1
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Kamino K, Kadakia N, Avgidis F, Liu ZX, Aoki K, Shimizu T, Emonet T. Optimal inference of molecular interaction dynamics in FRET microscopy. Proc Natl Acad Sci U S A 2023; 120:e2211807120. [PMID: 37014867 PMCID: PMC10104582 DOI: 10.1073/pnas.2211807120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2022] [Accepted: 02/10/2023] [Indexed: 04/05/2023] Open
Abstract
Intensity-based time-lapse fluorescence resonance energy transfer (FRET) microscopy has been a major tool for investigating cellular processes, converting otherwise unobservable molecular interactions into fluorescence time series. However, inferring the molecular interaction dynamics from the observables remains a challenging inverse problem, particularly when measurement noise and photobleaching are nonnegligible-a common situation in single-cell analysis. The conventional approach is to process the time-series data algebraically, but such methods inevitably accumulate the measurement noise and reduce the signal-to-noise ratio (SNR), limiting the scope of FRET microscopy. Here, we introduce an alternative probabilistic approach, B-FRET, generally applicable to standard 3-cube FRET-imaging data. Based on Bayesian filtering theory, B-FRET implements a statistically optimal way to infer molecular interactions and thus drastically improves the SNR. We validate B-FRET using simulated data and then apply it to real data, including the notoriously noisy in vivo FRET time series from individual bacterial cells to reveal signaling dynamics otherwise hidden in the noise.
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Affiliation(s)
- Keita Kamino
- Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, CT06511
- Quantitative Biology Institute, Yale University, New Haven, CT06511
- Institute of Molecular Biology, Academia Sinica, Taipei115, Taiwan
- PRESTO, Japan Science and Technology Agency, Kawaguchi-shi, Saitama332-0012, Japan
| | - Nirag Kadakia
- Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, CT06511
- Quantitative Biology Institute, Yale University, New Haven, CT06511
- Swartz Foundation for Theoretical Neuroscience, Yale University, New Haven, CT06511
| | | | - Zhe-Xuan Liu
- Institute of Physics, National Yang Ming Chiao Tung University, Hsinchu30010, Taiwan
| | - Kazuhiro Aoki
- Exploratory Research Center on Life and Living Systems, National Institutes of Natural Sciences, Okazaki, Aichi444-8787, Japan
- National Institute for Basic Biology, National Institutes of Natural Sciences, Okazaki, Aichi444-8585, Japan
- Department of Basic Biology, School of Life Science, SOKENDAI (The Graduate University for Advanced Studies), Okazaki, Aichi240-0193, Japan
| | | | - Thierry Emonet
- Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, CT06511
- Quantitative Biology Institute, Yale University, New Haven, CT06511
- Department of Physics, Yale University, New Haven, CT06511
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2
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Hochreiter B, Schmid JA, Berger J, Kunze M. Estimating the Interaction Strength Between PTS1-Peptides and Their Receptor PEX5 in Living Cells Using Flow-Cytometer-Based FRET (flowFRET) Measurements. Methods Mol Biol 2023; 2643:413-434. [PMID: 36952203 DOI: 10.1007/978-1-0716-3048-8_30] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/24/2023]
Abstract
The import of many peroxisomal matrix proteins is initiated by the interaction of type-1 peroxisomal targeting signals (PTS1) residing at the extreme C-terminus of cargo proteins and their receptor protein PEX5. This interaction has been amply investigated by biophysical methods using isolated proteins and peptides or heterologous systems such as two-hybrid assays. However, a recently developed novel application of Fluorescence resonance energy transfer (FRET) allows a quantifying measurement of this interaction in living cells. This method combines the systematic measurement of FRET-efficiency in a high number of cells with a well-suited normalization protocol and a fitting algorithm, which together allow the estimation of numerical values for the apparent interaction strength that correlates with other measures of binding strength but can be obtained under rather physiological conditions.
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Affiliation(s)
- Bernhard Hochreiter
- Institute for Vascular Biology and Thrombosis Research, Medical University of Vienna, Vienna, Austria.
| | - Johannes A Schmid
- Institute for Vascular Biology and Thrombosis Research, Medical University of Vienna, Vienna, Austria
| | - Johannes Berger
- Department of Pathobiology of the Nervous System, Medical University of Vienna, Vienna, Austria
| | - Markus Kunze
- Department of Pathobiology of the Nervous System, Medical University of Vienna, Vienna, Austria.
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3
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Amaning Danquah C, Minkah PAB, Osei Duah Junior I, Amankwah KB, Somuah SO. Antimicrobial Compounds from Microorganisms. Antibiotics (Basel) 2022; 11:285. [PMID: 35326749 PMCID: PMC8944786 DOI: 10.3390/antibiotics11030285] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2022] [Revised: 01/27/2022] [Accepted: 02/07/2022] [Indexed: 02/06/2023] Open
Abstract
Antimicrobial resistance is an exigent public health concern owing to the emergence of novel strains of human resistant pathogens and the concurrent rise in multi-drug resistance. An influx of new antimicrobials is urgently required to improve the treatment outcomes of infectious diseases and save lives. Plant metabolites and bioactive compounds from chemical synthesis have found their efficacy to be dwindling, despite some of them being developed as drugs and used to treat human infections for several decades. Microorganisms are considered untapped reservoirs for promising biomolecules with varying structural and functional antimicrobial activity. The advent of cost-effective and convenient model organisms, state-of-the-art molecular biology, omics technology, and machine learning has enhanced the bioprospecting of novel antimicrobial drugs and the identification of new drug targets. This review summarizes antimicrobial compounds isolated from microorganisms and reports on the modern tools and strategies for exploiting promising antimicrobial drug candidates. The investigation identified a plethora of novel compounds from microbial sources with excellent antimicrobial activity against disease-causing human pathogens. Researchers could maximize the use of novel model systems and advanced biomolecular and computational tools in exploiting lead antimicrobials, consequently ameliorating antimicrobial resistance.
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Affiliation(s)
- Cynthia Amaning Danquah
- Department of Pharmacology, Faculty of Pharmacy and Pharmaceutical Sciences, College of Health Sciences, Kwame Nkrumah University of Science and Technology, PMB, Kumasi, Ghana;
| | - Prince Amankwah Baffour Minkah
- Department of Pharmacology, Faculty of Pharmacy and Pharmaceutical Sciences, College of Health Sciences, Kwame Nkrumah University of Science and Technology, PMB, Kumasi, Ghana;
- Global Health and Infectious Disease Research Group, Kumasi Centre for Collaborative Research in Tropical Medicine, College of Health Sciences, Kwame Nkrumah University of Science and Technology, PMB, Kumasi, Ghana
| | - Isaiah Osei Duah Junior
- Department of Optometry and Visual Science, College of Science, Kwame Nkrumah University of Science and Technology, PMB, Kumasi, Ghana;
| | - Kofi Bonsu Amankwah
- Department of Biomedical Sciences, University of Cape Coast, PMB, Cape Coast, Ghana;
| | - Samuel Owusu Somuah
- Department of Pharmacy Practice, School of Pharmacy, University of Health and Allied Sciences, PMB, Ho, Ghana;
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4
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Hugelier S, Van den Eynde R, Vandenberg W, Dedecker P. Fluorophore unmixing based on bleaching and recovery kinetics using MCR-ALS. Talanta 2021; 226:122117. [PMID: 33676672 DOI: 10.1016/j.talanta.2021.122117] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2020] [Revised: 01/08/2021] [Accepted: 01/11/2021] [Indexed: 02/03/2023]
Abstract
Fluorescence microscopy is a key technology in the life sciences, though its performance is constrained by the number of labels that can be recorded. We propose to use the kinetics of fluorophore photodestruction and subsequent fluorescence recovery to distinguish multiple spectrally-overlapping emitters in fixed cells, thus enhancing the information that can be obtained from a single measurement. We show that the data can be directly processed using multivariate curve resolution - alternating least squares (MCR-ALS) to deliver distinct images for each fluorophore in their local environment, and apply this methodology to membrane imaging using DiBAC4(3) and concanavalin A - Alexa Fluor 488 as the fluorophores. We find that the DiBAC4(3) displays two distinct degradation/recovery kinetics that correspond to two different label distributions, allowing us to simultaneously distinguish three different fluorescence distributions from two spectrally overlapping fluorophores. We expect that our approach will scale to other dynamically-binding dyes, leading to similarly increased multiplexing capability.
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Affiliation(s)
- S Hugelier
- Laboratory for Nanobiology, KU Leuven, B-3001 Leuven, Belgium.
| | - R Van den Eynde
- Laboratory for Nanobiology, KU Leuven, B-3001 Leuven, Belgium
| | - W Vandenberg
- Laboratory for Nanobiology, KU Leuven, B-3001 Leuven, Belgium; Univ. Lille, CNRS, Laboratoire de Spectroscopie pour Les Interactions, La Réactivité et L'Environnement (LASIRE), F-59000 Lille, France
| | - P Dedecker
- Laboratory for Nanobiology, KU Leuven, B-3001 Leuven, Belgium
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Imaging Meets Cytometry: Analyzing Heterogeneous Functional Microscopic Data from Living Cell Populations. J Imaging 2021; 7:jimaging7010009. [PMID: 34460580 PMCID: PMC8321243 DOI: 10.3390/jimaging7010009] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Revised: 01/06/2021] [Accepted: 01/09/2021] [Indexed: 12/27/2022] Open
Abstract
Biological tissue consists of populations of cells exhibiting different responses to pharmacological stimuli. To probe the heterogeneity of cell function, we propose a multiplexed approach based on real‐time imaging of the secondary messenger levels within each cell of the tissue, followed by extraction of the changes of single‐cell fluorescence over time. By utilizing a piecewise baseline correction, we were able to quantify the effects of multiple pharmacological stimuli added and removed sequentially to pancreatic islets of Langerhans, thereby performing a deep functional profiling for each cell within the islet. Cluster analysis based on the functional profile demonstrated dose‐dependent changes in statistical inter‐relationships between islet cell populations. We therefore believe that the functional cytometric approach can be used for routine quantitative profiling of the tissue for drug screening or pathological testing.
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Trümper V, von Knethen A, Preuß A, Ermilov E, Hackbarth S, Kuchler L, Gunne S, Schäfer A, Bornhütter T, Vereb G, Ujlaky-Nagy L, Brüne B, Röder B, Schindler M, Parnham MJ, Knape T. Flow cytometry-based FRET identifies binding intensities in PPARγ1 protein-protein interactions in living cells. Theranostics 2019; 9:5444-5463. [PMID: 31534496 PMCID: PMC6735382 DOI: 10.7150/thno.29367] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2018] [Accepted: 05/01/2019] [Indexed: 01/10/2023] Open
Abstract
PPARγ is a pharmacological target in inflammatory and metabolic diseases. Upon agonistic treatment or following antagonism, binding of co-factors is altered, which consequently affects PPARγ-dependent transactivation as well as its DNA-independent properties. Therefore, establishing techniques to characterize these interactions is an important issue in living cells. Methods: Using the FRET pair Clover/mRuby2, we set up a flow cytometry-based FRET assay by analyzing PPARγ1 binding to its heterodimerization partner RXRα. Analyses of PPARγ-reporter and co-localization studies by laser-scanning microscopy validated this system. Refining the system, we created a new readout to distinguish strong from weak interactions, focusing on PPARγ-binding to the co-repressor N-CoR2. Results: We observed high FRET in cells expressing Clover-PPARγ1 and mRuby2-RXRα, but no FRET when cells express a mRuby2-RXRα deletion mutant, lacking the PPARγ interaction domain. Focusing on the co-repressor N-CoR2, we identified in HEK293T cells the new splice variant N-CoR2-ΔID1-exon. Overexpressing this isoform tagged with mRuby2, revealed no binding to Clover-PPARγ1, nor in murine J774A.1 macrophages. In HEK293T cells, binding was even lower in comparison to N-CoR2 constructs in which domains established to mediate interaction with PPARγ binding are deleted. These data suggest a possible role of N-CoR2-ΔID1-exon as a dominant negative variant. Because binding to N-CoR2-mRuby2 was not altered following activation or antagonism of Clover-PPARγ1, we determined the effect of pharmacological treatment on FRET intensity. Therefore, we calculated flow cytometry-based FRET efficiencies based on our flow cytometry data. As with PPARγ antagonism, PPARγ agonist treatment did not prevent binding of N-CoR2. Conclusion: Our system allows the close determination of protein-protein interactions with a special focus on binding intensity, allowing this system to characterize the role of protein domains as well as the effect of pharmacological agents on protein-protein interactions.
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Affiliation(s)
- Verena Trümper
- Institute of Biochemistry I - Pathobiochemistry, Faculty of Medicine, Goethe University Frankfurt, Theodor-Stern-Kai 7, 60590 Frankfurt/Main, Germany
| | - Andreas von Knethen
- Institute of Biochemistry I - Pathobiochemistry, Faculty of Medicine, Goethe University Frankfurt, Theodor-Stern-Kai 7, 60590 Frankfurt/Main, Germany
- Branch for Translational Medicine and Pharmacology, Fraunhofer Institute for Molecular Biology and Applied Ecology IME, Theodor-Stern-Kai 7, 60596 Frankfurt/Main, Germany
| | - Annegret Preuß
- Department of Physics, Humboldt University Berlin, Newtonstraße 15, 12489 Berlin, Germany
| | - Eugeny Ermilov
- Department of Physics, Humboldt University Berlin, Newtonstraße 15, 12489 Berlin, Germany
| | - Steffen Hackbarth
- Department of Physics, Humboldt University Berlin, Newtonstraße 15, 12489 Berlin, Germany
| | - Laura Kuchler
- Institute of Biochemistry I - Pathobiochemistry, Faculty of Medicine, Goethe University Frankfurt, Theodor-Stern-Kai 7, 60590 Frankfurt/Main, Germany
| | - Sandra Gunne
- Branch for Translational Medicine and Pharmacology, Fraunhofer Institute for Molecular Biology and Applied Ecology IME, Theodor-Stern-Kai 7, 60596 Frankfurt/Main, Germany
| | - Anne Schäfer
- Institute of Biochemistry I - Pathobiochemistry, Faculty of Medicine, Goethe University Frankfurt, Theodor-Stern-Kai 7, 60590 Frankfurt/Main, Germany
| | - Tobias Bornhütter
- Department of Physics, Humboldt University Berlin, Newtonstraße 15, 12489 Berlin, Germany
| | - György Vereb
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, Egyetem tér 1, 4032 Debrecen, Hungary
- MTA-DE Cell Biology and Signaling Research Group, Faculty of Medicine, University of Debrecen, Egyetem tér 1, 4032 Debrecen, Hungary
| | - Lázló Ujlaky-Nagy
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, Egyetem tér 1, 4032 Debrecen, Hungary
- MTA-DE Cell Biology and Signaling Research Group, Faculty of Medicine, University of Debrecen, Egyetem tér 1, 4032 Debrecen, Hungary
| | - Bernhard Brüne
- Institute of Biochemistry I - Pathobiochemistry, Faculty of Medicine, Goethe University Frankfurt, Theodor-Stern-Kai 7, 60590 Frankfurt/Main, Germany
- Branch for Translational Medicine and Pharmacology, Fraunhofer Institute for Molecular Biology and Applied Ecology IME, Theodor-Stern-Kai 7, 60596 Frankfurt/Main, Germany
| | - Beate Röder
- Department of Physics, Humboldt University Berlin, Newtonstraße 15, 12489 Berlin, Germany
| | - Michael Schindler
- Institute of Medical Virology and Epidemiology of Viral Diseases, University Hospital Tübingen, Karls University Tübingen, Elfriede-Aulhorn-Str. 6, 72076 Tübingen
| | - Michael J. Parnham
- Branch for Translational Medicine and Pharmacology, Fraunhofer Institute for Molecular Biology and Applied Ecology IME, Theodor-Stern-Kai 7, 60596 Frankfurt/Main, Germany
| | - Tilo Knape
- Branch for Translational Medicine and Pharmacology, Fraunhofer Institute for Molecular Biology and Applied Ecology IME, Theodor-Stern-Kai 7, 60596 Frankfurt/Main, Germany
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7
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Hochreiter B, Kunze M, Moser B, Schmid JA. Advanced FRET normalization allows quantitative analysis of protein interactions including stoichiometries and relative affinities in living cells. Sci Rep 2019; 9:8233. [PMID: 31160659 PMCID: PMC6547726 DOI: 10.1038/s41598-019-44650-0] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2018] [Accepted: 05/20/2019] [Indexed: 12/31/2022] Open
Abstract
FRET (Fluorescence Resonance Energy Transfer) measurements are commonly applied to proof protein-protein interactions. However, standard methods of live cell FRET microscopy and signal normalization only allow a principle assessment of mutual binding and are unable to deduce quantitative information of the interaction. We present an evaluation and normalization procedure for 3-filter FRET measurements, which reflects the process of complex formation by plotting FRET-saturation curves. The advantage of this approach relative to traditional signal normalizations is demonstrated by mathematical simulations. Thereby, we also identify the contribution of critical parameters such as the total amount of donor and acceptor molecules and their molar ratio. When combined with a fitting procedure, this normalization facilitates the extraction of key properties of protein complexes such as the interaction stoichiometry or the apparent affinity of the binding partners. Finally, the feasibility of our method is verified by investigating three exemplary protein complexes. Altogether, our approach offers a novel method for a quantitative analysis of protein interactions by 3-filter FRET microscopy, as well as flow cytometry. To facilitate the application of this method, we created macros and routines for the programs ImageJ, R and MS-Excel, which we make publicly available.
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Affiliation(s)
- Bernhard Hochreiter
- Medical University Vienna, Center for Physiology and Pharmacology, Institute for Vascular Biology and Thrombosis Research, Vienna, Austria
| | - Markus Kunze
- Medical University Vienna, Center for Brain Research, Department of Pathobiology of the Nervous System, Vienna, Austria
| | - Bernhard Moser
- Medical University Vienna, Center for Physiology and Pharmacology, Institute for Vascular Biology and Thrombosis Research, Vienna, Austria
| | - Johannes A Schmid
- Medical University Vienna, Center for Physiology and Pharmacology, Institute for Vascular Biology and Thrombosis Research, Vienna, Austria.
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8
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Gates EM, LaCroix AS, Rothenberg KE, Hoffman BD. Improving Quality, Reproducibility, and Usability of FRET-Based Tension Sensors. Cytometry A 2018; 95:201-213. [PMID: 30523675 DOI: 10.1002/cyto.a.23688] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2018] [Revised: 10/30/2018] [Accepted: 11/05/2018] [Indexed: 02/07/2023]
Abstract
Mechanobiology, the study of how mechanical forces affect cellular behavior, is an emerging field of study that has garnered broad and significant interest. Researchers are currently seeking to better understand how mechanical signals are transmitted, detected, and integrated at a subcellular level. One tool for addressing these questions is a Förster resonance energy transfer (FRET)-based tension sensor, which enables the measurement of molecular-scale forces across proteins based on changes in emitted light. However, the reliability and reproducibility of measurements made with these sensors has not been thoroughly examined. To address these concerns, we developed numerical methods that improve the accuracy of measurements made using sensitized emission-based imaging. To establish that FRET-based tension sensors are versatile tools that provide consistent measurements, we used these methods, and demonstrated that a vinculin tension sensor is unperturbed by cell fixation, permeabilization, and immunolabeling. This suggests FRET-based tension sensors could be coupled with a variety of immuno-fluorescent labeling techniques. Additionally, as tension sensors are frequently employed in complex biological samples where large experimental repeats may be challenging, we examined how sample size affects the uncertainty of FRET measurements. In total, this work establishes guidelines to improve FRET-based tension sensor measurements, validate novel implementations of these sensors, and ensure that results are precise and reproducible. © 2018 International Society for Advancement of Cytometry.
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Affiliation(s)
- Evan M Gates
- Department of Biomedical Engineering, Duke University, Durham, North Carolina, 27708
| | - Andrew S LaCroix
- Department of Biomedical Engineering, Duke University, Durham, North Carolina, 27708
| | - Katheryn E Rothenberg
- Department of Biomedical Engineering, Duke University, Durham, North Carolina, 27708
| | - Brenton D Hoffman
- Department of Biomedical Engineering, Duke University, Durham, North Carolina, 27708
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McNamara DE, Quarato G, Guy CS, Green DR, Moldoveanu T. Characterization of MLKL-mediated Plasma Membrane Rupture in Necroptosis. J Vis Exp 2018. [PMID: 30148498 DOI: 10.3791/58088] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Necroptosis is a programmed cell death pathway triggered by activation of receptor interacting protein kinase 3 (RIPK3), which phosphorylates and activates the mixed lineage kinase-like domain pseudokinase, MLKL, to rupture or permeabilize the plasma membrane. Necroptosis is an inflammatory pathway associated with multiple pathologies including autoimmunity, infectious and cardiovascular diseases, stroke, neurodegeneration, and cancer. Here, we describe protocols that can be used to characterize MLKL as the executioner of plasma membrane rupture in necroptosis. We visualize the process of necroptosis in cells using live-cell imaging with conventional and confocal fluorescence microscopy, and in fixed cells using electron microscopy, which together revealed the redistribution of MLKL from the cytosol to the plasma membrane prior to induction of large holes in the plasma membrane. We present in vitro nuclear magnetic resonance (NMR) analysis using lipids to identify putative modulators of MLKL-mediated necroptosis. Based on this method, we identified quantitative lipid-binding preferences and phosphatidyl-inositol phosphates (PIPs) as critical binders of MLKL that are required for plasma membrane targeting and permeabilization in necroptosis.
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Affiliation(s)
- Dan E McNamara
- Department of Structural Biology, St. Jude Children's Research Hospital; Department of Chemical Biology and Therapeutics, St. Jude Children's Research Hospital
| | | | - Cliff S Guy
- Department of Immunology, St. Jude Children's Research Hospital
| | - Douglas R Green
- Department of Immunology, St. Jude Children's Research Hospital
| | - Tudor Moldoveanu
- Department of Structural Biology, St. Jude Children's Research Hospital; Department of Chemical Biology and Therapeutics, St. Jude Children's Research Hospital;
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Mamontova AV, Grigoryev AP, Tsarkova AS, Lukyanov KA, Bogdanov AM. Struggle for photostability: Bleaching mechanisms of fluorescent proteins. RUSSIAN JOURNAL OF BIOORGANIC CHEMISTRY 2018. [DOI: 10.1134/s1068162017060085] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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11
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Unruh JR, Slaughter BD, Jaspersen SL. Functional Analysis of the Yeast LINC Complex Using Fluctuation Spectroscopy and Super-Resolution Imaging. Methods Mol Biol 2018; 1840:137-161. [PMID: 30141044 DOI: 10.1007/978-1-4939-8691-0_12] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
The Saccharomyces cerevisiae and Schizosaccharomyces pombe genomes encode a single SUN domain-containing protein, Mps3 and Sad1, respectively. Both localize to the yeast centrosome (known as the spindle pole body, SPB) and are essential for bipolar spindle formation. In addition, Mps3 and Sad1 play roles in chromosome organization in both mitotic and meiotic cells that are independent of their SPB function. To dissect the function of Mps3 at the nuclear envelope (NE) and SPB, we employed cell imaging methods such as scanning fluorescence cross-correlation spectroscopy (SFCCS) and single particle averaging with structured illumination microscopy (SPA-SIM) to determine the strength, nature, and location of protein-protein interactions in vivo. We describe how these same techniques can also be used in fission yeast to analyze Sad1, providing evidence of their applicability to other NE proteins and systems.
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Affiliation(s)
- Jay R Unruh
- Stowers Institute for Medical Research, Kansas City, MO, USA
| | | | - Sue L Jaspersen
- Stowers Institute for Medical Research, Kansas City, MO, USA.
- Department of Molecular and Integrative Physiology, University of Kansas Medical Center, Kansas City, KS, USA.
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12
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Acharya A, Bogdanov AM, Grigorenko BL, Bravaya KB, Nemukhin AV, Lukyanov KA, Krylov AI. Photoinduced Chemistry in Fluorescent Proteins: Curse or Blessing? Chem Rev 2016; 117:758-795. [PMID: 27754659 DOI: 10.1021/acs.chemrev.6b00238] [Citation(s) in RCA: 174] [Impact Index Per Article: 21.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Photoinduced reactions play an important role in the photocycle of fluorescent proteins from the green fluorescent protein (GFP) family. Among such processes are photoisomerization, photooxidation/photoreduction, breaking and making of covalent bonds, and excited-state proton transfer (ESPT). Many of these transformations are initiated by electron transfer (ET). The quantum yields of these processes vary significantly, from nearly 1 for ESPT to 10-4-10-6 for ET. Importantly, even when quantum yields are relatively small, at the conditions of repeated illumination the overall effect is significant. Depending on the task at hand, fluorescent protein photochemistry is regarded either as an asset facilitating new applications or as a nuisance leading to the loss of optical output. The phenomena arising due to phototransformations include (i) large Stokes shifts, (ii) photoconversions, photoactivation, and photoswitching, (iii) phototoxicity, (iv) blinking, (v) permanent bleaching, and (vi) formation of long-lived intermediates. The focus of this review is on the most recent experimental and theoretical work on photoinduced transformations in fluorescent proteins. We also provide an overview of the photophysics of fluorescent proteins, highlighting the interplay between photochemistry and other channels (fluorescence, radiationless relaxation, and intersystem crossing). The similarities and differences with photochemical processes in other biological systems and in dyes are also discussed.
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Affiliation(s)
- Atanu Acharya
- Department of Chemistry, University of Southern California , Los Angeles, California 90089-0482, United States
| | - Alexey M Bogdanov
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry , Moscow, Russia.,Nizhny Novgorod State Medical Academy , Nizhny Novgorod, Russia
| | - Bella L Grigorenko
- Department of Chemistry, Lomonosov Moscow State University , Moscow, Russia.,Emanuel Institute of Biochemical Physics, Russian Academy of Sciences , Moscow, Russia
| | - Ksenia B Bravaya
- Department of Chemistry, Boston University , Boston, Massachusetts United States
| | - Alexander V Nemukhin
- Department of Chemistry, Lomonosov Moscow State University , Moscow, Russia.,Emanuel Institute of Biochemical Physics, Russian Academy of Sciences , Moscow, Russia
| | - Konstantin A Lukyanov
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry , Moscow, Russia.,Nizhny Novgorod State Medical Academy , Nizhny Novgorod, Russia
| | - Anna I Krylov
- Department of Chemistry, University of Southern California , Los Angeles, California 90089-0482, United States
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13
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Bajar BT, Wang ES, Lam AJ, Kim BB, Jacobs CL, Howe ES, Davidson MW, Lin MZ, Chu J. Improving brightness and photostability of green and red fluorescent proteins for live cell imaging and FRET reporting. Sci Rep 2016; 6:20889. [PMID: 26879144 PMCID: PMC4754705 DOI: 10.1038/srep20889] [Citation(s) in RCA: 247] [Impact Index Per Article: 30.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2015] [Accepted: 01/06/2016] [Indexed: 11/08/2022] Open
Abstract
Many genetically encoded biosensors use Förster resonance energy transfer (FRET) to dynamically report biomolecular activities. While pairs of cyan and yellow fluorescent proteins (FPs) are most commonly used as FRET partner fluorophores, respectively, green and red FPs offer distinct advantages for FRET, such as greater spectral separation, less phototoxicity, and lower autofluorescence. We previously developed the green-red FRET pair Clover and mRuby2, which improves responsiveness in intramolecular FRET reporters with different designs. Here we report the engineering of brighter and more photostable variants, mClover3 and mRuby3. mClover3 improves photostability by 60% and mRuby3 by 200% over the previous generation of fluorophores. Notably, mRuby3 is also 35% brighter than mRuby2, making it both the brightest and most photostable monomeric red FP yet characterized. Furthermore, we developed a standardized methodology for assessing FP performance in mammalian cells as stand-alone markers and as FRET partners. We found that mClover3 or mRuby3 expression in mammalian cells provides the highest fluorescence signals of all jellyfish GFP or coral RFP derivatives, respectively. Finally, using mClover3 and mRuby3, we engineered an improved version of the CaMKIIα reporter Camuiα with a larger response amplitude.
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Affiliation(s)
- Bryce T. Bajar
- Department of Bioengineering, Stanford University, Stanford, CA, 94305, USA
- Department of Pediatrics, Stanford University, Stanford, CA, 94305, USA
| | - Emily S. Wang
- Department of Bioengineering, Stanford University, Stanford, CA, 94305, USA
- Department of Pediatrics, Stanford University, Stanford, CA, 94305, USA
| | - Amy J. Lam
- Department of Bioengineering, Stanford University, Stanford, CA, 94305, USA
- Department of Pediatrics, Stanford University, Stanford, CA, 94305, USA
| | - Bongjae B. Kim
- Department of Bioengineering, Stanford University, Stanford, CA, 94305, USA
- Department of Pediatrics, Stanford University, Stanford, CA, 94305, USA
| | - Conor L. Jacobs
- Department of Biology, Stanford University, Stanford, CA, 94305, USA
| | | | | | - Michael Z. Lin
- Department of Bioengineering, Stanford University, Stanford, CA, 94305, USA
- Department of Pediatrics, Stanford University, Stanford, CA, 94305, USA
- Department of Neurobiology, Stanford University, Stanford, CA 94305, USA
| | - Jun Chu
- Department of Bioengineering, Stanford University, Stanford, CA, 94305, USA
- Department of Pediatrics, Stanford University, Stanford, CA, 94305, USA
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14
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Amor R, McDonald A, Trägårdh J, Robb G, Wilson L, Abdul Rahman NZ, Dempster J, Amos WB, Bushell TJ, McConnell G. Widefield Two-Photon Excitation without Scanning: Live Cell Microscopy with High Time Resolution and Low Photo-Bleaching. PLoS One 2016; 11:e0147115. [PMID: 26824845 PMCID: PMC4732674 DOI: 10.1371/journal.pone.0147115] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2015] [Accepted: 11/16/2015] [Indexed: 12/16/2022] Open
Abstract
We demonstrate fluorescence imaging by two-photon excitation without scanning in biological specimens as previously described by Hwang and co-workers, but with an increased field size and with framing rates of up to 100 Hz. During recordings of synaptically-driven Ca(2+) events in primary rat hippocampal neurone cultures loaded with the fluorescent Ca(2+) indicator Fluo-4 AM, we have observed greatly reduced photo-bleaching in comparison with single-photon excitation. This method, which requires no costly additions to the microscope, promises to be useful for work where high time-resolution is required.
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Affiliation(s)
- Rumelo Amor
- Centre for Biophotonics, Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow, United Kingdom
- * E-mail:
| | - Alison McDonald
- Centre for Biophotonics, Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow, United Kingdom
| | - Johanna Trägårdh
- Centre for Biophotonics, Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow, United Kingdom
| | - Gillian Robb
- Centre for Biophotonics, Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow, United Kingdom
| | - Louise Wilson
- Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow, United Kingdom
| | - Nor Zaihana Abdul Rahman
- Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow, United Kingdom
| | - John Dempster
- Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow, United Kingdom
| | - William Bradshaw Amos
- Centre for Biophotonics, Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow, United Kingdom
- MRC Laboratory of Molecular Biology, Cambridge Biomedical Campus, Cambridge, United Kingdom
| | - Trevor J. Bushell
- Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow, United Kingdom
| | - Gail McConnell
- Centre for Biophotonics, Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow, United Kingdom
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15
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Han GM, Li H, Huang XX, Kong DM. Simple synthesis of carboxyl-functionalized upconversion nanoparticles for biosensing and bioimaging applications. Talanta 2016; 147:207-12. [DOI: 10.1016/j.talanta.2015.09.059] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2015] [Revised: 09/18/2015] [Accepted: 09/24/2015] [Indexed: 10/23/2022]
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16
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Hochreiter B, Garcia AP, Schmid JA. Fluorescent proteins as genetically encoded FRET biosensors in life sciences. SENSORS 2015; 15:26281-314. [PMID: 26501285 PMCID: PMC4634415 DOI: 10.3390/s151026281] [Citation(s) in RCA: 118] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/20/2015] [Accepted: 10/08/2015] [Indexed: 12/11/2022]
Abstract
Fluorescence- or Förster resonance energy transfer (FRET) is a measurable physical energy transfer phenomenon between appropriate chromophores, when they are in sufficient proximity, usually within 10 nm. This feature has made them incredibly useful tools for many biomedical studies on molecular interactions. Furthermore, this principle is increasingly exploited for the design of biosensors, where two chromophores are linked with a sensory domain controlling their distance and thus the degree of FRET. The versatility of these FRET-biosensors made it possible to assess a vast amount of biological variables in a fast and standardized manner, allowing not only high-throughput studies but also sub-cellular measurements of biological processes. In this review, we aim at giving an overview over the recent advances in genetically encoded, fluorescent-protein based FRET-biosensors, as these represent the largest and most vividly growing group of FRET-based sensors. For easy understanding, we are grouping them into four categories, depending on their molecular mechanism. These are based on: (a) cleavage; (b) conformational-change; (c) mechanical force and (d) changes in the micro-environment. We also address the many issues and considerations that come with the development of FRET-based biosensors, as well as the possibilities that are available to measure them.
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Affiliation(s)
- Bernhard Hochreiter
- Institute for Vascular Biology and Thrombosis Research, Medical University Vienna, Schwarzspanierstraße17, Vienna A-1090, Austria.
| | - Alan Pardo Garcia
- Institute for Vascular Biology and Thrombosis Research, Medical University Vienna, Schwarzspanierstraße17, Vienna A-1090, Austria.
| | - Johannes A Schmid
- Institute for Vascular Biology and Thrombosis Research, Medical University Vienna, Schwarzspanierstraße17, Vienna A-1090, Austria.
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17
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Doan-Xuan QM, Szalóki N, Tóth K, Szöllősi J, Bacso Z, Vámosi G. FRET Imaging by Laser Scanning Cytometry on Large Populations of Adherent Cells. ACTA ACUST UNITED AC 2014; 70:2.23.1-29. [PMID: 25271960 DOI: 10.1002/0471142956.cy0223s70] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The application of FRET (fluorescence resonance energy transfer) sensors for monitoring protein-protein interactions under vital conditions is attracting increasing attention in molecular and cell biology. Laser-scanning cytometry (LSC), a slide-based sister procedure to flow cytometry, provides an opportunity to analyze large populations of adherent cells or 2-D solid tissues in their undisturbed physiological settings. Here we provide an LSC-based three-laser protocol for high-throughput ratiometric FRET measurements utilizing cyan and yellow fluorescent proteins as a FRET pair. Membrane labeling with Cy5 dye is used for cell identification and contouring. Pixel-by-pixel and single-cell FRET efficiencies are calculated to estimate the extent of the molecular interactions and their distribution in the cell populations examined. We also present a non-high-throughput donor photobleaching FRET application, for obtaining the required instrument parameters for ratiometric FRET. In the biological model presented, HeLa cells are transfected with the ECFP- or EYFP-tagged Fos and Jun nuclear proteins, which heterodimerize to form active AP1 transcription factor.
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Affiliation(s)
- Quang-Minh Doan-Xuan
- Department of Biophysics and Cell Biology, Research Center for Molecular Medicine, University of Debrecen, Debrecen, Hungary; These authors contributed equally to this work
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18
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In cellulo evaluation of phototransformation quantum yields in fluorescent proteins used as markers for single-molecule localization microscopy. PLoS One 2014; 9:e98362. [PMID: 24915511 PMCID: PMC4051587 DOI: 10.1371/journal.pone.0098362] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2014] [Accepted: 05/01/2014] [Indexed: 11/19/2022] Open
Abstract
Single-molecule localization microscopy of biological samples requires a precise knowledge of the employed fluorescent labels. Photoactivation, photoblinking and photobleaching of phototransformable fluorescent proteins influence the data acquisition and data processing strategies to be used in (Fluorescence) Photoactivation Localization Microscopy ((F)-PALM), notably for reliable molecular counting. As these parameters might depend on the local environment, they should be measured in cellulo in biologically relevant experimental conditions. Here, we measured phototransformation quantum yields for Dendra2 fused to actin in fixed mammalian cells in typical (F)-PALM experiments. To this aim, we developed a data processing strategy based on the clustering optimization procedure proposed by Lee et al (PNAS 109, 17436–17441, 2012). Using simulations, we estimated the range of experimental parameters (molecular density, molecular orientation, background level, laser power, frametime) adequate for an accurate determination of the phototransformation yields. Under illumination at 561 nm in PBS buffer at pH 7.4, the photobleaching yield of Dendra2 fused to actin was measured to be (2.5±0.4)×10−5, whereas the blinking-off yield and thermally-activated blinking-on rate were measured to be (2.3±0.2)×10−5 and 11.7±0.5 s−1, respectively. These phototransformation yields differed from those measured in poly-vinyl alcohol (PVA) and were strongly affected by addition of the antifading agent 1,4-diazabicyclo[2.2.2]octane (DABCO). In the presence of DABCO, the photobleaching yield was reduced 2-fold, the blinking-off yield was decreased more than 3-fold, and the blinking-on rate was increased 2-fold. Therefore, DABCO largely improved Dendra2 photostability in fixed mammalian cells. These findings are consistent with redox-based bleaching and blinking mechanisms under (F)-PALM experimental conditions. Finally, the green-to-red photoconversion quantum yield of Dendra2 was estimated to be (1.4±0.6)×10−5in cellulo under 405 nm illumination.
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19
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Müller SM, Galliardt H, Schneider J, Barisas BG, Seidel T. Quantification of Förster resonance energy transfer by monitoring sensitized emission in living plant cells. FRONTIERS IN PLANT SCIENCE 2013; 4:413. [PMID: 24194740 PMCID: PMC3810607 DOI: 10.3389/fpls.2013.00413] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2013] [Accepted: 09/29/2013] [Indexed: 05/20/2023]
Abstract
Förster resonance energy transfer (FRET) describes excitation energy exchange between two adjacent molecules typically in distances ranging from 2 to 10 nm. The process depends on dipole-dipole coupling of the molecules and its probability of occurrence cannot be proven directly. Mostly, fluorescence is employed for quantification as it represents a concurring process of relaxation of the excited singlet state S1 so that the probability of fluorescence decreases as the probability of FRET increases. This reflects closer proximity of the molecules or an orientation of donor and acceptor transition dipoles that facilitates FRET. Monitoring sensitized emission by 3-Filter-FRET allows for fast image acquisition and is suitable for quantifying FRET in dynamic systems such as living cells. In recent years, several calibration protocols were established to overcome to previous difficulties in measuring FRET-efficiencies. Thus, we can now obtain by 3-filter FRET FRET-efficiencies that are comparable to results from sophisticated fluorescence lifetime measurements. With the discovery of fluorescent proteins and their improvement toward spectral variants and usability in plant cells, the tool box for in vivo FRET-analyses in plant cells was provided and FRET became applicable for the in vivo detection of protein-protein interactions and for monitoring conformational dynamics. The latter opened the door toward a multitude of FRET-sensors such as the widely applied Ca(2+)-sensor Cameleon. Recently, FRET-couples of two fluorescent proteins were supplemented by additional fluorescent proteins toward FRET-cascades in order to monitor more complex arrangements. Novel FRET-couples involving switchable fluorescent proteins promise to increase the utility of FRET through combination with photoactivation-based super-resolution microscopy.
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Affiliation(s)
- Sara M. Müller
- Dynamic Cell Imaging, Faculty of Biology, Bielefeld UniversityBielefeld, Germany
| | - Helena Galliardt
- Dynamic Cell Imaging, Faculty of Biology, Bielefeld UniversityBielefeld, Germany
| | - Jessica Schneider
- Bioinformatic Resource Facility, Center for Biotechnology, Bielefeld UniversityBielefeld, Germany
| | - B. George Barisas
- Chemistry Department, Colorado State UniversityFort Collins, CO, USA
| | - Thorsten Seidel
- Dynamic Cell Imaging, Faculty of Biology, Bielefeld UniversityBielefeld, Germany
- *Correspondence: Thorsten Seidel, Dynamic Cell Imaging, Faculty of Biology, Bielefeld University, Universitätsstraße 25, 33501 Bielefeld, Germany e-mail:
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20
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Poulsen CP, Vereb G, Geshi N, Schulz A. Inhibition of cytoplasmic streaming by cytochalasin D is superior to paraformaldehyde fixation for measuring FRET between fluorescent protein-tagged Golgi components. Cytometry A 2013; 83:830-8. [PMID: 23520174 DOI: 10.1002/cyto.a.22282] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2012] [Revised: 02/05/2013] [Accepted: 02/21/2013] [Indexed: 12/13/2022]
Abstract
Protein-protein interaction at the organelle level can be analyzed by using tagged proteins and assessing Förster resonance energy transfer (FRET) between fluorescent donor and acceptor proteins. Such studies are able to uncover partners in the regulation of proteins and enzymes. However, any organelle movement is an issue for live FRET microscopy, as the observed organelle must not change position during measurement. One of the mobile organelles in plants is the Golgi apparatus following cytoplasmic streaming. It is involved in the decoration of proteins and processing of complex glycan structures for the cell wall. Understanding of these processes is still limited, but evidence is emerging that protein-protein interaction plays a key role in the function of this organelle. In the past, mobile organelles were usually immobilized with paraformaldehyde (PFA) for FRET-based interaction studies. Here, we show that the actin inhibitor Cytochalasin D (CytD) is superior to PFA for immobilization of Golgi stacks in plant cells. Two glycosyltransferases known to interact were tagged with cyan fluorescent protein (CFP) and yellow fluorescent protein (YFP), respectively, coexpressed in Nicotiana benthamiana leaves and analyzed using confocal microscopy and spectral imaging. Fixation with PFA leads to reduced emission intensity when compared to CytD treatment. Furthermore, the calculated FRET efficiency was significantly higher with CytD than with PFA. The documented improvements are beneficial for all methods measuring FRET, where immobilization of the investigated molecules is necessary. It can be expected that FRET measurement in organelles of animal cells will also benefit from the use of inhibitors acting on the cytoskeleton.
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Affiliation(s)
- Christian Peter Poulsen
- Department of Plant and Environmental Sciences, University of Copenhagen, Copenhagen, Denmark
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21
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Staras K, Mikulincer D, Gitler D. Monitoring and quantifying dynamic physiological processes in live neurons using fluorescence recovery after photobleaching. J Neurochem 2013; 126:213-22. [PMID: 23496032 DOI: 10.1111/jnc.12240] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2013] [Revised: 03/12/2013] [Accepted: 03/13/2013] [Indexed: 12/27/2022]
Abstract
The direct visualization of subcellular dynamic processes is often hampered by limitations in the resolving power achievable with conventional microscopy techniques. Fluorescence recovery after photobleaching has emerged as a highly informative approach to address this challenge, permitting the quantitative measurement of the movement of small organelles and proteins in living functioning cells, and offering detailed insights into fundamental cellular phenomena of physiological importance. In recent years, its implementation has benefited from the increasing availability of confocal microscopy systems and of powerful labeling techniques based on genetically encoded fluorescent proteins or other chemical markers. In this review, we present fluorescence recovery after photobleaching and related techniques in the context of contemporary neurobiological research and discuss quantitative and semi-quantitative approaches to their interpretation.
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Affiliation(s)
- Kevin Staras
- School of Life Sciences, University of Sussex, Brighton, UK
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22
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Stender AS, Marchuk K, Liu C, Sander S, Meyer MW, Smith EA, Neupane B, Wang G, Li J, Cheng JX, Huang B, Fang N. Single cell optical imaging and spectroscopy. Chem Rev 2013; 113:2469-527. [PMID: 23410134 PMCID: PMC3624028 DOI: 10.1021/cr300336e] [Citation(s) in RCA: 166] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Anthony S. Stender
- Department of Chemistry, Iowa State University and Ames Laboratory, U. S. Department of Energy, Ames, IA 50011, USA
| | - Kyle Marchuk
- Department of Chemistry, Iowa State University and Ames Laboratory, U. S. Department of Energy, Ames, IA 50011, USA
| | - Chang Liu
- Department of Chemistry, Iowa State University and Ames Laboratory, U. S. Department of Energy, Ames, IA 50011, USA
| | - Suzanne Sander
- Department of Chemistry, Iowa State University and Ames Laboratory, U. S. Department of Energy, Ames, IA 50011, USA
| | - Matthew W. Meyer
- Department of Chemistry, Iowa State University and Ames Laboratory, U. S. Department of Energy, Ames, IA 50011, USA
| | - Emily A. Smith
- Department of Chemistry, Iowa State University and Ames Laboratory, U. S. Department of Energy, Ames, IA 50011, USA
| | - Bhanu Neupane
- Department of Chemistry, North Carolina State University, Raleigh, NC 27695, USA
| | - Gufeng Wang
- Department of Chemistry, North Carolina State University, Raleigh, NC 27695, USA
| | - Junjie Li
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN 47907
| | - Ji-Xin Cheng
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN 47907
| | - Bo Huang
- Department of Pharmaceutical Chemistry and Department of Biochemistry and Biophysics, University of California, San Francisco, CA 94158
| | - Ning Fang
- Department of Chemistry, Iowa State University and Ames Laboratory, U. S. Department of Energy, Ames, IA 50011, USA
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23
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Šimková E, Staněk D. Probing nucleic acid interactions and pre-mRNA splicing by Förster Resonance Energy Transfer (FRET) microscopy. Int J Mol Sci 2012; 13:14929-45. [PMID: 23203103 PMCID: PMC3509619 DOI: 10.3390/ijms131114929] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2012] [Revised: 10/31/2012] [Accepted: 10/31/2012] [Indexed: 01/11/2023] Open
Abstract
Förster resonance energy transfer (FRET) microscopy is a powerful technique routinely used to monitor interactions between biomolecules. Here, we focus on the techniques that are used for investigating the structure and interactions of nucleic acids (NAs). We present a brief overview of the most commonly used FRET microscopy techniques, their advantages and drawbacks. We list experimental approaches recently used for either in vitro or in vivo studies. Next, we summarize how FRET contributed to the understanding of pre-mRNA splicing and spliceosome assembly.
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Affiliation(s)
- Eva Šimková
- Institute of Molecular Genetics, Academy of Sciences of the Czech Republic, Videnska 1083, 142 20 Prague, Czech Republic; E-Mail:
| | - David Staněk
- Institute of Molecular Genetics, Academy of Sciences of the Czech Republic, Videnska 1083, 142 20 Prague, Czech Republic; E-Mail:
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24
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Lam AJ, St-Pierre F, Gong Y, Marshall JD, Cranfill PJ, Baird MA, McKeown MR, Wiedenmann J, Davidson MW, Schnitzer MJ, Tsien RY, Lin MZ. Improving FRET dynamic range with bright green and red fluorescent proteins. Nat Methods 2012; 9:1005-12. [PMID: 22961245 PMCID: PMC3461113 DOI: 10.1038/nmeth.2171] [Citation(s) in RCA: 561] [Impact Index Per Article: 46.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2011] [Accepted: 08/10/2012] [Indexed: 11/18/2022]
Abstract
A variety of genetically encoded reporters use changes in fluorescence (or Förster) resonance energy transfer (FRET) to report on biochemical processes in living cells. The standard genetically encoded FRET pair consists of CFPs and YFPs, but many CFP-YFP reporters suffer from low FRET dynamic range, phototoxicity from the CFP excitation light and complex photokinetic events such as reversible photobleaching and photoconversion. We engineered two fluorescent proteins, Clover and mRuby2, which are the brightest green and red fluorescent proteins to date and have the highest Förster radius of any ratiometric FRET pair yet described. Replacement of CFP and YFP with these two proteins in reporters of kinase activity, small GTPase activity and transmembrane voltage significantly improves photostability, FRET dynamic range and emission ratio changes. These improvements enhance detection of transient biochemical events such as neuronal action-potential firing and RhoA activation in growth cones.
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Affiliation(s)
- Amy J Lam
- Department of Bioengineering, Stanford University, Stanford, California, USA
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25
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Baird FJ, Wadsworth MP, Hill JE. Evaluation and optimization of multiple fluorophore analysis of a Pseudomonas aeruginosa biofilm. J Microbiol Methods 2012; 90:192-6. [PMID: 22587931 DOI: 10.1016/j.mimet.2012.05.004] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2012] [Revised: 05/01/2012] [Accepted: 05/01/2012] [Indexed: 11/29/2022]
Abstract
Conventional laser scanning microscopy for multiple fluorescent stains can be a useful tool if the problems of autofluorescence and cross-talk are eliminated. The technique of spectral imaging was employed to unmix five different fluorophores - ranging in emission from 435 to 665 nm - applied to a Pseudomonas aeruginosa biofilm with overlapping spectra and which was not possible using traditional channel mode operation. Using lambda scanning and linear unmixing, the five fluorophores could be distinguished with regions of differentiation apparent.
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Affiliation(s)
- Fiona J Baird
- University of Vermont, School of Engineering, Burlington, Vermont 05405-0156, USA
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26
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Lin M, Zhao Y, Wang S, Liu M, Duan Z, Chen Y, Li F, Xu F, Lu T. Recent advances in synthesis and surface modification of lanthanide-doped upconversion nanoparticles for biomedical applications. Biotechnol Adv 2012; 30:1551-61. [PMID: 22561011 DOI: 10.1016/j.biotechadv.2012.04.009] [Citation(s) in RCA: 163] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2011] [Revised: 04/06/2012] [Accepted: 04/21/2012] [Indexed: 12/12/2022]
Abstract
Lanthanide (Ln)-doped upconversion nanoparticles (UCNPs) with appropriate surface modification can be used for a wide range of biomedical applications such as bio-detection, cancer therapy, bio-labeling, fluorescence imaging, magnetic resonance imaging and drug delivery. The upconversion phenomenon exhibited by Ln-doped UCNPs renders them tremendous advantages in biological applications over other types of fluorescent materials (e.g., organic dyes, fluorescent proteins, gold nanoparticles, quantum dots, and luminescent transition metal complexes) for: (i) enhanced tissue penetration depths achieved by near-infrared (NIR) excitation; (ii) improved stability against photobleaching, photoblinking and photochemical degradation; (iii) non-photodamaging to DNA/RNA due to lower excitation light energy; (iv) lower cytotoxicity; and (v) higher detection sensitivity. Ln-doped UCNPs are therefore attracting increasing attentions in recent years. In this review, we present recent advances in the synthesis of Ln-doped UCNPs and their surface modification, as well as their emerging applications in biomedicine. The future prospects of Ln-doped UCNPs for biomedical applications are also discussed.
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Affiliation(s)
- Min Lin
- The Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology, Biomedical Engineering and Biomechanics Center, Department of Chemistry, Xi'an Jiaotong University, Xi'an, PR China
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27
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Koschatzky S, Tschammer N, Gmeiner P. Cross-receptor interactions between dopamine D2L and neurotensin NTS1 receptors modulate binding affinities of dopaminergics. ACS Chem Neurosci 2011; 2:308-16. [PMID: 22778874 DOI: 10.1021/cn200020y] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2011] [Accepted: 04/11/2011] [Indexed: 11/30/2022] Open
Abstract
Dopaminergic systems have been described to functionally interact with the neuromodulatory peptide neurotensin. Employing fluorescence detected coimmunoprecipitation and radioligand binding experiments, we herein demonstrate that coexpression of dopamine D(2L) receptor and the neurotensin receptor subtype NTS(1) leads to physical interaction and the formation of heteromers in transfected human embryonic kidney 293 cells. In this in vitro system, a trans-inhibitory effect on the agonist binding affinity of D(2) was observed in presence of neurotensin. To correlate between the functional properties of dopaminergic agents and the magnitude of neurotensin-induced modulation of D(2L) binding affinities in cells coexpressing D(2L) and NTS(1), a structurally diverse set of dopamine receptor agonists, partial agonists, and antagonists was tested. Ligand specific profiles indicating substantial bias between ligand efficacy and transmodulation were discovered, suggesting a heteromerization-based functional selectivity. In the presence of neurotensin, the novel D(2) agonist FAUC 326 displayed a 34-fold decrease of binding affinity in cells coexpressing D(2L) and NTS(1).
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Affiliation(s)
- Susanne Koschatzky
- Department of Chemistry and Pharmacy, Emil Fischer Center, Friedrich-Alexander University, Schuhstrasse 19, D- 91052 Erlangen, Germany
| | - Nuska Tschammer
- Department of Chemistry and Pharmacy, Emil Fischer Center, Friedrich-Alexander University, Schuhstrasse 19, D- 91052 Erlangen, Germany
| | - Peter Gmeiner
- Department of Chemistry and Pharmacy, Emil Fischer Center, Friedrich-Alexander University, Schuhstrasse 19, D- 91052 Erlangen, Germany
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