied. Here, we correlated fluorescence lifetime imaging microscopy (FLIM) and atomic force microscopy (AFM) of trimeric LHCII adsorbed to mica substrates and manipulated the environment to cause varying degrees of quenching. AFM showed that LHCII self-assembled onto mica forming 2D-aggregates (25-150 nm width). FLIM determined that LHCII in these aggregates were in a quenched state, with much lower fluorescence lifetimes (~0.25 ns) compared to free LHCII in solution (2.2-3.9 ns). LHCII-LHCII interactions were disrupted by thylakoid lipids or phospholipids, leading to intermediate fluorescent lifetimes (0.6-0.9 ns). To our knowledge, this is the first in vitro correlation of nanoscale membrane imaging with LHCII quenching. Our findings suggest that lipids could play a key role in modulating the extent of LHCII-LHCII interactions within the thylakoid membrane and so the propensity for NPQ activation.
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Affiliation(s)
- Peter G Adams
- School of Physics and Astronomy, University of Leeds, Leeds LS2 9JT, UK; Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds LS2 9JT, UK.
| | - Cvetelin Vasilev
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield S10 2TN, UK
| | - C Neil Hunter
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield S10 2TN, UK
| | - Matthew P Johnson
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield S10 2TN, UK
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14
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Wood WHJ, MacGregor-Chatwin C, Barnett SFH, Mayneord GE, Huang X, Hobbs JK, Hunter CN, Johnson MP. Dynamic thylakoid stacking regulates the balance between linear and cyclic photosynthetic electron transfer. NATURE PLANTS 2018; 4:116-127. [PMID: 29379151 DOI: 10.1038/s41477-017-0092-7] [Citation(s) in RCA: 76] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/03/2017] [Accepted: 12/13/2017] [Indexed: 05/05/2023]
Abstract
Upon transition of plants from darkness to light the initiation of photosynthetic linear electron transfer (LET) from H2O to NADP+ precedes the activation of CO2 fixation, creating a lag period where cyclic electron transfer (CET) around photosystem I (PSI) has an important protective role. CET generates ΔpH without net reduced NADPH formation, preventing overreduction of PSI via regulation of the cytochrome b 6 f (cytb 6 f) complex and protecting PSII from overexcitation by inducing non-photochemical quenching. The dark-to-light transition also provokes increased phosphorylation of light-harvesting complex II (LHCII). However, the relationship between LHCII phosphorylation and regulation of the LET/CET balance is not understood. Here, we show that the dark-to-light changes in LHCII phosphorylation profoundly alter thylakoid membrane architecture and the macromolecular organization of the photosynthetic complexes, without significantly affecting the antenna size of either photosystem. The grana diameter and number of membrane layers per grana are decreased in the light while the number of grana per chloroplast is increased, creating a larger contact area between grana and stromal lamellae. We show that these changes in thylakoid stacking regulate the balance between LET and CET pathways. Smaller grana promote more efficient LET by reducing the diffusion distance for the mobile electron carriers plastoquinone and plastocyanin, whereas larger grana enhance the partition of the granal and stromal lamellae plastoquinone pools, enhancing the efficiency of CET and thus photoprotection by non-photochemical quenching.
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Affiliation(s)
- William H J Wood
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, UK
| | | | - Samuel F H Barnett
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, UK
| | - Guy E Mayneord
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, UK
| | - Xia Huang
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, UK
| | - Jamie K Hobbs
- Department of Physics and Astronomy, University of Sheffield, Sheffield, UK
| | - C Neil Hunter
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, UK
| | - Matthew P Johnson
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, UK.
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15
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Casella S, Huang F, Mason D, Zhao GY, Johnson GN, Mullineaux CW, Liu LN. Dissecting the Native Architecture and Dynamics of Cyanobacterial Photosynthetic Machinery. MOLECULAR PLANT 2017; 10:1434-1448. [PMID: 29017828 PMCID: PMC5683893 DOI: 10.1016/j.molp.2017.09.019] [Citation(s) in RCA: 59] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/29/2017] [Revised: 09/25/2017] [Accepted: 09/29/2017] [Indexed: 05/18/2023]
Abstract
The structural dynamics and flexibility of cell membranes play fundamental roles in the functions of the cells, i.e., signaling, energy transduction, and physiological adaptation. The cyanobacterial thylakoid membrane represents a model membrane that can conduct both oxygenic photosynthesis and respiration simultaneously. In this study, we conducted direct visualization of the global organization and mobility of photosynthetic complexes in thylakoid membranes from a model cyanobacterium, Synechococcus elongatus PCC 7942, using high-resolution atomic force, confocal, and total internal reflection fluorescence microscopy. We visualized the native arrangement and dense packing of photosystem I (PSI), photosystem II (PSII), and cytochrome (Cyt) b6f within thylakoid membranes at the molecular level. Furthermore, we functionally tagged PSI, PSII, Cyt b6f, and ATP synthase individually with fluorescent proteins, and revealed the heterogeneous distribution of these four photosynthetic complexes and determined their dynamic features within the crowding membrane environment using live-cell fluorescence imaging. We characterized red light-induced clustering localization and adjustable diffusion of photosynthetic complexes in thylakoid membranes, representative of the reorganization of photosynthetic apparatus in response to environmental changes. Understanding the organization and dynamics of photosynthetic membranes is essential for rational design and construction of artificial photosynthetic systems to underpin bioenergy development. Knowledge of cyanobacterial thylakoid membranes could also be extended to other cell membranes, such as chloroplast and mitochondrial membranes.
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Affiliation(s)
- Selene Casella
- Institute of Integrative Biology, University of Liverpool, Crown Street, Liverpool L69 7ZB, UK
| | - Fang Huang
- Institute of Integrative Biology, University of Liverpool, Crown Street, Liverpool L69 7ZB, UK
| | - David Mason
- Institute of Integrative Biology, University of Liverpool, Crown Street, Liverpool L69 7ZB, UK; Centre for Cell Imaging, University of Liverpool, Crown Street, Liverpool L69 7ZB, UK
| | - Guo-Yan Zhao
- Institute of Integrative Biology, University of Liverpool, Crown Street, Liverpool L69 7ZB, UK; College of Life Science, Shandong Normal University, Jinan 250014, P. R. China
| | - Giles N Johnson
- School of Earth and Environmental Sciences, University of Manchester, Oxford Road, Manchester M13 9PT, UK
| | - Conrad W Mullineaux
- School of Biological and Chemical Sciences, Queen Mary University of London, Mile End Road, London E1 4NS, UK
| | - Lu-Ning Liu
- Institute of Integrative Biology, University of Liverpool, Crown Street, Liverpool L69 7ZB, UK.
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16
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MacGregor-Chatwin C, Sener M, Barnett SFH, Hitchcock A, Barnhart-Dailey MC, Maghlaoui K, Barber J, Timlin JA, Schulten K, Hunter CN. Lateral Segregation of Photosystem I in Cyanobacterial Thylakoids. THE PLANT CELL 2017; 29:1119-1136. [PMID: 28364021 PMCID: PMC5466035 DOI: 10.1105/tpc.17.00071] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2017] [Revised: 03/08/2017] [Accepted: 03/23/2017] [Indexed: 05/21/2023]
Abstract
Photosystem I (PSI) is the dominant photosystem in cyanobacteria and it plays a pivotal role in cyanobacterial metabolism. Despite its biological importance, the native organization of PSI in cyanobacterial thylakoid membranes is poorly understood. Here, we use atomic force microscopy (AFM) to show that ordered, extensive macromolecular arrays of PSI complexes are present in thylakoids from Thermosynechococcus elongatus, Synechococcus sp PCC 7002, and Synechocystis sp PCC 6803. Hyperspectral confocal fluorescence microscopy and three-dimensional structured illumination microscopy of Synechocystis sp PCC 6803 cells visualize PSI domains within the context of the complete thylakoid system. Crystallographic and AFM data were used to build a structural model of a membrane landscape comprising 96 PSI trimers and 27,648 chlorophyll a molecules. Rather than facilitating intertrimer energy transfer, the close associations between PSI primarily maximize packing efficiency; short-range interactions with Complex I and cytochrome b6f are excluded from these regions of the membrane, so PSI turnover is sustained by long-distance diffusion of the electron donors at the membrane surface. Elsewhere, PSI-photosystem II contact zones provide sites for docking phycobilisomes and the formation of megacomplexes. PSI-enriched domains in cyanobacteria might foreshadow the partitioning of PSI into stromal lamellae in plants, similarly sustained by long-distance diffusion of electron carriers.
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Affiliation(s)
- Craig MacGregor-Chatwin
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield S10 2TN, United Kingdom
| | - Melih Sener
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801
- Department of Physics, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801
| | - Samuel F H Barnett
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield S10 2TN, United Kingdom
| | - Andrew Hitchcock
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield S10 2TN, United Kingdom
| | - Meghan C Barnhart-Dailey
- Bioenergy and Defense Technologies Department, Sandia National Laboratories, Albuquerque, New Mexico 87185
| | - Karim Maghlaoui
- Division of Molecular Biosciences, Faculty of Natural Sciences, Imperial College London, London SW7 2AZ, United Kingdom
| | - James Barber
- Division of Molecular Biosciences, Faculty of Natural Sciences, Imperial College London, London SW7 2AZ, United Kingdom
| | - Jerilyn A Timlin
- Bioenergy and Defense Technologies Department, Sandia National Laboratories, Albuquerque, New Mexico 87185
| | - Klaus Schulten
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801
- Department of Physics, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801
- Center for Biophysics and Computational Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801
| | - C Neil Hunter
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield S10 2TN, United Kingdom
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17
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Zhao LS, Su HN, Li K, Xie BB, Liu LN, Zhang XY, Chen XL, Huang F, Zhou BC, Zhang YZ. Supramolecular architecture of photosynthetic membrane in red algae in response to nitrogen starvation. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2016; 1857:1751-1758. [PMID: 27528560 DOI: 10.1016/j.bbabio.2016.08.005] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/13/2016] [Revised: 08/06/2016] [Accepted: 08/11/2016] [Indexed: 12/15/2022]
Abstract
The availability of nitrogen is one of the most important determinants that can limit the growth of photosynthetic organisms including plants and algae; however, direct observations on the supramolecular architecture of photosynthetic membranes in response to nitrogen stress are still lacking. Red algae are an important evolutionary group of algae which contain phycobilisomes (PBSs) on their thylakoid membranes, as do cyanobacteria. PBSs function not only as light-harvesting antennae but also as nitrogen storage. In this report, alterations of the supramolecular architecture of thylakoid membranes from red alga Porphyridium cruentum during nitrogen starvation were characterized. The morphology of the intact thylakoid membrane was observed to be round vesicles. Thylakoid membranes were reduced in content and PBSs were degraded during nitrogen starvation. The size and density of PBSs were both found to be reduced. PBS size decreased by less than one-half after 20days of nitrogen starvation, but their hemispherical morphology was retained. The density of PBSs on thylakoid membranes was more seriously affected as time proceeded. Upon re-addition of nitrogen led to increasing of PBSs on thylakoid membranes. This work reports the first direct observation on alterations in the supramolecular architecture of thylakoid membranes from a photosynthetic organism in response to nitrogen stress.
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Affiliation(s)
- Long-Sheng Zhao
- State Key Laboratory of Microbial Technology, Marine Biotechnology Research Center, Institute of Marine Science and Technology, Shandong University, Jinan 250100, China
| | - Hai-Nan Su
- State Key Laboratory of Microbial Technology, Marine Biotechnology Research Center, Institute of Marine Science and Technology, Shandong University, Jinan 250100, China.
| | - Kang Li
- State Key Laboratory of Microbial Technology, Marine Biotechnology Research Center, Institute of Marine Science and Technology, Shandong University, Jinan 250100, China
| | - Bin-Bin Xie
- State Key Laboratory of Microbial Technology, Marine Biotechnology Research Center, Institute of Marine Science and Technology, Shandong University, Jinan 250100, China
| | - Lu-Ning Liu
- State Key Laboratory of Microbial Technology, Marine Biotechnology Research Center, Institute of Marine Science and Technology, Shandong University, Jinan 250100, China
| | - Xi-Ying Zhang
- State Key Laboratory of Microbial Technology, Marine Biotechnology Research Center, Institute of Marine Science and Technology, Shandong University, Jinan 250100, China
| | - Xiu-Lan Chen
- State Key Laboratory of Microbial Technology, Marine Biotechnology Research Center, Institute of Marine Science and Technology, Shandong University, Jinan 250100, China
| | - Feng Huang
- State Key Laboratory of Microbial Technology, Marine Biotechnology Research Center, Institute of Marine Science and Technology, Shandong University, Jinan 250100, China
| | - Bai-Cheng Zhou
- State Key Laboratory of Microbial Technology, Marine Biotechnology Research Center, Institute of Marine Science and Technology, Shandong University, Jinan 250100, China
| | - Yu-Zhong Zhang
- State Key Laboratory of Microbial Technology, Marine Biotechnology Research Center, Institute of Marine Science and Technology, Shandong University, Jinan 250100, China; Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China
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18
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Ruban AV, Johnson MP. Visualizing the dynamic structure of the plant photosynthetic membrane. NATURE PLANTS 2015; 1:15161. [PMID: 27251532 DOI: 10.1038/nplants.2015.161] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2015] [Accepted: 09/29/2015] [Indexed: 05/28/2023]
Abstract
The chloroplast thylakoid membrane is the site for the initial steps of photosynthesis that convert solar energy into chemical energy, ultimately powering almost all life on earth. The heterogeneous distribution of protein complexes within the membrane gives rise to an intricate three-dimensional structure that is nonetheless extremely dynamic on a timescale of seconds to minutes. These dynamics form the basis for the regulation of photosynthesis, and therefore the adaptability of plants to different environments. High-resolution microscopy has in recent years begun to provide new insights into the structural dynamics underlying a number of regulatory processes such as membrane stacking, photosystem II repair, photoprotective energy dissipation, state transitions and alternative electron transfer. Here we provide an overview of the essentials of thylakoid membrane structure in plants, and consider how recent advances, using a range of microscopies, have substantially increased our knowledge of the thylakoid dynamic structure. We discuss both the successes and limitations of the currently available techniques and highlight newly emerging microscopic methods that promise to move the field beyond the current 'static' view of membrane organization based on frozen snapshots to a 'live' view of functional membranes imaged under native aqueous conditions at ambient temperature and responding dynamically to external stimuli.
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Affiliation(s)
- Alexander V Ruban
- School of Biological and Chemical Sciences, Queen Mary, University of London, Mile End Road, London E1 4NS, UK
| | - Matthew P Johnson
- Department of Molecular Biology and Biotechnology, University of Sheffield, Firth Court, Western Bank, Sheffield, S10 2TN, UK
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19
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Ruban AV. Visualizing the Photosynthetic Membrane Proteins in Situ: Atomic Force Microscopy. PLANT PHYSIOLOGY 2015; 169:910. [PMID: 26417051 PMCID: PMC4587478 DOI: 10.1104/pp.15.01215] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Affiliation(s)
- Alexander V Ruban
- School of Biological and Chemical Sciences, Queen Mary University of London, London E1 4NS, United Kingdom
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