1
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Pan S, Gries K, Engel BD, Schroda M, Haselwandter CA, Scheuring S. The cyanobacterial protein VIPP1 forms ESCRT-III-like structures on lipid bilayers. Nat Struct Mol Biol 2024:10.1038/s41594-024-01367-7. [PMID: 39060677 DOI: 10.1038/s41594-024-01367-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2023] [Accepted: 07/03/2024] [Indexed: 07/28/2024]
Abstract
The biogenesis and maintenance of thylakoid membranes require vesicle-inducing protein in plastids 1 (VIPP1). VIPP1 is a member of the endosomal sorting complex required for transport-III (ESCRT-III) superfamily, whose members form diverse filament-based supramolecular structures that facilitate membrane deformation and fission. VIPP1 cryo-electron microscopy (EM) structures in solution revealed helical rods and baskets of stacked rings, with amphipathic membrane-binding domains in the lumen. However, how VIPP1 interacts with membranes remains largely unknown. Here, using high-speed atomic force microscopy (HS-AFM), we show that VIPP1 assembles into right-handed chiral spirals and regular polygons on supported lipid bilayers via ESCRT-III-like filament assembly and dynamics. VIPP1 filaments grow clockwise into spirals through polymerization at a ring-shaped central polymerization hub, and into polygons through clockwise polymerization at the sector peripheries. Interestingly, VIPP1 initially forms Archimedean spirals, which upon maturation transform into logarithmic spirals through lateral annealing of strands to the outermore low-curvature spiral turns.
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Affiliation(s)
- Sichen Pan
- Weill Cornell Medicine, Department of Anesthesiology, New York, NY, USA
| | - Karin Gries
- Molecular Biotechnology and Systems Biology, RPTU Kaiserslautern-Landau, Kaiserslautern, Germany
| | | | - Michael Schroda
- Molecular Biotechnology and Systems Biology, RPTU Kaiserslautern-Landau, Kaiserslautern, Germany
| | - Christoph A Haselwandter
- Department of Physics and Astronomy, University of Southern California, Los Angeles, CA, USA
- Department of Quantitative and Computational Biology, University of Southern California, Los Angeles, CA, USA
| | - Simon Scheuring
- Weill Cornell Medicine, Department of Anesthesiology, New York, NY, USA.
- Weill Cornell Medicine, Department of Physiology and Biophysics, New York, NY, USA.
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2
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Lübben MK, Klingl A, Nickelsen J, Ostermeier M. CLEM, a universal tool for analyzing structural organization in thylakoid membranes. PHYSIOLOGIA PLANTARUM 2024; 176:e14417. [PMID: 38945684 DOI: 10.1111/ppl.14417] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2023] [Accepted: 05/15/2024] [Indexed: 07/02/2024]
Abstract
Chlorophyll (Chl) plays a crucial role in photosynthesis, functioning as a photosensitizer. As an integral component of this process, energy absorbed by this pigment is partly emitted as red fluorescence. This signal can be readily imaged by fluorescence microscopy and provides a visualization of photosynthetic activity. However, due to limited resolution, signals cannot be assigned to specific subcellular/organellar membrane structures. By correlating fluorescence micrographs with transmission electron microscopy, researchers can identify sub-cellular compartments and membranes, enabling the monitoring of Chl distribution within thylakoid membrane substructures in cyanobacteria, algae, and higher plant single cells. Here, we describe a simple and effective protocol for correlative light-electron microscopy (CLEM) based on the autofluorescence of Chl and demonstrate its application to selected photosynthetic model organisms. Our findings illustrate the potential of this technique to identify areas of high Chl concentration and photochemical activity, such as grana regions in vascular plants, by mapping stacked thylakoids.
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Affiliation(s)
- Maximilian K Lübben
- Department of Molecular Plant Science, LMU Munich, Planegg-Martinsried, Germany
| | - Andreas Klingl
- Plant Development, LMU Munich, Planegg-Martinsried, Germany
| | - Jörg Nickelsen
- Department of Molecular Plant Science, LMU Munich, Planegg-Martinsried, Germany
| | - Matthias Ostermeier
- Department of Molecular Plant Science, LMU Munich, Planegg-Martinsried, Germany
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3
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Kreis E, König K, Misir M, Niemeyer J, Sommer F, Schroda M. TurboID reveals the proxiomes of Chlamydomonas proteins involved in thylakoid biogenesis and stress response. PLANT PHYSIOLOGY 2023; 193:1772-1796. [PMID: 37310689 PMCID: PMC10602608 DOI: 10.1093/plphys/kiad335] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/03/2023] [Revised: 04/24/2023] [Accepted: 05/04/2023] [Indexed: 06/14/2023]
Abstract
In Chlamydomonas (Chlamydomonas reinhardtii), the VESICLE-INDUCING PROTEIN IN PLASTIDS 1 and 2 (VIPP1 and VIPP2) play roles in the sensing and coping with membrane stress and in thylakoid membrane biogenesis. To gain more insight into these processes, we aimed to identify proteins interacting with VIPP1/2 in the chloroplast and chose proximity labeling (PL) for this purpose. We used the transient interaction between the nucleotide exchange factor CHLOROPLAST GRPE HOMOLOG 1 (CGE1) and the stromal HEAT SHOCK PROTEIN 70B (HSP70B) as test system. While PL with APEX2 and BioID proved to be inefficient, TurboID resulted in substantial biotinylation in vivo. TurboID-mediated PL with VIPP1/2 as baits under ambient and H2O2 stress conditions confirmed known interactions of VIPP1 with VIPP2, HSP70B, and the CHLOROPLAST DNAJ HOMOLOG 2 (CDJ2). Proteins identified in the VIPP1/2 proxiomes can be grouped into proteins involved in the biogenesis of thylakoid membrane complexes and the regulation of photosynthetic electron transport, including PROTON GRADIENT REGULATION 5-LIKE 1 (PGRL1). A third group comprises 11 proteins of unknown function whose genes are upregulated under chloroplast stress conditions. We named them VIPP PROXIMITY LABELING (VPL). In reciprocal experiments, we confirmed VIPP1 in the proxiomes of VPL2 and PGRL1. Our results demonstrate the robustness of TurboID-mediated PL for studying protein interaction networks in the chloroplast of Chlamydomonas and pave the way for analyzing functions of VIPPs in thylakoid biogenesis and stress responses.
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Affiliation(s)
- Elena Kreis
- Molekulare Biotechnologie & Systembiologie, RPTU Kaiserslautern-Landau, Paul-Ehrlich Straße 23, D-67663 Kaiserslautern, Germany
| | - Katharina König
- Molekulare Biotechnologie & Systembiologie, RPTU Kaiserslautern-Landau, Paul-Ehrlich Straße 23, D-67663 Kaiserslautern, Germany
| | - Melissa Misir
- Molekulare Biotechnologie & Systembiologie, RPTU Kaiserslautern-Landau, Paul-Ehrlich Straße 23, D-67663 Kaiserslautern, Germany
| | - Justus Niemeyer
- Molekulare Biotechnologie & Systembiologie, RPTU Kaiserslautern-Landau, Paul-Ehrlich Straße 23, D-67663 Kaiserslautern, Germany
| | - Frederik Sommer
- Molekulare Biotechnologie & Systembiologie, RPTU Kaiserslautern-Landau, Paul-Ehrlich Straße 23, D-67663 Kaiserslautern, Germany
| | - Michael Schroda
- Molekulare Biotechnologie & Systembiologie, RPTU Kaiserslautern-Landau, Paul-Ehrlich Straße 23, D-67663 Kaiserslautern, Germany
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4
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Whitman BT, Wang Y, Murray CRA, Glover MJN, Owttrim GW. Liquid-Liquid Phase Separation of the DEAD-Box Cyanobacterial RNA Helicase Redox (CrhR) into Dynamic Membraneless Organelles in Synechocystis sp. Strain PCC 6803. Appl Environ Microbiol 2023; 89:e0001523. [PMID: 36920190 PMCID: PMC10132119 DOI: 10.1128/aem.00015-23] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2023] [Accepted: 02/17/2023] [Indexed: 03/16/2023] Open
Abstract
Compartmentalization of macromolecules into discrete non-lipid-bound bodies by liquid-liquid phase separation (LLPS) is a well-characterized regulatory mechanism frequently associated with the cellular stress response in eukaryotes. In contrast, the formation and importance of similar complexes is just becoming evident in bacteria. Here, we identify LLPS as the mechanism by which the DEAD-box RNA helicase, cyanobacterial RNA helicase redox (CrhR), compartmentalizes into dynamic membraneless organelles in a temporal and spatial manner in response to abiotic stress in the cyanobacterium Synechocystis sp. strain PCC 6803. Stress conditions induced CrhR to form a single crescent localized exterior to the thylakoid membrane, indicating that this region is a crucial domain in the cyanobacterial stress response. These crescents rapidly dissipate upon alleviation of the stress conditions. Furthermore, CrhR aggregation was mediated by LLPS in an RNA-dependent reaction. We propose that dynamic CrhR condensation performs crucial roles in RNA metabolism, enabling rapid adaptation of the photosynthetic apparatus to environmental stresses. These results expand our understanding of the role that functional compartmentalization of RNA helicases and thus RNA processing in membraneless organelles by LLPS-mediated protein condensation performs in the bacterial response to environmental stress. IMPORTANCE Oxygen-evolving photosynthetic cyanobacteria evolved ~3 billion years ago, performing fundamental roles in the biogeochemical evolution of the early Earth and continue to perform fundamental roles in nutrient cycling and primary productivity today. The phylum consists of diverse species that flourish in heterogeneous environments. A prime driver for survival is the ability to alter photosynthetic performance in response to the shifting environmental conditions these organisms continuously encounter. This study demonstrated that diverse abiotic stresses elicit dramatic changes in localization and structural organization of the RNA helicase CrhR associated with the photosynthetic thylakoid membrane. These dynamic changes, mediated by a liquid-liquid phase separation (LLPS)-mediated mechanism, reveal a novel mechanism by which cyanobacteria can compartmentalize the activity of ribonucleoprotein complexes in membraneless organelles. The results have significant consequences for understanding bacterial adaptation and survival in response to changing environmental conditions.
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Affiliation(s)
- Brendan T. Whitman
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada
| | - Yixiong Wang
- Department of Oncology, Cross Cancer Institute, University of Alberta, Edmonton, Alberta, Canada
| | - Cameron R. A. Murray
- Department of Biochemistry, Faculty of Medicine & Dentistry, University of Alberta, Edmonton, Alberta, Canada
| | - Mark J. N. Glover
- Department of Biochemistry, Faculty of Medicine & Dentistry, University of Alberta, Edmonton, Alberta, Canada
| | - George W. Owttrim
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada
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5
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Wang Y, Ge H, Xiao Z, Huang C, Wang G, Duan X, Zheng L, Dong J, Huang X, Zhang Y, An H, Xu W, Wang Y. Spatial Proteome Reorganization of a Photosynthetic Model Cyanobacterium in Response to Abiotic Stresses. J Proteome Res 2023; 22:1255-1269. [PMID: 36930737 DOI: 10.1021/acs.jproteome.2c00759] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/19/2023]
Abstract
Spatial proteome reorganization in response to a changing environment represents a different layer of adaptation mechanism in addition to differential expression of a subset of stress responsive genes in photosynthetic organisms. Profiling such reorganization events is critically important to extend our understanding how photosynthetic organisms adapt to adverse environments. Thus, we treated a unicellular photosynthetic model cyanobacterium, Synechocystis sp. PCC 6803 (hereafter referred to as Synechocystis), with five different types of abiotic stresses including nitrogen starvation, iron deficiency, cold, heat, and darkness, and systematically identified proteins showing stress-induced differential expression and/or redistribution between the membrane and the soluble fractions using a quantitative proteomics approach. A number of proteins showing such a redistribution in response to a single or multiple types of abiotic stresses were identified. These include 12 ribosomal proteins displaying unanimous cold-induced redistribution to the membrane and the protein FurA, a master regulator of iron acquisition, displaying iron deficiency- and nitrogen starvation-induced redistribution to the membrane. Such findings shed light on a novel regulatory mechanism underlying the corresponding stress responses, and establish the results in the present study as an important resource for future studies intended to understand how photosynthetic organisms cope with adverse environments.
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Affiliation(s)
- Yan Wang
- State Key Laboratory of Molecular Developmental Biology, Innovation Academy for Seed Design, CAS, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, No.1 West Beichen Road, Beijing 100101, China.,University of Chinese Academy of Sciences, Huairou District, Beijing 101408, China
| | - Haitao Ge
- State Key Laboratory of Molecular Developmental Biology, Innovation Academy for Seed Design, CAS, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, No.1 West Beichen Road, Beijing 100101, China
| | - Zhen Xiao
- State Key Laboratory of Molecular Developmental Biology, Innovation Academy for Seed Design, CAS, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, No.1 West Beichen Road, Beijing 100101, China.,University of Chinese Academy of Sciences, Huairou District, Beijing 101408, China
| | - Chengcheng Huang
- State Key Laboratory of Molecular Developmental Biology, Innovation Academy for Seed Design, CAS, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, No.1 West Beichen Road, Beijing 100101, China.,University of Chinese Academy of Sciences, Huairou District, Beijing 101408, China
| | - Gaojie Wang
- State Key Laboratory of Molecular Developmental Biology, Innovation Academy for Seed Design, CAS, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, No.1 West Beichen Road, Beijing 100101, China.,University of Chinese Academy of Sciences, Huairou District, Beijing 101408, China
| | - Xiaoxiao Duan
- State Key Laboratory of Molecular Developmental Biology, Innovation Academy for Seed Design, CAS, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, No.1 West Beichen Road, Beijing 100101, China.,University of Chinese Academy of Sciences, Huairou District, Beijing 101408, China
| | - Limin Zheng
- State Key Laboratory of Molecular Developmental Biology, Innovation Academy for Seed Design, CAS, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, No.1 West Beichen Road, Beijing 100101, China.,University of Chinese Academy of Sciences, Huairou District, Beijing 101408, China
| | - Jinghui Dong
- State Key Laboratory of Molecular Developmental Biology, Innovation Academy for Seed Design, CAS, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, No.1 West Beichen Road, Beijing 100101, China.,University of Chinese Academy of Sciences, Huairou District, Beijing 101408, China
| | - Xiahe Huang
- State Key Laboratory of Molecular Developmental Biology, Innovation Academy for Seed Design, CAS, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, No.1 West Beichen Road, Beijing 100101, China
| | - Yuanya Zhang
- State Key Laboratory of Molecular Developmental Biology, Innovation Academy for Seed Design, CAS, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, No.1 West Beichen Road, Beijing 100101, China
| | - Hongyu An
- State Key Laboratory of Molecular Developmental Biology, Innovation Academy for Seed Design, CAS, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, No.1 West Beichen Road, Beijing 100101, China.,University of Chinese Academy of Sciences, Huairou District, Beijing 101408, China
| | - Wu Xu
- Department of Chemistry, University of Louisiana at Lafayette, Lafayette, Louisiana 70504, United States
| | - Yingchun Wang
- State Key Laboratory of Molecular Developmental Biology, Innovation Academy for Seed Design, CAS, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, No.1 West Beichen Road, Beijing 100101, China.,University of Chinese Academy of Sciences, Huairou District, Beijing 101408, China
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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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Cyanobacterial membrane dynamics in the light of eukaryotic principles. Biosci Rep 2023; 43:232406. [PMID: 36602300 PMCID: PMC9950537 DOI: 10.1042/bsr20221269] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2022] [Revised: 12/23/2022] [Accepted: 01/03/2023] [Indexed: 01/06/2023] Open
Abstract
Intracellular compartmentalization is a hallmark of eukaryotic cells. Dynamic membrane remodeling, involving membrane fission/fusion events, clearly is crucial for cell viability and function, as well as membrane stabilization and/or repair, e.g., during or after injury. In recent decades, several proteins involved in membrane stabilization and/or dynamic membrane remodeling have been identified and described in eukaryotes. Yet, while typically not having a cellular organization as complex as eukaryotes, also bacteria can contain extra internal membrane systems besides the cytoplasmic membranes (CMs). Thus, also in bacteria mechanisms must have evolved to stabilize membranes and/or trigger dynamic membrane remodeling processes. In fact, in recent years proteins, which were initially defined being eukaryotic inventions, have been recognized also in bacteria, and likely these proteins shape membranes also in these organisms. One example of a complex prokaryotic inner membrane system is the thylakoid membrane (TM) of cyanobacteria, which contains the complexes of the photosynthesis light reaction. Cyanobacteria are evolutionary closely related to chloroplasts, and extensive remodeling of the internal membrane systems has been observed in chloroplasts and cyanobacteria during membrane biogenesis and/or at changing light conditions. We here discuss common principles guiding eukaryotic and prokaryotic membrane dynamics and the proteins involved, with a special focus on the dynamics of the cyanobacterial TMs and CMs.
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8
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The increasing role of structural proteomics in cyanobacteria. Essays Biochem 2022; 67:269-282. [PMID: 36503929 PMCID: PMC10070481 DOI: 10.1042/ebc20220095] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2022] [Revised: 11/11/2022] [Accepted: 11/23/2022] [Indexed: 12/14/2022]
Abstract
Abstract
Cyanobacteria, also known as blue–green algae, are ubiquitous organisms on the planet. They contain tremendous protein machineries that are of interest to the biotechnology industry and beyond. Recently, the number of annotated cyanobacterial genomes has expanded, enabling structural studies on known gene-coded proteins to accelerate. This review focuses on the advances in mass spectrometry (MS) that have enabled structural proteomics studies to be performed on the proteins and protein complexes within cyanobacteria. The review also showcases examples whereby MS has revealed critical mechanistic information behind how these remarkable machines within cyanobacteria function.
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9
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Junglas B, Axt A, Siebenaller C, Sonel H, Hellmann N, Weber SAL, Schneider D. Membrane destabilization and pore formation induced by the Synechocystis IM30 protein. Biophys J 2022; 121:3411-3421. [PMID: 35986519 PMCID: PMC9515227 DOI: 10.1016/j.bpj.2022.08.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2022] [Revised: 07/21/2022] [Accepted: 08/15/2022] [Indexed: 11/18/2022] Open
Abstract
The inner membrane-associated protein of 30 kDa (IM30) is essential in chloroplasts and cyanobacteria. The spatio-temporal cellular localization of the protein appears to be highly dynamic and triggered by internal as well as external stimuli, mainly light intensity. The soluble fraction of the protein is localized in the cyanobacterial cytoplasm or the chloroplast stroma, respectively. Additionally, the protein attaches to the thylakoid membrane as well as to the chloroplast inner envelope or the cyanobacterial cytoplasmic membrane, respectively, especially under conditions of membrane stress. IM30 is involved in thylakoid membrane biogenesis and/or maintenance, where it either stabilizes membranes and/or triggers membrane-fusion processes. These apparently contradicting functions have to be tightly controlled and separated spatiotemporally in chloroplasts and cyanobacteria. IM30's fusogenic activity depends on Mg2+ binding to IM30; yet, it still is unclear how Mg2+-loaded IM30 interacts with membranes and promotes membrane fusion. Here, we show that the interaction of Mg2+ with IM30 results in increased binding of IM30 to native, as well as model, membranes. Via atomic force microscopy in liquid, IM30-induced bilayer defects were observed in solid-supported bilayers in the presence of Mg2+. These structures differ dramatically from the membrane-stabilizing carpet structures that were previously observed in the absence of Mg2+. Thus, Mg2+-induced alterations of the IM30 structure switch the IM30 activity from a membrane-stabilizing to a membrane-destabilizing function, a crucial step in membrane fusion.
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Affiliation(s)
- Benedikt Junglas
- Department of Chemistry, Biochemistry, Johannes Gutenberg University Mainz, Mainz, Germany
| | - Amelie Axt
- Max Planck-Institute for Polymer Research, Mainz, Germany; Institute of Physics, Johannes Gutenberg University Mainz, Mainz, Germany
| | - Carmen Siebenaller
- Department of Chemistry, Biochemistry, Johannes Gutenberg University Mainz, Mainz, Germany
| | - Hilal Sonel
- Department of Chemistry, Biochemistry, Johannes Gutenberg University Mainz, Mainz, Germany
| | - Nadja Hellmann
- Department of Chemistry, Biochemistry, Johannes Gutenberg University Mainz, Mainz, Germany
| | - Stefan A L Weber
- Max Planck-Institute for Polymer Research, Mainz, Germany; Institute of Physics, Johannes Gutenberg University Mainz, Mainz, Germany
| | - Dirk Schneider
- Department of Chemistry, Biochemistry, Johannes Gutenberg University Mainz, Mainz, Germany; Institute of Molecular Physiology, Johannes Gutenberg University Mainz, Mainz, Germany.
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10
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Santos-Merino M, Gutiérrez-Lanza R, Nogales J, García JL, de la Cruz F. Synechococcus elongatus PCC 7942 as a Platform for Bioproduction of Omega-3 Fatty Acids. Life (Basel) 2022; 12:life12060810. [PMID: 35743841 PMCID: PMC9224711 DOI: 10.3390/life12060810] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Revised: 05/25/2022] [Accepted: 05/27/2022] [Indexed: 12/22/2022] Open
Abstract
Alpha-linolenic acid and stearidonic acid are precursors of omega-3 polyunsaturated fatty acids, essential nutrients in the human diet. The ability of cyanobacteria to directly convert atmospheric carbon dioxide into bio-based compounds makes them promising microbial chassis to sustainably produce omega-3 fatty acids. However, their potential in this area remains unexploited, mainly due to important gaps in our knowledge of fatty acid synthesis pathways. To gain insight into the cyanobacterial fatty acid biosynthesis pathways, we analyzed two enzymes involved in the elongation cycle, FabG and FabZ, in Synechococcus elongatus PCC 7942. Overexpression of these two enzymes led to an increase in C18 fatty acids, key intermediates in omega-3 fatty acid production. Nevertheless, coexpression of these enzymes with desaturases DesA and DesB from Synechococcus sp. PCC 7002 did not improve alpha-linolenic acid production, possibly due to their limited role in fatty acid synthesis. In any case, efficient production of stearidonic acid was not achieved by cloning DesD from Synechocystis sp. PCC 6803 in combination with the aforementioned DesA and DesB, reaching maximum production at 48 h post induction. According to current knowledge, this is the first report demonstrating that S. elongatus PCC 7942 can be used as an autotrophic chassis to produce stearidonic acid.
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Affiliation(s)
- María Santos-Merino
- Instituto de Biomedicina y Biotecnología de Cantabria, Universidad de Cantabria—CSIC, 39011 Santander, Spain; (R.G.-L.); (F.d.l.C.)
- Correspondence:
| | - Raquel Gutiérrez-Lanza
- Instituto de Biomedicina y Biotecnología de Cantabria, Universidad de Cantabria—CSIC, 39011 Santander, Spain; (R.G.-L.); (F.d.l.C.)
| | - Juan Nogales
- Department of Systems Biology, Centro Nacional de Biotecnología (CSIC), 28049 Madrid, Spain;
- Interdisciplinary Platform for Sustainable Plastics towards a Circular Economy, Spanish National Research Council (SusPlast-CSIC), 28040 Madrid, Spain;
| | - José Luis García
- Interdisciplinary Platform for Sustainable Plastics towards a Circular Economy, Spanish National Research Council (SusPlast-CSIC), 28040 Madrid, Spain;
- Department of Microbial and Plant Biotechnology, Centro de Investigaciones Biológicas Margarita Salas (CSIC), 28040 Madrid, Spain
| | - Fernando de la Cruz
- Instituto de Biomedicina y Biotecnología de Cantabria, Universidad de Cantabria—CSIC, 39011 Santander, Spain; (R.G.-L.); (F.d.l.C.)
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11
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Wollman AJM, Leake MC. Single-Molecule Narrow-Field Microscopy of Protein-DNA Binding Dynamics in Glucose Signal Transduction of Live Yeast Cells. Methods Mol Biol 2022; 2476:5-16. [PMID: 35635693 DOI: 10.1007/978-1-0716-2221-6_2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Single-molecule narrow-field microscopy is a versatile tool to investigate a diverse range of protein dynamics in live cells and has been extensively used in bacteria. Here, we describe how these methods can be extended to larger eukaryotic, yeast cells, which contain subcellular compartments. We describe how to obtain single-molecule microscopy data but also how to analyze these data to track and obtain the stoichiometry of molecular complexes diffusing in the cell. We chose glucose-mediated signal transduction of live yeast cells as the system to demonstrate these single-molecule techniques as transcriptional regulation is fundamentally a single-molecule problem-a single repressor protein binding a single binding site in the genome can dramatically alter behavior at the whole cell and population levels.
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Affiliation(s)
- Adam J M Wollman
- Newcastle University Biosciences Institute, Newcastle University, Newcastle, UK.
| | - Mark C Leake
- Departments of Physics and Biology, University of York, York, UK
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12
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Badrinarayanan A, Leake MC. Fluorescence Recovery After Photobleaching (FRAP) to Study Dynamics of the Structural Maintenance of Chromosome (SMC) Complex in Live Escherichia coli Bacteria. Methods Mol Biol 2022; 2476:31-41. [PMID: 35635695 DOI: 10.1007/978-1-0716-2221-6_4] [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] [Indexed: 06/15/2023]
Abstract
MukBEF, a structural maintenance of chromosome (SMC) complex, is an important molecular machine for chromosome organization and segregation in Escherichia coli. Fluorescently tagged MukBEF forms distinct spots (or "foci") composed of molecular assemblies in the cell, where it is thought to carry out most of its chromosome-associated activities. Here, we outline the technique of fluorescence recovery after photobleaching (FRAP) as a method to study the properties of YFP-tagged MukB in fluorescent foci. This method can provide important insight into the dynamics of MukB on DNA and be used to study its biochemical properties in vivo.
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Affiliation(s)
| | - Mark C Leake
- Departments of Physics and Biology, University of York, York, UK
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13
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Leake MC. A Next Generation of Advances in Chromosome Architecture. Methods Mol Biol 2022; 2476:1-3. [PMID: 35635692 DOI: 10.1007/978-1-0716-2221-6_1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
New insight into the architecture of chromosomes, their molecular composition, structure and spatial location, and time-resolved features, has grown enormously through developments of a range of pioneering interdisciplinary approaches that lie at the interface of the life and physical sciences. These involve several state-of-the-art "physics of life" tools that are both experimental and theoretical, used in conjunction with molecular biology methods which enable investigation of chromosome structure and function in vitro, in vivo, and even in silico. In particular, a move towards far greater quantitation has enabled transformative leaps in our understanding. These have involved valuable improvements to the spatial and temporal resolution of quantitative measurements, such as in vivo super-resolved light microscopy and single-molecule biophysics methods, which facilitate probing of dynamic chromosome processes hitherto impossible. Similarly, there have been important advances in the theoretical biophysics approaches which have enabled advances in predictive modeling to generate new understanding of the modes of operation of chromosomes across all domains of life. Here, I discuss these advances, and review the current state of our knowledge of chromosome architecture and speculation where future advances may lead.
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Affiliation(s)
- Mark C Leake
- Departments of Physics and Biology, University of York, York, UK.
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14
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Anderson SA, Satyanarayan MB, Wessendorf RL, Lu Y, Fernandez DE. A homolog of GuidedEntry of Tail-anchored proteins3 functions in membrane-specific protein targeting in chloroplasts of Arabidopsis. THE PLANT CELL 2021; 33:2812-2833. [PMID: 34021351 PMCID: PMC8408437 DOI: 10.1093/plcell/koab145] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Accepted: 05/18/2021] [Indexed: 05/12/2023]
Abstract
The chloroplasts and mitochondria of photosynthetic eukaryotes contain proteins that are closely related to cytosolic Guided Entry of Tail-anchored proteins3 (Get3). Get3 is a targeting factor that efficiently escorts tail-anchored (TA) proteins to the ER. Because other components of the cytosolic-targeting pathway appear to be absent in organelles, previous investigators have asserted that organellar Get3 homologs are unlikely to act as targeting factors. However, we show here both that the Arabidopsis thaliana chloroplast homolog designated as GET3B is structurally similar to cytosolic Get3 proteins and that it selectively binds a thylakoid-localized TA protein. Based on genetic interactions between a get3b mutation and mutations affecting the chloroplast signal recognition particle-targeting pathway, as well as changes in the abundance of photosynthesis-related proteins in mutant plants, we propose that GET3B acts primarily to direct proteins to the thylakoids. Furthermore, through molecular complementation experiments, we show that function of GET3B depends on its ability to hydrolyze ATP, and this is consistent with action as a targeting factor. We propose that GET3B and related organellar Get3 homologs play a role that is analogous to that of cytosolic Get3 proteins, and that GET3B acts as a targeting factor in the chloroplast stroma to deliver TA proteins in a membrane-specific manner.
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Affiliation(s)
- Stacy A. Anderson
- Department of Botany, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
| | - Manasa B. Satyanarayan
- Department of Biological Sciences, Western Michigan University, Kalamazoo, Michigan 49008, USA
| | - Ryan L. Wessendorf
- Department of Biological Sciences, Western Michigan University, Kalamazoo, Michigan 49008, USA
| | - Yan Lu
- Department of Biological Sciences, Western Michigan University, Kalamazoo, Michigan 49008, USA
| | - Donna E. Fernandez
- Department of Botany, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
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15
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Liu J, Tassinari M, Souza DP, Naskar S, Noel JK, Bohuszewicz O, Buck M, Williams TA, Baum B, Low HH. Bacterial Vipp1 and PspA are members of the ancient ESCRT-III membrane-remodeling superfamily. Cell 2021; 184:3660-3673.e18. [PMID: 34166615 PMCID: PMC8281802 DOI: 10.1016/j.cell.2021.05.041] [Citation(s) in RCA: 44] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2020] [Revised: 11/24/2020] [Accepted: 05/25/2021] [Indexed: 12/31/2022]
Abstract
Membrane remodeling and repair are essential for all cells. Proteins that perform these functions include Vipp1/IM30 in photosynthetic plastids, PspA in bacteria, and ESCRT-III in eukaryotes. Here, using a combination of evolutionary and structural analyses, we show that these protein families are homologous and share a common ancient evolutionary origin that likely predates the last universal common ancestor. This homology is evident in cryo-electron microscopy structures of Vipp1 rings from the cyanobacterium Nostoc punctiforme presented over a range of symmetries. Each ring is assembled from rungs that stack and progressively tilt to form dome-shaped curvature. Assembly is facilitated by hinges in the Vipp1 monomer, similar to those in ESCRT-III proteins, which allow the formation of flexible polymers. Rings have an inner lumen that is able to bind and deform membranes. Collectively, these data suggest conserved mechanistic principles that underlie Vipp1, PspA, and ESCRT-III-dependent membrane remodeling across all domains of life.
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Affiliation(s)
- Jiwei Liu
- Department of Infectious Disease, Imperial College, London, UK
| | | | - Diorge P Souza
- MRC Laboratory for Molecular Cell Biology, University College London, London, UK; Division of Cell Biology, MRC Laboratory of Molecular Biology, Cambridge, UK
| | - Souvik Naskar
- Department of Infectious Disease, Imperial College, London, UK
| | - Jeffrey K Noel
- Max Delbrück Center for Molecular Medicine, Berlin, Germany
| | | | - Martin Buck
- Department of Life Sciences, Imperial College, London, UK
| | - Tom A Williams
- School of Biological Sciences, University of Bristol, Bristol, UK
| | - Buzz Baum
- MRC Laboratory for Molecular Cell Biology, University College London, London, UK; Division of Cell Biology, MRC Laboratory of Molecular Biology, Cambridge, UK; Institute for the Physics of Living Systems, University College London, London, UK.
| | - Harry H Low
- Department of Infectious Disease, Imperial College, London, UK.
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16
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Gupta TK, Klumpe S, Gries K, Heinz S, Wietrzynski W, Ohnishi N, Niemeyer J, Spaniol B, Schaffer M, Rast A, Ostermeier M, Strauss M, Plitzko JM, Baumeister W, Rudack T, Sakamoto W, Nickelsen J, Schuller JM, Schroda M, Engel BD. Structural basis for VIPP1 oligomerization and maintenance of thylakoid membrane integrity. Cell 2021; 184:3643-3659.e23. [PMID: 34166613 DOI: 10.1016/j.cell.2021.05.011] [Citation(s) in RCA: 56] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Revised: 02/16/2021] [Accepted: 05/10/2021] [Indexed: 12/21/2022]
Abstract
Vesicle-inducing protein in plastids 1 (VIPP1) is essential for the biogenesis and maintenance of thylakoid membranes, which transform light into life. However, it is unknown how VIPP1 performs its vital membrane-remodeling functions. Here, we use cryo-electron microscopy to determine structures of cyanobacterial VIPP1 rings, revealing how VIPP1 monomers flex and interweave to form basket-like assemblies of different symmetries. Three VIPP1 monomers together coordinate a non-canonical nucleotide binding pocket on one end of the ring. Inside the ring's lumen, amphipathic helices from each monomer align to form large hydrophobic columns, enabling VIPP1 to bind and curve membranes. In vivo mutations in these hydrophobic surfaces cause extreme thylakoid swelling under high light, indicating an essential role of VIPP1 lipid binding in resisting stress-induced damage. Using cryo-correlative light and electron microscopy (cryo-CLEM), we observe oligomeric VIPP1 coats encapsulating membrane tubules within the Chlamydomonas chloroplast. Our work provides a structural foundation for understanding how VIPP1 directs thylakoid biogenesis and maintenance.
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Affiliation(s)
- Tilak Kumar Gupta
- Department of Molecular Structural Biology, Max Planck Institute of Biochemistry, 82152 Martinsried, Germany
| | - Sven Klumpe
- Department of Molecular Structural Biology, Max Planck Institute of Biochemistry, 82152 Martinsried, Germany
| | - Karin Gries
- Molecular Biotechnology and Systems Biology, Technische Universität Kaiserslautern, 67663 Kaiserslautern, Germany
| | - Steffen Heinz
- Department of Molecular Plant Sciences, LMU Munich, 82152 Martinsried, Germany
| | - Wojciech Wietrzynski
- Department of Molecular Structural Biology, Max Planck Institute of Biochemistry, 82152 Martinsried, Germany; Helmholtz Pioneer Campus, Helmholtz Zentrum München, 85764 Neuherberg, Germany
| | - Norikazu Ohnishi
- Institute of Plant Science and Resources, Okayama University, Kurashiki, Okayama 710-0046, Japan
| | - Justus Niemeyer
- Molecular Biotechnology and Systems Biology, Technische Universität Kaiserslautern, 67663 Kaiserslautern, Germany
| | - Benjamin Spaniol
- Molecular Biotechnology and Systems Biology, Technische Universität Kaiserslautern, 67663 Kaiserslautern, Germany
| | - Miroslava Schaffer
- Department of Molecular Structural Biology, Max Planck Institute of Biochemistry, 82152 Martinsried, Germany
| | - Anna Rast
- Department of Molecular Structural Biology, Max Planck Institute of Biochemistry, 82152 Martinsried, Germany; Department of Molecular Plant Sciences, LMU Munich, 82152 Martinsried, Germany
| | - Matthias Ostermeier
- Department of Molecular Plant Sciences, LMU Munich, 82152 Martinsried, Germany
| | - Mike Strauss
- Department of Anatomy and Cell Biology, McGill University, Montreal, QC H3A 17C, Canada
| | - Jürgen M Plitzko
- Department of Molecular Structural Biology, Max Planck Institute of Biochemistry, 82152 Martinsried, Germany
| | - Wolfgang Baumeister
- Department of Molecular Structural Biology, Max Planck Institute of Biochemistry, 82152 Martinsried, Germany
| | - Till Rudack
- Biospectroscopy, Center for Protein Diagnostics (PRODI), Ruhr University Bochum, 44801 Bochum, Germany; Department of Biophysics, Faculty of Biology & Biotechnology, Ruhr University Bochum, 44780 Bochum, Germany
| | - Wataru Sakamoto
- Institute of Plant Science and Resources, Okayama University, Kurashiki, Okayama 710-0046, Japan
| | - Jörg Nickelsen
- Department of Molecular Plant Sciences, LMU Munich, 82152 Martinsried, Germany
| | - Jan M Schuller
- SYNMIKRO Research Center and Department of Chemistry, Philipps-University Marburg, 35032 Marburg, Germany.
| | - Michael Schroda
- Molecular Biotechnology and Systems Biology, Technische Universität Kaiserslautern, 67663 Kaiserslautern, Germany.
| | - Benjamin D Engel
- Department of Molecular Structural Biology, Max Planck Institute of Biochemistry, 82152 Martinsried, Germany; Helmholtz Pioneer Campus, Helmholtz Zentrum München, 85764 Neuherberg, Germany; Department of Chemistry, Technical University of Munich, 85748 Garching, Germany.
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17
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Siebenaller C, Schlösser L, Junglas B, Schmidt-Dengler M, Jacob D, Hellmann N, Sachse C, Helm M, Schneider D. Binding and/or hydrolysis of purine-based nucleotides is not required for IM30 ring formation. FEBS Lett 2021; 595:1876-1885. [PMID: 34060653 DOI: 10.1002/1873-3468.14140] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Revised: 04/30/2021] [Accepted: 05/20/2021] [Indexed: 11/09/2022]
Abstract
IM30, the inner membrane-associated protein of 30 kDa, is conserved in cyanobacteria and chloroplasts. Although its exact physiological function is still mysterious, IM30 is clearly essential for thylakoid membrane biogenesis and/or dynamics. Recently, a cryptic IM30 GTPase activity has been reported, albeit thus far no physiological function has been attributed to this. Yet, it is still possible that GTP binding/hydrolysis affects formation of the prototypical large homo-oligomeric IM30 ring and rod structures. Here, we show that the Synechocystis sp. PCC 6803 IM30 protein in fact is an NTPase that hydrolyzes GTP and ATP, but not CTP or UTP, with about identical rates. While IM30 forms large oligomeric ring complexes, nucleotide binding and/or hydrolysis are clearly not required for ring formation.
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Affiliation(s)
- Carmen Siebenaller
- Department of Chemistry, Biochemistry, Johannes Gutenberg University Mainz, Germany
| | - Lukas Schlösser
- Department of Chemistry, Biochemistry, Johannes Gutenberg University Mainz, Germany
| | - Benedikt Junglas
- Department of Chemistry, Biochemistry, Johannes Gutenberg University Mainz, Germany.,Ernst-Ruska Centre for Microscopy and Spectroscopy with Electrons (ER-C-3/Structural Biology), Forschungszentrum Jülich, Germany.,JuStruct: Jülich Center for Structural Biology, Forschungszentrum Jülich, Germany
| | - Martina Schmidt-Dengler
- Institute for Pharmaceutical and Biomedical Sciences, Johannes Gutenberg University Mainz, Germany
| | - Dominik Jacob
- Institute for Pharmaceutical and Biomedical Sciences, Johannes Gutenberg University Mainz, Germany
| | - Nadja Hellmann
- Department of Chemistry, Biochemistry, Johannes Gutenberg University Mainz, Germany
| | - Carsten Sachse
- Ernst-Ruska Centre for Microscopy and Spectroscopy with Electrons (ER-C-3/Structural Biology), Forschungszentrum Jülich, Germany.,JuStruct: Jülich Center for Structural Biology, Forschungszentrum Jülich, Germany
| | - Mark Helm
- Institute for Pharmaceutical and Biomedical Sciences, Johannes Gutenberg University Mainz, Germany
| | - Dirk Schneider
- Department of Chemistry, Biochemistry, Johannes Gutenberg University Mainz, Germany.,Institute of Molecular Physiology, Johannes Gutenberg University Mainz, Germany
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18
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Messant M, Krieger-Liszkay A, Shimakawa G. Dynamic Changes in Protein-Membrane Association for Regulating Photosynthetic Electron Transport. Cells 2021; 10:cells10051216. [PMID: 34065690 PMCID: PMC8155901 DOI: 10.3390/cells10051216] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2021] [Revised: 05/13/2021] [Accepted: 05/13/2021] [Indexed: 01/08/2023] Open
Abstract
Photosynthesis has to work efficiently in contrasting environments such as in shade and full sun. Rapid changes in light intensity and over-reduction of the photosynthetic electron transport chain cause production of reactive oxygen species, which can potentially damage the photosynthetic apparatus. Thus, to avoid such damage, photosynthetic electron transport is regulated on many levels, including light absorption in antenna, electron transfer reactions in the reaction centers, and consumption of ATP and NADPH in different metabolic pathways. Many regulatory mechanisms involve the movement of protein-pigment complexes within the thylakoid membrane. Furthermore, a certain number of chloroplast proteins exist in different oligomerization states, which temporally associate to the thylakoid membrane and modulate their activity. This review starts by giving a short overview of the lipid composition of the chloroplast membranes, followed by describing supercomplex formation in cyclic electron flow. Protein movements involved in the various mechanisms of non-photochemical quenching, including thermal dissipation, state transitions and the photosystem II damage–repair cycle are detailed. We highlight the importance of changes in the oligomerization state of VIPP and of the plastid terminal oxidase PTOX and discuss the factors that may be responsible for these changes. Photosynthesis-related protein movements and organization states of certain proteins all play a role in acclimation of the photosynthetic organism to the environment.
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Affiliation(s)
- Marine Messant
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Université Paris-Saclay, CEDEX, 91198 Gif-sur-Yvette, France;
| | - Anja Krieger-Liszkay
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Université Paris-Saclay, CEDEX, 91198 Gif-sur-Yvette, France;
- Correspondence:
| | - Ginga Shimakawa
- Research Center for Solar Energy Chemistry, Osaka University, 1-3 Machikaneyama, Toyonaka, Osaka 560-8531, Japan;
- Department of Bioscience, School of Biological and Environmental Sciences, Kwansei-Gakuin University, 2-1 Gakuen, Sanda, Hyogo 669-1337, Japan
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19
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Nymark M, Grønbech Hafskjold MC, Volpe C, Fonseca DDM, Sharma A, Tsirvouli E, Serif M, Winge P, Finazzi G, Bones AM. Functional studies of CpSRP54 in diatoms show that the mechanism of thylakoid protein insertion differs from that in plants and green algae. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2021; 106:113-132. [PMID: 33372269 DOI: 10.1111/tpj.15149] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Revised: 12/16/2020] [Accepted: 12/22/2020] [Indexed: 06/12/2023]
Abstract
The chloroplast signal recognition particle 54 kDa (CpSRP54) protein is a member of the CpSRP pathway known to target proteins to thylakoid membranes in plants and green algae. Loss of CpSRP54 in the marine diatom Phaeodactylum tricornutum lowers the accumulation of a selection of chloroplast-encoded subunits of photosynthetic complexes, indicating a role in the co-translational part of the CpSRP pathway. In contrast to plants and green algae, absence of CpSRP54 does not have a negative effect on the content of light-harvesting antenna complex proteins and pigments in P. tricornutum, indicating that the diatom CpSRP54 protein has not evolved to function in the post-translational part of the CpSRP pathway. Cpsrp54 KO mutants display altered photophysiological responses, with a stronger induction of photoprotective mechanisms and lower growth rates compared to wild type when exposed to increased light intensities. Nonetheless, their phenotype is relatively mild, thanks to the activation of mechanisms alleviating the loss of CpSRP54, involving upregulation of chaperones. We conclude that plants, green algae, and diatoms have evolved differences in the pathways for co-translational and post-translational insertion of proteins into the thylakoid membranes.
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Affiliation(s)
- Marianne Nymark
- Department of Biology, Norwegian University of Science and Technology, Trondheim, N-7491, Norway
| | - Marthe Caroline Grønbech Hafskjold
- Department of Biology, Norwegian University of Science and Technology, Trondheim, N-7491, Norway
- Department of Biotechnology and Food Science, Norwegian University of Science and Technology, Trondheim, N-7491, Norway
| | - Charlotte Volpe
- Department of Biotechnology and Food Science, Norwegian University of Science and Technology, Trondheim, N-7491, Norway
| | - Davi de Miranda Fonseca
- Department of Clinical and Molecular Medicine, Norwegian University of Science and Technology, NTNU, Trondheim, N-7491, Norway
- Proteomics and Modomics Experimental Core Facility (PROMEC), NTNU and Central Administration, St Olavs Hospital, The University Hospital in Trondheim, Trondheim, Norway
| | - Animesh Sharma
- Department of Clinical and Molecular Medicine, Norwegian University of Science and Technology, NTNU, Trondheim, N-7491, Norway
- Proteomics and Modomics Experimental Core Facility (PROMEC), NTNU and Central Administration, St Olavs Hospital, The University Hospital in Trondheim, Trondheim, Norway
| | - Eirini Tsirvouli
- Department of Biology, Norwegian University of Science and Technology, Trondheim, N-7491, Norway
| | - Manuel Serif
- Department of Biology, Norwegian University of Science and Technology, Trondheim, N-7491, Norway
| | - Per Winge
- Department of Biology, Norwegian University of Science and Technology, Trondheim, N-7491, Norway
| | - Giovanni Finazzi
- Université Grenoble Alpes (UGA), Laboratoire de Physiologie Cellulaire et Végétale, UMR 5168, Centre National de la Recherche Scientifique (CNRS), Commissariat à l'Energie Atomique et aux Energies Alternatives (CEA), Interdisciplinary Research Institute of Grenoble (IRIG), CEA-Grenoble, Grenoble, 38000, France
| | - Atle Magnar Bones
- Department of Biology, Norwegian University of Science and Technology, Trondheim, N-7491, Norway
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20
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Junglas B, Orru R, Axt A, Siebenaller C, Steinchen W, Heidrich J, Hellmich UA, Hellmann N, Wolf E, Weber SAL, Schneider D. IM30 IDPs form a membrane-protective carpet upon super-complex disassembly. Commun Biol 2020; 3:595. [PMID: 33087858 PMCID: PMC7577978 DOI: 10.1038/s42003-020-01314-4] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Accepted: 09/22/2020] [Indexed: 12/26/2022] Open
Abstract
Members of the phage shock protein A (PspA) family, including the inner membrane-associated protein of 30 kDa (IM30), are suggested to stabilize stressed cellular membranes. Furthermore, IM30 is essential in thylakoid membrane-containing chloroplasts and cyanobacteria, where it is involved in membrane biogenesis and/or remodeling. While it is well known that PspA and IM30 bind to membranes, the mechanism of membrane stabilization is still enigmatic. Here we report that ring-shaped IM30 super-complexes disassemble on membranes, resulting in formation of a membrane-protecting protein carpet. Upon ring dissociation, the C-terminal domain of IM30 unfolds, and the protomers self-assemble on membranes. IM30 assemblies at membranes have been observed before in vivo and were associated with stress response in cyanobacteria and chloroplasts. These assemblies likely correspond to the here identified carpet structures. Our study defines the thus far enigmatic structural basis for the physiological function of IM30 and related proteins, including PspA, and highlights a hitherto unrecognized concept of membrane stabilization by intrinsically disordered proteins.
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Affiliation(s)
- Benedikt Junglas
- Department of Chemistry, Biochemistry, Johannes Gutenberg University Mainz, 55128, Mainz, Germany
| | - Roberto Orru
- Institute of Molecular Physiology, Johannes Gutenberg University Mainz, 55128, Mainz, Germany
| | - Amelie Axt
- Max Planck-Institute for Polymer Research, 55128, Mainz, Germany
- Institute of Physics, Johannes Gutenberg University Mainz, 55099, Mainz, Germany
| | - Carmen Siebenaller
- Department of Chemistry, Biochemistry, Johannes Gutenberg University Mainz, 55128, Mainz, Germany
| | - Wieland Steinchen
- Philipps-University Marburg, Center for Synthetic Microbiology (SYNMIKRO) and Department of Chemistry, 35032, Marburg, Germany
| | - Jennifer Heidrich
- Department of Chemistry, Biochemistry, Johannes Gutenberg University Mainz, 55128, Mainz, Germany
| | - Ute A Hellmich
- Department of Chemistry, Biochemistry, Johannes Gutenberg University Mainz, 55128, Mainz, Germany
- Centre for Biomolecular Magnetic Resonance (BMRZ), Goethe-University Frankfurt, 60438, Frankfurt, Germany
| | - Nadja Hellmann
- Department of Chemistry, Biochemistry, Johannes Gutenberg University Mainz, 55128, Mainz, Germany
| | - Eva Wolf
- Institute of Molecular Physiology, Johannes Gutenberg University Mainz, 55128, Mainz, Germany
- Institute of Molecular Biology (IMB), 55128, Mainz, Germany
| | - Stefan A L Weber
- Max Planck-Institute for Polymer Research, 55128, Mainz, Germany
- Institute of Physics, Johannes Gutenberg University Mainz, 55099, Mainz, Germany
| | - Dirk Schneider
- Department of Chemistry, Biochemistry, Johannes Gutenberg University Mainz, 55128, Mainz, Germany.
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21
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Russo DA, Zedler JAZ. Genomic insights into cyanobacterial protein translocation systems. Biol Chem 2020; 402:39-54. [PMID: 33544489 DOI: 10.1515/hsz-2020-0247] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Accepted: 09/25/2020] [Indexed: 02/07/2023]
Abstract
Cyanobacteria are ubiquitous oxygenic photosynthetic bacteria with a versatile metabolism that is highly dependent on effective protein targeting. Protein sorting in diderm bacteria is not trivial and, in cyanobacteria, even less so due to the presence of a complex membrane system: the outer membrane, the plasma membrane and the thylakoid membrane. In cyanobacteria, protein import into the thylakoids is essential for photosynthesis, export to the periplasm fulfills a multifunctional role in maintaining cell homeostasis, and secretion mediates motility, DNA uptake and environmental interactions. Intriguingly, only one set of genes for the general secretory and the twin-arginine translocation pathways seem to be present. However, these systems have to operate in both plasma and thylakoid membranes. This raises the question of how substrates are recognized and targeted to their correct, final destination. Additional complexities arise when a protein has to be secreted across the outer membrane, where very little is known regarding the mechanisms involved. Given their ecological importance and biotechnological interest, a better understanding of protein targeting in cyanobacteria is of great value. This review will provide insights into the known knowns of protein targeting, propose hypotheses based on available genomic sequences and discuss future directions.
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Affiliation(s)
- David A Russo
- Bioorganic Analytics, Institute for Inorganic and Analytical Chemistry, Friedrich Schiller University Jena, D-07743 Jena, Germany
| | - Julie A Z Zedler
- Matthias Schleiden Institute for Genetics, Bioinformatics and Molecular Botany, Friedrich Schiller University Jena, Dornburgerstr. 159, D-07743 Jena, Germany
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22
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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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23
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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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Junglas B, Siebenaller C, Schlösser L, Hellmann N, Schneider D. GTP hydrolysis by Synechocystis IM30 does not decisively affect its membrane remodeling activity. Sci Rep 2020; 10:9793. [PMID: 32555292 PMCID: PMC7299955 DOI: 10.1038/s41598-020-66818-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2020] [Accepted: 05/26/2020] [Indexed: 01/28/2023] Open
Abstract
The function of IM30 (also known as Vipp1) is linked to protection and/or remodeling of the thylakoid membrane system in chloroplasts and cyanobacteria. Recently, it has been revealed that the Arabidopsis IM30 protein exhibits GTP hydrolyzing activity in vitro, which was unexpected, as IM30 does not show any classical GTPase features. In the present study, we addressed the question, whether an apparent GTPase activity is conserved in IM30 proteins and can also be observed for IM30 of the cyanobacterium Synechocystis sp. PCC 6803. We show that Synechocystis IM30 is indeed able to bind and hydrolyze GTP followed by the release of Pi. Yet, the apparent GTPase activity of Synechocystis IM30 does not depend on Mg2+, which, together with the lack of classical GTPase features, renders IM30 an atypical GTPase. To elucidate the impact of this cryptic GTPase activity on the membrane remodeling activity of IM30, we tested whether GTP hydrolysis influences IM30 membrane binding and/or IM30-mediated membrane fusion. We show that membrane remodeling by Synechocystis IM30 is slightly affected by nucleotides. Yet, despite IM30 clearly catalyzing GTP hydrolysis, this does not seem to be vital for its membrane remodeling function.
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Affiliation(s)
- Benedikt Junglas
- Department of Chemistry, Biochemistry, Johannes Gutenberg University Mainz, 55128, Mainz, Germany
| | - Carmen Siebenaller
- Department of Chemistry, Biochemistry, Johannes Gutenberg University Mainz, 55128, Mainz, Germany
| | - Lukas Schlösser
- Department of Chemistry, Biochemistry, Johannes Gutenberg University Mainz, 55128, Mainz, Germany
| | - Nadja Hellmann
- Department of Chemistry, Biochemistry, Johannes Gutenberg University Mainz, 55128, Mainz, Germany
| | - Dirk Schneider
- Department of Chemistry, Biochemistry, Johannes Gutenberg University Mainz, 55128, Mainz, Germany.
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Theis J, Niemeyer J, Schmollinger S, Ries F, Rütgers M, Gupta TK, Sommer F, Muranaka LS, Venn B, Schulz-Raffelt M, Willmund F, Engel BD, Schroda M. VIPP2 interacts with VIPP1 and HSP22E/F at chloroplast membranes and modulates a retrograde signal for HSP22E/F gene expression. PLANT, CELL & ENVIRONMENT 2020; 43:1212-1229. [PMID: 31994740 DOI: 10.1111/pce.13732] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/13/2018] [Revised: 01/22/2020] [Accepted: 01/23/2020] [Indexed: 06/10/2023]
Abstract
VIPP proteins aid thylakoid biogenesis and membrane maintenance in cyanobacteria, algae, and plants. Some members of the Chlorophyceae contain two VIPP paralogs termed VIPP1 and VIPP2, which originate from an early gene duplication event during the evolution of green algae. VIPP2 is barely expressed under nonstress conditions but accumulates in cells exposed to high light intensities or H2 O2 , during recovery from heat stress, and in mutants with defective integration (alb3.1) or translocation (secA) of thylakoid membrane proteins. Recombinant VIPP2 forms rod-like structures in vitro and shows a strong affinity for phosphatidylinositol phosphate. Under stress conditions, >70% of VIPP2 is present in membrane fractions and localizes to chloroplast membranes. A vipp2 knock-out mutant displays no growth phenotypes and no defects in the biogenesis or repair of photosystem II. However, after exposure to high light intensities, the vipp2 mutant accumulates less HSP22E/F and more LHCSR3 protein and transcript. This suggests that VIPP2 modulates a retrograde signal for the expression of nuclear genes HSP22E/F and LHCSR3. Immunoprecipitation of VIPP2 from solubilized cells and membrane-enriched fractions revealed major interactions with VIPP1 and minor interactions with HSP22E/F. Our data support a distinct role of VIPP2 in sensing and coping with chloroplast membrane stress.
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Affiliation(s)
- Jasmine Theis
- Molekulare Biotechnologie & Systembiologie, TU Kaiserslautern, Kaiserslautern, Germany
| | - Justus Niemeyer
- Molekulare Biotechnologie & Systembiologie, TU Kaiserslautern, Kaiserslautern, Germany
| | - Stefan Schmollinger
- Molekulare Biotechnologie & Systembiologie, TU Kaiserslautern, Kaiserslautern, Germany
| | - Fabian Ries
- Molecular Genetics of Eukaryotes, TU Kaiserslautern, Kaiserslautern, Germany
| | - Mark Rütgers
- Molekulare Biotechnologie & Systembiologie, TU Kaiserslautern, Kaiserslautern, Germany
| | - Tilak Kumar Gupta
- Department of Molecular Structural Biology, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Frederik Sommer
- Molekulare Biotechnologie & Systembiologie, TU Kaiserslautern, Kaiserslautern, Germany
| | | | - Benedikt Venn
- Molekulare Biotechnologie & Systembiologie, TU Kaiserslautern, Kaiserslautern, Germany
| | - Miriam Schulz-Raffelt
- Molekulare Biotechnologie & Systembiologie, TU Kaiserslautern, Kaiserslautern, Germany
| | - Felix Willmund
- Molecular Genetics of Eukaryotes, TU Kaiserslautern, Kaiserslautern, Germany
| | - Benjamin D Engel
- Department of Molecular Structural Biology, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Michael Schroda
- Molekulare Biotechnologie & Systembiologie, TU Kaiserslautern, Kaiserslautern, Germany
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Baers LL, Breckels LM, Mills LA, Gatto L, Deery MJ, Stevens TJ, Howe CJ, Lilley KS, Lea-Smith DJ. Proteome Mapping of a Cyanobacterium Reveals Distinct Compartment Organization and Cell-Dispersed Metabolism. PLANT PHYSIOLOGY 2019; 181:1721-1738. [PMID: 31578229 PMCID: PMC6878006 DOI: 10.1104/pp.19.00897] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/29/2019] [Accepted: 09/11/2019] [Indexed: 05/23/2023]
Abstract
Cyanobacteria are complex prokaryotes, incorporating a Gram-negative cell wall and internal thylakoid membranes (TMs). However, localization of proteins within cyanobacterial cells is poorly understood. Using subcellular fractionation and quantitative proteomics, we produced an extensive subcellular proteome map of an entire cyanobacterial cell, identifying ∼67% of proteins in Synechocystis sp. PCC 6803, ∼1000 more than previous studies. Assigned to six specific subcellular regions were 1,712 proteins. Proteins involved in energy conversion localized to TMs. The majority of transporters, with the exception of a TM-localized copper importer, resided in the plasma membrane (PM). Most metabolic enzymes were soluble, although numerous pathways terminated in the TM (notably those involved in peptidoglycan monomer, NADP+, heme, lipid, and carotenoid biosynthesis) or PM (specifically, those catalyzing lipopolysaccharide, molybdopterin, FAD, and phylloquinol biosynthesis). We also identified the proteins involved in the TM and PM electron transport chains. The majority of ribosomal proteins and enzymes synthesizing the storage compound polyhydroxybuyrate formed distinct clusters within the data, suggesting similar subcellular distributions to one another, as expected for proteins operating within multicomponent structures. Moreover, heterogeneity within membrane regions was observed, indicating further cellular complexity. Cyanobacterial TM protein localization was conserved in Arabidopsis (Arabidopsis thaliana) chloroplasts, suggesting similar proteome organization in more developed photosynthetic organisms. Successful application of this technique in Synechocystis suggests it could be applied to mapping the proteomes of other cyanobacteria and single-celled organisms. The organization of the cyanobacterial cell revealed here substantially aids our understanding of these environmentally and biotechnologically important organisms.
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Affiliation(s)
- Laura L Baers
- Department of Biochemistry, University of Cambridge, Cambridge CB2 1QW, United Kingdom
| | - Lisa M Breckels
- Department of Biochemistry, University of Cambridge, Cambridge CB2 1QW, United Kingdom
- Computational Proteomics Unit, Cambridge Centre for Proteomics, University of Cambridge, Cambridge CB2 1QW, United Kingdom
| | - Lauren A Mills
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, United Kingdom
| | - Laurent Gatto
- Department of Biochemistry, University of Cambridge, Cambridge CB2 1QW, United Kingdom
- Computational Proteomics Unit, Cambridge Centre for Proteomics, University of Cambridge, Cambridge CB2 1QW, United Kingdom
| | - Michael J Deery
- Department of Biochemistry, University of Cambridge, Cambridge CB2 1QW, United Kingdom
| | - Tim J Stevens
- MRC Laboratory of Molecular Biology, Cambridge CB2 0QH United Kingdom
| | - Christopher J Howe
- Department of Biochemistry, University of Cambridge, Cambridge CB2 1QW, United Kingdom
| | - Kathryn S Lilley
- Department of Biochemistry, University of Cambridge, Cambridge CB2 1QW, United Kingdom
| | - David J Lea-Smith
- Department of Biochemistry, University of Cambridge, Cambridge CB2 1QW, United Kingdom
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, United Kingdom
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Siebenaller C, Junglas B, Schneider D. Functional Implications of Multiple IM30 Oligomeric States. FRONTIERS IN PLANT SCIENCE 2019; 10:1500. [PMID: 31824532 PMCID: PMC6882379 DOI: 10.3389/fpls.2019.01500] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/21/2019] [Accepted: 10/29/2019] [Indexed: 05/03/2023]
Abstract
The inner membrane-associated protein of 30 kDa (IM30), also known as the vesicle-inducing protein in plastids 1 (Vipp1), is essential for photo-autotrophic growth of cyanobacteria, algae and higher plants. While its exact function still remains largely elusive, it is commonly accepted that IM30 is crucially involved in thylakoid membrane biogenesis, stabilization and/or maintenance. A characteristic feature of IM30 is its intrinsic propensity to form large homo-oligomeric protein complexes. 15 years ago, it has been reported that these supercomplexes have a ring-shaped structure. However, the in vivo significance of these ring structures is not finally resolved yet and the formation of more complex assemblies has been reported. We here present and discuss research on IM30 conducted within the past 25 years with a special emphasis on the question of why we potentially need IM30 supercomplexes in vivo.
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Affiliation(s)
| | | | - Dirk Schneider
- Department of Pharmacy and Biochemistry, Johannes Gutenberg University Mainz, Mainz, Germany
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Factors Controlling Floc Formation and Structure in the Cyanobacterium Synechocystis sp. Strain PCC 6803. J Bacteriol 2019; 201:JB.00344-19. [PMID: 31262837 PMCID: PMC6755745 DOI: 10.1128/jb.00344-19] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2019] [Accepted: 06/25/2019] [Indexed: 02/07/2023] Open
Abstract
Motile strains of the unicellular cyanobacterium Synechocystis sp. strain PCC 6803 readily aggregate into flocs, or floating multicellular assemblages, when grown in liquid culture. As described here, we used confocal imaging to probe the structure of these flocs, and we developed a quantitative assay for floc formation based on fluorescence imaging of 6-well plates. The flocs are formed from strands of linked cells, sometimes packed into dense clusters but also containing voids with very few cells. Cells within the dense clusters show signs of nutrient stress, as judged by the subcellular distribution of green fluorescent protein (GFP)-tagged Vipp1 protein. We analyzed the effects on flocculation of a series of mutations that alter piliation and motility, including Δhfq, ΔpilB1, ΔpilT1, and ΔushA mutations and deletion mutations affecting major and minor pilins. The extent of flocculation is increased in the hyperpiliated ΔpilT1 mutant, but active cycles of pilus extension and retraction are not required for flocculation. Deletion of PilA1, the major subunit of type IV pili, has no effect on flocculation; however, flocculation is lost in mutants lacking an operon coding for the minor pilins PilA9 to -11. Therefore, minor pilins appear crucial for flocculation. We show that flocculation is a tightly regulated process that is promoted by blue light perception by the cyanobacteriochrome Cph2. Floc formation also seems to be a highly cooperative process. A proportion of nonflocculating Δhfq cells can be incorporated into wild-type flocs, but the presence of a high proportion of Δhfq cells disrupts the large-scale architecture of the floc.IMPORTANCE Some bacteria form flocs, which are multicellular floating assemblages of many thousands of cells. Flocs have been relatively little studied compared to surface-adherent biofilms, but flocculation could play many physiological roles, be a crucial factor in marine carbon burial, and enable more efficient biotechnological cell harvesting. We studied floc formation and architecture in the model cyanobacterium Synechocystis sp. strain PCC 6803, using mutants to identify specific cell surface structures required for floc formation. We show that floc formation is regulated by blue and green light perceived by the photoreceptor Cph2. The flocs have a characteristic structure based on strands of linked cells aggregating into dense clusters. Cells within the dense clusters show signs of nutrient stress, pointing to a disadvantage of floc formation.
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Thurotte A, Schneider D. The Fusion Activity of IM30 Rings Involves Controlled Unmasking of the Fusogenic Core. FRONTIERS IN PLANT SCIENCE 2019; 10:108. [PMID: 30792728 PMCID: PMC6374351 DOI: 10.3389/fpls.2019.00108] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Accepted: 01/23/2019] [Indexed: 05/20/2023]
Abstract
The inner membrane-associated protein of 30 kDa (IM30, also known as Vipp1) is required for thylakoid membrane biogenesis and maintenance in cyanobacteria and chloroplasts. The protein forms large rings of ∼2 MDa and triggers membrane fusion in presence of Mg2+. Based on the here presented observations, IM30 rings are built from dimers of dimers, and formation of these tetrameric building blocks is driven by interactions of the central coiled-coil, formed by helices 2 and 3, and stabilized via additional interactions mainly involving helix 1. Furthermore, helix 1 as well as C-terminal regions of IM30 together negatively regulate ring-ring contacts. We propose that IM30 rings represent the inactive form of IM30, and upon binding to negatively charged membrane surfaces, the here identified fusogenic core of IM30 rings eventually interacts with the lipid bilayer, resulting in membrane destabilization and membrane fusion. Unmasking of the IM30 fusogenic core likely is controlled by Mg2+, which triggers rearrangement of the IM30 ring structure.
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30
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Leake MC. Transcription factors in eukaryotic cells can functionally regulate gene expression by acting in oligomeric assemblies formed from an intrinsically disordered protein phase transition enabled by molecular crowding. Transcription 2018; 9:298-306. [PMID: 29895219 PMCID: PMC6150617 DOI: 10.1080/21541264.2018.1475806] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
High-speed single-molecule fluorescence microscopy in vivo shows that transcription factors in eukaryotes can act in oligomeric clusters mediated by molecular crowding and intrinsically disordered protein. This finding impacts on the longstanding puzzle of how transcription factors find their gene targets so efficiently in the complex, heterogeneous environment of the cell. Abbreviations CDF - cumulative distribution function; FRAP - fluorescence recovery after photobleaching; GFP - Green fluorescent protein; STORM - stochastic optical reconstruction microscopy; TF - Transcription factor; YFP - Yellow fluorescent protein
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Affiliation(s)
- Mark C Leake
- a Departments of Physics and Biology , Biological Physical Sciences Institute, University of York , York , UK
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31
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Heidrich J, Junglas B, Grytsyk N, Hellmann N, Rusitzka K, Gebauer W, Markl J, Hellwig P, Schneider D. Mg 2+ binding triggers rearrangement of the IM30 ring structure, resulting in augmented exposure of hydrophobic surfaces competent for membrane binding. J Biol Chem 2018; 293:8230-8241. [PMID: 29618510 DOI: 10.1074/jbc.ra117.000991] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2017] [Revised: 03/20/2018] [Indexed: 12/24/2022] Open
Abstract
The "inner membrane-associated protein of 30 kDa" (IM30), also known as "vesicle-inducing protein in plastids 1" (Vipp1), is found in the majority of photosynthetic organisms that use oxygen as an energy source, and its occurrence appears to be coupled to the existence of thylakoid membranes in cyanobacteria and chloroplasts. IM30 is most likely involved in thylakoid membrane biogenesis and/or maintenance, and has recently been shown to function as a membrane fusion protein in presence of Mg2+ However, the precise role of Mg2+ in this process and its impact on the structure and function of IM30 remains unknown. Here, we show that Mg2+ binds directly to IM30 with a binding affinity of ∼1 mm Mg2+ binding compacts the IM30 structure coupled with an increase in the thermodynamic stability of the proteins' secondary, tertiary, and quaternary structures. Furthermore, the structural alterations trigger IM30 double ring formation in vitro because of increased exposure of hydrophobic surface regions. However, in vivo Mg2+-triggered exposure of hydrophobic surface regions most likely modulates membrane binding and induces membrane fusion.
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Affiliation(s)
- Jennifer Heidrich
- Institut für Pharmazie und Biochemie, Johannes-Gutenberg-Universität Mainz, 55128 Mainz, Germany
| | - Benedikt Junglas
- Institut für Pharmazie und Biochemie, Johannes-Gutenberg-Universität Mainz, 55128 Mainz, Germany
| | - Natalia Grytsyk
- Laboratoire de bioelectrochimie et spectroscopie, UMR 7140, CNRS Université de Strasbourg, 1 rue Blaise Pascal, 67000 Strasbourg, Germany
| | - Nadja Hellmann
- Institut für Pharmazie und Biochemie, Johannes-Gutenberg-Universität Mainz, 55128 Mainz, Germany
| | - Kristiane Rusitzka
- Institut für Molekulare Physiologie, Johannes Gutenberg-Universität Mainz, 55128 Mainz, Germany
| | - Wolfgang Gebauer
- Institut für Molekulare Physiologie, Johannes Gutenberg-Universität Mainz, 55128 Mainz, Germany
| | - Jürgen Markl
- Institut für Molekulare Physiologie, Johannes Gutenberg-Universität Mainz, 55128 Mainz, Germany
| | - Petra Hellwig
- Laboratoire de bioelectrochimie et spectroscopie, UMR 7140, CNRS Université de Strasbourg, 1 rue Blaise Pascal, 67000 Strasbourg, Germany
| | - Dirk Schneider
- Institut für Pharmazie und Biochemie, Johannes-Gutenberg-Universität Mainz, 55128 Mainz, Germany.
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Affiliation(s)
- Benedikt Junglas
- Institut für Pharmazie und Biochemie; Johannes Gutenberg-Universität Mainz; Mainz Germany
| | - Dirk Schneider
- Institut für Pharmazie und Biochemie; Johannes Gutenberg-Universität Mainz; Mainz Germany
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Gutu A, Chang F, O'Shea EK. Dynamical localization of a thylakoid membrane binding protein is required for acquisition of photosynthetic competency. Mol Microbiol 2018; 108:16-31. [PMID: 29357135 PMCID: PMC5910887 DOI: 10.1111/mmi.13912] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2017] [Accepted: 01/02/2018] [Indexed: 11/29/2022]
Abstract
Vipp1 is highly conserved and essential for photosynthesis, but its function is unclear as it does not participate directly in light-dependent reactions. We analyzed Vipp1 localization in live cyanobacterial cells and show that Vipp1 is highly dynamic, continuously exchanging between a diffuse fraction that is uniformly distributed throughout the cell and a punctate fraction that is concentrated at high curvature regions of the thylakoid located at the cell periphery. Experimentally perturbing the spatial distribution of Vipp1 by relocalizing it to the nucleoid causes a severe growth defect during the transition from non-photosynthetic (dark) to photosynthetic (light) growth. However, the same perturbation of Vipp1 in dark alone or light alone growth conditions causes no growth or thylakoid morphology defects. We propose that the punctuated dynamics of Vipp1 at the cell periphery in regions of high thylakoid curvature enable acquisition of photosynthetic competency, perhaps by facilitating biogenesis of photosynthetic complexes involved in light-dependent reactions of photosynthesis.
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Affiliation(s)
- Andrian Gutu
- Howard Hughes Medical Institute, Harvard University Faculty of Arts and Sciences Center for Systems Biology, Cambridge, MA 02138, USA.,Department of Molecular and Cellular Biology, Harvard University Faculty of Arts and Sciences, Cambridge, MA 02138, USA.,Department of Chemistry and Chemical Biology, Harvard University Faculty of Arts and Sciences Center for Systems Biology, Cambridge, MA 02138, USA
| | - Frederick Chang
- Department of Molecular and Cellular Biology, Harvard University Faculty of Arts and Sciences, Cambridge, MA 02138, USA
| | - Erin K O'Shea
- Howard Hughes Medical Institute, Harvard University Faculty of Arts and Sciences Center for Systems Biology, Cambridge, MA 02138, USA.,Department of Molecular and Cellular Biology, Harvard University Faculty of Arts and Sciences, Cambridge, MA 02138, USA.,Department of Chemistry and Chemical Biology, Harvard University Faculty of Arts and Sciences Center for Systems Biology, Cambridge, MA 02138, USA
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Miller H, Zhou Z, Shepherd J, Wollman AJM, Leake MC. Single-molecule techniques in biophysics: a review of the progress in methods and applications. REPORTS ON PROGRESS IN PHYSICS. PHYSICAL SOCIETY (GREAT BRITAIN) 2018; 81:024601. [PMID: 28869217 DOI: 10.1088/1361-6633/aa8a02] [Citation(s) in RCA: 70] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Single-molecule biophysics has transformed our understanding of biology, but also of the physics of life. More exotic than simple soft matter, biomatter lives far from thermal equilibrium, covering multiple lengths from the nanoscale of single molecules to up to several orders of magnitude higher in cells, tissues and organisms. Biomolecules are often characterized by underlying instability: multiple metastable free energy states exist, separated by levels of just a few multiples of the thermal energy scale k B T, where k B is the Boltzmann constant and T absolute temperature, implying complex inter-conversion kinetics in the relatively hot, wet environment of active biological matter. A key benefit of single-molecule biophysics techniques is their ability to probe heterogeneity of free energy states across a molecular population, too challenging in general for conventional ensemble average approaches. Parallel developments in experimental and computational techniques have catalysed the birth of multiplexed, correlative techniques to tackle previously intractable biological questions. Experimentally, progress has been driven by improvements in sensitivity and speed of detectors, and the stability and efficiency of light sources, probes and microfluidics. We discuss the motivation and requirements for these recent experiments, including the underpinning mathematics. These methods are broadly divided into tools which detect molecules and those which manipulate them. For the former we discuss the progress of super-resolution microscopy, transformative for addressing many longstanding questions in the life sciences, and for the latter we include progress in 'force spectroscopy' techniques that mechanically perturb molecules. We also consider in silico progress of single-molecule computational physics, and how simulation and experimentation may be drawn together to give a more complete understanding. Increasingly, combinatorial techniques are now used, including correlative atomic force microscopy and fluorescence imaging, to probe questions closer to native physiological behaviour. We identify the trade-offs, limitations and applications of these techniques, and discuss exciting new directions.
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Affiliation(s)
- Helen Miller
- Clarendon Laboratory, Department of Physics, University of Oxford, Oxford, OX1 3PU, United Kingdom
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Kirchhoff H. Structure-function relationships in photosynthetic membranes: Challenges and emerging fields. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2018; 266:76-82. [PMID: 29241569 DOI: 10.1016/j.plantsci.2017.09.021] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2017] [Revised: 09/26/2017] [Accepted: 09/29/2017] [Indexed: 05/17/2023]
Abstract
Oxygenic photosynthesis is a fundamental biological process that shaped the earth's biosphere. The process of energy transformation is hosted in highly specialized thylakoid membranes that adjust their architecture in response to environmental cues at different structural levels leading to the adjustment of photosynthetic functions. This review presents structure-function dynamics ranging from the whole membrane system over the mesoscopic level (protein ensembles) down to interactions between lipids and protein complexes. On the whole membrane level, thylakoid membranes constantly change their overall shape (e.g. membranes swell and shrink or destack and stack) that controls vital functions of energy transformation. Furthermore, the physical connection and transition between stacked grana thylakoid and unstacked membrane regions that determines mass transport between these sub-compartments is a crucial open question. On the mesoscopic level, it turns out that reorganizations between disordered and ordered protein arrangements is central for light harvesting and lateral diffusion processes. It has to be unraveled how changes in mesoscopic protein organization are controlled. Finally, dynamic physicochemical properties of the lipid bilayer can determine the structure and organization of photosynthetic membrane proteins, a field that is highly neglected so far. This review focusses on open questions and challenging problems in photosynthesis research.
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Affiliation(s)
- Helmut Kirchhoff
- Institute of Biological Chemistry, Washington State University, P.O. Box 646340, Pullman, 99164, WA, USA.
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37
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Shashkova S, Leake MC. Single-molecule fluorescence microscopy review: shedding new light on old problems. Biosci Rep 2017; 37:BSR20170031. [PMID: 28694303 PMCID: PMC5520217 DOI: 10.1042/bsr20170031] [Citation(s) in RCA: 147] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2017] [Revised: 07/08/2017] [Accepted: 07/10/2017] [Indexed: 12/19/2022] Open
Abstract
Fluorescence microscopy is an invaluable tool in the biosciences, a genuine workhorse technique offering exceptional contrast in conjunction with high specificity of labelling with relatively minimal perturbation to biological samples compared with many competing biophysical techniques. Improvements in detector and dye technologies coupled to advances in image analysis methods have fuelled recent development towards single-molecule fluorescence microscopy, which can utilize light microscopy tools to enable the faithful detection and analysis of single fluorescent molecules used as reporter tags in biological samples. For example, the discovery of GFP, initiating the so-called 'green revolution', has pushed experimental tools in the biosciences to a completely new level of functional imaging of living samples, culminating in single fluorescent protein molecule detection. Today, fluorescence microscopy is an indispensable tool in single-molecule investigations, providing a high signal-to-noise ratio for visualization while still retaining the key features in the physiological context of native biological systems. In this review, we discuss some of the recent discoveries in the life sciences which have been enabled using single-molecule fluorescence microscopy, paying particular attention to the so-called 'super-resolution' fluorescence microscopy techniques in live cells, which are at the cutting-edge of these methods. In particular, how these tools can reveal new insights into long-standing puzzles in biology: old problems, which have been impossible to tackle using other more traditional tools until the emergence of new single-molecule fluorescence microscopy techniques.
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Affiliation(s)
- Sviatlana Shashkova
- Department of Physics, Biological Physical Sciences Institute (BPSI), University of York, York YO10 5DD, U.K
- Department of Biology, Biological Physical Sciences Institute (BPSI), University of York, York YO10 5DD, U.K
| | - Mark C Leake
- Department of Physics, Biological Physical Sciences Institute (BPSI), University of York, York YO10 5DD, U.K.
- Department of Biology, Biological Physical Sciences Institute (BPSI), University of York, York YO10 5DD, U.K
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38
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Lee A, Tsekouras K, Calderon C, Bustamante C, Pressé S. Unraveling the Thousand Word Picture: An Introduction to Super-Resolution Data Analysis. Chem Rev 2017; 117:7276-7330. [PMID: 28414216 PMCID: PMC5487374 DOI: 10.1021/acs.chemrev.6b00729] [Citation(s) in RCA: 65] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Super-resolution microscopy provides direct insight into fundamental biological processes occurring at length scales smaller than light's diffraction limit. The analysis of data at such scales has brought statistical and machine learning methods into the mainstream. Here we provide a survey of data analysis methods starting from an overview of basic statistical techniques underlying the analysis of super-resolution and, more broadly, imaging data. We subsequently break down the analysis of super-resolution data into four problems: the localization problem, the counting problem, the linking problem, and what we've termed the interpretation problem.
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Affiliation(s)
- Antony Lee
- Department of Physics, University of California at Berkeley, Berkeley, California 94720, United States
- Jason L. Choy Laboratory of Single-Molecule Biophysics, University of California at Berkeley, Berkeley, California 94720, United States
| | - Konstantinos Tsekouras
- Department of Physics, University of California at Berkeley, Berkeley, California 94720, United States
- Department of Physics, Arizona State University, Tempe, Arizona 85287, United States
| | | | - Carlos Bustamante
- Jason L. Choy Laboratory of Single-Molecule Biophysics, University of California at Berkeley, Berkeley, California 94720, United States
- Biophysics Graduate Group, University of California at Berkeley, Berkeley, California 94720, United States
- Institute for Quantitative Biosciences-QB3, University of California at Berkeley, Berkeley, California 94720, United States
- Department of Molecular and Cell Biology, University of California at Berkeley, Berkeley, California 94720, United States
- Department of Chemistry, University of California at Berkeley, Berkeley, California 94720, United States
- Howard Hughes Medical Institute, University of California at Berkeley, Berkeley, California 94720, United States
- Kavli Energy Nanosciences Institute, University of California at Berkeley, Berkeley, California 94720, United States
| | - Steve Pressé
- Department of Physics, University of California at Berkeley, Berkeley, California 94720, United States
- Department of Chemistry and Chemical Biology, Indiana University–Purdue University Indianapolis, Indianapolis, Indiana 46202, United States
- Department of Cell and Integrative Physiology, Indiana University School of Medicine, Indianapolis, Indiana 46202, United States
- School of Molecular Sciences, Arizona State University, Tempe, Arizona 85287, United States
- Department of Physics, Arizona State University, Tempe, Arizona 85287, United States
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39
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Thurotte A, Brüser T, Mascher T, Schneider D. Membrane chaperoning by members of the PspA/IM30 protein family. Commun Integr Biol 2017. [PMCID: PMC5333519 DOI: 10.1080/19420889.2016.1264546] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
PspA, IM30 (Vipp1) and LiaH, which all belong to the PspA/IM30 protein family, form high molecular weight oligomeric structures. For all proteins membrane binding and protection of the membrane structure and integrity has been shown or postulated. Here we discuss the possible membrane chaperoning activity of PspA, IM30 and LiaH and propose that larger oligomeric structures bind to stressed membrane regions, followed by oligomer disassembly and membrane stabilization by protein monomers or smaller/different oligomeric scaffolds.
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Affiliation(s)
- Adrien Thurotte
- Institut für Pharmazie und Biochemie, Johannes Gutenberg-Universität Mainz, Mainz, Germany
| | - Thomas Brüser
- Institut für Mikrobiologie, Leibniz Universität Hannover, Hannover, Germany
| | - Thorsten Mascher
- Institut für Mikrobiologie, Technische Universität Dresden, Dresden, Germany
| | - Dirk Schneider
- Institut für Pharmazie und Biochemie, Johannes Gutenberg-Universität Mainz, Mainz, Germany
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Structure and function of PspA and Vipp1 N-terminal peptides: Insights into the membrane stress sensing and mitigation. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2017; 1859:28-39. [DOI: 10.1016/j.bbamem.2016.10.018] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2016] [Revised: 10/18/2016] [Accepted: 10/27/2016] [Indexed: 12/20/2022]
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41
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Hennig R, West A, Debus M, Saur M, Markl J, Sachs JN, Schneider D. The IM30/Vipp1 C-terminus associates with the lipid bilayer and modulates membrane fusion. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2016; 1858:126-136. [PMID: 27836697 DOI: 10.1016/j.bbabio.2016.11.004] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2016] [Revised: 11/04/2016] [Accepted: 11/05/2016] [Indexed: 11/17/2022]
Abstract
IM30/Vipp1 proteins are crucial for thylakoid membrane biogenesis in chloroplasts and cyanobacteria. A characteristic C-terminal extension distinguishes these proteins from the homologous bacterial PspA proteins, and this extension has been discussed to be key for the IM30/Vipp1 activity. Here we report that the extension of the Synechocystis IM30 protein is indispensable, and argue that both, the N-terminal PspA-domain as well as the C-terminal extension are needed in order for the IM30 protein to conduct its in vivo function. In vitro, we show that the PspA-domain of IM30 is vital for stability/folding and oligomer formation of IM30 as well as for IM30-triggered membrane fusion. In contrast, the IM30 C-terminal domain is involved in and necessary to stabilize defined contacts to negatively charged membrane surfaces, and to modulate the IM30-induced membrane fusion activity. Although the two IM30 protein domains have distinct functional roles, only together they enable IM30 to work properly.
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Affiliation(s)
- Raoul Hennig
- Institut für Pharmazie und Biochemie, Johannes Gutenberg-Universität Mainz, 55128 Mainz, Germany
| | - Ana West
- Department of Biomedical Engineering, University of Minnesota, Twin Cities, MN, USA
| | - Martina Debus
- Institut für Pharmazie und Biochemie, Johannes Gutenberg-Universität Mainz, 55128 Mainz, Germany
| | - Michael Saur
- Institut für Zoologie, Johannes Gutenberg-Universität Mainz, 55128 Mainz, Germany
| | - Jürgen Markl
- Institut für Zoologie, Johannes Gutenberg-Universität Mainz, 55128 Mainz, Germany
| | - Jonathan N Sachs
- Department of Biomedical Engineering, University of Minnesota, Twin Cities, MN, USA
| | - Dirk Schneider
- Institut für Pharmazie und Biochemie, Johannes Gutenberg-Universität Mainz, 55128 Mainz, Germany.
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42
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Wollman AJM, Miller H, Foster S, Leake MC. An automated image analysis framework for segmentation and division plane detection of single liveStaphylococcus aureuscells which can operate at millisecond sampling time scales using bespoke Slimfield microscopy. Phys Biol 2016; 13:055002. [DOI: 10.1088/1478-3975/13/5/055002] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Heidrich J, Thurotte A, Schneider D. Specific interaction of IM30/Vipp1 with cyanobacterial and chloroplast membranes results in membrane remodeling and eventually in membrane fusion. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2016; 1859:537-549. [PMID: 27693914 DOI: 10.1016/j.bbamem.2016.09.025] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2016] [Revised: 09/19/2016] [Accepted: 09/21/2016] [Indexed: 12/22/2022]
Abstract
The photosynthetic light reaction takes place within the thylakoid membrane system in cyanobacteria and chloroplasts. Besides its global importance, the biogenesis, maintenance and dynamics of this membrane system are still a mystery. In the last two decades, strong evidence supported the idea that these processes involve IM30, the inner membrane-associated protein of 30kDa, a protein also known as the vesicle-inducing protein in plastids 1 (Vipp1). Even though we just only begin to understand the precise physiological function of this protein, it is clear that interaction of IM30 with membranes is crucial for biogenesis of thylakoid membranes. Here we summarize and discuss forces guiding IM30-membrane interactions, as the membrane properties as well as the oligomeric state of IM30 appear to affect proper interaction of IM30 with membrane surfaces. Interaction of IM30 with membranes results in an altered membrane structure and can finally trigger fusion of adjacent membranes, when Mg2+ is present. Based on recent results, we finally present a model summarizing individual steps involved in IM30-mediated membrane fusion. This article is part of a Special Issue entitled: Lipid order/lipid defects and lipid-control of protein activity edited by Dirk Schneider.
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Affiliation(s)
- Jennifer Heidrich
- Institute of Pharmacy and Biochemistry, Johannes Gutenberg-University Mainz, Johann-Joachim-Becher-Weg 30, 55128 Mainz, Germany
| | - Adrien Thurotte
- Institute of Pharmacy and Biochemistry, Johannes Gutenberg-University Mainz, Johann-Joachim-Becher-Weg 30, 55128 Mainz, Germany
| | - Dirk Schneider
- Institute of Pharmacy and Biochemistry, Johannes Gutenberg-University Mainz, Johann-Joachim-Becher-Weg 30, 55128 Mainz, Germany.
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44
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Santamaría-Gómez J, Ochoa de Alda JAG, Olmedo-Verd E, Bru-Martínez R, Luque I. Sub-Cellular Localization and Complex Formation by Aminoacyl-tRNA Synthetases in Cyanobacteria: Evidence for Interaction of Membrane-Anchored ValRS with ATP Synthase. Front Microbiol 2016; 7:857. [PMID: 27375579 PMCID: PMC4893482 DOI: 10.3389/fmicb.2016.00857] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2016] [Accepted: 05/23/2016] [Indexed: 01/09/2023] Open
Abstract
tRNAs are charged with cognate amino acids by aminoacyl-tRNA synthetases (aaRSs) and subsequently delivered to the ribosome to be used as substrates for gene translation. Whether aminoacyl-tRNAs are channeled to the ribosome by transit within translational complexes that avoid their diffusion in the cytoplasm is a matter of intense investigation in organisms of the three domains of life. In the cyanobacterium Anabaena sp. PCC 7120, the valyl-tRNA synthetase (ValRS) is anchored to thylakoid membranes by means of the CAAD domain. We have investigated whether in this organism ValRS could act as a hub for the nucleation of a translational complex by attracting other aaRSs to the membranes. Out of the 20 aaRSs, only ValRS was found to localize in thylakoid membranes whereas the other enzymes occupied the soluble portion of the cytoplasm. To investigate the basis for this asymmetric distribution of aaRSs, a global search for proteins interacting with the 20 aaRSs was conducted. The interaction between ValRS and the FoF1 ATP synthase complex here reported is of utmost interest and suggests a functional link between elements of the gene translation and energy production machineries.
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Affiliation(s)
- Javier Santamaría-Gómez
- Instituto de Bioquímica Vegetal y Fotosíntesis, Consejo Superior de Investigaciones Científicas and Universidad de SevillaSeville, Spain
| | | | - Elvira Olmedo-Verd
- Instituto de Bioquímica Vegetal y Fotosíntesis, Consejo Superior de Investigaciones Científicas and Universidad de SevillaSeville, Spain
| | - Roque Bru-Martínez
- Department of Agrochemistry and Biochemistry, Faculty of Science, University of AlicanteAlicante, Spain
| | - Ignacio Luque
- Instituto de Bioquímica Vegetal y Fotosíntesis, Consejo Superior de Investigaciones Científicas and Universidad de SevillaSeville, Spain
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Wollman AJM, Leake MC. Single-Molecule Narrow-Field Microscopy of Protein-DNA Binding Dynamics in Glucose Signal Transduction of Live Yeast Cells. Methods Mol Biol 2016; 1431:5-15. [PMID: 27283298 DOI: 10.1007/978-1-4939-3631-1_2] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Single-molecule narrow-field microscopy is a versatile tool to investigate a diverse range of protein dynamics in live cells and has been extensively used in bacteria. Here, we describe how these methods can be extended to larger eukaryotic, yeast cells, which contain subcellular compartments. We describe how to obtain single-molecule microscopy data but also how to analyze these data to track and obtain the stoichiometry of molecular complexes diffusing in the cell. We chose glucose mediated signal transduction of live yeast cells as the system to demonstrate these single-molecule techniques as transcriptional regulation is fundamentally a single-molecule problem-a single repressor protein binding a single binding site in the genome can dramatically alter behavior at the whole cell and population level.
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Affiliation(s)
- Adam J M Wollman
- Biological Physical Sciences Institute (BPSI), University of York, Heslington, York, YO10 5DD, UK.
| | - Mark C Leake
- Biological Physical Sciences Institute (BPSI), University of York, Heslington, York, YO10 5DD, UK
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46
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Using Fluorescence Recovery After Photobleaching (FRAP) to Study Dynamics of the Structural Maintenance of Chromosome (SMC) Complex In Vivo. Methods Mol Biol 2016; 1431:37-46. [PMID: 27283300 DOI: 10.1007/978-1-4939-3631-1_4] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The SMC complex, MukBEF, is important for chromosome organization and segregation in Escherichia coli. Fluorescently tagged MukBEF forms distinct spots (or "foci") in the cell, where it is thought to carry out most of its chromosome associated activities. This chapter outlines the technique of Fluorescence Recovery After Photobleaching (FRAP) as a method to study the properties of YFP-tagged MukB in fluorescent foci. This method can provide important insight into the dynamics of MukB on DNA and be used to study its biochemical properties in vivo.
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47
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Selão TT, Zhang L, Knoppová J, Komenda J, Norling B. Photosystem II Assembly Steps Take Place in the Thylakoid Membrane of the Cyanobacterium Synechocystis sp. PCC6803. PLANT & CELL PHYSIOLOGY 2016; 57:95-104. [PMID: 26578692 DOI: 10.1093/pcp/pcv178] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/23/2015] [Accepted: 11/09/2015] [Indexed: 05/09/2023]
Abstract
Thylakoid biogenesis is an intricate process requiring accurate and timely assembly of proteins, pigments and other cofactors into functional, photosynthetically competent membranes. PSII assembly is studied in particular as its core protein, D1, is very susceptible to photodamage and has a high turnover rate, particularly in high light. PSII assembly is a modular process, with assembly steps proceeding in a specific order. Using aqueous two-phase partitioning to separate plasma membranes (PM) and thylakoid membranes (TM), we studied the subcellular localization of the early assembly steps for PSII biogenesis in a Synechocystis sp. PCC6803 cyanobacterium strain lacking the CP47 antenna. This strain accumulates the early D1-D2 assembly complex which was localized in TM along with associated PSII assembly factors. We also followed insertion and processing of the D1 precursor (pD1) by radioactive pulse-chase labeling. D1 is inserted into the membrane with a C-terminal extension which requires cleavage by a specific protease, the C-terminal processing protease (CtpA), to allow subsequent assembly of the oxygen-evolving complex. pD1 insertion as well as its conversion to mature D1 under various light conditions was seen only in the TM. Epitope-tagged CtpA was also localized in the same membrane, providing further support for the thylakoid location of pD1 processing. However, Vipp1 and PratA, two proteins suggested to be part of the so-called 'thylakoid centers', were found to associate with the PM. Together, these results suggest that early PSII assembly steps occur in TM or specific areas derived from them, with interaction with PM needed for efficient PSII and thylakoid biogenesis.
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Affiliation(s)
- Tiago T Selão
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, 637551 Singapore
| | - Lifang Zhang
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, 637551 Singapore
| | - Jana Knoppová
- Institute of Microbiology, Center Algatech, Opatovický mlýn, Novohradská 237, 379 81 Třeboň, Czech Republic
| | - Josef Komenda
- Institute of Microbiology, Center Algatech, Opatovický mlýn, Novohradská 237, 379 81 Třeboň, Czech Republic
| | - Birgitta Norling
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, 637551 Singapore
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Single-Molecule Observation of DNA Replication Repair Pathways in E. coli. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2016; 915:5-16. [PMID: 27193534 DOI: 10.1007/978-3-319-32189-9_2] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The method of action of many antibiotics is to interfere with DNA replication-quinolones trap DNA gyrase and topoisomerase proteins onto DNA while metronidazole causes single- and double-stranded breaks in DNA. To understand how bacteria respond to these drugs, it is important to understand the repair processes utilised when DNA replication is blocked. We have used tandem lac operators inserted into the chromosome bound by fluorescently labelled lac repressors as a model protein block to replication in E. coli. We have used dual-colour, alternating-laser, single-molecule narrowfield microscopy to quantify the amount of operator at the block and simultaneously image fluorescently labelled DNA polymerase. We anticipate use of this system as a quantitative platform to study replication stalling and repair proteins.
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49
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Abstract
Our knowledge of the "architecture" of chromosomes has grown enormously in the past decade. This new insight has been enabled largely through advances in interdisciplinary research methods at the cutting-edge interface of the life and physical sciences. Importantly this has involved several state-of-the-art biophysical tools used in conjunction with molecular biology approaches which enable investigation of chromosome structure and function in living cells. Also, there are new and emerging interfacial science tools which enable significant improvements to the spatial and temporal resolution of quantitative measurements, such as in vivo super-resolution and powerful new single-molecule biophysics methods, which facilitate probing of dynamic chromosome processes hitherto impossible. And there are also important advances in the methods of theoretical biophysics which have enabled advances in predictive modeling of this high quality experimental data from molecular and physical biology to generate new understanding of the modes of operation of chromosomes, both in eukaryotic and prokaryotic cells. Here, I discuss these advances, and take stock on the current state of our knowledge of chromosome architecture and speculate where future advances may lead.
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Affiliation(s)
- Mark C Leake
- Biological Physical Sciences Institute (BPSI), University of York, Heslington, York, YO10 5DD, UK.
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50
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Abstract
Our understanding of the processes involved in infection has grown enormously in the past decade due in part to emerging methods of biophysics. This new insight has been enabled through advances in interdisciplinary experimental technologies and theoretical methods at the cutting-edge interface of the life and physical sciences. For example, this has involved several state-of-the-art biophysical tools used in conjunction with molecular and cell biology approaches, which enable investigation of infection in living cells. There are also new, emerging interfacial science tools which enable significant improvements to the resolution of quantitative measurements both in space and time. These include single-molecule biophysics methods and super-resolution microscopy approaches. These new technological tools in particular have underpinned much new understanding of dynamic processes of infection at a molecular length scale. Also, there are many valuable advances made recently in theoretical approaches of biophysics which enable advances in predictive modelling to generate new understanding of infection. Here, I discuss these advances, and take stock on our knowledge of the biophysics of infection and discuss where future advances may lead.
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Affiliation(s)
- Mark C Leake
- Department of Physics and Biology, Biological Physical Sciences Institute (BPSI), University of York, York, YO10 5DD, UK.
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