1
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Murmiliuk A, Iwase H, Kang JJ, Mohanakumar S, Appavou MS, Wood K, Almásy L, Len A, Schwärzer K, Allgaier J, Dulle M, Gensch T, Förster B, Ito K, Nakagawa H, Wiegand S, Förster S, Radulescu A. Polyelectrolyte-protein synergism: pH-responsive polyelectrolyte/insulin complexes as versatile carriers for targeted protein and drug delivery. J Colloid Interface Sci 2024; 665:801-813. [PMID: 38555748 DOI: 10.1016/j.jcis.2024.03.156] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2023] [Revised: 03/10/2024] [Accepted: 03/23/2024] [Indexed: 04/02/2024]
Abstract
The co-assembly of polyelectrolytes (PE) with proteins offers a promising approach for designing complex structures with customizable morphologies, charge distribution, and stability for targeted cargo delivery. However, the complexity of protein structure limits our ability to predict the properties of the formed nanoparticles, and our goal is to identify the key triggers of the morphological transition in protein/PE complexes and evaluate their ability to encapsulate multivalent ionic drugs. A positively charged PE can assemble with a protein at pH above isoelectric point due to the electrostatic attraction and disassemble at pH below isoelectric point due to the repulsion. The additional hydrophilic block of the polymer should stabilize the particles in solution and enable them to encapsulate a negatively charged drug in the presence of PE excess. We demonstrated that diblock copolymers, poly(ethylene oxide)-block-poly(N,N-dimethylaminoethyl methacrylate) and poly(ethylene oxide)-block-poly(N,N,N-trimethylammonioethyl methacrylate), consisting of a polycation block and a neutral hydrophilic block, reversibly co-assemble with insulin in pH range between 5 and 8. Using small-angle neutron and X-ray scattering (SANS, SAXS), we showed that insulin arrangement within formed particles is controlled by intermolecular electrostatic forces between protein molecules, and can be tuned by varying ionic strength. For the first time, we observed by fluorescence that formed protein/PE complexes with excess of positive charges exhibited potential for encapsulating and controlled release of negatively charged bivalent drugs, protoporphyrin-IX and zinc(II) protoporphyrin-IX, enabling the development of nanocarriers for combination therapies with adjustable charge, stability, internal structure, and size.
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Affiliation(s)
- Anastasiia Murmiliuk
- Jülich Centre for Neutron Science (JCNS) at Heinz Maier-Leibnitz Zentrum (MLZ), Forschungszentrum Jülich GmbH, Lichtenbergstraße 1, 85747 Garching, Germany.
| | - Hiroki Iwase
- Neutron Science and Technology Center, Comprehensive Research Organization for Science and Society (CROSS), Tokai, Ibaraki 319-1106, Japan
| | - Jia-Jhen Kang
- Jülich Centre for Neutron Science (JCNS) at Heinz Maier-Leibnitz Zentrum (MLZ), Forschungszentrum Jülich GmbH, Lichtenbergstraße 1, 85747 Garching, Germany
| | - Shilpa Mohanakumar
- Physics of Complex Fluids, University of Twente, 7522 NB Enschede, The Netherlands
| | - Marie-Sousai Appavou
- Jülich Centre for Neutron Science (JCNS) at Heinz Maier-Leibnitz Zentrum (MLZ), Forschungszentrum Jülich GmbH, Lichtenbergstraße 1, 85747 Garching, Germany
| | - Kathleen Wood
- Australian Centre for Neutron Scattering, Australian Nuclear Science and Technology Organization, New Illawarra Road, Lucas Heights, NSW 2234, Australia
| | - László Almásy
- Neutron Spectroscopy Department, HUN-REN Centre for Energy Research, Konkoly-Thege str. 29-33, 1121 Budapest, Hungary
| | - Adél Len
- Neutron Spectroscopy Department, HUN-REN Centre for Energy Research, Konkoly-Thege str. 29-33, 1121 Budapest, Hungary; University of Pécs, Faculty of Engineering and Information Technology, Boszorkány str 2., 7624 Pécs, Hungary
| | - Kuno Schwärzer
- Jülich Centre for Neutron Science (JCNS-1/IBI-8), Forschungszentrum Jülich, Wilhelm-Johnen-Straße, 52425 Jülich, Germany
| | - Jürgen Allgaier
- Jülich Centre for Neutron Science (JCNS-1/IBI-8), Forschungszentrum Jülich, Wilhelm-Johnen-Straße, 52425 Jülich, Germany
| | - Martin Dulle
- Jülich Centre for Neutron Science (JCNS-1/IBI-8), Forschungszentrum Jülich, Wilhelm-Johnen-Straße, 52425 Jülich, Germany
| | - Thomas Gensch
- Institute of Biological Information Processing, IBI-1 (Molecular and Cellular Physiology), Forschungszentrum Jülich, 52425 Jülich, Germany
| | - Beate Förster
- Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons, Physics of Nanoscale Systems (ER-C-1), Forschungszentrum Jülich, Wilhelm-Johnen-Straße, 52425 Jülich, Germany
| | - Kanae Ito
- Industrial Application Division, Spring-8, Japan Synchrotron Radiation Research Institute (JASRI), 1-1-1 Kouto, Sayo, Hyogo 679-5198, Japan
| | - Hiroshi Nakagawa
- Materials Sciences Research Center, Japan Atomic Energy Agency, Tokai, Ibaraki, Japan
| | - Simone Wiegand
- IBI-4-Biomacromolecular Systems and Processes, Forschungszentrum Jülich GmbH, D-52428 Jülich, Germany; Chemistry Department - Physical Chemistry, University Cologne, D-50939 Cologne, Germany
| | - Stephan Förster
- Jülich Centre for Neutron Science (JCNS-1/IBI-8), Forschungszentrum Jülich, Wilhelm-Johnen-Straße, 52425 Jülich, Germany
| | - Aurel Radulescu
- Jülich Centre for Neutron Science (JCNS) at Heinz Maier-Leibnitz Zentrum (MLZ), Forschungszentrum Jülich GmbH, Lichtenbergstraße 1, 85747 Garching, Germany
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2
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Bestsennaia E, Maslov I, Balandin T, Alekseev A, Yudenko A, Abu Shamseye A, Zabelskii D, Baumann A, Catapano C, Karathanasis C, Gordeliy V, Heilemann M, Gensch T, Borshchevskiy V. Channelrhodopsin-2 Oligomerization in Cell Membrane Revealed by Photo-Activated Localization Microscopy. Angew Chem Int Ed Engl 2024; 63:e202307555. [PMID: 38226794 DOI: 10.1002/anie.202307555] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2023] [Revised: 01/03/2024] [Accepted: 01/15/2024] [Indexed: 01/17/2024]
Abstract
Microbial rhodopsins are retinal membrane proteins that found a broad application in optogenetics. The oligomeric state of rhodopsins is important for their functionality and stability. Of particular interest is the oligomeric state in the cellular native membrane environment. Fluorescence microscopy provides powerful tools to determine the oligomeric state of membrane proteins directly in cells. Among these methods is quantitative photoactivated localization microscopy (qPALM) allowing the investigation of molecular organization at the level of single protein clusters. Here, we apply qPALM to investigate the oligomeric state of the first and most used optogenetic tool Channelrhodopsin-2 (ChR2) in the plasma membrane of eukaryotic cells. ChR2 appeared predominantly as a dimer in the cell membrane and did not form higher oligomers. The disulfide bonds between Cys34 and Cys36 of adjacent ChR2 monomers were not required for dimer formation and mutations disrupting these bonds resulted in only partial monomerization of ChR2. The monomeric fraction increased when the total concentration of mutant ChR2 in the membrane was low. The dissociation constant was estimated for this partially monomerized mutant ChR2 as 2.2±0.9 proteins/μm2 . Our findings are important for understanding the mechanistic basis of ChR2 activity as well as for improving existing and developing future optogenetic tools.
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Affiliation(s)
- Ekaterina Bestsennaia
- Institute of Biological Information Processing 1, IBI-1 (Molecular and Cellular Physiology), Forschungszentrum Jülich, 52428, Jülich, Germany
| | - Ivan Maslov
- Dynamic Bioimaging Lab, Advanced Optical Microscopy Centre and the Biomedical Research Institute, Hasselt University, B3590, Diepenbeek, Belgium
- Laboratory for Photochemistry and Spectroscopy, Division for Molecular Imaging and Photonics, Department of Chemistry, KU Leuven, 3001, Leuven, Belgium
| | - Taras Balandin
- Institute of Biological Information Processing 7, IBI-7 (Structural Biochemistry), Forschungszentrum Jülich, 52428, Jülich, Germany
| | - Alexey Alekseev
- Institute for Auditory Neuroscience and InnerEarLab, University Medical Center Göttingen, 37075, Göttingen, Germany
| | - Anna Yudenko
- Department of Biomedical Sciences, University Medical Center Groningen, University of Groningen, 9713 AV, Groningen, The Netherlands
| | - Assalla Abu Shamseye
- Institute of Biological Information Processing 1, IBI-1 (Molecular and Cellular Physiology), Forschungszentrum Jülich, 52428, Jülich, Germany
- Institute of Biological Information Processing 7, IBI-7 (Structural Biochemistry), Forschungszentrum Jülich, 52428, Jülich, Germany
| | - Dmitrii Zabelskii
- Institute of Biological Information Processing 7, IBI-7 (Structural Biochemistry), Forschungszentrum Jülich, 52428, Jülich, Germany
- European XFEL, 22869, Schenefeld, Germany
| | - Arnd Baumann
- Institute of Biological Information Processing 1, IBI-1 (Molecular and Cellular Physiology), Forschungszentrum Jülich, 52428, Jülich, Germany
| | - Claudia Catapano
- Institute of Physical and Theoretical Chemistry, Goethe-University Frankfurt, 60438, Frankfurt, Germany
| | - Christos Karathanasis
- Institute of Physical and Theoretical Chemistry, Goethe-University Frankfurt, 60438, Frankfurt, Germany
| | - Valentin Gordeliy
- Institute of Biological Information Processing 7, IBI-7 (Structural Biochemistry), Forschungszentrum Jülich, 52428, Jülich, Germany
| | - Mike Heilemann
- Institute of Physical and Theoretical Chemistry, Goethe-University Frankfurt, 60438, Frankfurt, Germany
| | - Thomas Gensch
- Institute of Biological Information Processing 1, IBI-1 (Molecular and Cellular Physiology), Forschungszentrum Jülich, 52428, Jülich, Germany
| | - Valentin Borshchevskiy
- Institute of Biological Information Processing 7, IBI-7 (Structural Biochemistry), Forschungszentrum Jülich, 52428, Jülich, Germany
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3
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Luginina A, Maslov I, Khorn P, Volkov O, Khnykin A, Kuzmichev P, Shevtsov M, Belousov A, Kapranov I, Dashevskii D, Kornilov D, Bestsennaia E, Hofkens J, Hendrix J, Gensch T, Cherezov V, Ivanovich V, Mishin A, Borshchevskiy V. Functional GPCR Expression in Eukaryotic LEXSY System. J Mol Biol 2023; 435:168310. [PMID: 37806553 DOI: 10.1016/j.jmb.2023.168310] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Revised: 10/03/2023] [Accepted: 10/04/2023] [Indexed: 10/10/2023]
Abstract
G protein-coupled receptors (GPCRs) form the largest superfamily of membrane proteins in the human genome, and represent one of the most important classes of drug targets. Their structural studies facilitate rational drug discovery. However, atomic structures of only about 20% of human GPCRs have been solved to date. Recombinant production of GPCRs for structural studies at a large scale is challenging due to their low expression levels and stability. Therefore, in this study, we explored the efficacy of the eukaryotic system LEXSY (Leishmania tarentolae) for GPCR production. We selected the human A2A adenosine receptor (A2AAR), as a model protein, expressed it in LEXSY, purified it, and compared with the same receptor produced in insect cells, which is the most popular expression system for structural studies of GPCRs. The A2AAR purified from both expression systems showed similar purity, stability, ligand-induced conformational changes and structural dynamics, with a remarkably higher protein yield in the case of LEXSY expression. Overall, our results suggest that LEXSY is a promising platform for large-scale production of GPCRs for structural studies.
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Affiliation(s)
- Aleksandra Luginina
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, Dolgoprudny, Moscow Region, Russia
| | - Ivan Maslov
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, Dolgoprudny, Moscow Region, Russia; Dynamic Bioimaging Lab, Advanced Optical Microscopy Centre, Biomedical Research Institute, Agoralaan C (BIOMED), Hasselt University, Diepenbeek, Belgium; Laboratory for Photochemistry and Spectroscopy, Division for Molecular Imaging and Photonics, Department of Chemistry, KU Leuven, Leuven, Belgium
| | - Polina Khorn
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, Dolgoprudny, Moscow Region, Russia
| | | | - Andrey Khnykin
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, Dolgoprudny, Moscow Region, Russia
| | - Pavel Kuzmichev
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, Dolgoprudny, Moscow Region, Russia
| | - Mikhail Shevtsov
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, Dolgoprudny, Moscow Region, Russia
| | - Anatoliy Belousov
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, Dolgoprudny, Moscow Region, Russia
| | - Ivan Kapranov
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, Dolgoprudny, Moscow Region, Russia
| | - Dmitrii Dashevskii
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, Dolgoprudny, Moscow Region, Russia
| | - Daniil Kornilov
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, Dolgoprudny, Moscow Region, Russia
| | - Ekaterina Bestsennaia
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, Dolgoprudny, Moscow Region, Russia
| | - Johan Hofkens
- Laboratory for Photochemistry and Spectroscopy, Division for Molecular Imaging and Photonics, Department of Chemistry, KU Leuven, Leuven, Belgium; Max Planck Institute for Polymer Research, Mainz, Germany
| | - Jelle Hendrix
- Dynamic Bioimaging Lab, Advanced Optical Microscopy Centre, Biomedical Research Institute, Agoralaan C (BIOMED), Hasselt University, Diepenbeek, Belgium; Laboratory for Photochemistry and Spectroscopy, Division for Molecular Imaging and Photonics, Department of Chemistry, KU Leuven, Leuven, Belgium
| | - Thomas Gensch
- Laboratory for Photochemistry and Spectroscopy, Division for Molecular Imaging and Photonics, Department of Chemistry, KU Leuven, Leuven, Belgium
| | - Vadim Cherezov
- Bridge Institute, Department of Chemistry, University of Southern California, Los Angeles, CA, USA
| | - Valentin Ivanovich
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, Dolgoprudny, Moscow Region, Russia
| | - Alexey Mishin
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, Dolgoprudny, Moscow Region, Russia
| | - Valentin Borshchevskiy
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, Dolgoprudny, Moscow Region, Russia; Joint Institute for Nuclear Research, Dubna, Russia.
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4
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Tharmasothirajan A, Melcr J, Linney J, Gensch T, Krumbach K, Ernst KM, Brasnett C, Poggi P, Pitt AR, Goddard AD, Chatgilialoglu A, Marrink SJ, Marienhagen J. Membrane manipulation by free fatty acids improves microbial plant polyphenol synthesis. Nat Commun 2023; 14:5619. [PMID: 37699874 PMCID: PMC10497605 DOI: 10.1038/s41467-023-40947-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Accepted: 08/16/2023] [Indexed: 09/14/2023] Open
Abstract
Microbial synthesis of nutraceutically and pharmaceutically interesting plant polyphenols represents a more environmentally friendly alternative to chemical synthesis or plant extraction. However, most polyphenols are cytotoxic for microorganisms as they are believed to negatively affect cell integrity and transport processes. To increase the production performance of engineered cell factories, strategies have to be developed to mitigate these detrimental effects. Here, we examine the accumulation of the stilbenoid resveratrol in the cell membrane and cell wall during its production using Corynebacterium glutamicum and uncover the membrane rigidifying effect of this stilbenoid experimentally and with molecular dynamics simulations. A screen of free fatty acid supplements identifies palmitelaidic acid and linoleic acid as suitable additives to attenuate resveratrol's cytotoxic effects resulting in a three-fold higher product titer. This cost-effective approach to counteract membrane-damaging effects of product accumulation is transferable to the microbial production of other polyphenols and may represent an engineering target for other membrane-active bioproducts.
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Affiliation(s)
- Apilaasha Tharmasothirajan
- Institute of Bio- and Geosciences, IBG-1: Biotechnology, Forschungszentrum Jülich, 52425, Jülich, Germany
- Institute of Biotechnology, RWTH Aachen University, Worringer Weg 3, 52074, Aachen, Germany
| | - Josef Melcr
- Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, 9747 AG, Groningen, The Netherlands
| | - John Linney
- College of Health and Life Sciences, Aston University, Birmingham, B4 7ET, UK
| | - Thomas Gensch
- Institute for Information Processing, IBI-1: Molecular and Cellular Physiology, Forschungszentrum Jülich, 52425, Jülich, Germany
| | - Karin Krumbach
- Institute of Bio- and Geosciences, IBG-1: Biotechnology, Forschungszentrum Jülich, 52425, Jülich, Germany
| | - Karla Marlen Ernst
- Institute of Bio- and Geosciences, IBG-1: Biotechnology, Forschungszentrum Jülich, 52425, Jülich, Germany
| | - Christopher Brasnett
- Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, 9747 AG, Groningen, The Netherlands
| | - Paola Poggi
- Remembrane Srl, via San Francesco 40, 40026, Imola, Italy
| | - Andrew R Pitt
- College of Health and Life Sciences, Aston University, Birmingham, B4 7ET, UK
- Manchester Institute of Biotechnology and Department of Chemistry, University of Manchester, Manchester, UK
| | - Alan D Goddard
- College of Health and Life Sciences, Aston University, Birmingham, B4 7ET, UK
| | | | - Siewert J Marrink
- Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, 9747 AG, Groningen, The Netherlands
| | - Jan Marienhagen
- Institute of Bio- and Geosciences, IBG-1: Biotechnology, Forschungszentrum Jülich, 52425, Jülich, Germany.
- Institute of Biotechnology, RWTH Aachen University, Worringer Weg 3, 52074, Aachen, Germany.
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5
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Matamouros S, Gensch T, Cerff M, Sachs CC, Abdollahzadeh I, Hendriks J, Horst L, Tenhaef N, Tenhaef J, Noack S, Graf M, Takors R, Nöh K, Bott M. Growth-rate dependency of ribosome abundance and translation elongation rate in Corynebacterium glutamicum differs from that in Escherichia coli. Nat Commun 2023; 14:5611. [PMID: 37699882 PMCID: PMC10497606 DOI: 10.1038/s41467-023-41176-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2021] [Accepted: 08/24/2023] [Indexed: 09/14/2023] Open
Abstract
Bacterial growth rate (µ) depends on the protein synthesis capacity of the cell and thus on the number of active ribosomes and their translation elongation rate. The relationship between these fundamental growth parameters have only been described for few bacterial species, in particular Escherichia coli. Here, we analyse the growth-rate dependency of ribosome abundance and translation elongation rate for Corynebacterium glutamicum, a gram-positive model species differing from E. coli by a lower growth temperature optimum and a lower maximal growth rate. We show that, unlike in E. coli, there is little change in ribosome abundance for µ <0.4 h-1 in C. glutamicum and the fraction of active ribosomes is kept above 70% while the translation elongation rate declines 5-fold. Mathematical modelling indicates that the decrease in the translation elongation rate can be explained by a depletion of translation precursors.
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Affiliation(s)
- Susana Matamouros
- Institute of Bio- and Geosciences, IBG-1: Biotechnology, Forschungszentrum Jülich, Jülich, Germany.
| | - Thomas Gensch
- Institute of Biological Information Processing, IBI-1: Molecular and Cellular Physiology, Forschungszentrum Jülich, Jülich, Germany
| | - Martin Cerff
- Institute of Bio- and Geosciences, IBG-1: Biotechnology, Forschungszentrum Jülich, Jülich, Germany
| | - Christian C Sachs
- Institute of Bio- and Geosciences, IBG-1: Biotechnology, Forschungszentrum Jülich, Jülich, Germany
| | - Iman Abdollahzadeh
- Institute of Biological Information Processing, IBI-1: Molecular and Cellular Physiology, Forschungszentrum Jülich, Jülich, Germany
| | - Johnny Hendriks
- Institute of Biological Information Processing, IBI-1: Molecular and Cellular Physiology, Forschungszentrum Jülich, Jülich, Germany
| | - Lucas Horst
- Institute of Bio- and Geosciences, IBG-1: Biotechnology, Forschungszentrum Jülich, Jülich, Germany
| | - Niklas Tenhaef
- Institute of Bio- and Geosciences, IBG-1: Biotechnology, Forschungszentrum Jülich, Jülich, Germany
| | - Julia Tenhaef
- Institute of Bio- and Geosciences, IBG-1: Biotechnology, Forschungszentrum Jülich, Jülich, Germany
| | - Stephan Noack
- Institute of Bio- and Geosciences, IBG-1: Biotechnology, Forschungszentrum Jülich, Jülich, Germany
| | - Michaela Graf
- Institute of Biochemical Engineering, University of Stuttgart, Stuttgart, Germany
| | - Ralf Takors
- Institute of Biochemical Engineering, University of Stuttgart, Stuttgart, Germany
| | - Katharina Nöh
- Institute of Bio- and Geosciences, IBG-1: Biotechnology, Forschungszentrum Jülich, Jülich, Germany
| | - Michael Bott
- Institute of Bio- and Geosciences, IBG-1: Biotechnology, Forschungszentrum Jülich, Jülich, Germany.
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6
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Byvaltcev E, Behbood M, Schleimer JH, Gensch T, Semyanov A, Schreiber S, Strauss U. KCC2 reverse mode helps to clear postsynaptically released potassium at glutamatergic synapses. Cell Rep 2023; 42:112934. [PMID: 37537840 PMCID: PMC10480490 DOI: 10.1016/j.celrep.2023.112934] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2023] [Revised: 07/09/2023] [Accepted: 07/18/2023] [Indexed: 08/05/2023] Open
Abstract
Extracellular potassium [K+]o elevation during synaptic activity retrogradely modifies presynaptic release and astrocytic uptake of glutamate. Hence, local K+ clearance and replenishment mechanisms are crucial regulators of glutamatergic transmission and plasticity. Based on recordings of astrocytic inward rectifier potassium current IKir and K+-sensitive electrodes as sensors of [K+]o as well as on in silico modeling, we demonstrate that the neuronal K+-Cl- co-transporter KCC2 clears local perisynaptic [K+]o during synaptic excitation by operating in an activity-dependent reversed mode. In reverse mode, KCC2 replenishes K+ in dendritic spines and complements clearance of [K+]o, therewith attenuating presynaptic glutamate release and shortening LTP. We thus demonstrate a physiological role of KCC2 in neuron-glial interactions and regulation of synaptic signaling and plasticity through the uptake of postsynaptically released K+.
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Affiliation(s)
- Egor Byvaltcev
- Charité - Universitätsmedizin Berlin, Institute of Cell- and Neurobiology, Charitéplatz 1, 10117 Berlin, Germany
| | - Mahraz Behbood
- Institute for Theoretical Biology, Department of Biology, Humboldt-Universität zu Berlin, 10115 Berlin, Germany; Bernstein Center for Computational Neuroscience Berlin, 10115 Berlin, Germany
| | - Jan-Hendrik Schleimer
- Institute for Theoretical Biology, Department of Biology, Humboldt-Universität zu Berlin, 10115 Berlin, Germany; Bernstein Center for Computational Neuroscience Berlin, 10115 Berlin, Germany
| | - Thomas Gensch
- Institute of Biological Information Processing 1 (IBI-1, Molecular and Cellular Physiology), Forschungszentrum Jülich, Wilhem-Jonen Straße, 52428 Jülich, Germany
| | - Alexey Semyanov
- Department of Physiology, Jiaxing University College of Medicine, Zhejiang Pro, Jiaxing 314033, China
| | - Susanne Schreiber
- Institute for Theoretical Biology, Department of Biology, Humboldt-Universität zu Berlin, 10115 Berlin, Germany; Bernstein Center for Computational Neuroscience Berlin, 10115 Berlin, Germany
| | - Ulf Strauss
- Charité - Universitätsmedizin Berlin, Institute of Cell- and Neurobiology, Charitéplatz 1, 10117 Berlin, Germany.
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7
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Maslov I, Volkov O, Khorn P, Orekhov P, Gusach A, Kuzmichev P, Gerasimov A, Luginina A, Coucke Q, Bogorodskiy A, Gordeliy V, Wanninger S, Barth A, Mishin A, Hofkens J, Cherezov V, Gensch T, Hendrix J, Borshchevskiy V. Sub-millisecond conformational dynamics of the A 2A adenosine receptor revealed by single-molecule FRET. Commun Biol 2023; 6:362. [PMID: 37012383 PMCID: PMC10070357 DOI: 10.1038/s42003-023-04727-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2022] [Accepted: 03/17/2023] [Indexed: 04/05/2023] Open
Abstract
The complex pharmacology of G-protein-coupled receptors (GPCRs) is defined by their multi-state conformational dynamics. Single-molecule Förster Resonance Energy Transfer (smFRET) is well suited to quantify dynamics for individual protein molecules; however, its application to GPCRs is challenging. Therefore, smFRET has been limited to studies of inter-receptor interactions in cellular membranes and receptors in detergent environments. Here, we performed smFRET experiments on functionally active human A2A adenosine receptor (A2AAR) molecules embedded in freely diffusing lipid nanodiscs to study their intramolecular conformational dynamics. We propose a dynamic model of A2AAR activation that involves a slow (>2 ms) exchange between the active-like and inactive-like conformations in both apo and antagonist-bound A2AAR, explaining the receptor's constitutive activity. For the agonist-bound A2AAR, we detected faster (390 ± 80 µs) ligand efficacy-dependent dynamics. Our work establishes a general smFRET platform for GPCR investigations that can potentially be used for drug screening and/or mechanism-of-action studies.
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Affiliation(s)
- Ivan Maslov
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, Dolgoprudny, Moscow Region, Russia
- Dynamic Bioimaging Lab, Advanced Optical Microscopy Centre, Biomedical Research Institute, Agoralaan C (BIOMED), Hasselt University, Diepenbeek, Belgium
- Laboratory for Photochemistry and Spectroscopy, Division for Molecular Imaging and Photonics, Department of Chemistry, KU Leuven, Leuven, Belgium
| | | | - Polina Khorn
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, Dolgoprudny, Moscow Region, Russia
| | - Philipp Orekhov
- Faculty of Biology, Shenzhen MSU-BIT University, Shenzhen, China
| | - Anastasiia Gusach
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, Dolgoprudny, Moscow Region, Russia
- MRC Laboratory of Molecular Biology, Cambridge, UK
| | - Pavel Kuzmichev
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, Dolgoprudny, Moscow Region, Russia
| | - Andrey Gerasimov
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, Dolgoprudny, Moscow Region, Russia
- Vyatka State University, Kirov, Russia
| | - Aleksandra Luginina
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, Dolgoprudny, Moscow Region, Russia
| | - Quinten Coucke
- Laboratory for Photochemistry and Spectroscopy, Division for Molecular Imaging and Photonics, Department of Chemistry, KU Leuven, Leuven, Belgium
| | - Andrey Bogorodskiy
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, Dolgoprudny, Moscow Region, Russia
| | - Valentin Gordeliy
- Institut de Biologie Structurale J.-P. Ebel, Université Grenoble Alpes-CEA-CNRS, Grenoble, France
| | - Simon Wanninger
- Physical Chemistry, Department of Chemistry, Center for Nano Science (CENS), Center for Integrated Protein Science (CIPSM) and Nanosystems Initiative München (NIM), Ludwig-Maximilians-Universität Munich, Munich, Germany
| | - Anders Barth
- Physical Chemistry, Department of Chemistry, Center for Nano Science (CENS), Center for Integrated Protein Science (CIPSM) and Nanosystems Initiative München (NIM), Ludwig-Maximilians-Universität Munich, Munich, Germany
- Department of Bionanoscience, Kavli Institute of Nanoscience, Delft University of Technology, HZ, Delft, The Netherlands
| | - Alexey Mishin
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, Dolgoprudny, Moscow Region, Russia
| | - Johan Hofkens
- Laboratory for Photochemistry and Spectroscopy, Division for Molecular Imaging and Photonics, Department of Chemistry, KU Leuven, Leuven, Belgium
- Max Plank Institute for Polymer Research, Mainz, Germany
| | - Vadim Cherezov
- Bridge Institute, Department of Chemistry, University of Southern California, Los Angeles, CA, USA
| | - Thomas Gensch
- Laboratory for Photochemistry and Spectroscopy, Division for Molecular Imaging and Photonics, Department of Chemistry, KU Leuven, Leuven, Belgium
| | - Jelle Hendrix
- Dynamic Bioimaging Lab, Advanced Optical Microscopy Centre, Biomedical Research Institute, Agoralaan C (BIOMED), Hasselt University, Diepenbeek, Belgium.
- Laboratory for Photochemistry and Spectroscopy, Division for Molecular Imaging and Photonics, Department of Chemistry, KU Leuven, Leuven, Belgium.
| | - Valentin Borshchevskiy
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, Dolgoprudny, Moscow Region, Russia.
- Joint Institute for Nuclear Research, Dubna, Russian Federation.
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8
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Bitzenhofer NL, Hilgers F, Bosio GN, Torra J, Casini G, Beinlich FRM, Knieps-Grünhagen E, Gordeliy V, Jaeger KE, Nonell S, Krauss U, Gensch T, Drepper T. Development and Characterization of Flavin-Binding Fluorescent Proteins, Part II: Advanced Characterization. Methods Mol Biol 2023; 2564:143-183. [PMID: 36107341 DOI: 10.1007/978-1-0716-2667-2_7] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Flavin-based fluorescent proteins (FbFPs), a class of small fluorescent proteins derived from light-oxygen-voltage (LOV) domains, bind ubiquitous endogenous flavins as chromophores. Due to their unique properties, they can be used as versatile in vivo reporter proteins under aerobic and anaerobic conditions. This chapter presents methodologies for in-depth characterization of the biochemical, spectroscopic, photophysical, and photochemical properties of FbFPs.
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Affiliation(s)
- Nora Lisa Bitzenhofer
- Institute of Molecular Enzyme Technology, Heinrich Heine University Düsseldorf, Forschungszentrum Jülich, Jülich, Germany
| | - Fabienne Hilgers
- Institute of Molecular Enzyme Technology, Heinrich Heine University Düsseldorf, Forschungszentrum Jülich, Jülich, Germany
| | - Gabriela N Bosio
- Institute of Biological Information Processing IBI-1: Molecular and Cellular Physiology, Forschungszentrum Jülich GmbH, Jülich, Germany
| | - Joaquim Torra
- Institut Químic de Sarrià, Universitat Ramon Llull, Barcelona, Spain
| | - Giorgia Casini
- Institute of Biological Information Processing IBI-1: Molecular and Cellular Physiology, Forschungszentrum Jülich GmbH, Jülich, Germany
| | - Felix R M Beinlich
- Institute of Biological Information Processing IBI-1: Molecular and Cellular Physiology, Forschungszentrum Jülich GmbH, Jülich, Germany
| | - Esther Knieps-Grünhagen
- Institute of Molecular Enzyme Technology, Heinrich Heine University Düsseldorf, Forschungszentrum Jülich, Jülich, Germany
| | - Valentin Gordeliy
- Institute of Bio-and Geosciences IBG-1: Biotechnology, Forschungszentrum Jülich, Jülich, Germany
- Institut de Biologie Structurale J.-P. Ebel, Université Grenoble Alpes-CEA-CNRS, Grenoble, France
| | - Karl-Erich Jaeger
- Institute of Molecular Enzyme Technology, Heinrich Heine University Düsseldorf, Forschungszentrum Jülich, Jülich, Germany
- Institute of Biological Information Processing IBI-1: Molecular and Cellular Physiology, Forschungszentrum Jülich GmbH, Jülich, Germany
| | - Santi Nonell
- Institut Químic de Sarrià, Universitat Ramon Llull, Barcelona, Spain.
| | - Ulrich Krauss
- Institute of Molecular Enzyme Technology, Heinrich Heine University Düsseldorf, Forschungszentrum Jülich, Jülich, Germany.
- Institute of Bio- and Geosciences IBG-1: Biotechnology, Forschungszentrum Jülich GmbH, Jülich, Germany.
| | - Thomas Gensch
- Institute of Biological Information Processing IBI-1: Molecular and Cellular Physiology, Forschungszentrum Jülich GmbH, Jülich, Germany.
| | - Thomas Drepper
- Institute of Molecular Enzyme Technology, Heinrich Heine University Düsseldorf, Forschungszentrum Jülich, Jülich, Germany.
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9
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Montali C, Abbruzzetti S, Franzen A, Casini G, Bruno S, Delcanale P, Burgstaller S, Ramadani-Muja J, Malli R, Gensch T, Viappiani C. Nitric Oxide Sensing by a Blue Fluorescent Protein. Antioxidants (Basel) 2022; 11:2229. [PMID: 36421416 PMCID: PMC9686608 DOI: 10.3390/antiox11112229] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2022] [Revised: 11/07/2022] [Accepted: 11/09/2022] [Indexed: 09/19/2023] Open
Abstract
S-Nitrosylation of cysteine residues is an important molecular mechanism for dynamic, post-translational regulation of several proteins, providing a ubiquitous redox regulation. Cys residues are present in several fluorescent proteins (FP), including members of the family of Aequorea victoria Green Fluorescent Protein (GFP)-derived FPs, where two highly conserved cysteine residues contribute to a favorable environment for the autocatalytic chromophore formation reaction. The effect of nitric oxide on the fluorescence properties of FPs has not been investigated thus far, despite the tremendous role FPs have played for 25 years as tools in cell biology. We have examined the response to nitric oxide of fluorescence emission by the blue-emitting fluorescent protein mTagBFP2. To our surprise, upon exposure to micromolar concentrations of nitric oxide, we observed a roughly 30% reduction in fluorescence quantum yield and lifetime. Recovery of fluorescence emission is observed after treatment with Na-dithionite. Experiments on related fluorescent proteins from different families show similar nitric oxide sensitivity of their fluorescence. We correlate the effect with S-nitrosylation of Cys residues. Mutation of Cys residues in mTagBFP2 removes its nitric oxide sensitivity. Similarly, fluorescent proteins devoid of Cys residues are insensitive to nitric oxide. We finally show that mTagBFP2 can sense exogenously generated nitric oxide when expressed in a living mammalian cell. We propose mTagBFP2 as the starting point for a new class of genetically encoded nitric oxide sensors based on fluorescence lifetime imaging.
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Affiliation(s)
- Chiara Montali
- Dipartimento di Scienze Matematiche, Fisiche e Informatiche, Università di Parma, Parco Area delle Scienze 7A, 43124 Parma, Italy
| | - Stefania Abbruzzetti
- Dipartimento di Scienze Matematiche, Fisiche e Informatiche, Università di Parma, Parco Area delle Scienze 7A, 43124 Parma, Italy
| | - Arne Franzen
- Institute of Biological Information Processing (IBI-1: Molecular and Cellular Physiology), Forschungszentrum Jülich, Leo-Brandt-Straße, D-52428 Jülich, Germany
| | - Giorgia Casini
- Institute of Biological Information Processing (IBI-1: Molecular and Cellular Physiology), Forschungszentrum Jülich, Leo-Brandt-Straße, D-52428 Jülich, Germany
| | - Stefano Bruno
- Dipartimento di Scienze degli Alimenti e del Farmaco, Università di Parma, Parco Area delle Scienze 23/A, 43124 Parma, Italy
| | - Pietro Delcanale
- Dipartimento di Scienze Matematiche, Fisiche e Informatiche, Università di Parma, Parco Area delle Scienze 7A, 43124 Parma, Italy
| | - Sandra Burgstaller
- Molecular Biology and Biochemistry, Gottfried Schatz Research Center, Medical University of Graz, Neue Stiftingtalstraße 6/6, 8010 Graz, Austria
| | - Jeta Ramadani-Muja
- Molecular Biology and Biochemistry, Gottfried Schatz Research Center, Medical University of Graz, Neue Stiftingtalstraße 6/6, 8010 Graz, Austria
| | - Roland Malli
- Molecular Biology and Biochemistry, Gottfried Schatz Research Center, Medical University of Graz, Neue Stiftingtalstraße 6/6, 8010 Graz, Austria
| | - Thomas Gensch
- Institute of Biological Information Processing (IBI-1: Molecular and Cellular Physiology), Forschungszentrum Jülich, Leo-Brandt-Straße, D-52428 Jülich, Germany
| | - Cristiano Viappiani
- Dipartimento di Scienze Matematiche, Fisiche e Informatiche, Università di Parma, Parco Area delle Scienze 7A, 43124 Parma, Italy
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10
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Kempmann A, Gensch T, Offenhäusser A, Tihaa I, Maybeck V, Balfanz S, Baumann A. The Functional Characterization of GCaMP3.0 Variants Specifically Targeted to Subcellular Domains. Int J Mol Sci 2022; 23:ijms23126593. [PMID: 35743038 PMCID: PMC9223625 DOI: 10.3390/ijms23126593] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2022] [Revised: 05/31/2022] [Accepted: 06/06/2022] [Indexed: 11/16/2022] Open
Abstract
Calcium (Ca2+) ions play a pivotal role in physiology and cellular signaling. The intracellular Ca2+ concentration ([Ca2+]i) is about three orders of magnitude lower than the extracellular concentration, resulting in a steep transmembrane concentration gradient. Thus, the spatial and the temporal dynamics of [Ca2+]i are ideally suited to modulate Ca2+-mediated cellular responses to external signals. A variety of highly sophisticated methods have been developed to gain insight into cellular Ca2+ dynamics. In addition to electrophysiological measurements and the application of synthetic dyes that change their fluorescent properties upon interaction with Ca2+, the introduction and the ongoing development of genetically encoded Ca2+ indicators (GECI) opened a new era to study Ca2+-driven processes in living cells and organisms. Here, we have focused on one well-established GECI, i.e., GCaMP3.0. We have systematically modified the protein with sequence motifs, allowing localization of the sensor in the nucleus, in the mitochondrial matrix, at the mitochondrial outer membrane, and at the plasma membrane. The individual variants and a cytosolic version of GCaMP3.0 were overexpressed and purified from E. coli cells to study their biophysical properties in solution. All versions were examined to monitor Ca2+ signaling in stably transfected cell lines and in primary cortical neurons transduced with recombinant Adeno-associated viruses (rAAV). In this comparative study, we provide evidence for a robust approach to reliably trace Ca2+ signals at the (sub)-cellular level with pronounced temporal resolution.
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Affiliation(s)
- Annika Kempmann
- Institute of Biological Information Processing, IBI-1, Research Center Jülich, 52428 Jülich, Germany; (A.K.); (T.G.); (S.B.)
| | - Thomas Gensch
- Institute of Biological Information Processing, IBI-1, Research Center Jülich, 52428 Jülich, Germany; (A.K.); (T.G.); (S.B.)
| | - Andreas Offenhäusser
- Institute of Biological Information Processing, IBI-3, Research Center Jülich, 52428 Jülich, Germany; (A.O.); (I.T.); (V.M.)
| | - Irina Tihaa
- Institute of Biological Information Processing, IBI-3, Research Center Jülich, 52428 Jülich, Germany; (A.O.); (I.T.); (V.M.)
| | - Vanessa Maybeck
- Institute of Biological Information Processing, IBI-3, Research Center Jülich, 52428 Jülich, Germany; (A.O.); (I.T.); (V.M.)
| | - Sabine Balfanz
- Institute of Biological Information Processing, IBI-1, Research Center Jülich, 52428 Jülich, Germany; (A.K.); (T.G.); (S.B.)
| | - Arnd Baumann
- Institute of Biological Information Processing, IBI-1, Research Center Jülich, 52428 Jülich, Germany; (A.K.); (T.G.); (S.B.)
- Correspondence: ; Tel.: +49-2461-614014
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11
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Bogorodskiy A, Okhrimenko I, Burkatovskii D, Jakobs P, Maslov I, Gordeliy V, Dencher NA, Gensch T, Voos W, Altschmied J, Haendeler J, Borshchevskiy V. Role of Mitochondrial Protein Import in Age-Related Neurodegenerative and Cardiovascular Diseases. Cells 2021; 10:3528. [PMID: 34944035 PMCID: PMC8699856 DOI: 10.3390/cells10123528] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Revised: 12/10/2021] [Accepted: 12/12/2021] [Indexed: 11/17/2022] Open
Abstract
Mitochondria play a critical role in providing energy, maintaining cellular metabolism, and regulating cell survival and death. To carry out these crucial functions, mitochondria employ more than 1500 proteins, distributed between two membranes and two aqueous compartments. An extensive network of dedicated proteins is engaged in importing and sorting these nuclear-encoded proteins into their designated mitochondrial compartments. Defects in this fundamental system are related to a variety of pathologies, particularly engaging the most energy-demanding tissues. In this review, we summarize the state-of-the-art knowledge about the mitochondrial protein import machinery and describe the known interrelation of its failure with age-related neurodegenerative and cardiovascular diseases.
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Affiliation(s)
- Andrey Bogorodskiy
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, 141701 Dolgoprudny, Russia; (A.B.); (I.O.); (D.B.); (I.M.); (V.G.); (N.A.D.)
| | - Ivan Okhrimenko
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, 141701 Dolgoprudny, Russia; (A.B.); (I.O.); (D.B.); (I.M.); (V.G.); (N.A.D.)
| | - Dmitrii Burkatovskii
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, 141701 Dolgoprudny, Russia; (A.B.); (I.O.); (D.B.); (I.M.); (V.G.); (N.A.D.)
| | - Philipp Jakobs
- Environmentally-Induced Cardiovascular Degeneration, Central Institute of Clinical Chemistry and Laboratory Medicine, Medical Faculty, University Hospital and Heinrich-Heine-University Düsseldorf, 40225 Düsseldorf, Germany; (P.J.); (J.A.); (J.H.)
| | - Ivan Maslov
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, 141701 Dolgoprudny, Russia; (A.B.); (I.O.); (D.B.); (I.M.); (V.G.); (N.A.D.)
| | - Valentin Gordeliy
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, 141701 Dolgoprudny, Russia; (A.B.); (I.O.); (D.B.); (I.M.); (V.G.); (N.A.D.)
- Institute of Biological Information Processing (IBI-7: Structural Biochemistry), Forschungszentrum Jülich, 52428 Jülich, Germany
- JuStruct: Jülich Center for Structural Biology, Forschungszentrum Jülich, 52428 Jülich, Germany
- Institut de Biologie Structurale (IBS), Université Grenoble Alpes, CEA, CNRS, 38400 Grenoble, France
| | - Norbert A. Dencher
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, 141701 Dolgoprudny, Russia; (A.B.); (I.O.); (D.B.); (I.M.); (V.G.); (N.A.D.)
- Physical Biochemistry, Chemistry Department, Technical University of Darmstadt, 64289 Darmstadt, Germany
| | - Thomas Gensch
- Institute of Biological Information Processing (IBI-1: Molecular and Cellular Physiology), Forschungszentrum Jülich, 52428 Jülich, Germany;
| | - Wolfgang Voos
- Institute of Biochemistry and Molecular Biology (IBMB), Faculty of Medicine, University of Bonn, 53113 Bonn, Germany;
| | - Joachim Altschmied
- Environmentally-Induced Cardiovascular Degeneration, Central Institute of Clinical Chemistry and Laboratory Medicine, Medical Faculty, University Hospital and Heinrich-Heine-University Düsseldorf, 40225 Düsseldorf, Germany; (P.J.); (J.A.); (J.H.)
- IUF—Leibniz Research Institute for Environmental Medicine, 40225 Düsseldorf, Germany
| | - Judith Haendeler
- Environmentally-Induced Cardiovascular Degeneration, Central Institute of Clinical Chemistry and Laboratory Medicine, Medical Faculty, University Hospital and Heinrich-Heine-University Düsseldorf, 40225 Düsseldorf, Germany; (P.J.); (J.A.); (J.H.)
| | - Valentin Borshchevskiy
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, 141701 Dolgoprudny, Russia; (A.B.); (I.O.); (D.B.); (I.M.); (V.G.); (N.A.D.)
- Institute of Biological Information Processing (IBI-7: Structural Biochemistry), Forschungszentrum Jülich, 52428 Jülich, Germany
- JuStruct: Jülich Center for Structural Biology, Forschungszentrum Jülich, 52428 Jülich, Germany
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12
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Engels M, Kalia M, Rahmati S, Petersilie L, Kovermann P, van Putten MJAM, Rose CR, Meijer HGE, Gensch T, Fahlke C. Glial Chloride Homeostasis Under Transient Ischemic Stress. Front Cell Neurosci 2021; 15:735300. [PMID: 34602981 PMCID: PMC8481871 DOI: 10.3389/fncel.2021.735300] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Accepted: 08/23/2021] [Indexed: 12/17/2022] Open
Abstract
High water permeabilities permit rapid adjustments of glial volume upon changes in external and internal osmolarity, and pathologically altered intracellular chloride concentrations ([Cl–]int) and glial cell swelling are often assumed to represent early events in ischemia, infections, or traumatic brain injury. Experimental data for glial [Cl–]int are lacking for most brain regions, under normal as well as under pathological conditions. We measured [Cl–]int in hippocampal and neocortical astrocytes and in hippocampal radial glia-like (RGL) cells in acute murine brain slices using fluorescence lifetime imaging microscopy with the chloride-sensitive dye MQAE at room temperature. We observed substantial heterogeneity in baseline [Cl–]int, ranging from 14.0 ± 2.0 mM in neocortical astrocytes to 28.4 ± 3.0 mM in dentate gyrus astrocytes. Chloride accumulation by the Na+-K+-2Cl– cotransporter (NKCC1) and chloride outward transport (efflux) through K+-Cl– cotransporters (KCC1 and KCC3) or excitatory amino acid transporter (EAAT) anion channels control [Cl–]int to variable extent in distinct brain regions. In hippocampal astrocytes, blocking NKCC1 decreased [Cl–]int, whereas KCC or EAAT anion channel inhibition had little effect. In contrast, neocortical astrocytic or RGL [Cl–]int was very sensitive to block of chloride outward transport, but not to NKCC1 inhibition. Mathematical modeling demonstrated that higher numbers of NKCC1 and KCC transporters can account for lower [Cl–]int in neocortical than in hippocampal astrocytes. Energy depletion mimicking ischemia for up to 10 min did not result in pronounced changes in [Cl–]int in any of the tested glial cell types. However, [Cl–]int changes occurred under ischemic conditions after blocking selected anion transporters. We conclude that stimulated chloride accumulation and chloride efflux compensate for each other and prevent glial swelling under transient energy deprivation.
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Affiliation(s)
- Miriam Engels
- Institute of Biological Information Processing, Molekular-und Zellphysiologie (IBI-1), Forschungszentrum Jülich, Jülich, Germany
| | - Manu Kalia
- Applied Analysis, Department of Applied Mathematics, University of Twente, Enschede, Netherlands.,Institute of Neurobiology, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | - Sarah Rahmati
- Institute of Biological Information Processing, Molekular-und Zellphysiologie (IBI-1), Forschungszentrum Jülich, Jülich, Germany
| | - Laura Petersilie
- Institute of Neurobiology, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | - Peter Kovermann
- Institute of Biological Information Processing, Molekular-und Zellphysiologie (IBI-1), Forschungszentrum Jülich, Jülich, Germany
| | | | - Christine R Rose
- Institute of Neurobiology, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | - Hil G E Meijer
- Applied Analysis, Department of Applied Mathematics, University of Twente, Enschede, Netherlands
| | - Thomas Gensch
- Institute of Biological Information Processing, Molekular-und Zellphysiologie (IBI-1), Forschungszentrum Jülich, Jülich, Germany
| | - Christoph Fahlke
- Institute of Biological Information Processing, Molekular-und Zellphysiologie (IBI-1), Forschungszentrum Jülich, Jülich, Germany
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13
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Bogorodskiy A, Okhrimenko I, Maslov I, Maliar N, Burkatovskii D, von Ameln F, Schulga A, Jakobs P, Altschmied J, Haendeler J, Katranidis A, Sorokin I, Mishin A, Gordeliy V, Büldt G, Voos W, Gensch T, Borshchevskiy V. Accessing Mitochondrial Protein Import in Living Cells by Protein Microinjection. Front Cell Dev Biol 2021; 9:698658. [PMID: 34307376 PMCID: PMC8292824 DOI: 10.3389/fcell.2021.698658] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2021] [Accepted: 06/15/2021] [Indexed: 01/06/2023] Open
Abstract
Mitochondrial protein biogenesis relies almost exclusively on the expression of nuclear-encoded polypeptides. The current model postulates that most of these proteins have to be delivered to their final mitochondrial destination after their synthesis in the cytoplasm. However, the knowledge of this process remains limited due to the absence of proper experimental real-time approaches to study mitochondria in their native cellular environment. We developed a gentle microinjection procedure for fluorescent reporter proteins allowing a direct non-invasive study of protein transport in living cells. As a proof of principle, we visualized potential-dependent protein import into mitochondria inside intact cells in real-time. We validated that our approach does not distort mitochondrial morphology and preserves the endogenous expression system as well as mitochondrial protein translocation machinery. We observed that a release of nascent polypeptides chains from actively translating cellular ribosomes by puromycin strongly increased the import rate of the microinjected pre-protein. This suggests that a substantial amount of mitochondrial translocase complexes was involved in co-translational protein import of endogenously expressed pre-proteins. Our protein microinjection method opens new possibilities to study the role of mitochondrial protein import in cell models of various pathological conditions as well as aging processes.
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Affiliation(s)
- Andrey Bogorodskiy
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, Dolgoprudny, Russia
| | - Ivan Okhrimenko
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, Dolgoprudny, Russia
| | - Ivan Maslov
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, Dolgoprudny, Russia
| | - Nina Maliar
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, Dolgoprudny, Russia
| | - Dmitrii Burkatovskii
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, Dolgoprudny, Russia
| | - Florian von Ameln
- Environmentally-Induced Cardiovascular Degeneration, Central Institute of Clinical Chemistry and Laboratory Medicine, Medical Faculty, University Hospital and Heinrich-Heine-University Düsseldorf, Düsseldorf, Germany
- IUF–Leibniz Research Institute for Environmental Medicine, Düsseldorf, Germany
| | - Alexey Schulga
- Molecular Immunology Laboratory, Shemyakin & Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia
| | - Philipp Jakobs
- Environmentally-Induced Cardiovascular Degeneration, Central Institute of Clinical Chemistry and Laboratory Medicine, Medical Faculty, University Hospital and Heinrich-Heine-University Düsseldorf, Düsseldorf, Germany
| | - Joachim Altschmied
- Environmentally-Induced Cardiovascular Degeneration, Central Institute of Clinical Chemistry and Laboratory Medicine, Medical Faculty, University Hospital and Heinrich-Heine-University Düsseldorf, Düsseldorf, Germany
- IUF–Leibniz Research Institute for Environmental Medicine, Düsseldorf, Germany
| | - Judith Haendeler
- Environmentally-Induced Cardiovascular Degeneration, Central Institute of Clinical Chemistry and Laboratory Medicine, Medical Faculty, University Hospital and Heinrich-Heine-University Düsseldorf, Düsseldorf, Germany
| | - Alexandros Katranidis
- Institute of Biological Information Processing (IBI-6: Cellular Structural Biology), Forschungszentrum Jülich, Jülich, Germany
| | - Ivan Sorokin
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, Dolgoprudny, Russia
- Institute of Protein Research, Russian Academy of Sciences, Pushchino, Russia
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russia
| | - Alexey Mishin
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, Dolgoprudny, Russia
| | - Valentin Gordeliy
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, Dolgoprudny, Russia
- Institute of Biological Information Processing (IBI-7: Structural Biochemistry), Forschungszentrum Jülich, Jülich, Germany
- JuStruct: Jülich Center for Structural Biology, Forschungszentrum Jülich, Jülich, Germany
- Institut de Biologie Structurale (IBS), Université Grenoble Alpes, CEA, CNRS, Grenoble, France
| | - Georg Büldt
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, Dolgoprudny, Russia
| | - Wolfgang Voos
- Institute of Biochemistry and Molecular Biology (IBMB), Faculty of Medicine, University of Bonn, Bonn, Germany
| | - Thomas Gensch
- Institute of Biological Information Processing (IBI-1: Molecular and Cellular Physiology), Forschungszentrum Jülich, Jülich, Germany
| | - Valentin Borshchevskiy
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, Dolgoprudny, Russia
- Institute of Biological Information Processing (IBI-7: Structural Biochemistry), Forschungszentrum Jülich, Jülich, Germany
- JuStruct: Jülich Center for Structural Biology, Forschungszentrum Jülich, Jülich, Germany
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14
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Maslov I, Volkov O, Khorn P, Orekhov P, Gusach A, Kuzmichev P, Gerasimov A, Luginina A, Coucke Q, Bogorodskiy A, Gordeliy V, Wanninger S, Barth A, Mishin A, Hofkens J, Cherezov V, Gensch T, Hendrix J, Borshchevskiy V. Structural dynamics of the A
2A
adenosine receptor revealed by single‐molecule FRET. FASEB J 2021. [DOI: 10.1096/fasebj.2021.35.s1.04977] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Ivan Maslov
- Recearch Center for Molecular Mechanisms of Ageing and Age‐Related DiseasesMoscow Institute of Physics and TechnologyDolgoprudniy
- Dynamic Bioimaging LabHasselt UniversityDiepenbeek
- Molecular Imaging and PhotonicsKU LeuvenLeuven
| | | | - Polina Khorn
- Recearch Center for Molecular Mechanisms of Ageing and Age‐Related DiseasesMoscow Institute of Physics and TechnologyDolgoprudniy
| | - Philipp Orekhov
- Recearch Center for Molecular Mechanisms of Ageing and Age‐Related DiseasesMoscow Institute of Physics and TechnologyDolgoprudniy
| | - Anastasiia Gusach
- Recearch Center for Molecular Mechanisms of Ageing and Age‐Related DiseasesMoscow Institute of Physics and TechnologyDolgoprudniy
- MRC Laboratory of Molecular BiologyCambridge
| | - Pavel Kuzmichev
- Recearch Center for Molecular Mechanisms of Ageing and Age‐Related DiseasesMoscow Institute of Physics and TechnologyDolgoprudniy
| | - Andrey Gerasimov
- Recearch Center for Molecular Mechanisms of Ageing and Age‐Related DiseasesMoscow Institute of Physics and TechnologyDolgoprudniy
- Vyatka State UniversityKirov
| | - Aleksandra Luginina
- Recearch Center for Molecular Mechanisms of Ageing and Age‐Related DiseasesMoscow Institute of Physics and TechnologyDolgoprudniy
| | | | - Andrey Bogorodskiy
- Recearch Center for Molecular Mechanisms of Ageing and Age‐Related DiseasesMoscow Institute of Physics and TechnologyDolgoprudniy
| | - Valentin Gordeliy
- Recearch Center for Molecular Mechanisms of Ageing and Age‐Related DiseasesMoscow Institute of Physics and TechnologyDolgoprudniy
| | | | - Anders Barth
- Ludwig‐Maximilians‐Universität MunichMunich
- Department of BionanoscienceDelft University of TechnologyHZ Delft
| | - Alexey Mishin
- Recearch Center for Molecular Mechanisms of Ageing and Age‐Related DiseasesMoscow Institute of Physics and TechnologyDolgoprudniy
| | - Johan Hofkens
- Molecular Imaging and PhotonicsKU LeuvenLeuven
- Max Plank Institute for Polymer ResearchMainz
| | - Vadim Cherezov
- Recearch Center for Molecular Mechanisms of Ageing and Age‐Related DiseasesMoscow Institute of Physics and TechnologyDolgoprudniy
- Bridge InstituteUniversity of Southern CaliforniaLos AngelesCA
| | | | - Jelle Hendrix
- Molecular Imaging and PhotonicsKU LeuvenLeuven
- Hasselt UniversityDiepenbeek
| | - Valentin Borshchevskiy
- Recearch Center for Molecular Mechanisms of Ageing and Age‐Related DiseasesMoscow Institute of Physics and TechnologyDolgoprudniy
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15
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Röllen K, Granzin J, Remeeva A, Davari MD, Gensch T, Nazarenko VV, Kovalev K, Bogorodskiy A, Borshchevskiy V, Hemmer S, Schwaneberg U, Gordeliy V, Jaeger KE, Batra-Safferling R, Gushchin I, Krauss U. The molecular basis of spectral tuning in blue- and red-shifted flavin-binding fluorescent proteins. J Biol Chem 2021; 296:100662. [PMID: 33862085 PMCID: PMC8131319 DOI: 10.1016/j.jbc.2021.100662] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2021] [Revised: 04/09/2021] [Accepted: 04/12/2021] [Indexed: 01/09/2023] Open
Abstract
Photoactive biological systems modify the optical properties of their chromophores, known as spectral tuning. Determining the molecular origin of spectral tuning is instrumental for understanding the function and developing applications of these biomolecules. Spectral tuning in flavin-binding fluorescent proteins (FbFPs), an emerging class of fluorescent reporters, is limited by their dependency on protein-bound flavins, whose structure and hence electronic properties cannot be altered by mutation. A blue-shifted variant of the plant-derived improved light, oxygen, voltage FbFP has been created by introducing a lysine within the flavin-binding pocket, but the molecular basis of this shift remains unconfirmed. We here structurally characterize the blue-shifted improved light, oxygen, voltage variant and construct a new blue-shifted CagFbFP protein by introducing an analogous mutation. X-ray structures of both proteins reveal displacement of the lysine away from the chromophore and opening up of the structure as instrumental for the blue shift. Site saturation mutagenesis and high-throughput screening yielded a red-shifted variant, and structural analysis revealed that the lysine side chain of the blue-shifted variant is stabilized close to the flavin by a secondary mutation, accounting for the red shift. Thus, a single additional mutation in a blue-shifted variant is sufficient to generate a red-shifted FbFP. Using spectroscopy, X-ray crystallography, and quantum mechanics molecular mechanics calculations, we provide a firm structural and functional understanding of spectral tuning in FbFPs. We also show that the identified blue- and red-shifted variants allow for two-color microscopy based on spectral separation. In summary, the generated blue- and red-shifted variants represent promising new tools for application in life sciences.
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Affiliation(s)
- Katrin Röllen
- Institut für Molekulare Enzymtechnologie, Heinrich-Heine-Universität Düsseldorf, Forschungszentrum Jülich GmbH, Jülich, Germany
| | - Joachim Granzin
- IBI-7: Structural Biochemistry, Forschungszentrum Jülich GmbH, Jülich, Germany; JuStruct: Jülich Center for Structural Biology, Forschungszentrum Jülich, Jülich, Germany
| | - Alina Remeeva
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, Dolgoprudny, Russia
| | - Mehdi D Davari
- Institute of Biotechnology, RWTH Aachen University, Aachen, Germany
| | - Thomas Gensch
- IBI-1: Molecular and Cellular Physiology, Forschungszentrum Jülich GmbH, Jülich, Germany
| | - Vera V Nazarenko
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, Dolgoprudny, Russia
| | - Kirill Kovalev
- IBI-7: Structural Biochemistry, Forschungszentrum Jülich GmbH, Jülich, Germany; JuStruct: Jülich Center for Structural Biology, Forschungszentrum Jülich, Jülich, Germany; Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, Dolgoprudny, Russia; Institut de Biologie Structurale Jean-Pierre Ebel, Université Grenoble Alpes-Commissariat à l'Energie Atomique et aux Energies Alternatives-CNRS, Grenoble, France; Institute of Crystallography, RWTH Aachen University, Aachen, Germany
| | - Andrey Bogorodskiy
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, Dolgoprudny, Russia
| | - Valentin Borshchevskiy
- IBI-7: Structural Biochemistry, Forschungszentrum Jülich GmbH, Jülich, Germany; JuStruct: Jülich Center for Structural Biology, Forschungszentrum Jülich, Jülich, Germany; Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, Dolgoprudny, Russia
| | - Stefanie Hemmer
- Institut für Molekulare Enzymtechnologie, Heinrich-Heine-Universität Düsseldorf, Forschungszentrum Jülich GmbH, Jülich, Germany; IBG-1: Biotechnology, Forschungszentrum Jülich GmbH, Jülich, Germany
| | - Ulrich Schwaneberg
- Institute of Biotechnology, RWTH Aachen University, Aachen, Germany; DWI-Leibniz Institute for Interactive Materials, Aachen, Germany
| | - Valentin Gordeliy
- IBI-7: Structural Biochemistry, Forschungszentrum Jülich GmbH, Jülich, Germany; JuStruct: Jülich Center for Structural Biology, Forschungszentrum Jülich, Jülich, Germany; Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, Dolgoprudny, Russia; Institut de Biologie Structurale Jean-Pierre Ebel, Université Grenoble Alpes-Commissariat à l'Energie Atomique et aux Energies Alternatives-CNRS, Grenoble, France
| | - Karl-Erich Jaeger
- Institut für Molekulare Enzymtechnologie, Heinrich-Heine-Universität Düsseldorf, Forschungszentrum Jülich GmbH, Jülich, Germany; IBG-1: Biotechnology, Forschungszentrum Jülich GmbH, Jülich, Germany
| | - Renu Batra-Safferling
- IBI-7: Structural Biochemistry, Forschungszentrum Jülich GmbH, Jülich, Germany; JuStruct: Jülich Center for Structural Biology, Forschungszentrum Jülich, Jülich, Germany
| | - Ivan Gushchin
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, Dolgoprudny, Russia.
| | - Ulrich Krauss
- Institut für Molekulare Enzymtechnologie, Heinrich-Heine-Universität Düsseldorf, Forschungszentrum Jülich GmbH, Jülich, Germany; IBG-1: Biotechnology, Forschungszentrum Jülich GmbH, Jülich, Germany.
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16
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Rivas Aiello MB, Azcárate JC, Zelaya E, David Gara P, Bosio GN, Gensch T, Mártire DO. Photothermal therapy with silver nanoplates in HeLa cells studied by in situ fluorescence microscopy. Biomater Sci 2021; 9:2608-2619. [PMID: 33595000 DOI: 10.1039/d0bm01952f] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Photothermal therapy (PTT) is a noninvasive treatment for cancer relying on the incorporation of NIR-light absorbing nanomaterials into cells, which upon illumination release heat causing thermally induced cell death. We prove that irradiation of aqueous suspensions of poly(vinylpyrrolidone)-coated silver nanoplates (PVPAgNP) or PVPAgNP in HeLa cells with red or NIR lasers causes a sizeable photothermal effect, which in cells can be visualized with the temperature sensing fluorophore Rhodamine B (RhB) using spinning disk confocal fluorescence microscopy or fluorescence lifetime imaging. Upon red-light irradiation of cells that were incubated with both, RhB and PVPAgNP at concentrations with no adverse effects on cell viability, a substantial heat release is detected. Initiation of cell death by photothermal effect is observed by positive signals of fluorescent markers for early and late apoptosis. Surprisingly, a new nanomaterial-assisted cell killing mode is operating when PVPAgNP-loaded HeLa cells are excited with moderate powers of fs-pulsed NIR light. Small roundish areas are generated with bright and fast (<1 ns) decaying emission, which expand fast and destroy the whole cell in seconds. This characteristic emission is assigned to efficient optical breakdown initiation around the strongly absorbing PVPAgNP leading to plasma formation that spreads fast through the cell.
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Affiliation(s)
- María Belén Rivas Aiello
- Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas (INIFTA), Facultad de Ciencias Exactas, Universidad Nacional de La Plata, C. C. 16, Suc. 4, (1900) La Plata, Argentina.
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17
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Maslov I, Khorn P, Bogorodskiy A, Volgozhannikova A, Zykov I, Belousov A, Permyakov S, Zernii E, Hofkens J, Hendrix J, Gensch T, Borshchevskiy V. Single-Molecule Fluorescence-Based Measurements of Conformational Dynamics of Calcium-Binding Protein Recoverin. Biophys J 2021. [DOI: 10.1016/j.bpj.2020.11.1272] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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18
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Bogorodskiy AO, Maslov I, Burkatovsky D, Mishin A, Okhrimenko I, Bueldt G, Altschmied J, Haendeler J, Gensch T, Borshchevskiy V. Puromycin Causes Protein Uptake by Cells from the Medium. Biophys J 2021. [DOI: 10.1016/j.bpj.2020.11.1102] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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19
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Fan X, Gensch T, Büldt G, Zhang Y, Musha Z, Zhang W, Roncarati R, Huang R. Three dimensional drift control at nano-scale in single molecule localization microscopy. Opt Express 2020; 28:32750-32763. [PMID: 33114953 DOI: 10.1364/oe.404123] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Accepted: 10/04/2020] [Indexed: 06/11/2023]
Abstract
Super-resolution imaging based on single molecule localization of cellular structures on nanometer scale requires to record a series of wide-field or TIRF images resulting in a considerable recording time (typically of minutes). Therefore, sample drift becomes a critical problem and will lower the imaging precision. Herein we utilized morphological features of the specimen (mammalian cells) itself as reference markers replacing the traditionally used markers (e.g., artificial fiduciary markers, fluorescent beads, or metal nanoparticles) for sample drift compensation. We achieved sub-nanometer localization precision <1.0 nm in lateral direction and <6.0 nm in axial direction, which is well comparable with the precision achieved with the established methods using artificial position markers added to the specimen. Our method does not require complex hardware setup, extra labelling or markers, and has the additional advantage of the absence of photobleaching, which caused precision decrease during the course of super-resolution measurement. The achieved improvement of quality and resolution in reconstructed super-resolution images by application of our drift-correction method is demonstrated by single molecule localization-based super-resolution imaging of F-actin in fixed A549 cells.
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20
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Rodenbücher C, Bittkau K, Bihlmayer G, Wrana D, Gensch T, Korte C, Krok F, Szot K. Mapping the conducting channels formed along extended defects in SrTiO 3 by means of scanning near-field optical microscopy. Sci Rep 2020; 10:17763. [PMID: 33082447 PMCID: PMC7576817 DOI: 10.1038/s41598-020-74645-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2020] [Accepted: 09/30/2020] [Indexed: 12/23/2022] Open
Abstract
Mixed ionic-electronic-conducting perovskites such as SrTiO3 are promising materials to be employed in efficient energy conversion or information processing. These materials exhibit a self-doping effect related to the formation of oxygen vacancies and electronic charge carriers upon reduction. It has been found that dislocations play a prominent role in this self-doping process, serving as easy reduction sites, which result in the formation of conducting filaments along the dislocations. While this effect has been investigated in detail with theoretical calculations and direct observations using local-conductivity atomic force microscopy, the present work highlights the optical properties of dislocations in SrTiO3 single crystals. Using the change in optical absorption upon reduction as an indicator, two well-defined arrangements of dislocations, namely a bicrystal boundary and a slip band induced by mechanical deformation, are investigated by means of scanning near-field optical microscopy. In both cases, the regions with enhanced dislocation density can be clearly identified as regions with higher optical absorption. Assisted by ab initio calculations, confirming that the agglomeration of oxygen vacancies significantly change the local dielectric constants of the material, the results provide direct evidence that reduced dislocations can be classified as alien matter embedded in the SrTiO3 matrix.
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Affiliation(s)
- Christian Rodenbücher
- Institute of Energy and Climate Research (IEK-14), Forschungszentrum Jülich GmbH, 52425, Jülich, Germany.
| | - Karsten Bittkau
- Institute of Energy and Climate Research (IEK-5), Forschungszentrum Jülich GmbH, 52425, Jülich, Germany
| | - Gustav Bihlmayer
- Peter Grünberg Institut (PGI-1) and JARA-FIT, Forschungszentrum Jülich GmbH, 52425, Jülich, Germany
| | - Dominik Wrana
- Marian Smoluchowski Institute of Physics, Jagiellonian University, 30-348, Krakow, Poland
| | - Thomas Gensch
- Institute of Biological Information Processing (IBI-1), Forschungszentrum Jülich GmbH, 52425, Jülich, Germany
| | - Carsten Korte
- Institute of Energy and Climate Research (IEK-14), Forschungszentrum Jülich GmbH, 52425, Jülich, Germany
| | - Franciszek Krok
- Marian Smoluchowski Institute of Physics, Jagiellonian University, 30-348, Krakow, Poland
| | - Kristof Szot
- Institute of Physics, University of Silesia, 41-500, Chorzów, Poland
- aixACCT Systems GmbH, 52068, Aachen, Germany
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21
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Dobner J, Simons IM, Rufinatscha K, Hänsch S, Schwarten M, Weiergräber OH, Abdollahzadeh I, Gensch T, Bode JG, Hoffmann S, Willbold D. Deficiency of GABARAP but not its Paralogs Causes Enhanced EGF-induced EGFR Degradation. Cells 2020; 9:E1296. [PMID: 32456010 PMCID: PMC7291022 DOI: 10.3390/cells9051296] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Revised: 05/19/2020] [Accepted: 05/20/2020] [Indexed: 12/20/2022] Open
Abstract
The γ-aminobutyric acid type A receptor-associated protein (GABARAP) and its close paralogs GABARAPL1 and GABARAPL2 constitute a subfamily of the autophagy-related 8 (Atg8) protein family. Being associated with a variety of dynamic membranous structures of autophagic and non-autophagic origin, Atg8 proteins functionalize membranes by either serving as docking sites for other proteins or by acting as membrane tethers or adhesion factors. In this study, we describe that deficiency for GABARAP alone, but not for its close paralogs, is sufficient for accelerated EGF receptor (EGFR) degradation in response to EGF, which is accompanied by the downregulation of EGFR-mediated MAPK signaling, altered target gene expression, EGF uptake, and EGF vesicle composition over time. We further show that GABARAP and EGFR converge in the same distinct compartments at endogenous GABARAP expression levels in response to EGF stimulation. Furthermore, GABARAP associates with EGFR in living cells and binds to synthetic peptides that are derived from the EGFR cytoplasmic tail in vitro. Thus, our data strongly indicate a unique and novel role for GABARAP during EGFR trafficking.
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Affiliation(s)
- Jochen Dobner
- Institut für Physikalische Biologie, Heinrich-Heine-Universität Düsseldorf, 40225 Düsseldorf, Germany; (J.D.); (I.M.S.)
| | - Indra M. Simons
- Institut für Physikalische Biologie, Heinrich-Heine-Universität Düsseldorf, 40225 Düsseldorf, Germany; (J.D.); (I.M.S.)
- Institute of Biological Information Processing: Structural Biochemistry (IBI-7), Forschungszentrum Jülich, 52425 Jülich, Germany; (M.S.); (O.H.W.); (I.A.); (S.H.)
| | - Kerstin Rufinatscha
- Department of Gastroenterology, Hepatology and Infectiology, University Hospital, Heinrich-Heine-Universität Düsseldorf, 40225 Düsseldorf, Germany; (K.R.); (J.G.B.)
| | - Sebastian Hänsch
- Department of Biology, Center for Advanced Imaging (CAi), Heinrich-Heine-Universität Düsseldorf, 40225 Düsseldorf, Germany;
| | - Melanie Schwarten
- Institute of Biological Information Processing: Structural Biochemistry (IBI-7), Forschungszentrum Jülich, 52425 Jülich, Germany; (M.S.); (O.H.W.); (I.A.); (S.H.)
| | - Oliver H. Weiergräber
- Institute of Biological Information Processing: Structural Biochemistry (IBI-7), Forschungszentrum Jülich, 52425 Jülich, Germany; (M.S.); (O.H.W.); (I.A.); (S.H.)
| | - Iman Abdollahzadeh
- Institute of Biological Information Processing: Structural Biochemistry (IBI-7), Forschungszentrum Jülich, 52425 Jülich, Germany; (M.S.); (O.H.W.); (I.A.); (S.H.)
- Institute of Biological Information Processing: Molecular and Cell Physiology (IBI-1), Forschungszentrum Jülich, 52425 Jülich, Germany;
| | - Thomas Gensch
- Institute of Biological Information Processing: Molecular and Cell Physiology (IBI-1), Forschungszentrum Jülich, 52425 Jülich, Germany;
| | - Johannes G. Bode
- Department of Gastroenterology, Hepatology and Infectiology, University Hospital, Heinrich-Heine-Universität Düsseldorf, 40225 Düsseldorf, Germany; (K.R.); (J.G.B.)
| | - Silke Hoffmann
- Institute of Biological Information Processing: Structural Biochemistry (IBI-7), Forschungszentrum Jülich, 52425 Jülich, Germany; (M.S.); (O.H.W.); (I.A.); (S.H.)
| | - Dieter Willbold
- Institut für Physikalische Biologie, Heinrich-Heine-Universität Düsseldorf, 40225 Düsseldorf, Germany; (J.D.); (I.M.S.)
- Institute of Biological Information Processing: Structural Biochemistry (IBI-7), Forschungszentrum Jülich, 52425 Jülich, Germany; (M.S.); (O.H.W.); (I.A.); (S.H.)
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22
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Fan X, Hendriks J, Comini M, Katranidis A, Büldt G, Gensch T. Spatial filter and its application in three-dimensional single molecule localization microscopy. Methods Appl Fluoresc 2020; 8:025008. [PMID: 32150730 DOI: 10.1088/2050-6120/ab7e0f] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Single molecule localization microscopy (SMLM) allows the imaging of cellular structures with resolutions five to ten times below the diffraction limit of optical microscopy. It was originally introduced as a two-dimensional technique based on the localization of single emitters as projection onto the x-y imaging plane. The determination of the axial position of a fluorescent emitter is only possible by additional information. Here we report a method (spatial filter SMLM (SFSMLM)) that allows to determine the axial positions of fluorescent molecules and nanoparticles on the nanometer scale by the usage of two spatial filters, which are placed in two otherwise identical emission detection channels. SFSMLM allows axial localization in a range of ca. 1.5 μm with a localization precision of 15 - 30 nm in axial direction. The technique was utilized for localizing and imaging small cellular structures - e.g. actin filaments, vesicles and mitochondria - in three dimensions.
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Affiliation(s)
- Xiaoming Fan
- Institute of Complex Systems (ICS-4, Cellular Biophysics), Forschungszentrum Jülich, Leo-Brandt-Str., 52428 Jülich, Germany. Institute of Complex Systems (ICS-5, Molecular Biophysics), Forschungszentrum Jülich, Leo-Brandt-Str., 52428 Jülich, Germany. Shanghai Institute of Materia Medica, Chinese Academy of Sciences, 201203 Shanghai, People's Republic of China
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23
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Bogorodskiy AO, Bolkhovitina EL, Gensch T, Troyanova NI, Mishin AV, Okhrimenko IS, Braun A, Spies E, Gordeliy VI, Sapozhnikov AM, Borshchevskiy VI, Shevchenko MA. Murine Intraepithelial Dendritic Cells Interact With Phagocytic Cells During Aspergillus fumigatus-Induced Inflammation. Front Immunol 2020; 11:298. [PMID: 32161590 PMCID: PMC7053491 DOI: 10.3389/fimmu.2020.00298] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2019] [Accepted: 02/05/2020] [Indexed: 11/13/2022] Open
Abstract
People are constantly exposed to airborne fungal spores, including Aspergillus fumigatus conidia that can cause life-threatening conditions in immunocompromised patients or acute exacerbations in allergics. However, immunocompetent hosts do not exhibit mycoses or systemic inflammation, due to the sufficient but not excessive antifungal immune response that prevent fungal invasion. Intraepithelial dendritic cells (IE-DCs) of the conducting airway mucosa are located in the primary site of the inhalant pathogen entry; these cells can sense A. fumigatus conidia and maintain homeostasis. The mechanisms by which IE-DCs contribute to regulating the antifungal immune response and controlling conidia dissemination are not understood. To clarify the role of IE-DCs in the balance between pathogen sensing and immune tolerance we investigated the A. fumigatus conidia distribution in optically cleared mouse lungs and estimated the kinetics of the local phagocytic response during the course of inflammation. MHCII+ antigen-presenting cells, including IE-DCs, and CD11b+ phagocytes were identified by immunohistochemistry and three-dimensional fluorescence confocal laser-scanning microscopy of conducting airway whole-mounts. Application of A. fumigatus conidia increased the number of CD11b+ phagocytes in the conducting airway mucosa and induced the trafficking of these cells through the conducting airway wall to the luminal side of the epithelium. Some CD11b+ phagocytes internalized conidia in the conducting airway lumen. During the migration through the airway wall, CD11b+ phagocytes formed clusters. Permanently located in the airway wall IE-DCs contacted both single CD11b+ phagocytes and clusters. Based on the spatiotemporal characteristics of the interactions between IE-DCs and CD11b+ phagocytes, we provide a novel anatomical rationale for the contribution of IE-DCs to controlling the excessive phagocyte-mediated immune response rather than participating in pathogen uptake.
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Affiliation(s)
- Andrey O Bogorodskiy
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, Dolgoprudny, Russia
| | - Elena L Bolkhovitina
- Laboratory of Cell Interactions, Department of Immunology, Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia
| | - Thomas Gensch
- Institute of Biological Information Processing (IBI-1: Molecular and Cellular Physiology), Forschungszentrum Jülich, Jülich, Germany
| | - Natalia I Troyanova
- Laboratory of Cell Interactions, Department of Immunology, Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia
| | - Alexey V Mishin
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, Dolgoprudny, Russia
| | - Ivan S Okhrimenko
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, Dolgoprudny, Russia
| | - Armin Braun
- Fraunhofer Institute for Toxicology and Experimental Medicine ITEM, Biomedical Research in Endstage and Obstructive Lung Disease Hannover (BREATH), Member of the German Center for Lung Research (DZL), Member of Fraunhofer International Consortium for Anti-Infective Research (iCAIR), Hanover, Germany.,Institute of Immunology, Hannover Medical School, Hanover, Germany
| | - Emma Spies
- Fraunhofer Institute for Toxicology and Experimental Medicine ITEM, Biomedical Research in Endstage and Obstructive Lung Disease Hannover (BREATH), Member of the German Center for Lung Research (DZL), Member of Fraunhofer International Consortium for Anti-Infective Research (iCAIR), Hanover, Germany.,Institute of Immunology, Hannover Medical School, Hanover, Germany
| | - Valentin I Gordeliy
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, Dolgoprudny, Russia.,Institute of Biological Information Processing (IBI-7: Structural Biochemistry), Forschungszentrum Jülich, Jülich, Germany.,Institut de Biologie Structurale, Université Grenoble Alpes-CEA-CNRS, Grenoble, France
| | - Alexander M Sapozhnikov
- Laboratory of Cell Interactions, Department of Immunology, Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia
| | - Valentin I Borshchevskiy
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, Dolgoprudny, Russia.,Institute of Biological Information Processing (IBI-7: Structural Biochemistry), Forschungszentrum Jülich, Jülich, Germany
| | - Marina A Shevchenko
- Laboratory of Cell Interactions, Department of Immunology, Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia
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Meyer J, Untiet V, Fahlke C, Gensch T, Rose CR. Quantitative determination of cellular [Na +] by fluorescence lifetime imaging with CoroNaGreen. J Gen Physiol 2019; 151:1319-1331. [PMID: 31597684 PMCID: PMC6829561 DOI: 10.1085/jgp.201912404] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2019] [Accepted: 09/11/2019] [Indexed: 12/23/2022] Open
Abstract
Meyer et al. establish the suitability of the sodium-sensitive indicator dye CoroNaGreen for fluorescence lifetime imaging inside cells. This approach represents a valuable tool for quantitative and dynamic determination of intracellular sodium concentrations independent of dye concentration. Fluorescence lifetime imaging microscopy (FLIM) with fluorescent ion sensors enables the measurement of ion concentrations based on the detection of photon emission events after brief excitation with a pulsed laser source. In contrast to intensity-based imaging, it is independent of dye concentration, photobleaching, or focus drift and has thus been successfully employed for quantitative analysis of, e.g., calcium levels in different cell types and cellular microdomains. Here, we tested the suitability of CoroNaGreen for FLIM-based determination of sodium concentration ([Na+]) inside cells. In vitro measurements confirmed that fluorescence lifetimes of CoroNaGreen (CoroNaFL) increased with increasing [Na+]. Moreover, CoroNaFL was largely independent of changes in potassium concentration or viscosity. Changes in pH slightly affected FL in the acidic range (pH ≤ 5.5). For intracellular determination of [Na+], HEK293T cells were loaded with the membrane-permeable form of CoroNaGreen. Fluorescence decay curves of CoroNaGreen, derived from time-correlated single-photon counting, were approximated by a bi-exponential decay. In situ calibrations revealed a sigmoidal dependence of CoroNaFL on [Na+] between 0 and 150 mM, exhibiting an apparent Kd of ∼80 mM. Based on these calibrations, a [Na+] of 17.6 mM was determined in the cytosol. Cellular nuclei showed a significantly lower [Na+] of 13.0 mM, whereas [Na+] in perinuclear regions was significantly higher (26.5 mM). Metabolic inhibition or blocking the Na+/K+-ATPase by removal of extracellular K+ caused significant [Na+] increases in all cellular subcompartments. Using an alternative approach for data analysis (“Ratio FLIM”) increased the temporal resolution and revealed a sequential response to K+ removal, with cytosolic [Na+] increasing first, followed by the nucleus and finally the perinuclear regions. Taken together, our results show that CoroNaGreen is suitable for dynamic, FLIM-based determination of intracellular [Na+]. This approach thus represents a valuable tool for quantitative determination of [Na+] and changes thereof in different subcellular compartments.
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Affiliation(s)
- Jan Meyer
- Institute of Neurobiology, Faculty of Mathematics and Natural Sciences, Heinrich Heine University Düsseldorf, Düsseldorf, Germany.,Institute of Complex Systems 4 (ICS-4), Zelluläre Biophysik, Forschungszentrum Jülich, Jülich, Germany
| | - Verena Untiet
- Institute of Complex Systems 4 (ICS-4), Zelluläre Biophysik, Forschungszentrum Jülich, Jülich, Germany
| | - Christoph Fahlke
- Institute of Complex Systems 4 (ICS-4), Zelluläre Biophysik, Forschungszentrum Jülich, Jülich, Germany
| | - Thomas Gensch
- Institute of Complex Systems 4 (ICS-4), Zelluläre Biophysik, Forschungszentrum Jülich, Jülich, Germany
| | - Christine R Rose
- Institute of Neurobiology, Faculty of Mathematics and Natural Sciences, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
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Burgstaller S, Bischof H, Gensch T, Stryeck S, Gottschalk B, Ramadani-Muja J, Eroglu E, Rost R, Balfanz S, Baumann A, Waldeck-Weiermair M, Hay JC, Madl T, Graier WF, Malli R. pH-Lemon, a Fluorescent Protein-Based pH Reporter for Acidic Compartments. ACS Sens 2019; 4:883-891. [PMID: 30864782 PMCID: PMC6488996 DOI: 10.1021/acssensors.8b01599] [Citation(s) in RCA: 83] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Distinct subcellular pH levels, especially in lysosomes and endosomes, are essential for the degradation, modification, sorting, accumulation, and secretion of macromolecules. Here, we engineered a novel genetically encoded pH probe by fusing the pH-stable cyan fluorescent protein (FP) variant, mTurquoise2, to the highly pH-sensitive enhanced yellow fluorescent protein, EYFP. This approach yielded a ratiometric biosensor-referred to as pH-Lemon-optimized for live imaging of distinct pH conditions within acidic cellular compartments. Protonation of pH-Lemon under acidic conditions significantly decreases the yellow fluorescence while the cyan fluorescence increases due to reduced Förster resonance energy transfer (FRET) efficiency. Because of its freely reversible and ratiometric responses, pH-Lemon represents a fluorescent biosensor for pH dynamics. pH-Lemon also shows a sizable pH-dependent fluorescence lifetime change that can be used in fluorescence lifetime imaging microscopy as an alternative observation method for the study of pH in acidic cellular compartments. Fusion of pH-Lemon to the protein microtubule-associated protein 1A/1B-light chain 3B (LC3B), a specific marker of autophagic membranes, resulted in its targeting within autolysosomes of HeLa cells. Moreover, fusion of pH-Lemon to a glycophosphatidylinositol (GPI) anchor allowed us to monitor the entire luminal space of the secretory pathway and the exoplasmic leaflet of the plasma membrane. Utilizing this new pH probe, we revealed neutral and acidic vesicles and substructures inside cells, highlighting compartments of distinct pH throughout the endomembrane system. These data demonstrate, that this novel pH sensor, pH-Lemon, is very suitable for the study of local pH dynamics of subcellular microstructures in living cells.
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Affiliation(s)
- Sandra Burgstaller
- Molecular Biology and Biochemistry, Gottfried Schatz Research Center, Medical University of Graz, Neue Stiftingtalstraße 6/6, 8010 Graz, Austria
| | - Helmut Bischof
- Molecular Biology and Biochemistry, Gottfried Schatz Research Center, Medical University of Graz, Neue Stiftingtalstraße 6/6, 8010 Graz, Austria
| | - Thomas Gensch
- Institute of Complex Systems, Zelluläre Biophysik (ICS-4), Forschungszentrum Jülich, 52428 Jülich, Germany
| | - Sarah Stryeck
- Molecular Biology and Biochemistry, Gottfried Schatz Research Center, Medical University of Graz, Neue Stiftingtalstraße 6/6, 8010 Graz, Austria
| | - Benjamin Gottschalk
- Molecular Biology and Biochemistry, Gottfried Schatz Research Center, Medical University of Graz, Neue Stiftingtalstraße 6/6, 8010 Graz, Austria
| | - Jeta Ramadani-Muja
- Molecular Biology and Biochemistry, Gottfried Schatz Research Center, Medical University of Graz, Neue Stiftingtalstraße 6/6, 8010 Graz, Austria
| | - Emrah Eroglu
- Molecular Biology and Biochemistry, Gottfried Schatz Research Center, Medical University of Graz, Neue Stiftingtalstraße 6/6, 8010 Graz, Austria
| | - Rene Rost
- Molecular Biology and Biochemistry, Gottfried Schatz Research Center, Medical University of Graz, Neue Stiftingtalstraße 6/6, 8010 Graz, Austria
| | - Sabine Balfanz
- Institute of Complex Systems, Zelluläre Biophysik (ICS-4), Forschungszentrum Jülich, 52428 Jülich, Germany
| | - Arnd Baumann
- Institute of Complex Systems, Zelluläre Biophysik (ICS-4), Forschungszentrum Jülich, 52428 Jülich, Germany
| | - Markus Waldeck-Weiermair
- Molecular Biology and Biochemistry, Gottfried Schatz Research Center, Medical University of Graz, Neue Stiftingtalstraße 6/6, 8010 Graz, Austria
| | - Jesse C. Hay
- Molecular Biology and Biochemistry, Gottfried Schatz Research Center, Medical University of Graz, Neue Stiftingtalstraße 6/6, 8010 Graz, Austria
- Division of Biological Sciences and Center for Structural and Functional Neuroscience, The University of Montana, 32 Campus Drive, HS410, Missoula 59812-4824, Montana United States
| | - Tobias Madl
- Molecular Biology and Biochemistry, Gottfried Schatz Research Center, Medical University of Graz, Neue Stiftingtalstraße 6/6, 8010 Graz, Austria
- BioTechMed Graz, Mozartgasse 12/II, 8010 Graz, Austria
| | - Wolfgang F. Graier
- Molecular Biology and Biochemistry, Gottfried Schatz Research Center, Medical University of Graz, Neue Stiftingtalstraße 6/6, 8010 Graz, Austria
- BioTechMed Graz, Mozartgasse 12/II, 8010 Graz, Austria
| | - Roland Malli
- Molecular Biology and Biochemistry, Gottfried Schatz Research Center, Medical University of Graz, Neue Stiftingtalstraße 6/6, 8010 Graz, Austria
- BioTechMed Graz, Mozartgasse 12/II, 8010 Graz, Austria
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Rodenbücher C, Menzel S, Wrana D, Gensch T, Korte C, Krok F, Szot K. Current channeling along extended defects during electroreduction of SrTiO 3. Sci Rep 2019; 9:2502. [PMID: 30792458 PMCID: PMC6385180 DOI: 10.1038/s41598-019-39372-2] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2018] [Accepted: 01/23/2019] [Indexed: 11/09/2022] Open
Abstract
Electroreduction experiments on metal oxides are well established for investigating the nature of the material change in memresistive devices, whose basic working principle is an electrically-induced reduction. While numerous research studies on this topic have been conducted, the influence of extended defects such as dislocations has not been addressed in detail hitherto. Here, we show by employing thermal microscopy to detect local Joule heating effects in the first stage of electroreduction of SrTiO3 that the current is channelled along extended defects such as dislocations which were introduced mechanically by scratching or sawing. After prolonged degradation, the matrix of the crystal is also electroreduced and the influence of the initially present dislocations diminished. At this stage, a hotspot at the anode develops due to stoichiometry polarisation leading not only to the gliding of existing dislocations, but also to the evolution of new dislocations. Such a formation is caused by electrical and thermal stress showing dislocations may play a significant role in resistive switching effects.
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Affiliation(s)
- Christian Rodenbücher
- Forschungszentrum Jülich GmbH, Institute of Energy and Climate Research (IEK-3), 52425, Jülich, Germany.
| | - Stephan Menzel
- Forschungszentrum Jülich GmbH, Peter Grünberg Institute (PGI-7), 52425, Jülich, Germany
- Forschungszentrum Jülich GmbH, JARA-FIT, 52425, Jülich, Germany
| | - Dominik Wrana
- Forschungszentrum Jülich GmbH, Peter Grünberg Institute (PGI-7), 52425, Jülich, Germany
- Forschungszentrum Jülich GmbH, JARA-FIT, 52425, Jülich, Germany
- Jagiellonian University, Marian Smoluchowski Institute of Physics, 30-348, Krakow, Poland
| | - Thomas Gensch
- Forschungszentrum Jülich GmbH, Institute of Complex Systems (ICS-4), 52425, Jülich, Germany
| | - Carsten Korte
- Forschungszentrum Jülich GmbH, Institute of Energy and Climate Research (IEK-3), 52425, Jülich, Germany
| | - Franciszek Krok
- Jagiellonian University, Marian Smoluchowski Institute of Physics, 30-348, Krakow, Poland
| | - Krzysztof Szot
- Forschungszentrum Jülich GmbH, Peter Grünberg Institute (PGI-7), 52425, Jülich, Germany
- Forschungszentrum Jülich GmbH, JARA-FIT, 52425, Jülich, Germany
- University of Silesia, A. Chełkowski Institute of Physics, 40-007, Katowice, Poland
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Conrad R, Stölting G, Hendriks J, Ruello G, Kortzak D, Jordan N, Gensch T, Hidalgo P. Rapid Turnover of the Cardiac L-Type Ca V1.2 Channel by Endocytic Recycling Regulates Its Cell Surface Availability. iScience 2018; 7:1-15. [PMID: 30267672 PMCID: PMC6135870 DOI: 10.1016/j.isci.2018.08.012] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2018] [Revised: 07/18/2018] [Accepted: 08/10/2018] [Indexed: 02/06/2023] Open
Abstract
Calcium entry through CaV1.2 L-type calcium channels regulates cardiac contractility. Here, we study the impact of exocytic and post-endocytic trafficking on cell surface channel abundance in cardiomyocytes. Single-molecule localization and confocal microscopy reveal an intracellular CaV1.2 pool tightly associated with microtubules from the perinuclear region to the cell periphery, and with actin filaments at the cell cortex. Channels newly inserted into the plasma membrane become internalized with an average time constant of 7.5 min and are sorted out to the Rab11a-recycling compartment. CaV1.2 recycling suffices for maintaining stable L-type current amplitudes over 20 hr independent of de novo channel transport along microtubules. Disruption of the actin cytoskeleton re-routes CaV1.2 from recycling toward lysosomal degradation. We identify endocytic recycling as essential for the homeostatic regulation of voltage-dependent calcium influx into cardiomyocytes. This mechanism provides the basis for a dynamic adjustment of the channel's surface availability and thus, of heart's contraction.
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Affiliation(s)
- Rachel Conrad
- Institute of Complex Systems 4, Zelluläre Biophysik, Forschungszentrum Jülich, 52425 Jülich, Germany
| | - Gabriel Stölting
- Institute of Complex Systems 4, Zelluläre Biophysik, Forschungszentrum Jülich, 52425 Jülich, Germany
| | - Johnny Hendriks
- Institute of Complex Systems 4, Zelluläre Biophysik, Forschungszentrum Jülich, 52425 Jülich, Germany
| | - Giovanna Ruello
- Institute of Complex Systems 4, Zelluläre Biophysik, Forschungszentrum Jülich, 52425 Jülich, Germany
| | - Daniel Kortzak
- Institute of Complex Systems 4, Zelluläre Biophysik, Forschungszentrum Jülich, 52425 Jülich, Germany
| | - Nadine Jordan
- Institute of Complex Systems 4, Zelluläre Biophysik, Forschungszentrum Jülich, 52425 Jülich, Germany
| | - Thomas Gensch
- Institute of Complex Systems 4, Zelluläre Biophysik, Forschungszentrum Jülich, 52425 Jülich, Germany
| | - Patricia Hidalgo
- Institute of Complex Systems 4, Zelluläre Biophysik, Forschungszentrum Jülich, 52425 Jülich, Germany; Institute of Biochemistry, Heinrich-Heine University, Düsseldorf, Germany.
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28
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Rivas Aiello MB, Castrogiovanni D, Parisi J, Azcárate JC, García Einschlag FS, Gensch T, Bosio GN, Mártire DO. Photodynamic Therapy in HeLa Cells Incubated with Riboflavin and Pectin-coated Silver Nanoparticles. Photochem Photobiol 2018; 94:1159-1166. [PMID: 29978491 DOI: 10.1111/php.12974] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2018] [Accepted: 06/26/2018] [Indexed: 01/04/2023]
Abstract
Riboflavin (Rf) is an endogenous photosensitizer, which can participate in Type I and Type II processes. We have recently shown that the yield of the triplet excited states of Rf is enhanced in the presence of pectin-coated silver nanoparticles (Pec@AgNP) due to formation of a complex between Rf and Pec@AgNP (Rf-Pec@AgNP). Consequently, under aerobic conditions, the amounts of singlet molecular oxygen and superoxide radical anion generated are also larger in the presence of the nanoparticles. This result made us suspect that the nanoparticles could have a beneficial effect in Rf-based PDT. To prove this hypothesis, we here compared the photodamage in HeLa cells incubated with Rf in the presence and in the absence of Pec@AgNP applying several optical assays. We used fluorescence imaging of irradiated HeLa cells incubated with Annexin V and propidium iodide to evaluate the occurrence of apoptosis/necrosis, the reduction of the tetrazolium dye MTT to formazan and neutral red uptake to prove cell viability, as well as synchrotron infrared microscopy of single cells to evaluate possible structural changes of DNA and nuclear proteins. The enhanced photodamage observed in the presence of Pec@AgNP seems to indicate that Rf enters into the cells complexed with the nanoparticles.
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Affiliation(s)
- María Belén Rivas Aiello
- Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas (INIFTA), Facultad de Ciencias Exactas, Universidad Nacional de La Plata, La Plata, Argentina
| | - Daniel Castrogiovanni
- CCT-La Plata-CONICET, Instituto Multidisciplinario de Biologia Celular (IMBICE), La Plata, Argentina
| | - Julieta Parisi
- CCT-La Plata-CONICET, Instituto Multidisciplinario de Biologia Celular (IMBICE), La Plata, Argentina
| | - Julio C Azcárate
- Centro Atómico Bariloche (CAB), CONICET, San Carlos de Bariloche, Río Negro, Argentina
| | - Fernando S García Einschlag
- Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas (INIFTA), Facultad de Ciencias Exactas, Universidad Nacional de La Plata, La Plata, Argentina
| | - Thomas Gensch
- Institute of Complex Systems (ICS-4 (Cellular Biophysics)), Forschungszentrum Jülich, Jülich, Germany
| | - Gabriela N Bosio
- Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas (INIFTA), Facultad de Ciencias Exactas, Universidad Nacional de La Plata, La Plata, Argentina.,Institute of Complex Systems (ICS-4 (Cellular Biophysics)), Forschungszentrum Jülich, Jülich, Germany
| | - Daniel O Mártire
- Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas (INIFTA), Facultad de Ciencias Exactas, Universidad Nacional de La Plata, La Plata, Argentina
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29
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Maslov I, Bogorodskiy A, Mishin A, Okhrimenko I, Gushchin I, Kalenov S, Dencher NA, Fahlke C, Büldt G, Gordeliy V, Gensch T, Borshchevskiy V. Efficient non-cytotoxic fluorescent staining of halophiles. Sci Rep 2018; 8:2549. [PMID: 29416075 PMCID: PMC5803262 DOI: 10.1038/s41598-018-20839-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2017] [Accepted: 01/19/2018] [Indexed: 11/09/2022] Open
Abstract
Research on halophilic microorganisms is important due to their relation to fundamental questions of survival of living organisms in a hostile environment. Here we introduce a novel method to stain halophiles with MitoTracker fluorescent dyes in their growth medium. The method is based on membrane-potential sensitive dyes, which were originally used to label mitochondria in eukaryotic cells. We demonstrate that these fluorescent dyes provide high staining efficiency and are beneficial for multi-staining purposes due to the spectral range covered (from orange to deep red). In contrast with other fluorescent dyes used so far, MitoTracker does not affect growth rate, and remains in cells after several washing steps and several generations in cell culture. The suggested dyes were tested on three archaeal (Hbt. salinarum, Haloferax sp., Halorubrum sp.) and two bacterial (Salicola sp., Halomonas sp.) strains of halophilic microorganisms. The new staining approach provides new insights into biology of Hbt. salinarum. We demonstrated the interconversion of rod-shaped cells of Hbt. salinarium to spheroplasts and submicron-sized spheres, as well as the cytoplasmic integrity of giant rod Hbt. salinarum species. By expanding the variety of tools available for halophile detection, MitoTracker dyes overcome long-standing limitations in fluorescence microscopy studies of halophiles.
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Affiliation(s)
- Ivan Maslov
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, 141700, Dolgoprudniy, Russia
| | - Andrey Bogorodskiy
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, 141700, Dolgoprudniy, Russia
| | - Alexey Mishin
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, 141700, Dolgoprudniy, Russia
| | - Ivan Okhrimenko
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, 141700, Dolgoprudniy, Russia
| | - Ivan Gushchin
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, 141700, Dolgoprudniy, Russia
| | - Sergei Kalenov
- Mendeleyev University of Chemical Technology of Russia, 125047, Moscow, Russia
| | - Norbert A Dencher
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, 141700, Dolgoprudniy, Russia
- CSI Organic Chemistry and Biochemistry, Technische Universität Darmstadt, 64287, Darmstadt, Germany
| | - Christoph Fahlke
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, 141700, Dolgoprudniy, Russia
- Institute of Complex Systems (ICS), ICS-4: Cellular Biophysics, Forschungszentrum Jülich GmbH, 52428, Jülich, Germany
| | - Georg Büldt
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, 141700, Dolgoprudniy, Russia
| | - Valentin Gordeliy
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, 141700, Dolgoprudniy, Russia
- Univ. Grenoble Alpes, CEA, CNRS, IBS, 38000, Grenoble, France
- Institute of Complex Systems (ICS), ICS-6: Structural Biochemistry, Forschungszentrum Jülich GmbH, 52425, Jülich, Germany
| | - Thomas Gensch
- Institute of Complex Systems (ICS), ICS-4: Cellular Biophysics, Forschungszentrum Jülich GmbH, 52428, Jülich, Germany
| | - Valentin Borshchevskiy
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, 141700, Dolgoprudniy, Russia.
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30
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Baumgart M, Huber I, Abdollahzadeh I, Gensch T, Frunzke J. Heterologous expression of the Halothiobacillus neapolitanus carboxysomal gene cluster in Corynebacterium glutamicum. J Biotechnol 2017; 258:126-135. [DOI: 10.1016/j.jbiotec.2017.03.019] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2016] [Revised: 03/16/2017] [Accepted: 03/18/2017] [Indexed: 12/20/2022]
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Abdollahzadeh I, Schwarten M, Gensch T, Willbold D, Weiergräber OH. The Atg8 Family of Proteins-Modulating Shape and Functionality of Autophagic Membranes. Front Genet 2017; 8:109. [PMID: 28894458 PMCID: PMC5581321 DOI: 10.3389/fgene.2017.00109] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2017] [Accepted: 08/07/2017] [Indexed: 12/23/2022] Open
Abstract
Aging is a multifactorial process involving an accumulation of alterations on various organizational levels, which finally compromises viability and limits the lifespan of organisms. It is now well-established that many aspects of aging can be positively affected by (macro)autophagy, a mechanism of self-digestion found in virtually all eukaryotic cells. A comprehensive understanding of autophagy is thus expected to not only deepen our insight into the mechanisms of aging but to also open up new avenues toward increasing the healthy lifespan in humans. In this review, we focus on the Atg8 family of ubiquitin-like proteins, which play a crucial role in the autophagy process by virtue of their unique mode of reversible membrane association.
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Affiliation(s)
- Iman Abdollahzadeh
- Institute of Complex Systems, Structural Biochemistry (ICS-6), Forschungszentrum JülichJülich, Germany.,Institute of Complex Systems, Cellular Biophysics (ICS-4), Forschungszentrum JülichJülich, Germany
| | - Melanie Schwarten
- Institute of Complex Systems, Structural Biochemistry (ICS-6), Forschungszentrum JülichJülich, Germany
| | - Thomas Gensch
- Institute of Complex Systems, Cellular Biophysics (ICS-4), Forschungszentrum JülichJülich, Germany
| | - Dieter Willbold
- Institute of Complex Systems, Structural Biochemistry (ICS-6), Forschungszentrum JülichJülich, Germany.,Institut für Physikalische Biologie und Biologisch-Medizinisches Forschungszentrum, Heinrich-Heine-Universität DüsseldorfDüsseldorf, Germany
| | - Oliver H Weiergräber
- Institute of Complex Systems, Structural Biochemistry (ICS-6), Forschungszentrum JülichJülich, Germany
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32
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Wingen M, Jaeger KE, Gensch T, Drepper T. Novel Thermostable Flavin-binding Fluorescent Proteins from Thermophilic Organisms. Photochem Photobiol 2017; 93:849-856. [DOI: 10.1111/php.12740] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2016] [Accepted: 12/28/2016] [Indexed: 01/13/2023]
Affiliation(s)
- Marcus Wingen
- Institute of Molecular Enzyme Technology; Heinrich Heine University Düsseldorf; Forschungszentrum Jülich; Jülich Germany
| | - Karl-Erich Jaeger
- Institute of Molecular Enzyme Technology; Heinrich Heine University Düsseldorf; Forschungszentrum Jülich; Jülich Germany
- Institute of Bio- and Geosciences; IBG-1: Biotechnology; Forschungszentrum Jülich; Jülich Germany
| | - Thomas Gensch
- Institute of Complex Systems 4 (Cellular Biophysics); Forschungszentrum Jülich; Jülich Germany
| | - Thomas Drepper
- Institute of Molecular Enzyme Technology; Heinrich Heine University Düsseldorf; Forschungszentrum Jülich; Jülich Germany
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33
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Rupprecht C, Wingen M, Potzkei J, Gensch T, Jaeger KE, Drepper T. A novel FbFP-based biosensor toolbox for sensitive in vivo determination of intracellular pH. J Biotechnol 2017; 258:25-32. [PMID: 28501596 DOI: 10.1016/j.jbiotec.2017.05.006] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2017] [Revised: 05/05/2017] [Accepted: 05/07/2017] [Indexed: 02/07/2023]
Abstract
The intracellular pH is an important modulator of various bio(techno)logical processes such as enzymatic conversion of metabolites or transport across the cell membrane. Changes of intracellular pH due to altered proton distribution can thus cause dysfunction of cellular processes. Consequently, accurate monitoring of intracellular pH allows elucidating the pH-dependency of (patho)physiological and biotechnological processes. In this context, genetically encoded biosensors represent a powerful tool to determine intracellular pH values non-invasively and with high spatiotemporal resolution. We have constructed a toolbox of novel genetically encoded FRET-based pH biosensors (named Fluorescence Biosensors for pH or FluBpH) that utilizes the FMN-binding fluorescent protein EcFbFP as donor domain. In contrast to many fluorescent proteins of the GFP family, EcFbFP exhibits a remarkable tolerance towards acidic pH (pKa∼3.2). To cover the broad range of physiologically relevant pH values, three EYFP variants exhibiting pKa values of 5.7, 6.1 and 7.5 were used as pH-sensing FRET acceptor domains. The resulting biosensors FluBpH 5.7, FluBpH 6.1 and FluBpH 7.5 were calibrated in vitro and in vivo to accurately evaluate their pH indicator properties. To demonstrate the in vivo applicability of FluBpH, changes of intracellular pH were ratiometrically measured in E. coli cells during acid stress.
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Affiliation(s)
- Christian Rupprecht
- Institute of Molecular Enzyme Technology, Heinrich-Heine-University Düsseldorf, Forschungszentrum Jülich, D-52425 Jülich, Germany
| | - Marcus Wingen
- Institute of Molecular Enzyme Technology, Heinrich-Heine-University Düsseldorf, Forschungszentrum Jülich, D-52425 Jülich, Germany
| | - Janko Potzkei
- Institute of Bio- and Geosciences IBG-1: Biotechnology, Forschungszentrum Jülich GmbH, D-52425 Jülich, Germany; GO-Bio Projekt SenseUP, Forschungszentrum Jülich, D-52425 Jülich GmbH, Germany
| | - Thomas Gensch
- Institute of Complex Systems ICS-4: Cellular Biophysics, Forschungszentrum Jülich GmbH, D-52425 Jülich, Germany
| | - Karl-Erich Jaeger
- Institute of Molecular Enzyme Technology, Heinrich-Heine-University Düsseldorf, Forschungszentrum Jülich, D-52425 Jülich, Germany; Institute of Bio- and Geosciences IBG-1: Biotechnology, Forschungszentrum Jülich GmbH, D-52425 Jülich, Germany
| | - Thomas Drepper
- Institute of Molecular Enzyme Technology, Heinrich-Heine-University Düsseldorf, Forschungszentrum Jülich, D-52425 Jülich, Germany.
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Candish L, Freitag M, Gensch T, Glorius F. Mild, visible light-mediated decarboxylation of aryl carboxylic acids to access aryl radicals. Chem Sci 2017; 8:3618-3622. [PMID: 28580100 PMCID: PMC5437376 DOI: 10.1039/c6sc05533h] [Citation(s) in RCA: 103] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2016] [Accepted: 02/27/2017] [Indexed: 12/22/2022] Open
Abstract
Herein we present the first example of aryl radical formation via the visible light-mediated decarboxylation of aryl carboxylic acids using photoredox catalysis.
Herein we present the first example of aryl radical formation via the visible light-mediated decarboxylation of aryl carboxylic acids using photoredox catalysis. This method constitutes a mild protocol for the decarboxylation of cheap and abundant aryl carboxylic acids and tolerates both electron-rich substrates and those lacking ortho-substitution. The in situ formation of an acyl hypobromite is proposed to prevent unproductive hydrogen atom abstraction and trapping of the intermediate aroyloxy radical, enabling mild decarboxylation.
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Affiliation(s)
- L Candish
- Organisch-Chemisches Institut , Westfälische Wilhelms-Universität Münster , Corrensstrasse 40 , 48149 , Münster , Germany .
| | - M Freitag
- Organisch-Chemisches Institut , Westfälische Wilhelms-Universität Münster , Corrensstrasse 40 , 48149 , Münster , Germany .
| | - T Gensch
- Organisch-Chemisches Institut , Westfälische Wilhelms-Universität Münster , Corrensstrasse 40 , 48149 , Münster , Germany .
| | - F Glorius
- Organisch-Chemisches Institut , Westfälische Wilhelms-Universität Münster , Corrensstrasse 40 , 48149 , Münster , Germany .
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Kube S, Hersch N, Naumovska E, Gensch T, Hendriks J, Franzen A, Landvogt L, Siebrasse JP, Kubitscheck U, Hoffmann B, Merkel R, Csiszár A. Fusogenic Liposomes as Nanocarriers for the Delivery of Intracellular Proteins. Langmuir 2017; 33:1051-1059. [PMID: 28059515 DOI: 10.1021/acs.langmuir.6b04304] [Citation(s) in RCA: 87] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Direct delivery of proteins and peptides into living mammalian cells has been accomplished using phospholipid liposomes as carrier particles. Such liposomes are usually taken up via endocytosis where the main part of their cargo is degraded in lysosomes before reaching its destination. Here, fusogenic liposomes, a newly developed molecular carrier system, were used for protein delivery. When such liposomes were loaded with water-soluble proteins and brought into contact with mammalian cells, the liposomal membrane efficiently fused with the cellular plasma membrane delivering the liposomal content to the cytoplasm without degradation. To explore the key factors of proteofection processes, the complex formation of fusogenic liposomes and proteins of interest and the size and zeta potential of the formed fusogenic proteoliposoms were monitored. Intracellular protein delivery was analyzed using fluorescence microscopy and flow cytometry. Proteins such as EGFP, Dendra2, and R-phycoerythrin or peptides such as LifeAct-FITC and NTF2-AlexaFluor488 were successfully incorporated into mammalian cells with high efficiency. Moreover, correct functionality and faithful transport to binding sites were also proven for the imported proteins.
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Affiliation(s)
| | | | | | | | | | | | - Lisa Landvogt
- Biophysical Chemistry, Friedrich-Wilhelms-University Bonn , D-53012 Bonn, Germany
| | - Jan-Peter Siebrasse
- Biophysical Chemistry, Friedrich-Wilhelms-University Bonn , D-53012 Bonn, Germany
| | - Ulrich Kubitscheck
- Biophysical Chemistry, Friedrich-Wilhelms-University Bonn , D-53012 Bonn, Germany
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Untiet V, Kovermann P, Gerkau NJ, Gensch T, Rose CR, Fahlke C. Glutamate transporter-associated anion channels adjust intracellular chloride concentrations during glial maturation. Glia 2016; 65:388-400. [PMID: 27859594 DOI: 10.1002/glia.23098] [Citation(s) in RCA: 65] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2016] [Revised: 10/18/2016] [Accepted: 10/24/2016] [Indexed: 01/09/2023]
Abstract
Astrocytic volume regulation and neurotransmitter uptake are critically dependent on the intracellular anion concentration, but little is known about the mechanisms controlling internal anion homeostasis in these cells. Here we used fluorescence lifetime imaging microscopy (FLIM) with the chloride-sensitive dye MQAE to measure intracellular chloride concentrations in murine Bergmann glial cells in acute cerebellar slices. We found Bergmann glial [Cl- ]int to be controlled by two opposing transport processes: chloride is actively accumulated by the Na+ -K+ -2Cl- cotransporter NKCC1, and chloride efflux through anion channels associated with excitatory amino acid transporters (EAATs) reduces [Cl- ]int to values that vary upon changes in expression levels or activity of these channels. EAATs transiently form anion-selective channels during glutamate transport, and thus represent a class of ligand-gated anion channels. Age-dependent upregulation of EAATs results in a developmental chloride switch from high internal chloride concentrations (51.6 ± 2.2 mM, mean ± 95% confidence interval) during early development to adult levels (35.3 ± 0.3 mM). Simultaneous blockade of EAAT1/GLAST and EAAT2/GLT-1 increased [Cl- ]int in adult glia to neonatal values. Moreover, EAAT activation by synaptic stimulations rapidly decreased [Cl- ]int . Other tested chloride channels or chloride transporters do not contribute to [Cl- ]int under our experimental conditions. Neither genetic removal of ClC-2 nor pharmacological block of K+ -Cl- cotransporter change resting Bergmann glial [Cl- ]int in acute cerebellar slices. We conclude that EAAT anion channels play an important and unexpected role in adjusting glial intracellular anion concentration during maturation and in response to cerebellar activity. GLIA 2017;65:388-400.
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Affiliation(s)
- Verena Untiet
- Institute of Complex Systems, Zelluläre Biophysik (ICS-4), Forschungszentrum Jülich, Germany
| | - Peter Kovermann
- Institute of Complex Systems, Zelluläre Biophysik (ICS-4), Forschungszentrum Jülich, Germany
| | - Niklas J Gerkau
- Institute of Neurobiology, Heinrich-Heine-Universität Düsseldorf, Germany
| | - Thomas Gensch
- Institute of Complex Systems, Zelluläre Biophysik (ICS-4), Forschungszentrum Jülich, Germany
| | - Christine R Rose
- Institute of Neurobiology, Heinrich-Heine-Universität Düsseldorf, Germany
| | - Christoph Fahlke
- Institute of Complex Systems, Zelluläre Biophysik (ICS-4), Forschungszentrum Jülich, Germany
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Untiet V, Moeller LM, Ibarra-Soria X, Sánchez-Andrade G, Stricker M, Neuhaus EM, Logan DW, Gensch T, Spehr M. Elevated Cytosolic Cl- Concentrations in Dendritic Knobs of Mouse Vomeronasal Sensory Neurons. Chem Senses 2016; 41:669-76. [PMID: 27377750 DOI: 10.1093/chemse/bjw077] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
In rodents, the vomeronasal system controls social and sexual behavior. However, several mechanistic aspects of sensory signaling in the vomeronasal organ remain unclear. Here, we investigate the biophysical basis of a recently proposed vomeronasal signal transduction component-a Ca(2+)-activated Cl(-) current. As the physiological role of such a current is a direct function of the Cl(-) equilibrium potential, we determined the intracellular Cl(-) concentration in dendritic knobs of vomeronasal neurons. Quantitative fluorescence lifetime imaging of a Cl(-)-sensitive dye at the apical surface of the intact vomeronasal neuroepithelium revealed increased cytosolic Cl(-) levels in dendritic knobs, a substantially lower Cl(-) concentration in vomeronasal sustentacular cells, and an apparent Cl(-) gradient in vomeronasal neurons along their dendritic apicobasal axis. Together, our data provide a biophysical basis for sensory signal amplification in vomeronasal neuron microvilli by opening Ca(2+)-activated Cl(-) channels.
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Affiliation(s)
- Verena Untiet
- Institute of Complex Systems, Cellular Biophysics (ICS-4), Forschungszentrum Jülich, Leo-Brandt-Straße, D-52428 Jülich, Germany
| | - Lisa M Moeller
- Department of Chemosensation, Institute for Biology II, RWTH Aachen University, Worringerweg 3, D-52074 Aachen, Germany
| | - Ximena Ibarra-Soria
- Wellcome Trust Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridge CB10 1SA, UK
| | | | - Miriam Stricker
- Institute of Complex Systems, Cellular Biophysics (ICS-4), Forschungszentrum Jülich, Leo-Brandt-Straße, D-52428 Jülich, Germany
| | - Eva M Neuhaus
- Pharmacology and Toxicology, University Hospital Jena, Drackendorfer Straße 1, Friedrich Schiller University Jena, D-07743 Jena, Germany and
| | - Darren W Logan
- Wellcome Trust Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridge CB10 1SA, UK, Monell Chemical Senses Center, 3500 Market Street, Philadelphia, PA 19104, USA
| | - Thomas Gensch
- Institute of Complex Systems, Cellular Biophysics (ICS-4), Forschungszentrum Jülich, Leo-Brandt-Straße, D-52428 Jülich, Germany
| | - Marc Spehr
- Department of Chemosensation, Institute for Biology II, RWTH Aachen University, Worringerweg 3, D-52074 Aachen, Germany,
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Affiliation(s)
- T. Gensch
- Organisch-Chemisches Institut, Westfälische Wilhelms-Universität Münster, Corrensstrasse 40, 48149 Münster, Germany
| | - F. Glorius
- Organisch-Chemisches Institut, Westfälische Wilhelms-Universität Münster, Corrensstrasse 40, 48149 Münster, Germany
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Abstract
C–H Activation reactions that proceed under mild conditions are more attractive for applications in complex molecule synthesis. Mild C–H transformations reported since 2011 are reviewed and the different concepts and strategies that have enabled their mildness are discussed.
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Affiliation(s)
- T. Gensch
- Westfälische Wilhelms-Universität Münster
- Organisch-Chemisches Institut
- 48149 Münster
- Germany
| | - M. N. Hopkinson
- Westfälische Wilhelms-Universität Münster
- Organisch-Chemisches Institut
- 48149 Münster
- Germany
| | - F. Glorius
- Westfälische Wilhelms-Universität Münster
- Organisch-Chemisches Institut
- 48149 Münster
- Germany
| | - J. Wencel-Delord
- Laboratoire de Chimie Moléculaire (UMR CNRS 7509)
- Université de Strasbourg
- 67087 Strasbourg
- France
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40
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Tang Y, Dai L, Zhang X, Li J, Hendriks J, Fan X, Gruteser N, Meisenberg A, Baumann A, Katranidis A, Gensch T. SNSMIL, a real-time single molecule identification and localization algorithm for super-resolution fluorescence microscopy. Sci Rep 2015; 5:11073. [PMID: 26098742 PMCID: PMC4476421 DOI: 10.1038/srep11073] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2014] [Accepted: 05/08/2015] [Indexed: 11/09/2022] Open
Abstract
Single molecule localization based super-resolution fluorescence microscopy offers significantly higher spatial resolution than predicted by Abbe's resolution limit for far field optical microscopy. Such super-resolution images are reconstructed from wide-field or total internal reflection single molecule fluorescence recordings. Discrimination between emission of single fluorescent molecules and background noise fluctuations remains a great challenge in current data analysis. Here we present a real-time, and robust single molecule identification and localization algorithm, SNSMIL (Shot Noise based Single Molecule Identification and Localization). This algorithm is based on the intrinsic nature of noise, i.e., its Poisson or shot noise characteristics and a new identification criterion, QSNSMIL, is defined. SNSMIL improves the identification accuracy of single fluorescent molecules in experimental or simulated datasets with high and inhomogeneous background. The implementation of SNSMIL relies on a graphics processing unit (GPU), making real-time analysis feasible as shown for real experimental and simulated datasets.
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Affiliation(s)
- Yunqing Tang
- 1] National Center for Nanoscience and Technology of China No.11, Beiyitiao Zhongguancun 100190 Beijing, P.R. China [2] Department of Physics, Chongqing University, Chongqing 400044, P.R. China [3] State Key Laboratory of Theoretical Physics, Institute of Theoretical Physics, Chinese Academy of Sciences, 100190 Beijing, P.R. China
| | - Luru Dai
- National Center for Nanoscience and Technology of China No.11, Beiyitiao Zhongguancun 100190 Beijing, P.R. China
| | - Xiaoming Zhang
- National Center for Nanoscience and Technology of China No.11, Beiyitiao Zhongguancun 100190 Beijing, P.R. China
| | - Junbai Li
- 1] National Center for Nanoscience and Technology of China No.11, Beiyitiao Zhongguancun 100190 Beijing, P.R. China [2] Institute of Chemistry, Chinese Academy of Sciences, 100190 Beijing, P.R. China
| | - Johnny Hendriks
- Institute of Complex Systems (ICS-4, Cellular Biophysics), Forschungszentrum Jülich, Leo-Brandt-Str., 52428 Jülich, Germany
| | - Xiaoming Fan
- Institute of Complex Systems (ICS-4, Cellular Biophysics), Forschungszentrum Jülich, Leo-Brandt-Str., 52428 Jülich, Germany
| | - Nadine Gruteser
- Institute of Complex Systems (ICS-4, Cellular Biophysics), Forschungszentrum Jülich, Leo-Brandt-Str., 52428 Jülich, Germany
| | - Annika Meisenberg
- Institute of Complex Systems (ICS-4, Cellular Biophysics), Forschungszentrum Jülich, Leo-Brandt-Str., 52428 Jülich, Germany
| | - Arnd Baumann
- Institute of Complex Systems (ICS-4, Cellular Biophysics), Forschungszentrum Jülich, Leo-Brandt-Str., 52428 Jülich, Germany
| | - Alexandros Katranidis
- Institute of Complex Systems (ICS-5, Molecular Biophysics), Forschungszentrum Jülich, Leo-Brandt-Str., 52428 Jülich, Germany
| | - Thomas Gensch
- Institute of Complex Systems (ICS-4, Cellular Biophysics), Forschungszentrum Jülich, Leo-Brandt-Str., 52428 Jülich, Germany
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Gushchin I, Shevchenko V, Polovinkin V, Kovalev K, Alekseev A, Round E, Borshchevskiy V, Balandin T, Popov A, Gensch T, Fahlke C, Bamann C, Willbold D, Büldt G, Bamberg E, Gordeliy V. Crystal structure of a light-driven sodium pump. Nat Struct Mol Biol 2015; 22:390-5. [PMID: 25849142 DOI: 10.1038/nsmb.3002] [Citation(s) in RCA: 130] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2015] [Accepted: 03/09/2015] [Indexed: 11/09/2022]
Abstract
Recently, the first known light-driven sodium pumps, from the microbial rhodopsin family, were discovered. We have solved the structure of one of them, Krokinobacter eikastus rhodopsin 2 (KR2), in the monomeric blue state and in two pentameric red states, at resolutions of 1.45 Å and 2.2 and 2.8 Å, respectively. The structures reveal the ion-translocation pathway and show that the sodium ion is bound outside the protein at the oligomerization interface, that the ion-release cavity is capped by a unique N-terminal α-helix and that the ion-uptake cavity is unexpectedly large and open to the surface. Obstruction of the cavity with the mutation G263F imparts KR2 with the ability to pump potassium. These results pave the way for the understanding and rational design of cation pumps with new specific properties valuable for optogenetics.
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Affiliation(s)
- Ivan Gushchin
- 1] Institut de Biologie Structurale, Université Grenoble Alpes, Grenoble, France. [2] Institut de Biologie Structurale, Centre National de la Recherche Scientifique, Grenoble, France. [3] Institut de Biologie Structurale, Commissariat à l'Énergie Atomique (CEA), Grenoble, France. [4] Laboratory for Advanced Studies of Membrane Proteins, Moscow Institute of Physics and Technology, Dolgoprudniy, Russia. [5] Institute of Complex Systems (ICS), ICS-6, Structural Biochemistry, Research Center Jülich, Jülich, Germany
| | - Vitaly Shevchenko
- 1] Laboratory for Advanced Studies of Membrane Proteins, Moscow Institute of Physics and Technology, Dolgoprudniy, Russia. [2] Institute of Complex Systems (ICS), ICS-6, Structural Biochemistry, Research Center Jülich, Jülich, Germany. [3] Institute of Crystallography, University of Aachen (RWTH), Aachen, Germany
| | - Vitaly Polovinkin
- 1] Institut de Biologie Structurale, Université Grenoble Alpes, Grenoble, France. [2] Institut de Biologie Structurale, Centre National de la Recherche Scientifique, Grenoble, France. [3] Institut de Biologie Structurale, Commissariat à l'Énergie Atomique (CEA), Grenoble, France. [4] Laboratory for Advanced Studies of Membrane Proteins, Moscow Institute of Physics and Technology, Dolgoprudniy, Russia. [5] Institute of Complex Systems (ICS), ICS-6, Structural Biochemistry, Research Center Jülich, Jülich, Germany
| | - Kirill Kovalev
- 1] Laboratory for Advanced Studies of Membrane Proteins, Moscow Institute of Physics and Technology, Dolgoprudniy, Russia. [2] Institute of Complex Systems (ICS), ICS-6, Structural Biochemistry, Research Center Jülich, Jülich, Germany
| | - Alexey Alekseev
- 1] Laboratory for Advanced Studies of Membrane Proteins, Moscow Institute of Physics and Technology, Dolgoprudniy, Russia. [2] Institute of Complex Systems (ICS), ICS-6, Structural Biochemistry, Research Center Jülich, Jülich, Germany
| | - Ekaterina Round
- Institute of Complex Systems (ICS), ICS-6, Structural Biochemistry, Research Center Jülich, Jülich, Germany
| | - Valentin Borshchevskiy
- 1] Laboratory for Advanced Studies of Membrane Proteins, Moscow Institute of Physics and Technology, Dolgoprudniy, Russia. [2] Institute of Complex Systems (ICS), ICS-6, Structural Biochemistry, Research Center Jülich, Jülich, Germany
| | - Taras Balandin
- Institute of Complex Systems (ICS), ICS-6, Structural Biochemistry, Research Center Jülich, Jülich, Germany
| | | | - Thomas Gensch
- ICS, ICS-4, Cellular Biophysics, Research Center Jülich, Jülich, Germany
| | - Christoph Fahlke
- ICS, ICS-4, Cellular Biophysics, Research Center Jülich, Jülich, Germany
| | | | - Dieter Willbold
- 1] Institute of Complex Systems (ICS), ICS-6, Structural Biochemistry, Research Center Jülich, Jülich, Germany. [2] Institut für Physikalische Biologie, Heinrich-Heine-Universität Düsseldorf, Düsseldorf, Germany
| | - Georg Büldt
- 1] Laboratory for Advanced Studies of Membrane Proteins, Moscow Institute of Physics and Technology, Dolgoprudniy, Russia. [2] ICS, ICS-5, Molecular Biophysics, Research Center Jülich, Jülich, Germany
| | - Ernst Bamberg
- Max Planck Institute of Biophysics, Frankfurt am Main, Germany
| | - Valentin Gordeliy
- 1] Institut de Biologie Structurale, Université Grenoble Alpes, Grenoble, France. [2] Institut de Biologie Structurale, Centre National de la Recherche Scientifique, Grenoble, France. [3] Institut de Biologie Structurale, Commissariat à l'Énergie Atomique (CEA), Grenoble, France. [4] Laboratory for Advanced Studies of Membrane Proteins, Moscow Institute of Physics and Technology, Dolgoprudniy, Russia. [5] Institute of Complex Systems (ICS), ICS-6, Structural Biochemistry, Research Center Jülich, Jülich, Germany
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Stölting G, de Oliveira RC, Guzman RE, Miranda-Laferte E, Conrad R, Jordan N, Schmidt S, Hendriks J, Gensch T, Hidalgo P. Direct interaction of CaVβ with actin up-regulates L-type calcium currents in HL-1 cardiomyocytes. J Biol Chem 2015; 290:4561-4572. [PMID: 25533460 PMCID: PMC4335199 DOI: 10.1074/jbc.m114.573956] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2014] [Revised: 12/05/2014] [Indexed: 12/14/2022] Open
Abstract
Expression of the β-subunit (CaVβ) is required for normal function of cardiac L-type calcium channels, and its up-regulation is associated with heart failure. CaVβ binds to the α1 pore-forming subunit of L-type channels and augments calcium current density by facilitating channel opening and increasing the number of channels in the plasma membrane, by a poorly understood mechanism. Actin, a key component of the intracellular trafficking machinery, interacts with Src homology 3 domains in different proteins. Although CaVβ encompasses a highly conserved Src homology 3 domain, association with actin has not yet been explored. Here, using co-sedimentation assays and FRET experiments, we uncover a direct interaction between CaVβ and actin filaments. Consistently, single-molecule localization analysis reveals streaklike structures composed by CaVβ2 that distribute over several micrometers along actin filaments in HL-1 cardiomyocytes. Overexpression of CaVβ2-N3 in HL-1 cells induces an increase in L-type current without altering voltage-dependent activation, thus reflecting an increased number of channels in the plasma membrane. CaVβ mediated L-type up-regulation, and CaVβ-actin association is prevented by disruption of the actin cytoskeleton with cytochalasin D. Our study reveals for the first time an interacting partner of CaVβ that is directly involved in vesicular trafficking. We propose a model in which CaVβ promotes anterograde trafficking of the L-type channels by anchoring them to actin filaments in their itinerary to the plasma membrane.
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Affiliation(s)
- Gabriel Stölting
- From the Institute of Complex Systems 4, Zelluläre Biophysik, Forschungszentrum Jülich, 52425 Jülich, Germany and
| | | | - Raul E Guzman
- From the Institute of Complex Systems 4, Zelluläre Biophysik, Forschungszentrum Jülich, 52425 Jülich, Germany and
| | - Erick Miranda-Laferte
- From the Institute of Complex Systems 4, Zelluläre Biophysik, Forschungszentrum Jülich, 52425 Jülich, Germany and
| | - Rachel Conrad
- From the Institute of Complex Systems 4, Zelluläre Biophysik, Forschungszentrum Jülich, 52425 Jülich, Germany and
| | - Nadine Jordan
- From the Institute of Complex Systems 4, Zelluläre Biophysik, Forschungszentrum Jülich, 52425 Jülich, Germany and
| | - Silke Schmidt
- the Institut für Neurophysiologie, Medizinische Hochschule Hannover, 30625 Hannover, Germany
| | - Johnny Hendriks
- From the Institute of Complex Systems 4, Zelluläre Biophysik, Forschungszentrum Jülich, 52425 Jülich, Germany and
| | - Thomas Gensch
- From the Institute of Complex Systems 4, Zelluläre Biophysik, Forschungszentrum Jülich, 52425 Jülich, Germany and
| | - Patricia Hidalgo
- From the Institute of Complex Systems 4, Zelluläre Biophysik, Forschungszentrum Jülich, 52425 Jülich, Germany and.
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Gensch T, Untiet V, Franzen A, Kovermann P, Fahlke C. Determination of Intracellular Chloride Concentrations by Fluorescence Lifetime Imaging. Springer Series in Chemical Physics 2015. [DOI: 10.1007/978-3-319-14929-5_4] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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Torra J, Burgos-Caminal A, Endres S, Wingen M, Drepper T, Gensch T, Ruiz-González R, Nonell S. Singlet oxygen photosensitisation by the fluorescent protein Pp2FbFP L30M, a novel derivative of Pseudomonas putida flavin-binding Pp2FbFP. Photochem Photobiol Sci 2015; 14:280-7. [DOI: 10.1039/c4pp00338a] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
The flavin-binding protein Pp2FbFP L30M shows a high singlet oxygen quantum yield.
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Affiliation(s)
- Joaquim Torra
- Institut Químic de Sarrià
- Universitat Ramon Llull
- Barcelona
- Spain
| | | | - Stephan Endres
- Institute of Molecular Enzyme Technology
- Heinrich-Heine-University Düsseldorf
- 52425 Jülich
- Germany
| | - Marcus Wingen
- Institute of Molecular Enzyme Technology
- Heinrich-Heine-University Düsseldorf
- 52425 Jülich
- Germany
| | - Thomas Drepper
- Institute of Molecular Enzyme Technology
- Heinrich-Heine-University Düsseldorf
- 52425 Jülich
- Germany
| | - Thomas Gensch
- Institute of Complex Systems 4 (ICS-4
- Cellular Biophysics)
- 52425 Jülich
- Germany
| | | | - Santi Nonell
- Institut Químic de Sarrià
- Universitat Ramon Llull
- Barcelona
- Spain
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45
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Drepper T, Gensch T, Pohl M. Advanced in vivo applications of blue light photoreceptors as alternative fluorescent proteins. Photochem Photobiol Sci 2014; 12:1125-34. [PMID: 23660639 DOI: 10.1039/c3pp50040c] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The ultimate ambition in cell biology, microbiology and biomedicine is to unravel complex physiological and pathophysiological processes within living organisms. To conquer this challenge, fluorescent proteins (FPs) are used as versatile in vivo reporters and biosensors to study gene regulation as well as the synthesis, localization and function of proteins in living cells. The most widely used FPs are the green fluorescent protein (GFP) and its derivatives and relatives. Their use as in vivo reporter proteins, however, is sometimes restricted by different environmental and cellular factors. Consequently, a whole range of alternative, cofactor-dependent reporter proteins have been developed recently. In this perspective, we summarize the advantages and limitations of the novel class of cyan-green fluorescent flavoproteins in comparison to members of the GFP family and discuss some correlated consequences for the use of FPs as in vivo reporters.
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Affiliation(s)
- Thomas Drepper
- Institute of Molecular Enzyme Technology, Heinrich-Heine-University Duesseldorf, Forschungszentrum Jülich, 52425 Juelich, Germany.
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46
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Wingen M, Potzkei J, Endres S, Casini G, Rupprecht C, Fahlke C, Krauss U, Jaeger KE, Drepper T, Gensch T. The photophysics of LOV-based fluorescent proteins – new tools for cell biology. Photochem Photobiol Sci 2014; 13:875-83. [DOI: 10.1039/c3pp50414j] [Citation(s) in RCA: 83] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
In this study photophysical characteristics of LOV-based fluorescent proteins which are essential for analytic methods as well as imaging approaches have been comparatively analyzed in detail.
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Affiliation(s)
- Marcus Wingen
- Institute of Molecular Enzyme Technology
- Heinrich-Heine-University Düsseldorf
- Forschungszentrum Jülich
- 52425 Jülich, Germany
| | - Janko Potzkei
- Institute of Molecular Enzyme Technology
- Heinrich-Heine-University Düsseldorf
- Forschungszentrum Jülich
- 52425 Jülich, Germany
| | - Stephan Endres
- Institute of Molecular Enzyme Technology
- Heinrich-Heine-University Düsseldorf
- Forschungszentrum Jülich
- 52425 Jülich, Germany
| | - Giorgia Casini
- Institute of Complex Systems 4 (ICS-4
- Cellular Biophysics)
- Forschungszentrum Jülich
- 52425 Jülich, Germany
| | - Christian Rupprecht
- Institute of Molecular Enzyme Technology
- Heinrich-Heine-University Düsseldorf
- Forschungszentrum Jülich
- 52425 Jülich, Germany
| | - Christoph Fahlke
- Institute of Complex Systems 4 (ICS-4
- Cellular Biophysics)
- Forschungszentrum Jülich
- 52425 Jülich, Germany
| | - Ulrich Krauss
- Institute of Molecular Enzyme Technology
- Heinrich-Heine-University Düsseldorf
- Forschungszentrum Jülich
- 52425 Jülich, Germany
| | - Karl-Erich Jaeger
- Institute of Molecular Enzyme Technology
- Heinrich-Heine-University Düsseldorf
- Forschungszentrum Jülich
- 52425 Jülich, Germany
| | - Thomas Drepper
- Institute of Molecular Enzyme Technology
- Heinrich-Heine-University Düsseldorf
- Forschungszentrum Jülich
- 52425 Jülich, Germany
| | - Thomas Gensch
- Institute of Complex Systems 4 (ICS-4
- Cellular Biophysics)
- Forschungszentrum Jülich
- 52425 Jülich, Germany
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Gensch T, Strassburger JM, Gärtner W, Braslavsky SE. Volume and Enthalpy Changes upon Photoexcitation of Bovine Rhodopsin Derived from Optoacoustic Studies by Using an Equilibrium between Bathorhodopsin and Blue-Shifted Intermediate. Isr J Chem 2013. [DOI: 10.1002/ijch.199800025] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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48
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Jásik J, Boggetti B, Baluška F, Volkmann D, Gensch T, Rutten T, Altmann T, Schmelzer E. PIN2 turnover in Arabidopsis root epidermal cells explored by the photoconvertible protein Dendra2. PLoS One 2013; 8:e61403. [PMID: 23637828 PMCID: PMC3630207 DOI: 10.1371/journal.pone.0061403] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2012] [Accepted: 03/10/2013] [Indexed: 11/18/2022] Open
Abstract
The steady state level of integral membrane proteins is dependent on a strictly controlled delivery and removal. Here we show that Dendra2, a green-to-red photoconvertible fluorescent protein, is a suitable tool to study protein turnover in plants. We characterized the fluorescence properties of Dendra2 expressed either as a free protein or as a tag in Arabidopsis thaliana roots and optimized photoconversion settings to study protein turnover. Dendra2 was fused to the PIN2 protein, an auxin transporter in the root tip, and by time-lapse imaging and assessment of red and green signal intensities in the membrane after photoconversion we quantified directly and simultaneously the rate of PIN2 delivery of the newly synthesized protein into the plasma membrane as well as the disappearance of the protein from the plasma membrane due to degradation. Additionally we have verified several factors which are expected to affect PIN2 protein turnover and therefore potentially regulate root growth.
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Affiliation(s)
- Ján Jásik
- Max Planck Institute for Plant Breeding Research, Köln, Germany.
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Geiger A, Russo L, Gensch T, Thestrup T, Becker S, Hopfner KP, Griesinger C, Witte G, Griesbeck O. Correlating calcium binding, Förster resonance energy transfer, and conformational change in the biosensor TN-XXL. Biophys J 2012; 102:2401-10. [PMID: 22677394 PMCID: PMC3353025 DOI: 10.1016/j.bpj.2012.03.065] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2012] [Revised: 03/21/2012] [Accepted: 03/27/2012] [Indexed: 11/23/2022] Open
Abstract
Genetically encoded calcium indicators have become instrumental in imaging signaling in complex tissues and neuronal circuits in vivo. Despite their importance, structure-function relationships of these sensors often remain largely uncharacterized due to their artificial and multimodular composition. Here, we describe a combination of protein engineering and kinetic, spectroscopic, and biophysical analysis of the Förster resonance energy transfer (FRET)-based calcium biosensor TN-XXL. Using fluorescence spectroscopy of engineered tyrosines, we show that two of the four calcium binding EF-hands dominate the FRET output of TN-XXL and that local conformational changes of these hands match the kinetics of FRET change. Using small-angle x-ray scattering and NMR spectroscopy, we show that TN-XXL changes from a flexible elongated to a rigid globular shape upon binding calcium, thus resulting in FRET signal output. Furthermore, we compare calcium titrations using fluorescence lifetime spectroscopy with the ratiometric approach and investigate potential non-FRET effects that may affect the fluorophores. Thus, our data characterize the biophysics of TN-XXL in detail and may form a basis for further rational engineering of FRET-based biosensors.
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Affiliation(s)
- Anselm Geiger
- Max-Planck-Institut für Neurobiologie, Martinsried, Germany
| | - Luigi Russo
- Max-Planck-Institut für biophysikalische Chemie, Göttingen, Germany
| | | | | | - Stefan Becker
- Max-Planck-Institut für biophysikalische Chemie, Göttingen, Germany
| | - Karl-Peter Hopfner
- Genzentrum und Department Biochemie, Ludwig-Maximilians-Universität, Munich, Germany
| | | | - Gregor Witte
- Genzentrum und Department Biochemie, Ludwig-Maximilians-Universität, Munich, Germany
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50
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Potzkei J, Kunze M, Drepper T, Gensch T, Jaeger KE, Büchs J. Real-time determination of intracellular oxygen in bacteria using a genetically encoded FRET-based biosensor. BMC Biol 2012; 10:28. [PMID: 22439625 PMCID: PMC3364895 DOI: 10.1186/1741-7007-10-28] [Citation(s) in RCA: 93] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2011] [Accepted: 03/22/2012] [Indexed: 11/20/2022] Open
Abstract
Background Molecular oxygen (O2) is one of the key metabolites of all obligate and facultative aerobic pro- and eukaryotes. It plays a fundamental role in energy homeostasis whereas oxygen deprivation, in turn, broadly affects various physiological and pathophysiological processes. Therefore, real-time monitoring of cellular oxygen levels is basically a prerequisite for the analysis of hypoxia-induced processes in living cells and tissues. Results We developed a genetically encoded Förster resonance energy transfer (FRET)-based biosensor allowing the observation of changing molecular oxygen concentrations inside living cells. This biosensor named FluBO (fluorescent protein-based biosensor for oxygen) consists of the yellow fluorescent protein (YFP) that is sensitive towards oxygen depletion and the hypoxia-tolerant flavin-binding fluorescent protein (FbFP). Since O2 is essential for the formation of the YFP chromophore, efficient FRET from the FbFP donor domain to the YFP acceptor domain only occurs in the presence but not in the absence of oxygen. The oxygen biosensor was used for continuous real-time monitoring of temporal changes of O2 levels in the cytoplasm of Escherichia coli cells during batch cultivation. Conclusions FluBO represents a unique FRET-based oxygen biosensor which allows the non-invasive ratiometric readout of cellular oxygen. Thus, FluBO can serve as a novel and powerful probe for investigating the occurrence of hypoxia and its effects on a variety of (patho)physiological processes in living cells.
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Affiliation(s)
- Janko Potzkei
- Institute of Molecular Enzyme Technology, Heinrich-Heine-University Duesseldorf, Juelich Research Center, Wilhelm-Johnen-Straße, D-52425 Juelich, Germany
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