1
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Radler P, Loose M. A dynamic duo: Understanding the roles of FtsZ and FtsA for Escherichia coli cell division through in vitro approaches. Eur J Cell Biol 2024; 103:151380. [PMID: 38218128 DOI: 10.1016/j.ejcb.2023.151380] [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] [Received: 07/25/2023] [Revised: 12/22/2023] [Accepted: 12/24/2023] [Indexed: 01/15/2024] Open
Abstract
Bacteria divide by binary fission. The protein machine responsible for this process is the divisome, a transient assembly of more than 30 proteins in and on the surface of the cytoplasmic membrane. Together, they constrict the cell envelope and remodel the peptidoglycan layer to eventually split the cell into two. For Escherichia coli, most molecular players involved in this process have probably been identified, but obtaining the quantitative information needed for a mechanistic understanding can often not be achieved from experiments in vivo alone. Since the discovery of the Z-ring more than 30 years ago, in vitro reconstitution experiments have been crucial to shed light on molecular processes normally hidden in the complex environment of the living cell. In this review, we summarize how rebuilding the divisome from purified components - or at least parts of it - have been instrumental to obtain the detailed mechanistic understanding of the bacterial cell division machinery that we have today.
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Affiliation(s)
- Philipp Radler
- Institute for Science and Technology Austria (ISTA), Am Campus 1, 3400 Klosterneuburg, Austria; University of Vienna, Djerassiplatz 1, 1030 Wien, Austria.
| | - Martin Loose
- Institute for Science and Technology Austria (ISTA), Am Campus 1, 3400 Klosterneuburg, Austria.
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2
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Hadjivasiliou Z, Kruse K. Selection for Size in Molecular Self-Assembly Drives the De Novo Evolution of a Molecular Machine. PHYSICAL REVIEW LETTERS 2023; 131:208402. [PMID: 38039477 DOI: 10.1103/physrevlett.131.208402] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2022] [Accepted: 09/27/2023] [Indexed: 12/03/2023]
Abstract
The functioning of machines typically requires a concerted action of their parts. This requirement also holds for molecular motors that drive vital cellular processes and imposes constraints on their conformational changes as well as the rates at which they occur. It remains unclear whether, during evolution, features required for functional molecular machines can emerge simultaneously or require sequential adaptation to different selection pressures. We address this question by theoretically analyzing the evolution of filament treadmilling. This process refers to the self-assembly of linear polymers that grow and shrink at equal rates at their opposite ends. It constitutes a simple biological molecular machine that is involved in bacterial cell division and requires that several conditions are met. In our simulation framework, treadmilling emerges as a consequence of selecting for a target average polymer length. We discuss why other forms of assembly dynamics, which also reach the imposed target length, do not emerge in our simulations. Our work shows that complex molecular functions can evolve de novo under selection for a single physical feature.
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Affiliation(s)
- Zena Hadjivasiliou
- London Centre for Nanotechnology, University College London, London, United Kingdom
- Department of Physics and Astronomy, University College London, London, United Kingdom
- Institute for the Physics of Living Systems, University College London, London, United Kingdom
- Mathematical and Physical Biology Laboratory, The Francis Crick Institute, London, United Kingdom
- Department of Biochemistry, University of Geneva, Geneva, Switzerland
| | - Karsten Kruse
- Department of Biochemistry, University of Geneva, Geneva, Switzerland
- NCCR for Chemical Biology, University of Geneva, Geneva, Switzerland
- Department of Theoretical Physics, University of Geneva, Geneva, Switzerland
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3
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Awal RP, Müller FD, Pfeiffer D, Monteil CL, Perrière G, Lefèvre CT, Schüler D. Experimental analysis of diverse actin-like proteins from various magnetotactic bacteria by functional expression in Magnetospirillum gryphiswaldense. mBio 2023; 14:e0164923. [PMID: 37823629 PMCID: PMC10653835 DOI: 10.1128/mbio.01649-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2023] [Accepted: 08/29/2023] [Indexed: 10/13/2023] Open
Abstract
IMPORTANCE To efficiently navigate within the geomagnetic field, magnetotactic bacteria (MTB) align their magnetosome organelles into chains, which are organized by the actin-like MamK protein. Although MamK is the most highly conserved magnetosome protein common to all MTB, its analysis has been confined to a small subgroup owing to the inaccessibility of most MTB. Our study takes advantage of a genetically tractable host where expression of diverse MamK orthologs together with a resurrected MamK LUCA and uncharacterized actin-like Mad28 proteins from deep-branching MTB resulted in gradual restoration of magnetosome chains in various mutants. Our results further indicate the existence of species-specific MamK interactors and shed light on the evolutionary relationships of one of the key proteins associated with bacterial magnetotaxis.
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Affiliation(s)
- Ram Prasad Awal
- Department of Microbiology, Universitat Bayreuth, Bayreuth, Germany
| | - Frank D. Müller
- Department of Microbiology, Universitat Bayreuth, Bayreuth, Germany
| | - Daniel Pfeiffer
- Department of Microbiology, Universitat Bayreuth, Bayreuth, Germany
| | - Caroline L. Monteil
- Aix-Marseille Université, CEA, CNRS, Institute of Biosciences and Biotechnologies of Aix-Marseille, Saint-Paul-lez-Durance, France
| | - Guy Perrière
- Laboratoire de Biométrie et Biologie Evolutive, Université Claude Bernard-Lyon 1, Villeurbanne, France
| | - Christopher T. Lefèvre
- Aix-Marseille Université, CEA, CNRS, Institute of Biosciences and Biotechnologies of Aix-Marseille, Saint-Paul-lez-Durance, France
| | - Dirk Schüler
- Department of Microbiology, Universitat Bayreuth, Bayreuth, Germany
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4
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Chevrier DM, Juhin A, Menguy N, Bolzoni R, Soto-Rodriguez PED, Kojadinovic-Sirinelli M, Paterson GA, Belkhou R, Williams W, Skouri-Panet F, Kosta A, Le Guenno H, Pereiro E, Faivre D, Benzerara K, Monteil CL, Lefevre CT. Collective magnetotaxis of microbial holobionts is optimized by the three-dimensional organization and magnetic properties of ectosymbionts. Proc Natl Acad Sci U S A 2023; 120:e2216975120. [PMID: 36848579 PMCID: PMC10013862 DOI: 10.1073/pnas.2216975120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2022] [Accepted: 01/17/2023] [Indexed: 03/01/2023] Open
Abstract
Over the last few decades, symbiosis and the concept of holobiont-a host entity with a population of symbionts-have gained a central role in our understanding of life functioning and diversification. Regardless of the type of partner interactions, understanding how the biophysical properties of each individual symbiont and their assembly may generate collective behaviors at the holobiont scale remains a fundamental challenge. This is particularly intriguing in the case of the newly discovered magnetotactic holobionts (MHB) whose motility relies on a collective magnetotaxis (i.e., a magnetic field-assisted motility guided by a chemoaerotaxis system). This complex behavior raises many questions regarding how magnetic properties of symbionts determine holobiont magnetism and motility. Here, a suite of light-, electron- and X-ray-based microscopy techniques [including X-ray magnetic circular dichroism (XMCD)] reveals that symbionts optimize the motility, the ultrastructure, and the magnetic properties of MHBs from the microscale to the nanoscale. In the case of these magnetic symbionts, the magnetic moment transferred to the host cell is in excess (102 to 103 times stronger than free-living magnetotactic bacteria), well above the threshold for the host cell to gain a magnetotactic advantage. The surface organization of symbionts is explicitly presented herein, depicting bacterial membrane structures that ensure longitudinal alignment of cells. Magnetic dipole and nanocrystalline orientations of magnetosomes were also shown to be consistently oriented in the longitudinal direction, maximizing the magnetic moment of each symbiont. With an excessive magnetic moment given to the host cell, the benefit provided by magnetosome biomineralization beyond magnetotaxis can be questioned.
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Affiliation(s)
- Daniel M. Chevrier
- Aix-Marseille Université, Centre national de la recherche scientifique (CNRS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), UMR7265, Bioscience and biotechnology institute of Aix-Marseille (BIAM), Saint-Paul-lez-Durance13108, France
| | - Amélie Juhin
- Sorbonne Université, UMR CNRS 7590, Muséum national d'Histoire naturelle (MNHN), Institut de recherche pour le développement (IRD), Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie (IMPMC), 75005Paris, France
| | - Nicolas Menguy
- Sorbonne Université, UMR CNRS 7590, Muséum national d'Histoire naturelle (MNHN), Institut de recherche pour le développement (IRD), Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie (IMPMC), 75005Paris, France
| | - Romain Bolzoni
- Aix-Marseille Université, Centre national de la recherche scientifique (CNRS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), UMR7265, Bioscience and biotechnology institute of Aix-Marseille (BIAM), Saint-Paul-lez-Durance13108, France
| | - Paul E. D. Soto-Rodriguez
- Aix-Marseille Université, Centre national de la recherche scientifique (CNRS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), UMR7265, Bioscience and biotechnology institute of Aix-Marseille (BIAM), Saint-Paul-lez-Durance13108, France
| | - Mila Kojadinovic-Sirinelli
- Aix-Marseille Université, Centre national de la recherche scientifique (CNRS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), UMR7265, Bioscience and biotechnology institute of Aix-Marseille (BIAM), Saint-Paul-lez-Durance13108, France
| | - Greig A. Paterson
- Department of Earth, Ocean and Ecological Sciences, University of Liverpool, L69 7ZELiverpool, UK
| | - Rachid Belkhou
- Synchrotron Soleil, L'Orme des Merisiers, 91192Gif-sur-Yvette Cedex, France
| | - Wyn Williams
- School of GeoSciences, Grant Institute, University of Edinburgh, EdinburghEH9 3JW, UK
| | - Fériel Skouri-Panet
- Sorbonne Université, UMR CNRS 7590, Muséum national d'Histoire naturelle (MNHN), Institut de recherche pour le développement (IRD), Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie (IMPMC), 75005Paris, France
| | - Artemis Kosta
- Plateforme de Microscopie de l'Institut de Microbiologie de la Méditerranée, Institut de Microbiologie, FR3479, Campus CNRS, 13402Marseille cedex 20, France
| | - Hugo Le Guenno
- Plateforme de Microscopie de l'Institut de Microbiologie de la Méditerranée, Institut de Microbiologie, FR3479, Campus CNRS, 13402Marseille cedex 20, France
| | - Eva Pereiro
- ALBA Synchrotron Light Source, Cerdanyola del Vallés, Barcelona08290, Spain
| | - Damien Faivre
- Aix-Marseille Université, Centre national de la recherche scientifique (CNRS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), UMR7265, Bioscience and biotechnology institute of Aix-Marseille (BIAM), Saint-Paul-lez-Durance13108, France
| | - Karim Benzerara
- Sorbonne Université, UMR CNRS 7590, Muséum national d'Histoire naturelle (MNHN), Institut de recherche pour le développement (IRD), Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie (IMPMC), 75005Paris, France
| | - Caroline L. Monteil
- Aix-Marseille Université, Centre national de la recherche scientifique (CNRS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), UMR7265, Bioscience and biotechnology institute of Aix-Marseille (BIAM), Saint-Paul-lez-Durance13108, France
| | - Christopher T. Lefevre
- Aix-Marseille Université, Centre national de la recherche scientifique (CNRS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), UMR7265, Bioscience and biotechnology institute of Aix-Marseille (BIAM), Saint-Paul-lez-Durance13108, France
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5
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Live-Cell Fluorescence Imaging of Magnetosome Organelle for Magnetotaxis Motility. Methods Mol Biol 2023; 2646:133-146. [PMID: 36842112 DOI: 10.1007/978-1-0716-3060-0_12] [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: 02/27/2023]
Abstract
The assessment of intracellular dynamics is crucial for understanding the function and formation process of bacterial organelle, just as it is for the inquisition of their eukaryotic counterparts. The methods for imaging magnetosome organelles in a magnetotactic bacterial cell using live-cell fluorescence imaging by highly inclined and laminated optical sheet (HILO) microscopy are presented in this chapter. Furthermore, we introduce methods for pH imaging in magnetosome lumen as an application of fluorescence magnetosome imaging.
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6
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Wan J, Monteil CL, Taoka A, Ernie G, Park K, Amor M, Taylor-Cornejo E, Lefevre CT, Komeili A. McaA and McaB control the dynamic positioning of a bacterial magnetic organelle. Nat Commun 2022; 13:5652. [PMID: 36163114 PMCID: PMC9512821 DOI: 10.1038/s41467-022-32914-9] [Citation(s) in RCA: 4] [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: 03/16/2022] [Accepted: 08/23/2022] [Indexed: 11/17/2022] Open
Abstract
Magnetotactic bacteria are a diverse group of microorganisms that use intracellular chains of ferrimagnetic nanocrystals, produced within magnetosome organelles, to align and navigate along the geomagnetic field. Several conserved genes for magnetosome formation have been described, but the mechanisms leading to distinct species-specific magnetosome chain configurations remain unclear. Here, we show that the fragmented nature of magnetosome chains in Magnetospirillum magneticum AMB-1 is controlled by genes mcaA and mcaB. McaA recognizes the positive curvature of the inner cell membrane, while McaB localizes to magnetosomes. Along with the MamK actin-like cytoskeleton, McaA and McaB create space for addition of new magnetosomes in between pre-existing magnetosomes. Phylogenetic analyses suggest that McaA and McaB homologs are widespread among magnetotactic bacteria and may represent an ancient strategy for magnetosome positioning.
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Affiliation(s)
- Juan Wan
- Department of Plant and Microbial Biology, University of California, Berkeley, CA, 94720, USA
| | - Caroline L Monteil
- Aix-Marseille Université, CEA, CNRS, Institute of Biosciences and Biotechnologies of Aix-Marseille, 13108, Saint-Paul-lez-Durance, France
| | - Azuma Taoka
- Institute of Science and Engineering, Kanazawa University, Kakuma-machi, Kanazawa, Ishikawa, 920-1192, Japan
| | - Gabriel Ernie
- Department of Plant and Microbial Biology, University of California, Berkeley, CA, 94720, USA
| | - Kieop Park
- Department of Plant and Microbial Biology, University of California, Berkeley, CA, 94720, USA
- Department of Biology, Duke University, Box 90338, Durham, NC, 27708, USA
| | - Matthieu Amor
- Department of Plant and Microbial Biology, University of California, Berkeley, CA, 94720, USA
- Aix-Marseille Université, CEA, CNRS, Institute of Biosciences and Biotechnologies of Aix-Marseille, 13108, Saint-Paul-lez-Durance, France
| | - Elias Taylor-Cornejo
- Department of Plant and Microbial Biology, University of California, Berkeley, CA, 94720, USA
- Department of Biology, Randolph-Macon College, Ashland, VA, 23005, USA
| | - Christopher T Lefevre
- Aix-Marseille Université, CEA, CNRS, Institute of Biosciences and Biotechnologies of Aix-Marseille, 13108, Saint-Paul-lez-Durance, France
| | - Arash Komeili
- Department of Plant and Microbial Biology, University of California, Berkeley, CA, 94720, USA.
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7
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Medvedeva AV, Rebrova AV, Zalomaeva ES, Turaeva SK, Nikitina EA, Tokmacheva EV, Vasileva SA, Shchegolev BF, Savvateeva-Popova EV. Role of LIM Kinase 1 in Dopaminergic and Serotonergic Neurons in Genome Stability, Learning and Memory during Stress Response to Weakening of Earth’s Magnetic Field in Drosophila. J EVOL BIOCHEM PHYS+ 2022. [DOI: 10.1134/s0022093022010033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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8
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Frank C, Pfeiffer D, Aktas M, Jendrossek D. Migration of Polyphosphate Granules in Agrobacterium tumefaciens. Microb Physiol 2022; 32:71-82. [PMID: 35168233 DOI: 10.1159/000521970] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2021] [Accepted: 01/12/2022] [Indexed: 01/29/2023]
Abstract
Agrobacterium tumefaciens has two polyphosphate (polyP) kinases, one of which (PPK1AT) is responsible for the formation of polyP granules, while the other (PPK2AT) is used for replenishing the NTP pools by using polyP as a phosphate donor to phosphorylate nucleoside diphosphates. Fusions of eYFP with PPK2AT or of the polyP granule-associated phosin PptA from Ralstonia eutropha always co-localized with polyP granules in A. tumefaciens and allowed the tracking of polyP granules in time-lapse microscopy experiments without the necessity to label the cells with the toxic dye DAPI. Fusions of PPK1AT with mCherry formed fluorescent signals often attached to, but not completely co-localizing with, polyP granules in wild-type cells. Time-lapse microscopy revealed that polyP granules in about one-third of a cell population migrated from the old pole to the new cell pole shortly before or during cell division. Many cells de novo formed a second (nonmigrating) polyP granule at the opposite cell pole before cell division was completed, resulting in two daughter cells each having a polyP granule at the old pole after septum formation. Migration of polyP granules was disordered in mitomycin C-treated or in PopZ-depleted cells, suggesting that polyP granules can associate with DNA or with other molecules that are segregated during the cell cycle.
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Affiliation(s)
- Celina Frank
- Institute of Microbiology, University of Stuttgart, Stuttgart, Germany
| | - Daniel Pfeiffer
- Department of Microbiology, University Bayreuth, Bayreuth, Germany
| | - Meriyem Aktas
- Microbial Biology, Ruhr University Bochum, Bochum, Germany
| | - Dieter Jendrossek
- Institute of Microbiology, University of Stuttgart, Stuttgart, Germany
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9
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Baaziz W, Ghica C, Cypriano J, Abreu F, Anselme K, Ersen O, Farina M, Werckmann J. New Phenotype and Mineralization of Biogenic Iron Oxide in Magnetotactic Bacteria. NANOMATERIALS 2021; 11:nano11123189. [PMID: 34947538 PMCID: PMC8706698 DOI: 10.3390/nano11123189] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/20/2021] [Revised: 11/22/2021] [Accepted: 11/23/2021] [Indexed: 12/15/2022]
Abstract
Many magnetotactic bacteria (MTB) biomineralize magnetite crystals that nucleate and grow inside intracellular membranous vesicles originating from invaginations of the cytoplasmic membrane. The crystals together with their surrounding membranes are referred to as magnetosomes. Magnetosome magnetite crystals nucleate and grow using iron transported inside the vesicle by specific proteins. Here, we tackle the question of the organization of magnetosomes, which are always described as constituted by linear chains of nanocrystals. In addition, it is commonly accepted that the iron oxide nanocrystals are in the magnetite-based phase. We show, in the case of a wild species of coccus-type bacterium, that there is a double organization of the magnetosomes, relatively perpendicular to each other, and that the nanocrystals are in fact maghemite. These findings were obtained, respectively, by using electron tomography of whole mounts of cells directly from the environment and high-resolution transmission electron microscopy and diffraction. Structure simulations were performed with the MacTempas software. This study opens new perspectives on the diversity of phenotypes within MTBs and allows to envisage other mechanisms of nucleation and formation of biogenic iron oxide crystals.
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Affiliation(s)
- Walid Baaziz
- Institut de Physique et Chimie des Matériaux de Strasbourg (IPCMS), University of Strasbourg, 23 rue du Loess BP 43, CEDEX 2, 67034 Strasbourg, France; (W.B.); (O.E.)
| | - Corneliu Ghica
- National Institute of Materials Physics, Atomistilor 405A, 077125 Magurele, Romania
- Correspondence: (C.G.); (J.W.)
| | - Jefferson Cypriano
- Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro, Avenida Carlos Chagas Filho, 373, CCS, UFRJ, Rio de Janeiro 21941-902, Brazil; (J.C.); (F.A.)
| | - Fernanda Abreu
- Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro, Avenida Carlos Chagas Filho, 373, CCS, UFRJ, Rio de Janeiro 21941-902, Brazil; (J.C.); (F.A.)
| | - Karine Anselme
- Institut de Science des Matériaux de Mulhouse, University of Haute Alsace, 68057 Mulhouse, France;
| | - Ovidiu Ersen
- Institut de Physique et Chimie des Matériaux de Strasbourg (IPCMS), University of Strasbourg, 23 rue du Loess BP 43, CEDEX 2, 67034 Strasbourg, France; (W.B.); (O.E.)
| | - Marcos Farina
- Instituto de Ciências Biomédicas, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-902, Brazil;
| | - Jacques Werckmann
- Instituto de Ciências Biomédicas, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-902, Brazil;
- Centro Brasiliero de Pesquisas Fisicas, LABNANO, Rio de Janeiro 22290-180, Brazil
- Correspondence: (C.G.); (J.W.)
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10
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Mickoleit F, Rosenfeldt S, Toro-Nahuelpan M, Schaffer M, Schenk AS, Plitzko JM, Schüler D. High-Yield Production, Characterization, and Functionalization of Recombinant Magnetosomes in the Synthetic Bacterium Rhodospirillum rubrum "magneticum". Adv Biol (Weinh) 2021; 5:e2101017. [PMID: 34296829 DOI: 10.1002/adbi.202101017] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2021] [Revised: 07/10/2021] [Indexed: 01/02/2023]
Abstract
Recently, the photosynthetic Rhodospirillum rubrum has been endowed with the ability of magnetosome biosynthesis by transfer and expression of biosynthetic gene clusters from the magnetotactic bacterium Magnetospirillum gryphiswaldense. However, the growth conditions for efficient magnetite biomineralization in the synthetic R. rubrum "magneticum", as well as the particles themselves (i.e., structure and composition), have so far not been fully characterized. In this study, different cultivation strategies, particularly the influence of temperature and light intensity, are systematically investigated to achieve optimal magnetosome biosynthesis. Reduced temperatures ≤16 °C and gradual increase in light intensities favor magnetite biomineralization at high rates, suggesting that magnetosome formation might utilize cellular processes, cofactors, and/or pathways that are linked to photosynthetic growth. Magnetosome yields of up to 13.6 mg magnetite per liter cell culture are obtained upon photoheterotrophic large-scale cultivation. Furthermore, it is shown that even more complex, i.e., oligomeric, catalytically active functional moieties like enzyme proteins can be efficiently expressed on the magnetosome surface, thereby enabling the in vivo functionalization by genetic engineering. In summary, it is demonstrated that the synthetic R. rubrum "magneticum" is a suitable host for high-yield magnetosome biosynthesis and the sustainable production of genetically engineered, bioconjugated magnetosomes.
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Affiliation(s)
- Frank Mickoleit
- Dept. Microbiology, University of Bayreuth, D-95447, Bayreuth, Germany
| | - Sabine Rosenfeldt
- Bavarian Polymer Institute (BPI)/Physical Chemistry 1, University of Bayreuth, D-95447, Bayreuth, Germany
| | - Mauricio Toro-Nahuelpan
- Dept. Microbiology, University of Bayreuth, D-95447, Bayreuth, Germany.,Dept. Molecular Structural Biology, Max Planck Institute of Biochemistry, D-82152, Martinsried, Germany
| | - Miroslava Schaffer
- Dept. Molecular Structural Biology, Max Planck Institute of Biochemistry, D-82152, Martinsried, Germany
| | - Anna S Schenk
- Bavarian Polymer Institute (BPI)/Physical Chemistry - Colloidal Systems, University of Bayreuth, D-95447, Bayreuth, Germany
| | - Jürgen M Plitzko
- Dept. Molecular Structural Biology, Max Planck Institute of Biochemistry, D-82152, Martinsried, Germany
| | - Dirk Schüler
- Dept. Microbiology, University of Bayreuth, D-95447, Bayreuth, Germany
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11
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MacCready JS, Basalla JL, Vecchiarelli AG. Origin and Evolution of Carboxysome Positioning Systems in Cyanobacteria. Mol Biol Evol 2021; 37:1434-1451. [PMID: 31899489 PMCID: PMC7182216 DOI: 10.1093/molbev/msz308] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Carboxysomes are protein-based organelles that are essential for allowing cyanobacteria to fix CO2. Previously, we identified a two-component system, McdAB, responsible for equidistantly positioning carboxysomes in the model cyanobacterium Synechococcus elongatus PCC 7942 (MacCready JS, Hakim P, Young EJ, Hu L, Liu J, Osteryoung KW, Vecchiarelli AG, Ducat DC. 2018. Protein gradients on the nucleoid position the carbon-fixing organelles of cyanobacteria. eLife 7:pii:e39723). McdA, a ParA-type ATPase, nonspecifically binds the nucleoid in the presence of ATP. McdB, a novel factor that directly binds carboxysomes, displaces McdA from the nucleoid. Removal of McdA from the nucleoid in the vicinity of carboxysomes by McdB causes a global break in McdA symmetry, and carboxysome motion occurs via a Brownian-ratchet-based mechanism toward the highest concentration of McdA. Despite the importance for cyanobacteria to properly position their carboxysomes, whether the McdAB system is widespread among cyanobacteria remains an open question. Here, we show that the McdAB system is widespread among β-cyanobacteria, often clustering with carboxysome-related components, and is absent in α-cyanobacteria. Moreover, we show that two distinct McdAB systems exist in β-cyanobacteria, with Type 2 systems being the most ancestral and abundant, and Type 1 systems, like that of S. elongatus, possibly being acquired more recently. Lastly, all McdB proteins share the sequence signatures of a protein capable of undergoing liquid–liquid phase separation. Indeed, we find that representatives of both McdB types undergo liquid–liquid phase separation in vitro, the first example of a ParA-type ATPase partner protein to exhibit this behavior. Our results have broader implications for understanding carboxysome evolution, biogenesis, homeostasis, and positioning in cyanobacteria.
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Affiliation(s)
- Joshua S MacCready
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI
| | - Joseph L Basalla
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI
| | - Anthony G Vecchiarelli
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI
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12
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Spatiotemporal Organization of Chemotaxis Pathways in Magnetospirillum gryphiswaldense. Appl Environ Microbiol 2020; 87:AEM.02229-20. [PMID: 33067189 DOI: 10.1128/aem.02229-20] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Accepted: 10/09/2020] [Indexed: 11/20/2022] Open
Abstract
Magnetospirillum gryphiswaldense employs iron-rich nanoparticles for magnetic navigation within environmental redox gradients. This behavior termed magneto-aerotaxis was previously shown to rely on the sensory pathway CheOp1, but the precise localization of CheOp1-related chemoreceptor arrays during the cell cycle and its possible interconnection with three other chemotaxis pathways have remained unstudied. Here, we analyzed the localization of chemoreceptor-associated adaptor protein CheW1 and histidine kinase CheA1 by superresolution microscopy in a spatiotemporal manner. CheW1 localized in dynamic clusters that undergo occasional segregation and fusion events at lateral sites of both cell poles. Newly formed smaller clusters originating at midcell before completion of cytokinesis were found to grow in size during the cell cycle. Bipolar CheA1 localization and formation of aerotactic swim halos were affected depending on the fluorescent protein tag, indicating that CheA1 localization is important for aerotaxis. Furthermore, polar CheW1 localization was independent of cheOp2 to cheOp4 but lost in the absence of cheOp1 or cheA1 Results were corroborated by the detection of a direct protein interaction between CheA1 and CheW1 and by the observation that cheOp2- and cheOp3-encoded CheW paralogs localized in spatially distinct smaller clusters at the cell boundary. Although the findings of a minor aerotaxis-related CheOp4 phenotype and weak protein interactions between CheOp1 and CheOp4 by two-hybrid analysis implied that CheW1 and CheW4 might be part of the same chemoreceptor array, CheW4 was localized in spatially distinct polar-lateral arrays independent of CheOp1, suggesting that CheOp1 and CheOp4 are also not connected at the molecular level.IMPORTANCE Magnetotactic bacteria (MTB) use the geomagnetic field for navigation in aquatic redox gradients. However, the highly complex signal transduction networks in these environmental microbes are poorly understood. Here, we analyzed the localization of selected chemotaxis proteins to spatially and temporally resolve chemotaxis array localization in Magnetospirillum gryphiswaldense Our findings suggest that bipolar localization of chemotaxis arrays related to the key signaling pathway CheOp1 is important for aerotaxis and that CheOp1 signaling units assemble independent of the three other chemotaxis pathways present in M. gryphiswaldense Overall, our results provide deeper insights into the complex organization of signaling pathways in MTB and add to the general understanding of environmental bacteria possessing multiple chemotaxis pathways.
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13
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A bacterial cytolinker couples positioning of magnetic organelles to cell shape control. Proc Natl Acad Sci U S A 2020; 117:32086-32097. [PMID: 33257551 DOI: 10.1073/pnas.2014659117] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Magnetotactic bacteria maneuver within the geomagnetic field by means of intracellular magnetic organelles, magnetosomes, which are aligned into a chain and positioned at midcell by a dedicated magnetosome-specific cytoskeleton, the "magnetoskeleton." However, how magnetosome chain organization and resulting magnetotaxis is linked to cell shape has remained elusive. Here, we describe the cytoskeletal determinant CcfM (curvature-inducing coiled-coil filament interacting with the magnetoskeleton), which links the magnetoskeleton to cell morphology regulation in Magnetospirillum gryphiswaldense Membrane-anchored CcfM localizes in a filamentous pattern along regions of inner positive-cell curvature by its coiled-coil motifs, and independent of the magnetoskeleton. CcfM overexpression causes additional circumferential localization patterns, associated with a dramatic increase in cell curvature, and magnetosome chain mislocalization or complete chain disruption. In contrast, deletion of ccfM results in decreased cell curvature, impaired cell division, and predominant formation of shorter, doubled chains of magnetosomes. Pleiotropic effects of CcfM on magnetosome chain organization and cell morphology are supported by the finding that CcfM interacts with the magnetoskeleton-related MamY and the actin-like MamK via distinct motifs, and with the cell shape-related cytoskeleton via MreB. We further demonstrate that CcfM promotes motility and magnetic alignment in structured environments, and thus likely confers a selective advantage in natural habitats of magnetotactic bacteria, such as aquatic sediments. Overall, we unravel the function of a prokaryotic cytoskeletal constituent that is widespread in magnetic and nonmagnetic spirilla-shaped Alphaproteobacteria.
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14
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Abstract
Magnetotactic bacteria are aquatic or sediment-dwelling microorganisms able to take advantage of the Earth's magnetic field for directed motility. The source of this amazing trait is magnetosomes, unique organelles used to synthesize single nanometer-sized crystals of magnetic iron minerals that are queued up to build an intracellular compass. Most of these microorganisms cannot be cultivated under controlled conditions, much less genetically engineered, with only few exceptions. However, two of the genetically amenable Magnetospirillum species have emerged as tractable model organisms to study magnetosome formation and magnetotaxis. Recently, much has been revealed about the process of magnetosome biogenesis and dedicated structures for magnetosome dynamics and positioning, which suggest an unexpected cellular intricacy of these organisms. In this minireview, we summarize new insights and place the molecular mechanisms of magnetosome formation in the context of the complex cell biology of Magnetospirillum spp. First, we provide an overview on magnetosome vesicle synthesis and magnetite biomineralization, followed by a discussion of the perceptions of dynamic organelle positioning and its biological implications, which highlight that magnetotactic bacteria have evolved sophisticated mechanisms to construct, incorporate, and inherit a unique navigational device. Finally, we discuss the impact of magnetotaxis on motility and its interconnection with chemotaxis, showing that magnetotactic bacteria are outstandingly adapted to lifestyle and habitat.
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15
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Intracellular amorphous Ca-carbonate and magnetite biomineralization by a magnetotactic bacterium affiliated to the Alphaproteobacteria. ISME JOURNAL 2020; 15:1-18. [PMID: 32839547 DOI: 10.1038/s41396-020-00747-3] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/01/2020] [Revised: 07/30/2020] [Accepted: 08/10/2020] [Indexed: 11/08/2022]
Abstract
Bacteria synthesize a wide range of intracellular submicrometer-sized inorganic precipitates of diverse chemical compositions and structures, called biominerals. Their occurrences, functions and ultrastructures are not yet fully described despite great advances in our knowledge of microbial diversity. Here, we report bacteria inhabiting the sediments and water column of the permanently stratified ferruginous Lake Pavin, that have the peculiarity to biomineralize both intracellular magnetic particles and calcium carbonate granules. Based on an ultrastructural characterization using transmission electron microscopy (TEM) and synchrotron-based scanning transmission X-ray microscopy (STXM), we showed that the calcium carbonate granules are amorphous and contained within membrane-delimited vesicles. Single-cell sorting, correlative fluorescent in situ hybridization (FISH), scanning electron microscopy (SEM) and molecular typing of populations inhabiting sediments affiliated these bacteria to a new genus of the Alphaproteobacteria. The partially assembled genome sequence of a representative isolate revealed an atypical structure of the magnetosome gene cluster while geochemical analyses indicate that calcium carbonate production is an active process that costs energy to the cell to maintain an environment suitable for their formation. This discovery further expands the diversity of organisms capable of intracellular Ca-carbonate biomineralization. If the role of such biomineralization is still unclear, cell behaviour suggests that it may participate to cell motility in aquatic habitats as magnetite biomineralization does.
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16
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Greening C, Lithgow T. Formation and function of bacterial organelles. Nat Rev Microbiol 2020; 18:677-689. [PMID: 32710089 DOI: 10.1038/s41579-020-0413-0] [Citation(s) in RCA: 68] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/22/2020] [Indexed: 01/28/2023]
Abstract
Advances in imaging technologies have revealed that many bacteria possess organelles with a proteomically defined lumen and a macromolecular boundary. Some are bound by a lipid bilayer (such as thylakoids, magnetosomes and anammoxosomes), whereas others are defined by a lipid monolayer (such as lipid bodies), a proteinaceous coat (such as carboxysomes) or have a phase-defined boundary (such as nucleolus-like compartments). These diverse organelles have various metabolic and physiological functions, facilitating adaptation to different environments and driving the evolution of cellular complexity. This Review highlights that, despite the diversity of reported organelles, some unifying concepts underlie their formation, structure and function. Bacteria have fundamental mechanisms of organelle formation, through which conserved processes can form distinct organelles in different species depending on the proteins recruited to the luminal space and the boundary of the organelle. These complex subcellular compartments provide evolutionary advantages as well as enabling metabolic specialization, biogeochemical processes and biotechnological advances. Growing evidence suggests that the presence of organelles is the rule, rather than the exception, in bacterial cells.
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Affiliation(s)
- Chris Greening
- Infection and Immunity Program, Biomedicine Discovery Institute and Department of Microbiology, Monash University, Clayton, Australia.
| | - Trevor Lithgow
- Infection and Immunity Program, Biomedicine Discovery Institute and Department of Microbiology, Monash University, Clayton, Australia.
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17
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Qin W, Wang CY, Ma YX, Shen MJ, Li J, Jiao K, Tay FR, Niu LN. Microbe-Mediated Extracellular and Intracellular Mineralization: Environmental, Industrial, and Biotechnological Applications. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2020; 32:e1907833. [PMID: 32270552 DOI: 10.1002/adma.201907833] [Citation(s) in RCA: 50] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2019] [Revised: 01/09/2020] [Indexed: 06/11/2023]
Abstract
Microbe-mediated mineralization is ubiquitous in nature, involving bacteria, fungi, viruses, and algae. These mineralization processes comprise calcification, silicification, and iron mineralization. The mechanisms for mineral formation include extracellular and intracellular biomineralization. The mineral precipitating capability of microbes is often harnessed for green synthesis of metal nanoparticles, which are relatively less toxic compared with those synthesized through physical or chemical methods. Microbe-mediated mineralization has important applications ranging from pollutant removal and nonreactive carriers, to other industrial and biomedical applications. Herein, the different types of microbe-mediated biomineralization that occur in nature, their mechanisms, as well as their applications are elucidated to create a backdrop for future research.
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Affiliation(s)
- Wen Qin
- State Key Laboratory of Military Stomatology & National Clinical Research Center for Oral Diseases & Shaanxi Key Laboratory of Stomatology, Department of Prosthodontics, School of Stomatology, The Fourth Military Medical University, Xi'an, 710032, Shaanxi, China
| | - Chen-Yu Wang
- State Key Laboratory of Military Stomatology & National Clinical Research Center for Oral Diseases & Shaanxi Key Laboratory of Stomatology, Department of Prosthodontics, School of Stomatology, The Fourth Military Medical University, Xi'an, 710032, Shaanxi, China
| | - Yu-Xuan Ma
- State Key Laboratory of Military Stomatology & National Clinical Research Center for Oral Diseases & Shaanxi Key Laboratory of Stomatology, Department of Prosthodontics, School of Stomatology, The Fourth Military Medical University, Xi'an, 710032, Shaanxi, China
| | - Min-Juan Shen
- State Key Laboratory of Military Stomatology & National Clinical Research Center for Oral Diseases & Shaanxi Key Laboratory of Stomatology, Department of Prosthodontics, School of Stomatology, The Fourth Military Medical University, Xi'an, 710032, Shaanxi, China
| | - Jing Li
- State Key Laboratory of Military Stomatology & National Clinical Research Center for Oral Diseases & Shaanxi Key Laboratory of Stomatology, Department of Prosthodontics, School of Stomatology, The Fourth Military Medical University, Xi'an, 710032, Shaanxi, China
| | - Kai Jiao
- State Key Laboratory of Military Stomatology & National Clinical Research Center for Oral Diseases & Shaanxi Key Laboratory of Stomatology, Department of Prosthodontics, School of Stomatology, The Fourth Military Medical University, Xi'an, 710032, Shaanxi, China
| | - Franklin R Tay
- College of Graduate Studies, Augusta University, Augusta, GA, 30912, USA
| | - Li-Na Niu
- State Key Laboratory of Military Stomatology & National Clinical Research Center for Oral Diseases & Shaanxi Key Laboratory of Stomatology, Department of Prosthodontics, School of Stomatology, The Fourth Military Medical University, Xi'an, 710032, Shaanxi, China
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18
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Abstract
Many species of bacteria can manufacture materials on a finer scale than those that are synthetically made. These products are often produced within intracellular compartments that bear many hallmarks of eukaryotic organelles. One unique and elegant group of organisms is at the forefront of studies into the mechanisms of organelle formation and biomineralization. Magnetotactic bacteria (MTB) produce organelles called magnetosomes that contain nanocrystals of magnetic material, and understanding the molecular mechanisms behind magnetosome formation and biomineralization is a rich area of study. In this Review, we focus on the genetics behind the formation of magnetosomes and biomineralization. We cover the history of genetic discoveries in MTB and key insights that have been found in recent years and provide a perspective on the future of genetic studies in MTB.
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Affiliation(s)
- Hayley C. McCausland
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, California, United States of America
| | - Arash Komeili
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, California, United States of America
- Department of Plant and Microbial Biology, University of California, Berkeley, Berkeley, California, United States of America
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19
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Quantifying the Benefit of a Dedicated "Magnetoskeleton" in Bacterial Magnetotaxis by Live-Cell Motility Tracking and Soft Agar Swimming Assay. Appl Environ Microbiol 2020; 86:AEM.01976-19. [PMID: 31732570 DOI: 10.1128/aem.01976-19] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2019] [Accepted: 11/08/2019] [Indexed: 12/20/2022] Open
Abstract
The alphaproteobacterium Magnetospirillum gryphiswaldense has the intriguing ability to navigate within magnetic fields, a behavior named magnetotaxis, governed by the formation of magnetosomes, intracellular membrane-enveloped crystals of magnetite. Magnetosomes are aligned in chains along the cell's motility axis by a dedicated multipart cytoskeleton ("magnetoskeleton"); however, precise estimates of its significance for magnetotaxis have not been reported. Here, we estimated the alignment of strains deficient in various magnetoskeletal constituents by live-cell motility tracking within defined magnetic fields ranging from 50 μT (reflecting the geomagnetic field) up to 400 μT. Motility tracking revealed that ΔmamY and ΔmamK strains (which assemble mispositioned and fragmented chains, respectively) are partially impaired in magnetotaxis, with approximately equal contributions of both proteins. This impairment was reflected by a required magnetic field strength of 200 μT to achieve a similar degree of alignment as for the wild-type strain in a 50-μT magnetic field. In contrast, the ΔmamJ strain, which predominantly forms clusters of magnetosomes, was only weakly aligned under any of the tested field conditions and could barely be distinguished from a nonmagnetic mutant. Most findings were corroborated by a soft agar swimming assay to analyze magnetotaxis based on the degree of distortion of swim halos formed in magnetic fields. Motility tracking further revealed that swimming speeds of M. gryphiswaldense are highest within the field strength equaling the geomagnetic field. In conclusion, magnetic properties and intracellular positioning of magnetosomes by a dedicated magnetoskeleton are required and optimized for bacterial magnetotaxis and most efficient locomotion within the geomagnetic field.IMPORTANCE In Magnetospirillum gryphiswaldense, magnetosomes are aligned in quasi-linear chains in a helical cell by a complex cytoskeletal network, including the actin-like MamK and adapter MamJ for magnetosome chain concatenation and segregation and MamY to position magnetosome chains along the shortest cellular axis of motility. Magnetosome chain positioning is assumed to be required for efficient magnetic navigation; however, the significance and contribution of all key constituents have not been quantified within defined and weak magnetic fields reflecting the geomagnetic field. Employing two different motility-based methods to consider the flagellum-mediated propulsion of cells, we depict individual benefits of all magnetoskeletal constituents for magnetotaxis. Whereas lack of mamJ resulted almost in an inability to align cells in weak magnetic fields, an approximately 4-fold-increased magnetic field strength was required to compensate for the loss of mamK or mamY In summary, the magnetoskeleton and optimal positioning of magnetosome chains are required for efficient magnetotaxis.
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20
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The in vivo mechanics of the magnetotactic backbone as revealed by correlative FLIM-FRET and STED microscopy. Sci Rep 2019; 9:19615. [PMID: 31873083 PMCID: PMC6928011 DOI: 10.1038/s41598-019-55804-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2019] [Accepted: 11/22/2019] [Indexed: 11/29/2022] Open
Abstract
Protein interaction and protein imaging strongly benefit from the advancements in time-resolved and superresolution fluorescence microscopic techniques. However, the techniques were typically applied separately and ex vivo because of technical challenges and the absence of suitable fluorescent protein pairs. Here, we show correlative in vivo fluorescence lifetime imaging microscopy Förster resonance energy transfer (FLIM-FRET) and stimulated emission depletion (STED) microscopy to unravel protein mechanics and structure in living cells. We use magnetotactic bacteria as a model system where two proteins, MamJ and MamK, are used to assemble magnetic particles called magnetosomes. The filament polymerizes out of MamK and the magnetosomes are connected via the linker MamJ. Our system reveals that bacterial filamentous structures are more fragile than the connection of biomineralized particles to this filament. More importantly, we anticipate the technique to find wide applicability for the study and quantification of biological processes in living cells and at high resolution.
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21
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Probing the Nanostructure and Arrangement of Bacterial Magnetosomes by Small-Angle X-Ray Scattering. Appl Environ Microbiol 2019; 85:AEM.01513-19. [PMID: 31604767 PMCID: PMC6881800 DOI: 10.1128/aem.01513-19] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2019] [Accepted: 10/06/2019] [Indexed: 12/02/2022] Open
Abstract
This study explores lab-based small-angle X-ray scattering (SAXS) as a novel quantitative stand-alone technique to monitor the size, shape, and arrangement of magnetosomes during different stages of particle biogenesis in the model organism Magnetospirillum gryphiswaldense. The SAXS data sets contain volume-averaged, statistically accurate information on both the diameter of the inorganic nanocrystal and the enveloping protein-rich magnetosome membrane. As a robust and nondestructive in situ technique, SAXS can provide new insights into the physicochemical steps involved in the biosynthesis of magnetosome nanoparticles as well as their assembly into well-ordered chains. The proposed fit model can easily be adapted to account for different particle shapes and arrangements produced by other strains of magnetotactic bacteria, thus rendering SAXS a highly versatile method. Magnetosomes are membrane-enveloped single-domain ferromagnetic nanoparticles enabling the navigation of magnetotactic bacteria along magnetic field lines. Strict control over each step of biomineralization generates particles of high crystallinity, strong magnetization, and remarkable uniformity in size and shape, which is particularly interesting for many biomedical and biotechnological applications. However, to understand the physicochemical processes involved in magnetite biomineralization, close and precise monitoring of particle production is required. Commonly used techniques, such as transmission electron microscopy (TEM) or Fe measurements, allow only for semiquantitative assessment of the magnetosome formation without routinely revealing quantitative structural information. In this study, lab-based small-angle X-ray scattering (SAXS) is explored as a means to monitor the different stages of magnetosome biogenesis in the model organism Magnetospirillum gryphiswaldense. SAXS is evaluated as a quantitative stand-alone technique to analyze the size, shape, and arrangement of magnetosomes in cells cultivated under different growth conditions. By applying a simple and robust fitting procedure based on spheres aligned in linear chains, it is demonstrated that the SAXS data sets contain information on both the diameter of the inorganic crystal and the protein-rich magnetosome membrane. The analyses corroborate a narrow particle size distribution with an overall magnetosome radius of 19 nm in Magnetospirillum gryphiswaldense. Furthermore, the averaged distance between individual magnetosomes is determined, revealing a chain-like particle arrangement with a center-to-center distance of 53 nm. Overall, these data demonstrate that SAXS can be used as a novel stand-alone technique allowing for the at-line monitoring of magnetosome biosynthesis, thereby providing accurate information on the particle nanostructure. IMPORTANCE This study explores lab-based small-angle X-ray scattering (SAXS) as a novel quantitative stand-alone technique to monitor the size, shape, and arrangement of magnetosomes during different stages of particle biogenesis in the model organism Magnetospirillum gryphiswaldense. The SAXS data sets contain volume-averaged, statistically accurate information on both the diameter of the inorganic nanocrystal and the enveloping protein-rich magnetosome membrane. As a robust and nondestructive in situ technique, SAXS can provide new insights into the physicochemical steps involved in the biosynthesis of magnetosome nanoparticles as well as their assembly into well-ordered chains. The proposed fit model can easily be adapted to account for different particle shapes and arrangements produced by other strains of magnetotactic bacteria, thus rendering SAXS a highly versatile method.
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22
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Illukkumbura R, Bland T, Goehring NW. Patterning and polarization of cells by intracellular flows. Curr Opin Cell Biol 2019; 62:123-134. [PMID: 31760155 PMCID: PMC6968950 DOI: 10.1016/j.ceb.2019.10.005] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2019] [Revised: 10/11/2019] [Accepted: 10/16/2019] [Indexed: 11/19/2022]
Abstract
Beginning with Turing’s seminal work [1], decades of research have demonstrated the fundamental ability of biochemical networks to generate and sustain the formation of patterns. However, it is increasingly appreciated that biochemical networks both shape and are shaped by physical and mechanical processes [2, 3, 4]. One such process is fluid flow. In many respects, the cytoplasm, membrane and actin cortex all function as fluids, and as they flow, they drive bulk transport of molecules throughout the cell. By coupling biochemical activity to long range molecular transport, flows can shape the distributions of molecules in space. Here we review the various types of flows that exist in cells, with the aim of highlighting recent advances in our understanding of how flows are generated and how they contribute to intracellular patterning processes, such as the establishment of cell polarity.
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Affiliation(s)
| | - Tom Bland
- The Francis Crick Institute, London, UK; Institute for the Physics of Living Systems, University College London, London, UK
| | - Nathan W Goehring
- The Francis Crick Institute, London, UK; Institute for the Physics of Living Systems, University College London, London, UK; MRC Laboratory for Molecular Cell Biology, University College London, London, UK.
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23
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Abstract
Spin wave logic circuits using quantum oscillations of spins (magnons) as carriers of information have been proposed for next generation computing with reduced energy demands and the benefit of easy parallelization. Current realizations of magnonic devices have micrometer sized patterns. Here we demonstrate the feasibility of biogenic nanoparticle chains as the first step to truly nanoscale magnonics at room temperature. Our measurements on magnetosome chains (ca 12 magnetite crystals with 35 nm particle size each), combined with micromagnetic simulations, show that the topology of the magnon bands, namely anisotropy, band deformation, and band gaps are determined by local arrangement and orientation of particles, which in turn depends on the genotype of the bacteria. Our biomagnonic approach offers the exciting prospect of genetically engineering magnonic quantum states in nanoconfined geometries. By connecting mutants of magnetotactic bacteria with different arrangements of magnetite crystals, novel architectures for magnonic computing may be (self-) assembled. The capability to engineer magnon states in confined geometries is vital to future nano-magnonics. Here the authors demonstrate that the topology of the magnon bands is determined by the local arrangement and orientation of nanoparticles and can be controlled by the genotype of magnetotactic bacteria.
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24
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Toro-Nahuelpan M, Corrales-Guerrero L, Zwiener T, Osorio-Valeriano M, Müller FD, Plitzko JM, Bramkamp M, Thanbichler M, Schüler D. A gradient-forming MipZ protein mediating the control of cell division in the magnetotactic bacterium Magnetospirillum gryphiswaldense. Mol Microbiol 2019; 112:1423-1439. [PMID: 31419361 DOI: 10.1111/mmi.14369] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Cell division needs to be tightly regulated and closely coordinated with other cellular processes to ensure the generation of fully viable offspring. Here, we investigate division site placement by the cell division regulator MipZ in the alphaproteobacterium Magnetospirillum gryphiswaldense, a species that forms linear chains of magnetosomes to navigate within the geomagnetic field. We show that M. gryphiswaldense contains two MipZ homologs, termed MipZ1 and MipZ2. MipZ2 localizes to the division site, but its absence does not cause any obvious phenotype. MipZ1, by contrast, forms a dynamic bipolar gradient, and its deletion or overproduction cause cell filamentation, suggesting an important role in cell division. The monomeric form of MipZ1 interacts with the chromosome partitioning protein ParB, whereas its ATP-dependent dimeric form shows non-specific DNA-binding activity. Notably, both the dimeric and, to a lesser extent, the monomeric form inhibit FtsZ polymerization in vitro. MipZ1 thus represents a canonical gradient-forming MipZ homolog that critically contributes to the spatiotemporal control of FtsZ ring formation. Collectively, our findings add to the view that the regulatory role of MipZ proteins in cell division is conserved among many alphaproteobacteria. However, their number and biochemical properties may have adapted to the specific needs of the host organism.
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Affiliation(s)
- Mauricio Toro-Nahuelpan
- Institute of Microbiology, University of Bayreuth, Bayreuth, Germany.,Department of Molecular Structural Biology, Max Planck Institute of Biochemistry, Planegg-Martinsried, Germany
| | | | - Theresa Zwiener
- Institute of Microbiology, University of Bayreuth, Bayreuth, Germany
| | - Manuel Osorio-Valeriano
- Faculty of Biology, Philipps-Universität, Marburg, Germany.,Max Planck Fellow Group "Bacterial Cell Biology", Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
| | | | - Jürgen M Plitzko
- Department of Molecular Structural Biology, Max Planck Institute of Biochemistry, Planegg-Martinsried, Germany
| | - Marc Bramkamp
- Department of Biology I, Ludwig-Maximilians-Universität München, Planegg-Martinsried, Germany
| | - Martin Thanbichler
- Faculty of Biology, Philipps-Universität, Marburg, Germany.,Max Planck Fellow Group "Bacterial Cell Biology", Max Planck Institute for Terrestrial Microbiology, Marburg, Germany.,Center for Synthetic Microbiology, Marburg, Germany
| | - Dirk Schüler
- Institute of Microbiology, University of Bayreuth, Bayreuth, Germany
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25
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Toro-Nahuelpan M, Giacomelli G, Raschdorf O, Borg S, Plitzko JM, Bramkamp M, Schüler D, Müller FD. MamY is a membrane-bound protein that aligns magnetosomes and the motility axis of helical magnetotactic bacteria. Nat Microbiol 2019; 4:1978-1989. [PMID: 31358981 PMCID: PMC6817358 DOI: 10.1038/s41564-019-0512-8] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2018] [Accepted: 06/11/2019] [Indexed: 11/09/2022]
Abstract
To navigate within the geomagnetic field, magnetotactic bacteria synthesize magnetosomes, which are unique organelles consisting of membrane-enveloped magnetite nanocrystals. In magnetotactic spirilla, magnetosomes become actively organized into chains by the filament-forming actin-like MamK and the adaptor protein MamJ, thereby assembling a magnetic dipole much like a compass needle. However, in Magnetospirillum gryphiswaldense, discontinuous chains are still formed in the absence of MamK. Moreover, these fragmented chains persist in a straight conformation indicating undiscovered structural determinants able to accommodate a bar magnet-like magnetoreceptor in a helical bacterium. Here, we identify MamY, a membrane-bound protein that generates a sophisticated mechanical scaffold for magnetosomes. MamY localizes linearly along the positive inner cell curvature (the geodetic cell axis), probably by self-interaction and curvature sensing. In a mamY deletion mutant, magnetosome chains detach from the geodetic axis and fail to accommodate a straight conformation coinciding with reduced cellular magnetic orientation. Codeletion of mamKY completely abolishes chain formation, whereas on synthetic tethering of magnetosomes to MamY, the chain configuration is regained, emphasizing the structural properties of the protein. Our results suggest MamY is membrane-anchored mechanical scaffold that is essential to align the motility axis of magnetotactic spirilla with their magnetic moment vector and to perfectly reconcile magnetoreception with swimming direction.
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Affiliation(s)
- Mauricio Toro-Nahuelpan
- Department of Microbiology, University of Bayreuth, Bayreuth, Germany.,Department of Molecular Structural Biology, Max Planck Institute of Biochemistry, Planegg-Martinsried, Germany.,European Molecular Biology Laboratory, Heidelberg, Germany
| | - Giacomo Giacomelli
- Department of Biology I, Ludwig-Maximilian-University Munich, Planegg-Martinsried, Germany
| | - Oliver Raschdorf
- Department of Microbiology, University of Bayreuth, Bayreuth, Germany.,Department of Molecular Structural Biology, Max Planck Institute of Biochemistry, Planegg-Martinsried, Germany.,ThermoFisher Scientific (formerly FEI Company), Eindhoven, the Netherlands
| | - Sarah Borg
- Department of Microbiology, University of Bayreuth, Bayreuth, Germany.,Bundeswehr Institute of Microbiology, Bundeswehr, Munich, Germany
| | - Jürgen M Plitzko
- Department of Molecular Structural Biology, Max Planck Institute of Biochemistry, Planegg-Martinsried, Germany
| | - Marc Bramkamp
- Department of Biology I, Ludwig-Maximilian-University Munich, Planegg-Martinsried, Germany
| | - Dirk Schüler
- Department of Microbiology, University of Bayreuth, Bayreuth, Germany
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26
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Dieudonné A, Pignol D, Prévéral S. Magnetosomes: biogenic iron nanoparticles produced by environmental bacteria. Appl Microbiol Biotechnol 2019; 103:3637-3649. [PMID: 30903215 DOI: 10.1007/s00253-019-09728-9] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2019] [Revised: 02/22/2019] [Accepted: 02/25/2019] [Indexed: 01/10/2023]
Abstract
The scientific community's interest in magnetotactic bacteria has increased substantially in recent decades. These prokaryotes have the particularity of synthesizing nanomagnets, called magnetosomes. The majority of research is based on several scientific questions. Where do magnetotactic bacteria live, what are their characteristics, and why are they magnetic? What are the molecular phenomena of magnetosome biomineralization and what are the physical characteristics of magnetosomes? In addition to scientific curiosity to better understand these stunning organisms, there are biotechnological opportunities to consider. Magnetotactic bacteria, as well as magnetosomes, are used in medical applications, for example cancer treatment, or in environmental ones, for example bioremediation. In this mini-review, we investigated all the aspects mentioned above and summarized the currently available knowledge.
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Affiliation(s)
- Anissa Dieudonné
- UMR 7265, Aix Marseille Univ, CEA, CNRS, BIAM, LBC, Saint Paul-Lez-Durance, France
| | - David Pignol
- UMR 7265, Aix Marseille Univ, CEA, CNRS, BIAM, LBC, Saint Paul-Lez-Durance, France
| | - Sandra Prévéral
- UMR 7265, Aix Marseille Univ, CEA, CNRS, BIAM, LBC, Saint Paul-Lez-Durance, France.
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The Polar Organizing Protein PopZ Is Fundamental for Proper Cell Division and Segregation of Cellular Content in Magnetospirillum gryphiswaldense. mBio 2019; 10:mBio.02716-18. [PMID: 30862753 PMCID: PMC6414705 DOI: 10.1128/mbio.02716-18] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Magnetotactic bacteria (MTB) share the unique capability of magnetic navigation, one of the most complex behavioral responses found in prokaryotes, by means of magnetosomes, which act as an internal compass. Due to formation of these unique nanoparticles, MTB have emerged as a model to study prokaryotic organelle formation and cytoskeletal organization in conjunction with complex motility systems. Despite the high degree of subcellular organization required in MTB, less is known about cell-cycle-related factors or proteins responsible for spatiotemporal polarity control. Here, we investigate the function of the polar organizer PopZ in the magnetotactic alphaproteobacterium Magnetospirillum gryphiswaldense. Although PopZ is widely distributed among the alphaproteobacteria, its function in MTB belonging to this class has remained unexplored. Our results suggest that in M. gryphiswaldense, PopZ has a key role during cell division and subcellular organization. Furthermore, we show that PopZ localization and function differ from other nonmagnetotactic alphaproteobacterial model organisms. Magnetotactic bacteria (MTB) are of special scientific interest due to the formation of magnetosomes, intracellular membrane-enveloped magnetite crystals arranged into a linear chain by a dedicated cytoskeleton. Magnetotaxis relies on the formation and proper inheritance of these unique magnetic organelles, both of which need to be coordinated with the segregation of other cellular content such as chromosomes or motility and chemotaxis related structures. Thus, elaborated mechanisms are required in MTB to coordinate and maintain a high level of spatial and temporal subcellular organization during cytokinesis. However, thus far, underlying mechanisms and polarity determinants such as landmark proteins remained obscure in MTB. Here, we analyzed an ortholog of the polar organizing protein Z in the alphaproteobacterium Magnetospirillum gryphiswaldense termed PopZMgr. We show that deletion of the popZMgr gene causes abnormal cell elongation, minicell formation, DNA missegregation, and impairs motility. Overproduction of PopZMgr results in PopZ-rich regions near the poles, which are devoid of larger macromolecules, such as ribosomes, chromosomal DNA, and polyhydroxybutyrate (PHB) granules. Using superresolution microscopy, we show that PopZMgr exhibits a bipolar localization pattern throughout the cell cycle, indicating that the definition of new poles in M. gryphiswaldense occurs immediately upon completion of cytokinesis. Moreover, substitution of PopZ orthologs between M. gryphiswaldense and the related alphaproteobacterium Caulobacter crescentus indicated that PopZ localization depends on host-specific cues and that both orthologs have diverged to an extent that allows only partial reciprocal functional complementation. Altogether, our results indicate that in M. gryphiswaldense, PopZ plays a critical role during cell division and segregation of cellular content.
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Mickoleit F, Schüler D. Generation of nanomagnetic biocomposites by genetic engineering of bacterial magnetosomes. BIOINSPIRED BIOMIMETIC AND NANOBIOMATERIALS 2019. [DOI: 10.1680/jbibn.18.00005] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Frank Mickoleit
- Department of Microbiology, University of Bayreuth, Bayreuth, Germany
| | - Dirk Schüler
- Department of Microbiology, University of Bayreuth, Bayreuth, Germany
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29
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Monteil CL, Perrière G, Menguy N, Ginet N, Alonso B, Waisbord N, Cruveiller S, Pignol D, Lefèvre CT. Genomic study of a novel magnetotactic Alphaproteobacteria uncovers the multiple ancestry of magnetotaxis. Environ Microbiol 2018; 20:4415-4430. [PMID: 30043533 DOI: 10.1111/1462-2920.14364] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2018] [Accepted: 07/19/2018] [Indexed: 01/06/2023]
Abstract
Ecological and evolutionary processes involved in magnetotactic bacteria (MTB) adaptation to their environment have been a matter of debate for many years. Ongoing efforts for their characterization are progressively contributing to understand these processes, including the genetic and molecular mechanisms responsible for biomineralization. Despite numerous culture-independent MTB characterizations, essentially within the Proteobacteria phylum, only few species have been isolated in culture because of their complex growth conditions. Here, we report a newly cultivated magnetotactic, microaerophilic and chemoorganoheterotrophic bacterium isolated from the Mediterranean Sea in Marseille, France: Candidatus Terasakiella magnetica strain PR-1 that belongs to an Alphaproteobacteria genus with no magnetotactic relative. By comparing the morphology and the whole genome shotgun sequence of this MTB with those of closer relatives, we brought further evidence that the apparent vertical ancestry of magnetosome genes suggested by previous studies within Alphaproteobacteria hides a more complex evolutionary history involving horizontal gene transfers and/or duplication events before and after the emergence of Magnetospirillum, Magnetovibrio and Magnetospira genera. A genome-scale comparative genomics analysis identified several additional candidate functions and genes that could be specifically associated to MTB lifestyle in this class of bacteria.
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Affiliation(s)
- Caroline L Monteil
- Institute of Biosciences and Biotechnologies of Aix Marseille (BIAM), UMR7265 CEA - CNRS - Aix Marseille University, CEA Cadarache, 13108, Saint-Paul-lez-Durance, France
| | - Guy Perrière
- Laboratoire de Biométrie et Biologie Evolutive, CNRS, UMR5558, Université Claude Bernard - Lyon 1, 69622, Villeurbanne, France
| | - Nicolas Menguy
- Sorbonne Université, Muséum National d'Histoire Naturelle, UMR CNRS 7590, IRD - IMPMC, 4 place Jussieu, 75005, Paris, France
| | - Nicolas Ginet
- Laboratoire de Chimie Bactérienne, UMR 7283 CNRS, Aix-Marseille Université, Institut de Microbiologie de la Méditerranée, 13402, Marseille, France
| | - Béatrice Alonso
- Institute of Biosciences and Biotechnologies of Aix Marseille (BIAM), UMR7265 CEA - CNRS - Aix Marseille University, CEA Cadarache, 13108, Saint-Paul-lez-Durance, France
| | - Nicolas Waisbord
- Department of Mechanical Engineering, Tufts University, 200 College Avenue, Medford, MA, 02155, USA
| | - Stéphane Cruveiller
- Commissariat à l'Energie Atomique et aux Energies Alternatives - Institut de Biologie François Jacob - Genoscope - Laboratoire d'Analyses Bioinformatiques pour la Génomique et le Métabolisme, UMR - CNRS 8030 Génomique Métabolique, Université d'Evry, Université Paris-Saclay, 91057 Evry, France
| | - David Pignol
- Institute of Biosciences and Biotechnologies of Aix Marseille (BIAM), UMR7265 CEA - CNRS - Aix Marseille University, CEA Cadarache, 13108, Saint-Paul-lez-Durance, France
| | - Christopher T Lefèvre
- Institute of Biosciences and Biotechnologies of Aix Marseille (BIAM), UMR7265 CEA - CNRS - Aix Marseille University, CEA Cadarache, 13108, Saint-Paul-lez-Durance, France
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Abstract
Uncovering the mechanisms that underlie the biogenesis and maintenance of eukaryotic organelles is a vibrant and essential area of biological research. In comparison, little attention has been paid to the process of compartmentalization in bacteria and archaea. This lack of attention is in part due to the common misconception that organelles are a unique evolutionary invention of the "complex" eukaryotic cell and are absent from the "primitive" bacterial and archaeal cells. Comparisons across the tree of life are further complicated by the nebulous criteria used to designate subcellular structures as organelles. Here, with the aid of a unified definition of a membrane-bounded organelle, we present some of the recent findings in the study of lipid-bounded organelles in bacteria and archaea.
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Affiliation(s)
- Carly R Grant
- Department of Plant and Microbial Biology, University of California, Berkeley, California 94720, USA;
| | - Juan Wan
- Department of Plant and Microbial Biology, University of California, Berkeley, California 94720, USA;
| | - Arash Komeili
- Department of Plant and Microbial Biology, University of California, Berkeley, California 94720, USA;
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31
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LaSarre B, Kysela DT, Stein BD, Ducret A, Brun YV, McKinlay JB. Restricted Localization of Photosynthetic Intracytoplasmic Membranes (ICMs) in Multiple Genera of Purple Nonsulfur Bacteria. mBio 2018; 9:e00780-18. [PMID: 29970460 PMCID: PMC6030561 DOI: 10.1128/mbio.00780-18] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2018] [Accepted: 06/06/2018] [Indexed: 01/18/2023] Open
Abstract
In bacteria and eukaryotes alike, proper cellular physiology relies on robust subcellular organization. For the phototrophic purple nonsulfur bacteria (PNSB), this organization entails the use of a light-harvesting, membrane-bound compartment known as the intracytoplasmic membrane (ICM). Here we show that ICMs are spatially and temporally localized in diverse patterns among PNSB. We visualized ICMs in live cells of 14 PNSB species across nine genera by exploiting the natural autofluorescence of the photosynthetic pigment bacteriochlorophyll (BChl). We then quantitatively characterized ICM localization using automated computational analysis of BChl fluorescence patterns within single cells across the population. We revealed that while many PNSB elaborate ICMs along the entirety of the cell, species across as least two genera restrict ICMs to discrete, nonrandom sites near cell poles in a manner coordinated with cell growth and division. Phylogenetic and phenotypic comparisons established that ICM localization and ICM architecture are not strictly interdependent and that neither trait fully correlates with the evolutionary relatedness of the species. The natural diversity of ICM localization revealed herein has implications for both the evolution of phototrophic organisms and their light-harvesting compartments and the mechanisms underpinning spatial organization of bacterial compartments.IMPORTANCE Many bacteria organize their cellular space by constructing subcellular compartments that are arranged in specific, physiologically relevant patterns. The purple nonsulfur bacteria (PNSB) utilize a membrane-bound compartment known as the intracytoplasmic membrane (ICM) to harvest light for photosynthesis. It was previously unknown whether ICM localization within cells is systematic or irregular and if ICM localization is conserved among PNSB. Here we surveyed ICM localization in diverse PNSB and show that ICMs are spatially organized in species-specific patterns. Most strikingly, several PNSB resolutely restrict ICMs to regions near the cell poles, leaving much of the cell devoid of light-harvesting machinery. Our results demonstrate that bacteria of a common lifestyle utilize unequal portions of their intracellular space to harvest light, despite light harvesting being a process that is intuitively influenced by surface area. Our findings therefore raise fundamental questions about ICM biology and evolution.
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Affiliation(s)
- Breah LaSarre
- Department of Biology, Indiana University, Bloomington, Indiana, USA
| | - David T Kysela
- Department of Biology, Indiana University, Bloomington, Indiana, USA
| | - Barry D Stein
- Department of Biology, Indiana University, Bloomington, Indiana, USA
| | - Adrien Ducret
- Department of Biology, Indiana University, Bloomington, Indiana, USA
| | - Yves V Brun
- Department of Biology, Indiana University, Bloomington, Indiana, USA
| | - James B McKinlay
- Department of Biology, Indiana University, Bloomington, Indiana, USA
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32
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Mickoleit F, Borkner CB, Toro-Nahuelpan M, Herold HM, Maier DS, Plitzko JM, Scheibel T, Schüler D. In Vivo Coating of Bacterial Magnetic Nanoparticles by Magnetosome Expression of Spider Silk-Inspired Peptides. Biomacromolecules 2018; 19:962-972. [PMID: 29357230 DOI: 10.1021/acs.biomac.7b01749] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Magnetosomes are natural magnetic nanoparticles with exceptional properties that are synthesized in magnetotactic bacteria by a highly regulated biomineralization process. Their usability in many applications could be further improved by encapsulation in biocompatible polymers. In this study, we explored the production of spider silk-inspired peptides on magnetosomes of the alphaproteobacterium Magnetospirillum gryphiswaldense. Genetic fusion of different silk sequence-like variants to abundant magnetosome membrane proteins enhanced magnetite biomineralization and caused the formation of a proteinaceous capsule, which increased the colloidal stability of isolated particles. Furthermore, we show that spider silk peptides fused to a magnetosome membrane protein can be used as seeds for silk fibril growth on the magnetosome surface. In summary, we demonstrate that the combination of two different biogenic materials generates a genetically encoded hybrid composite with engineerable new properties and enhanced potential for various applications.
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Affiliation(s)
| | | | - Mauricio Toro-Nahuelpan
- Department of Molecular Structural Biology , Max Planck Institute of Biochemistry , D-82152 Martinsried , Germany
| | | | | | - Jürgen M Plitzko
- Department of Molecular Structural Biology , Max Planck Institute of Biochemistry , D-82152 Martinsried , Germany
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33
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Wagstaff J, Löwe J. Prokaryotic cytoskeletons: protein filaments organizing small cells. Nat Rev Microbiol 2018; 16:187-201. [PMID: 29355854 DOI: 10.1038/nrmicro.2017.153] [Citation(s) in RCA: 72] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Most, if not all, bacterial and archaeal cells contain at least one protein filament system. Although these filament systems in some cases form structures that are very similar to eukaryotic cytoskeletons, the term 'prokaryotic cytoskeletons' is used to refer to many different kinds of protein filaments. Cytoskeletons achieve their functions through polymerization of protein monomers and the resulting ability to access length scales larger than the size of the monomer. Prokaryotic cytoskeletons are involved in many fundamental aspects of prokaryotic cell biology and have important roles in cell shape determination, cell division and nonchromosomal DNA segregation. Some of the filament-forming proteins have been classified into a small number of conserved protein families, for example, the almost ubiquitous tubulin and actin superfamilies. To understand what makes filaments special and how the cytoskeletons they form enable cells to perform essential functions, the structure and function of cytoskeletal molecules and their filaments have been investigated in diverse bacteria and archaea. In this Review, we bring these data together to highlight the diverse ways that linear protein polymers can be used to organize other molecules and structures in bacteria and archaea.
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Affiliation(s)
- James Wagstaff
- Medical Research Council Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, UK
| | - Jan Löwe
- Medical Research Council Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, UK
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34
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Kiani B, Faivre D, Klumpp S. Self-organization and stability of magnetosome chains-A simulation study. PLoS One 2018; 13:e0190265. [PMID: 29315342 PMCID: PMC5760029 DOI: 10.1371/journal.pone.0190265] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2017] [Accepted: 12/11/2017] [Indexed: 11/18/2022] Open
Abstract
Magnetotactic bacteria orient in magnetic fields with the help of their magnetosome chain, a linear structure of membrane enclosed magnetic nanoparticles (magnetosomes) anchored to a cytoskeletal filament. Here, we use simulations to study the assembly and the stability of magnetosome chains. We introduce a computational model describing the attachment of the magnetosomes to the filament and their magnetic interactions. We show that the filamentous backbone is crucial for the robust assembly of the magnetic particles into a linear chain, which in turn is key for the functionality of the chain in cellular orientation and magnetically directed swimming. In addition, we simulate the response to an external magnetic field that is rotated away from the axis of the filament, an experimental method used to probe the mechanical stability of the chain. The competition between alignment along the filament and alignment with the external fields leads to the rupture of a chain if the applied field exceeeds a threshold value. These observations are in agreement with previous experiments at the population level. Beyond that, our simulations provide a detailed picture of chain rupture at the single cell level, which is found to happen through two abrupt events, which both depend on the field strength and orientation. The re-formation of the chain structure after such rupture is found to be strongly sped up in the presence of a magnetic field parallel to the filament, an observation that may also be of interest for the design of self-healing materials. Our simulations underline the dynamic nature of the magnetosome chain. More generally, they show the rich complexity of self-assembly in systems with competing driving forces for alignment.
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Affiliation(s)
- Bahareh Kiani
- Department Theory & Bio-Systems, Max Planck Institute of Colloids and Interfaces, Science Park Golm 14424 Potsdam, Germany
- Department Biomaterials, Max Planck Institute of Colloids and Interfaces, Science Park Golm, 14424 Potsdam, Germany
- * E-mail: (BK); (SK)
| | - Damien Faivre
- Department Biomaterials, Max Planck Institute of Colloids and Interfaces, Science Park Golm, 14424 Potsdam, Germany
| | - Stefan Klumpp
- Department Theory & Bio-Systems, Max Planck Institute of Colloids and Interfaces, Science Park Golm 14424 Potsdam, Germany
- Institute for Nonlinear Dynamics, Georg August University of Goettingen, Friedrich-Hund-Platz 1, 37077 Goettingen, Germany
- * E-mail: (BK); (SK)
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35
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Uebe R, Keren-Khadmy N, Zeytuni N, Katzmann E, Navon Y, Davidov G, Bitton R, Plitzko JM, Schüler D, Zarivach R. The dual role of MamB in magnetosome membrane assembly and magnetite biomineralization. Mol Microbiol 2018; 107:542-557. [PMID: 29243866 DOI: 10.1111/mmi.13899] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2017] [Revised: 12/11/2017] [Accepted: 12/13/2017] [Indexed: 11/30/2022]
Abstract
Magnetospirillum gryphiswaldense MSR-1 synthesizes membrane-enclosed magnetite (Fe3 O4 ) nanoparticles, magnetosomes, for magnetotaxis. Formation of these organelles involves a complex process comprising key steps which are governed by specific magnetosome-associated proteins. MamB, a cation diffusion facilitator (CDF) family member has been implicated in magnetosome-directed iron transport. However, deletion mutagenesis studies revealed that MamB is essential for the formation of magnetosome membrane vesicles, but its precise role remains elusive. In this study, we employed a multi-disciplinary approach to define the role of MamB during magnetosome formation. Using site-directed mutagenesis complemented by structural analyses, fluorescence microscopy and cryo-electron tomography, we show that MamB is most likely an active magnetosome-directed transporter serving two distinct, yet essential functions. First, MamB initiates magnetosome vesicle formation in a transport-independent process, probably by serving as a landmark protein. Second, MamB transport activity is required for magnetite nucleation. Furthermore, by determining the crystal structure of the MamB cytosolic C-terminal domain, we also provide mechanistic insight into transport regulation. Additionally, we present evidence that magnetosome vesicle growth and chain formation are independent of magnetite nucleation and magnetic interactions respectively. Together, our data provide novel insight into the role of the key bifunctional magnetosome protein MamB, and the early steps of magnetosome formation.
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Affiliation(s)
- René Uebe
- Department of Microbiology, University of Bayreuth, Universitätsstraße 30, 95447 Bayreuth, Germany
| | - Noa Keren-Khadmy
- Department of Life Sciences, Ben-Gurion University of the Negev, P.O.B. 653, Beer-Sheva 84105, Israel.,The National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev, P.O.B. 653, Beer-Sheva 84105, Israel.,Ilse Katz Institute for Nanoscale Science & Technology, Ben-Gurion University of the Negev, P.O.B. 653, Beer-Sheva 84105, Israel
| | - Natalie Zeytuni
- Department of Life Sciences, Ben-Gurion University of the Negev, P.O.B. 653, Beer-Sheva 84105, Israel.,The National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev, P.O.B. 653, Beer-Sheva 84105, Israel.,Ilse Katz Institute for Nanoscale Science & Technology, Ben-Gurion University of the Negev, P.O.B. 653, Beer-Sheva 84105, Israel
| | - Emanuel Katzmann
- Department of Molecular Structural Biology, Am Klopferspitz 18, Max Planck Institute of Biochemistry, D-82152 Martinsried, Germany
| | - Yotam Navon
- The National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev, P.O.B. 653, Beer-Sheva 84105, Israel.,Department of Chemical Engineering, Ben-Gurion University of the Negev, P.O.B. 653, Beer-Sheva 84105, Israel
| | - Geula Davidov
- Department of Life Sciences, Ben-Gurion University of the Negev, P.O.B. 653, Beer-Sheva 84105, Israel.,The National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev, P.O.B. 653, Beer-Sheva 84105, Israel.,Ilse Katz Institute for Nanoscale Science & Technology, Ben-Gurion University of the Negev, P.O.B. 653, Beer-Sheva 84105, Israel
| | - Ronit Bitton
- The National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev, P.O.B. 653, Beer-Sheva 84105, Israel.,Department of Chemical Engineering, Ben-Gurion University of the Negev, P.O.B. 653, Beer-Sheva 84105, Israel
| | - Jürgen M Plitzko
- Department of Molecular Structural Biology, Am Klopferspitz 18, Max Planck Institute of Biochemistry, D-82152 Martinsried, Germany
| | - Dirk Schüler
- Department of Microbiology, University of Bayreuth, Universitätsstraße 30, 95447 Bayreuth, Germany
| | - Raz Zarivach
- Department of Life Sciences, Ben-Gurion University of the Negev, P.O.B. 653, Beer-Sheva 84105, Israel.,The National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev, P.O.B. 653, Beer-Sheva 84105, Israel.,Ilse Katz Institute for Nanoscale Science & Technology, Ben-Gurion University of the Negev, P.O.B. 653, Beer-Sheva 84105, Israel
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36
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Stoddard PR, Williams TA, Garner E, Baum B. Evolution of polymer formation within the actin superfamily. Mol Biol Cell 2017; 28:2461-2469. [PMID: 28904122 PMCID: PMC5597319 DOI: 10.1091/mbc.e15-11-0778] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2017] [Revised: 07/13/2017] [Accepted: 07/18/2017] [Indexed: 01/02/2023] Open
Abstract
While many are familiar with actin as a well-conserved component of the eukaryotic cytoskeleton, it is less often appreciated that actin is a member of a large superfamily of structurally related protein families found throughout the tree of life. Actin-related proteins include chaperones, carbohydrate kinases, and other enzymes, as well as a staggeringly diverse set of proteins that use the energy from ATP hydrolysis to form dynamic, linear polymers. Despite differing widely from one another in filament structure and dynamics, these polymers play important roles in ordering cell space in bacteria, archaea, and eukaryotes. It is not known whether these polymers descended from a single ancestral polymer or arose multiple times by convergent evolution from monomeric actin-like proteins. In this work, we provide an overview of the structures, dynamics, and functions of this diverse set. Then, using a phylogenetic analysis to examine actin evolution, we show that the actin-related protein families that form polymers are more closely related to one another than they are to other nonpolymerizing members of the actin superfamily. Thus all the known actin-like polymers are likely to be the descendants of a single, ancestral, polymer-forming actin-like protein.
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Affiliation(s)
- Patrick R Stoddard
- Molecular and Cellular Biology, Faculty of Arts and Sciences Center for Systems Biology, Harvard University, Cambridge, MA 02138
| | - Tom A Williams
- School of Biological Sciences, University of Bristol, Bristol BS8 1TQ, UK
| | - Ethan Garner
- Molecular and Cellular Biology, Faculty of Arts and Sciences Center for Systems Biology, Harvard University, Cambridge, MA 02138
| | - Buzz Baum
- MRC-Laboratory for Molecular Cell Biology, University College London, London WC1E 6BT, UK
- Institute of Physics of Living Systems, University College London, London WC1E 6BT, UK
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Tethered Magnets Are the Key to Magnetotaxis: Direct Observations of Magnetospirillum magneticum AMB-1 Show that MamK Distributes Magnetosome Organelles Equally to Daughter Cells. mBio 2017; 8:mBio.00679-17. [PMID: 28790202 PMCID: PMC5550748 DOI: 10.1128/mbio.00679-17] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Magnetotactic bacteria are a unique group of bacteria that synthesize a magnetic organelle termed the magnetosome, which they use to assist with their magnetic navigation in a specific type of bacterial motility called magneto-aerotaxis. Cytoskeletal filaments consisting of the actin-like protein MamK are associated with the magnetosome chain. Previously, the function of MamK was thought to be in positioning magnetosome organelles; this was proposed based on observations via electron microscopy still images. Here, we conducted live-cell time-lapse fluorescence imaging analyses employing highly inclined and laminated optical sheet microscopy, and these methods enabled us to visualize detailed dynamic movement of magnetosomes in growing cells during the entire cell cycle with high-temporal resolution and a high signal/noise ratio. We found that the MamK cytoskeleton anchors magnetosomes through a mechanism that requires MamK-ATPase activity throughout the cell cycle to prevent simple diffusion of magnetosomes within the cell. We concluded that the static chain-like arrangement of the magnetosomes is required to precisely and consistently segregate the magnetosomes to daughter cells. Thus, the daughter cells inherit a functional magnetic sensor that mediates magneto-reception. Half a century ago, bacterial cells were considered a simple “bag of enzymes”; only recently have they been shown to comprise ordered complexes of macromolecular structures, such as bacterial organelles and cytoskeletons, similar to their eukaryotic counterparts. In eukaryotic cells, the positioning of organelles is regulated by cytoskeletal elements. However, the role of cytoskeletal elements in the positioning of bacterial organelles, such as magnetosomes, remains unclear. Magnetosomes are associated with cytoskeletal filaments that consist of the actin-like protein MamK. In this study, we focused on how the MamK cytoskeleton regulates the dynamic movement of magnetosome organelles in living magnetotactic bacterial cells. Here, we used fluorescence imaging to visualize the dynamics of magnetosomes throughout the cell cycle in living magnetotactic bacterial cells to understand how they use the actin-like cytoskeleton to maintain and to make functional their nano-sized magnetic organelles.
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Forde AJ, Albrecht N, Klingl A, Donovan C, Bramkamp M. Polymerization Dynamics of the Prophage-Encoded Actin-Like Protein AlpC Is Influenced by the DNA-Binding Adapter AlpA. Front Microbiol 2017; 8:1429. [PMID: 28824563 PMCID: PMC5539076 DOI: 10.3389/fmicb.2017.01429] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2017] [Accepted: 07/14/2017] [Indexed: 11/13/2022] Open
Abstract
The Corynebacterium glutamicum ATCC 13032 prophage CGP3 encodes an actin-like protein, AlpC that was shown to be involved in viral DNA transport and efficient viral DNA replication. AlpC binds to an adapter, AlpA that in turn binds to specific DNA sequences, termed alpS sites. Thus, the AlpAC system is similar to the known plasmid segregation system ParMRS. So far it is unclear how the AlpACS system mediates DNA transport and, whether AlpA and AlpC functionally interact. We show here that AlpA modulates AlpC filamentation dynamics in a dual way. Unbound AlpA stimulates AlpC filament disassembly, while AlpA bound to alpS sites allows for AlpC filament formation. Based on these results we propose a simple search and capture model that explains DNA segregation by viral AlpACS DNA segregation system.
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Zahn C, Keller S, Toro-Nahuelpan M, Dorscht P, Gross W, Laumann M, Gekle S, Zimmermann W, Schüler D, Kress H. Measurement of the magnetic moment of single Magnetospirillum gryphiswaldense cells by magnetic tweezers. Sci Rep 2017; 7:3558. [PMID: 28620230 PMCID: PMC5472611 DOI: 10.1038/s41598-017-03756-z] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2017] [Accepted: 05/03/2017] [Indexed: 11/26/2022] Open
Abstract
Magnetospirillum gryphiswaldense is a helix-shaped magnetotactic bacterium that synthesizes iron-oxide nanocrystals, which allow navigation along the geomagnetic field. The bacterium has already been thoroughly investigated at the molecular and cellular levels. However, the fundamental physical property enabling it to perform magnetotaxis, its magnetic moment, remains to be elucidated at the single cell level. We present a method based on magnetic tweezers; in combination with Stokesian dynamics and Boundary Integral Method calculations, this method allows the simultaneous measurement of the magnetic moments of multiple single bacteria. The method is demonstrated by quantifying the distribution of the individual magnetic moments of several hundred cells of M. gryphiswaldense. In contrast to other techniques for measuring the average magnetic moment of bacterial populations, our method accounts for the size and the helical shape of each individual cell. In addition, we determined the distribution of the saturation magnetic moments of the bacteria from electron microscopy data. Our results are in agreement with the known relative magnetization behavior of the bacteria. Our method can be combined with single cell imaging techniques and thus can address novel questions about the functions of components of the molecular magnetosome biosynthesis machinery and their correlation with the resulting magnetic moment.
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Affiliation(s)
- C Zahn
- Biological Physics, Department of Physics, University of Bayreuth, Bayreuth, Germany
| | - S Keller
- Biological Physics, Department of Physics, University of Bayreuth, Bayreuth, Germany
| | - M Toro-Nahuelpan
- Department of Microbiology, University of Bayreuth, Bayreuth, Germany
- Department of Molecular Structural Biology, Max Planck Institute of Biochemistry, Planegg-Martinsried, Germany
| | - P Dorscht
- Biological Physics, Department of Physics, University of Bayreuth, Bayreuth, Germany
| | - W Gross
- Biological Physics, Department of Physics, University of Bayreuth, Bayreuth, Germany
| | - M Laumann
- Theoretical Physics I, Department of Physics, University of Bayreuth, Bayreuth, Germany
| | - S Gekle
- Biofluid Simulation and Modeling, Department of Physics, University of Bayreuth, Bayreuth, Germany
| | - W Zimmermann
- Theoretical Physics I, Department of Physics, University of Bayreuth, Bayreuth, Germany
| | - D Schüler
- Department of Microbiology, University of Bayreuth, Bayreuth, Germany
| | - H Kress
- Biological Physics, Department of Physics, University of Bayreuth, Bayreuth, Germany.
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