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Lim J, Petersen M, Bunz M, Simon C, Schindler M. Flow cytometry based-FRET: basics, novel developments and future perspectives. Cell Mol Life Sci 2022; 79:217. [PMID: 35352201 PMCID: PMC8964568 DOI: 10.1007/s00018-022-04232-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Accepted: 03/07/2022] [Indexed: 12/29/2022]
Abstract
Förster resonance energy transfer (FRET) is a widespread technology used to analyze and quantify protein interactions in multiple settings. While FRET is traditionally measured by microscopy, flow cytometry based-FRET is becoming popular within the last decade and more commonly used. Flow cytometry based-FRET offers the possibility to assess FRET in a short time-frame in a high number of cells thereby allowing stringent and statistically robust quantification of FRET in multiple samples. Furthermore, established, simple and easy to implement gating strategies facilitate the adaptation of flow cytometry based-FRET measurements to most common flow cytometers. We here summarize the basics of flow cytometry based-FRET, highlight recent novel developments in this field and emphasize on exciting future perspectives.
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Affiliation(s)
- JiaWen Lim
- Institute for Medical Virology and Epidemiology of Viral Diseases, University Hospital Tübingen, Tübingen, Germany
| | - Moritz Petersen
- Institute for Medical Virology and Epidemiology of Viral Diseases, University Hospital Tübingen, Tübingen, Germany
| | - Maximilian Bunz
- Institute for Medical Virology and Epidemiology of Viral Diseases, University Hospital Tübingen, Tübingen, Germany
| | - Claudia Simon
- Institute for Medical Virology and Epidemiology of Viral Diseases, University Hospital Tübingen, Tübingen, Germany
| | - Michael Schindler
- Institute for Medical Virology and Epidemiology of Viral Diseases, University Hospital Tübingen, Tübingen, Germany.
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2
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Szabó Á, Szendi-Szatmári T, Szöllősi J, Nagy P. Quo vadis FRET? Förster's method in the era of superresolution. Methods Appl Fluoresc 2020; 8:032003. [PMID: 32521530 DOI: 10.1088/2050-6120/ab9b72] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Although the theoretical foundations of Förster resonance energy transfer (FRET) were laid in the 1940s as part of the quantum physical revolution of the 20th century, it was only in the 1970s that it made its way to biology as a result of the availability of suitable measuring and labeling technologies. Thanks to its ease of application, FRET became widely used for studying molecular associations on the nanometer scale. The development of superresolution techniques at the turn of the millennium promised an unprecedented insight into the structure and function of molecular complexes. Without downplaying the significance of superresolution microscopies this review expresses our view that FRET is still a legitimate tool in the armamentarium of biologists for studying molecular associations since it offers distinct advantages and overcomes certain limitations of superresolution approaches.
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Affiliation(s)
- Ágnes Szabó
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, Egyetem square 1, 4032 Debrecen, Hungary. MTA-DE Cell Biology and Signaling Research Group, Faculty of Medicine, University of Debrecen, Egyetem square 1, 4032 Debrecen, Hungary
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3
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Kuo JCH, Goudge MC, Metzloff AE, Huang LT, Colville MJ, Park S, Zipfel WR, Paszek MJ. Litmus-Body: A Molecularly Targeted Sensor for Cell-Surface pH Measurements. ACS Sens 2020; 5:1555-1566. [PMID: 32337979 DOI: 10.1021/acssensors.9b02080] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Precise pH measurements in the immediate environment of receptors is essential for elucidating the mechanisms through which local pH changes associated with diseased phenotypes manifest into aberrant receptor function. However, current pH sensors lack the ability to localize and target specific receptor molecules required to make these measurements. Herein we present the Litmus-body, our recombinant protein-based pH sensor, which through fusion to an anti-IgG nanobody is capable of piggybacking on IgG antibodies for molecular targeting to specific proteins on the cell surface. By normalizing a pH-dependent green fluorescent protein to a long Stokes shift red fluorophore or fluorescent protein, we readily report pH independent of sensor concentration using a single 488 nm excitation. Our Litmus-body showed excellent responsiveness in solution, with a greater than 50-fold change across the regime of physiological pH. The sensor was further validated for use on live cells and shown to be specific to the protein of interest. In complex with our Litmus-body, cetuximab therapeutic antibody retained its functionality in binding and inhibiting ligand interaction of its target epidermal growth factor receptor (EGFR), triggering receptor-mediated endocytosis that allowed tracking of local pH from the cell surface through the endocytic pathway.
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Affiliation(s)
- Joe Chin-Hun Kuo
- Robert Frederick Smith School of Chemical and Biomolecular Engineering, Cornell University, Ithaca, New York 14853, United States
| | - Marc C. Goudge
- Nancy E. and Peter C. Meinig School of Biomedical Engineering, Cornell University, Ithaca, New York 14853, United States
| | - Ann E. Metzloff
- Robert Frederick Smith School of Chemical and Biomolecular Engineering, Cornell University, Ithaca, New York 14853, United States
| | - Ling-Ting Huang
- Robert Frederick Smith School of Chemical and Biomolecular Engineering, Cornell University, Ithaca, New York 14853, United States
| | | | - Sangwoo Park
- Field of Biophysics, Cornell University, Ithaca, New York 14853, United States
| | - Warren R. Zipfel
- Nancy E. and Peter C. Meinig School of Biomedical Engineering, Cornell University, Ithaca, New York 14853, United States
- Field of Biophysics, Cornell University, Ithaca, New York 14853, United States
- Kavli Institute at Cornell for Nanoscale Science, Ithaca, New York 14853, United States
| | - Matthew J. Paszek
- Robert Frederick Smith School of Chemical and Biomolecular Engineering, Cornell University, Ithaca, New York 14853, United States
- Nancy E. and Peter C. Meinig School of Biomedical Engineering, Cornell University, Ithaca, New York 14853, United States
- Field of Biophysics, Cornell University, Ithaca, New York 14853, United States
- Kavli Institute at Cornell for Nanoscale Science, Ithaca, New York 14853, United States
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4
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Atmanli A, Hu D, Deiman FE, van de Vrugt AM, Cherbonneau F, Black LD, Domian IJ. Multiplex live single-cell transcriptional analysis demarcates cellular functional heterogeneity. eLife 2019; 8:49599. [PMID: 31591966 PMCID: PMC6861004 DOI: 10.7554/elife.49599] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2019] [Accepted: 10/07/2019] [Indexed: 12/21/2022] Open
Abstract
A fundamental goal in the biological sciences is to determine how individual cells with varied gene expression profiles and diverse functional characteristics contribute to development, physiology, and disease. Here, we report a novel strategy to assess gene expression and cell physiology in single living cells. Our approach utilizes fluorescently labeled mRNA-specific anti-sense RNA probes and dsRNA-binding protein to identify the expression of specific genes in real-time at single-cell resolution via FRET. We use this technology to identify distinct myocardial subpopulations expressing the structural proteins myosin heavy chain α and myosin light chain 2a in real-time during early differentiation of human pluripotent stem cells. We combine this live-cell gene expression analysis with detailed physiologic phenotyping to capture the functional evolution of these early myocardial subpopulations during lineage specification and diversification. This live-cell mRNA imaging approach will have wide ranging application wherever heterogeneity plays an important biological role.
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Affiliation(s)
- Ayhan Atmanli
- Cardiovascular Research Center, Massachusetts General Hospital, Boston, United States.,Harvard Medical School, Boston, United States.,Department of Biomedical Engineering, Tufts University, Medford, United States
| | - Dongjian Hu
- Cardiovascular Research Center, Massachusetts General Hospital, Boston, United States.,Harvard Medical School, Boston, United States.,Department of Biomedical Engineering, Boston University, Boston, United States
| | - Frederik Ernst Deiman
- Cardiovascular Research Center, Massachusetts General Hospital, Boston, United States.,Harvard Medical School, Boston, United States
| | - Annebel Marjolein van de Vrugt
- Cardiovascular Research Center, Massachusetts General Hospital, Boston, United States.,Harvard Medical School, Boston, United States
| | - François Cherbonneau
- Cardiovascular Research Center, Massachusetts General Hospital, Boston, United States
| | - Lauren Deems Black
- Department of Biomedical Engineering, Tufts University, Medford, United States.,Sackler School of Graduate Biomedical Sciences, Tufts University School of Medicine, Boston, United States
| | - Ibrahim John Domian
- Cardiovascular Research Center, Massachusetts General Hospital, Boston, United States.,Harvard Medical School, Boston, United States.,Harvard Stem Cell Institute, Cambridge, United States
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5
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Toolbox for In Vivo Imaging of Host-Parasite Interactions at Multiple Scales. Trends Parasitol 2019; 35:193-212. [PMID: 30745251 DOI: 10.1016/j.pt.2019.01.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2018] [Revised: 01/04/2019] [Accepted: 01/04/2019] [Indexed: 12/19/2022]
Abstract
Animal models have for long been pivotal for parasitology research. Over the last few years, techniques such as intravital, optoacoustic and magnetic resonance imaging, optical projection tomography, and selective plane illumination microscopy developed promising potential for gaining insights into host-pathogen interactions by allowing different visualization forms in vivo and ex vivo. Advances including increased resolution, penetration depth, and acquisition speed, together with more complex image analysis methods, facilitate tackling biological problems previously impossible to study and/or quantify. Here we discuss advances and challenges in the in vivo imaging toolbox, which hold promising potential for the field of parasitology.
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6
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Kostyuk AI, Panova AS, Bilan DS, Belousov VV. Redox biosensors in a context of multiparameter imaging. Free Radic Biol Med 2018; 128:23-39. [PMID: 29630928 DOI: 10.1016/j.freeradbiomed.2018.04.004] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/24/2017] [Revised: 03/18/2018] [Accepted: 04/04/2018] [Indexed: 12/22/2022]
Abstract
A wide variety of genetically encoded fluorescent biosensors are available to date. Some of them have already contributed significantly to our understanding of biological processes occurring at cellular and organismal levels. Using such an approach, outstanding success has been achieved in the field of redox biology. The probes allowed researchers to observe, for the first time, the dynamics of important redox parameters in vivo during embryogenesis, aging, the inflammatory response, the pathogenesis of various diseases, and many other processes. Given the differences in the readout and spectra of the probes, they can be used in multiparameter imaging in which several processes are monitored simultaneously in the cell. Intracellular processes form an extensive network of interactions. For example, redox changes are often accompanied by changes in many other biochemical reactions related to cellular metabolism and signaling. Therefore, multiparameter imaging can provide important information concerning the temporal and spatial relationship of various signaling and metabolic processes. In this review, we will describe the main types of genetically encoded biosensors, the most frequently used readout, and their use in multiplexed imaging mode.
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Affiliation(s)
- Alexander I Kostyuk
- Faculty of Biology, Moscow State University, Moscow, Russia; Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Moscow 117997, Russia
| | - Anastasiya S Panova
- Faculty of Biology, Moscow State University, Moscow, Russia; Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Moscow 117997, Russia
| | - Dmitry S Bilan
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Moscow 117997, Russia; Pirogov Russian National Research Medical University, Moscow 117997, Russia
| | - Vsevolod V Belousov
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Moscow 117997, Russia; Pirogov Russian National Research Medical University, Moscow 117997, Russia; Institute for Cardiovascular Physiology, Georg August University Göttingen, Göttingen D-37073, Germany.
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7
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Farsi Z, Woehler A. Imaging Activity-Dependent Signaling Dynamics at the Neuronal Synapse Using FRET-Based Biosensors. Methods Mol Biol 2018; 1538:261-275. [PMID: 27943196 DOI: 10.1007/978-1-4939-6688-2_18] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
In this chapter, we introduce the combined use of FRET-based biosensors and synaptic markers as an effective tool for studying intracellular signaling pathways in small synaptic terminals of neuronal cells. The approach is based on the unmixing of excitation/emission spectral fingerprints of a FRET donor and acceptor pair, as well as a lipophilic styryl dye, FM1-43, loaded into presynaptic terminals. The destaining of FM1-43 during evoked release provides a map to guide the sampling of fluorescence for FRET analysis. In the example presented here, we measure the temporal dynamics of cAMP at the presynaptic terminal using an intramolecular CFP/YFP-based FRET sensor. However, this methodology can be applied to investigate the spatial and temporal regulation of a variety of signaling processes, as well as dynamic changes in protein-protein interaction.
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Affiliation(s)
- Zohreh Farsi
- Department of Neurobiology, Max Planck Institute for Biophysical Chemistry, 37077, Göttingen, Germany
| | - Andrew Woehler
- Department of Membrane Biophysics, Max Planck Institute for Biophysical Chemistry, 37077, Göttingen, Germany. .,DFG-Research Center for Nanoscale Microscopy and Molecular Physiology of the Brain (CNMPB), 37073, Göttingen, Germany. .,Berlin Institute for Medical Systems Biology, Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Robert-Rössle-Straße 10, 13125, Berlin-Buch, Germany.
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8
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Lin F, Du M, Yang F, Wei L, Chen T. Improved spectrometer-microscope for quantitative fluorescence resonance energy transfer measurement based on simultaneous spectral unmixing of excitation and emission spectra. JOURNAL OF BIOMEDICAL OPTICS 2018; 23:1-10. [PMID: 29313324 DOI: 10.1117/1.jbo.23.1.016006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/18/2017] [Accepted: 12/07/2017] [Indexed: 06/07/2023]
Abstract
Based on our recently developed quantitative fluorescence resonance energy transfer (FRET) measurement method using simultaneous spectral unmixing of excitation and emission spectra (ExEm-spFRET), we here set up an improved spectrometer-microscope (SM) for implementing modified ExEm-spFRET (mExEm-spFRET), in which a system correction factor (fsc) is introduced. Our SM system is very stable for at least six months. Implementation of mExEm-spFRET with four or two excitation wavelengths on SM for single living cells expressing different FRET constructs obtained consistent FRET efficiency (E) and acceptor-donor concentration ratio (Rc) values. We also performed mExEm-spFRET measurement for single living cells coexpressing cyan fluorescent protein (CFP)-Bax and yellow fluorescent protein (YFP)-Bax and found that the E values between CFP-Bax and YFP-Bax were very low (2.2%) and independent of Rc for control cells, indicating that Bax did not exist as homooligomer in healthy cells, but positively proportional to Rc in the case of Rc<1 and kept constant value (25%) when Rc>1 for staurosporine (STS)-treated cells, demonstrating that all Bax formed homooligomer after STS treatment for 6 h.
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Affiliation(s)
- Fangrui Lin
- South China Normal University, MOE Key Laboratory of Laser Life Science and College of Life Science,, China
| | - Mengyan Du
- South China Normal University, MOE Key Laboratory of Laser Life Science and College of Life Science,, China
| | - Fangfang Yang
- South China Normal University, MOE Key Laboratory of Laser Life Science and College of Life Science,, China
| | - Lichun Wei
- South China Normal University, MOE Key Laboratory of Laser Life Science and College of Life Science,, China
| | - Tongsheng Chen
- South China Normal University, MOE Key Laboratory of Laser Life Science and College of Life Science,, China
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9
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Yasuda R. Biophysics of Biochemical Signaling in Dendritic Spines: Implications in Synaptic Plasticity. Biophys J 2017; 113:2152-2159. [PMID: 28866426 DOI: 10.1016/j.bpj.2017.07.029] [Citation(s) in RCA: 54] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2017] [Revised: 07/12/2017] [Accepted: 07/20/2017] [Indexed: 11/24/2022] Open
Abstract
Dendritic spines are mushroom-shaped postsynaptic compartments that host biochemical signal cascades important for synaptic plasticity and, ultimately, learning and memory. Signaling events in spines involve a signaling network composed of hundreds of signaling proteins interacting with each other extensively. Synaptic plasticity is typically induced by Ca2+ elevation in spines, which activates a variety of signaling pathways. This leads to changes in the actin cytoskeleton and membrane dynamics, which in turn causes structural and functional changes of the spine. Recent studies have demonstrated that the activities of these proteins have a variety of spatiotemporal patterns, which orchestrate signaling activity in different subcellular compartments at different timescales. The diffusion and the decay kinetics of signaling molecules play important roles in determining the degree of their spatial spreading, and thereby the degree of the spine specificity of the signaling pathway.
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Affiliation(s)
- Ryohei Yasuda
- Max Planck Florida Institute for Neuroscience, Jupiter, Florida.
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10
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DU M, MAI Z, YANG F, LIN F, WEI L, CHEN T. Multichannel wide-field microscopic FRET imaging based on simultaneous spectral unmixing of excitation and emission spectra. J Microsc 2017; 269:66-77. [DOI: 10.1111/jmi.12609] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2017] [Revised: 06/24/2017] [Accepted: 07/10/2017] [Indexed: 12/23/2022]
Affiliation(s)
- M. DU
- MOE Key Laboratory of Laser Life Science & College of Life Science; South China Normal University; Guangzhou China
| | - Z. MAI
- MOE Key Laboratory of Laser Life Science & College of Life Science; South China Normal University; Guangzhou China
| | - F. YANG
- MOE Key Laboratory of Laser Life Science & College of Life Science; South China Normal University; Guangzhou China
| | - F. LIN
- MOE Key Laboratory of Laser Life Science & College of Life Science; South China Normal University; Guangzhou China
| | - L. WEI
- MOE Key Laboratory of Laser Life Science & College of Life Science; South China Normal University; Guangzhou China
| | - T. CHEN
- MOE Key Laboratory of Laser Life Science & College of Life Science; South China Normal University; Guangzhou China
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11
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Abstract
Förster resonance energy transfer (FRET) is a powerful tool for the visualization of molecular signaling events such as protein activities and interactions in cells. In its different implementations, FRET microscopy has been mainly used for monitoring single events. Recently, there has been a trend of extending FRET imaging towards the simultaneous detection of multiple events and interactions. The concomitant increase in experimental complexity requires a deeper understanding of the biophysical background of FRET. The presence of multiple acceptors for one donor affects the well-known formalism for FRET between two molecules, increasing distance sensitivity through mechanisms that have become known as the ‘antenna’ and ‘surplus’ effect. We will discuss the nature of these effects and present the imaging methods that have been used to unravel the combined transfer rates in the multi-protein interactions of multiplexed FRET experiments. Multiplexing strategies are becoming invaluable analytical tools for the elucidation of biological complexes and for the visualization of decision points in cellular signaling networks in physiological and pathological conditions.
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12
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Newman RH, Zhang J. Integrated Strategies to Gain a Systems-Level View of Dynamic Signaling Networks. Methods Enzymol 2017; 589:133-170. [PMID: 28336062 DOI: 10.1016/bs.mie.2017.01.016] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
In order to survive and function properly in the face of an ever changing environment, cells must be able to sense changes in their surroundings and respond accordingly. Cells process information about their environment through complex signaling networks composed of many discrete signaling molecules. Individual pathways within these networks are often tightly integrated and highly dynamic, allowing cells to respond to a given stimulus (or, as is typically the case under physiological conditions, a combination of stimuli) in a specific and appropriate manner. However, due to the size and complexity of many cellular signaling networks, it is often difficult to predict how cellular signaling networks will respond under a particular set of conditions. Indeed, crosstalk between individual signaling pathways may lead to responses that are nonintuitive (or even counterintuitive) based on examination of the individual pathways in isolation. Therefore, to gain a more comprehensive view of cell signaling processes, it is important to understand how signaling networks behave at the systems level. This requires integrated strategies that combine quantitative experimental data with computational models. In this chapter, we first examine some of the progress that has recently been made toward understanding the systems-level regulation of cellular signaling networks, with a particular emphasis on phosphorylation-dependent signaling networks. We then discuss how genetically targetable fluorescent biosensors are being used together with computational models to gain unique insights into the spatiotemporal regulation of signaling networks within single, living cells.
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Affiliation(s)
- Robert H Newman
- North Carolina Agricultural and Technical State University, Greensboro, NC, United States.
| | - Jin Zhang
- University of California, San Diego, San Diego, CA, United States.
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13
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Multiplexing PKA and ERK1&2 kinases FRET biosensors in living cells using single excitation wavelength dual colour FLIM. Sci Rep 2017; 7:41026. [PMID: 28106114 PMCID: PMC5247693 DOI: 10.1038/srep41026] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2016] [Accepted: 12/14/2016] [Indexed: 02/04/2023] Open
Abstract
Monitoring of different signalling enzymes in a single assay using multiplex biosensing provides a multidimensional workspace to elucidate biological processes, signalling pathway crosstalk, and determine precise sequence of events at the single living cell level. In this study, we interrogate the complexity in cAMP/PKA-MAPK/ERK1&2 crosstalk by using multi-parameter biosensing experiments to correlate biochemical activities simultaneously in time and space. Using a single excitation wavelength dual colour FLIM method we are able to detect fluorescence lifetime images of two donors to simultaneously measure PKA and ERK1&2 kinase activities in the same cellular localization by using FRET biosensors. To this end, we excite two FRET donors mTFP1 and LSSmOrange with a 440 nm wavelength and we alleviate spectral bleed-through associated limitations with the very dim-fluorescent acceptor ShadowG for mTFP1 and the red-shifted mKate2 for LSSmOrange. The simultaneous recording of PKA and ERK1&2 kinase activities reveals concomitant EGF-mediated activations of both kinases in HeLa cells. Under these conditions the subsequent Forskolin-induced cAMP release reverses the transient increase of EGF-mediated ERK1&2 kinase activity while reinforcing PKA activation. Here we propose a validated methodology for multiparametric kinase biosensing in living cells using FRET-FLIM.
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14
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Tenner B, Mehta S, Zhang J. Optical sensors to gain mechanistic insights into signaling assemblies. Curr Opin Struct Biol 2016; 41:203-210. [PMID: 27611602 PMCID: PMC5423777 DOI: 10.1016/j.sbi.2016.07.021] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2016] [Accepted: 07/29/2016] [Indexed: 11/17/2022]
Abstract
Protein complexes play a major role in transducing information from outside the cell into instructions for growth and survival, and understanding how these complexes relay and shape intracellular signals has been a central question in signaling biology. Fluorescent proteins have proven paramount in opening windows for researchers to peer into the architecture and inner workings of signaling assemblies within the living cell and in real-time. In this review, we will provide readers with a current perspective on the development and use of genetically encoded optical probes to dissect the function of signaling complexes.
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Affiliation(s)
- Brian Tenner
- Department of Pharmacology, University of California, San Diego, La Jolla, CA, United States; Department of Biophysics and Biophysical Chemistry, Johns Hopkins School of Medicine, Baltimore, MD, United States
| | - Sohum Mehta
- Department of Pharmacology, University of California, San Diego, La Jolla, CA, United States
| | - Jin Zhang
- Department of Pharmacology, University of California, San Diego, La Jolla, CA, United States; Department of Pharmacology and Molecular Sciences, Johns Hopkins School of Medicine, Baltimore, MD, United States.
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15
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Zhang J, Zhang L, Chai L, Yang F, Du M, Chen T. Reliable measurement of the FRET sensitized-quenching transition factor for FRET quantification in living cells. Micron 2016; 88:7-15. [DOI: 10.1016/j.micron.2016.04.005] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2016] [Revised: 04/17/2016] [Accepted: 04/18/2016] [Indexed: 11/15/2022]
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16
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Du M, Zhang L, Xie S, Chen T. Wide-field microscopic FRET imaging using simultaneous spectral unmixing of excitation and emission spectra. OPTICS EXPRESS 2016; 24:16037-16051. [PMID: 27410873 PMCID: PMC5025230 DOI: 10.1364/oe.24.016037] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2016] [Revised: 07/05/2016] [Accepted: 07/06/2016] [Indexed: 06/06/2023]
Abstract
Simultaneous spectral unmixing of excitation and emission spectra (ExEm unmixing) has the inherent ability to resolve donor emission, fluorescence resonance energy transfer (FRET)-sensitized acceptor emission and directly excited acceptor emission. We here develop an ExEm unmixing-based quantitative FRET measurement method (EES-FRET) independent of excitation intensity and detector parameter setting. The ratio factor (rK), predetermined using a donor-acceptor tandem construct, of total acceptor absorption to total donor absorption in excitation wavelengths used is introduced for determining the concentration ratio of acceptor to donor. We implemented EES-FRET method on a wide-field microscope to image living cells expressing tandem FRET constructs with different donor-acceptor stoichiometry.
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Affiliation(s)
- Mengyan Du
- MOE Key Laboratory of Laser Life Science & College of Life Science, South China Normal University, Guangzhou 510631,
China
- M.Y. Du and L.L. Zhang contributed equally
| | - Lili Zhang
- MOE Key Laboratory of Laser Life Science & College of Life Science, South China Normal University, Guangzhou 510631,
China
- M.Y. Du and L.L. Zhang contributed equally
| | - Shusen Xie
- Key Laboratory of Optoelectronic Science and Technology for Medicine of Ministry of Education, Institute of Laser and Optoelectronics Technology, Fujian Normal University, Fuzhou 350007,
China
- (SS Xie)
| | - Tongsheng Chen
- MOE Key Laboratory of Laser Life Science & College of Life Science, South China Normal University, Guangzhou 510631,
China
- and (TS Chen)
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17
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Doucette J, Zhao Z, Geyer RJ, Barra MM, Balunas MJ, Zweifach A. Flow Cytometry Enables Multiplexed Measurements of Genetically Encoded Intramolecular FRET Sensors Suitable for Screening. ACTA ACUST UNITED AC 2016; 21:535-47. [DOI: 10.1177/1087057116634007] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2015] [Accepted: 01/31/2016] [Indexed: 11/16/2022]
Abstract
Genetically encoded sensors based on intramolecular FRET between CFP and YFP are used extensively in cell biology research. Flow cytometry has been shown to offer a means to measure CFP-YFP FRET; we suspected it would provide a unique way to conduct multiplexed measurements from cells expressing different FRET sensors, which is difficult to do with microscopy, and that this could be used for screening. We confirmed that flow cytometry accurately measures FRET signals using cells transiently transfected with an ERK activity reporter, comparing responses measured with imaging and cytometry. We created polyclonal long-term transfectant lines, each expressing a different intramolecular FRET sensor, and devised a way to bar-code four distinct populations of cells. We demonstrated the feasibility of multiplexed measurements and determined that robust multiplexed measurements can be conducted in plate format. To validate the suitability of the method for screening, we measured responses from a plate of bacterial extracts that in unrelated experiments we had determined contained the protein kinase C (PKC)–activating compound teleocidin A-1. The multiplexed assay correctly identifying the teleocidin A-1-containing well. We propose that multiplexed cytometric FRET measurements will be useful for analyzing cellular function and for screening compound collections.
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Affiliation(s)
- Jaimee Doucette
- Department of Molecular and Cell Biology, University of Connecticut at Storrs, Storrs, CT
| | - Ziyan Zhao
- Department of Molecular and Cell Biology, University of Connecticut at Storrs, Storrs, CT
| | - Rory J. Geyer
- Department of Molecular and Cell Biology, University of Connecticut at Storrs, Storrs, CT
| | - Melanie M. Barra
- Department of Molecular and Cell Biology, University of Connecticut at Storrs, Storrs, CT
| | - Marcy J. Balunas
- Division of Medicinal Chemistry, Department of Pharmaceutical Sciences, University of Connecticut at Storrs, Storrs, CT
| | - Adam Zweifach
- Department of Molecular and Cell Biology, University of Connecticut at Storrs, Storrs, CT
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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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Multiplexed 3D FRET imaging in deep tissue of live embryos. Sci Rep 2015; 5:13991. [PMID: 26387920 PMCID: PMC4585674 DOI: 10.1038/srep13991] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2015] [Accepted: 07/29/2015] [Indexed: 02/03/2023] Open
Abstract
Current deep tissue microscopy techniques are mostly restricted to intensity mapping of fluorophores, which significantly limit their applications in investigating biochemical processes in vivo. We present a deep tissue multiplexed functional imaging method that probes multiple Förster resonant energy transfer (FRET) sensors in live embryos with high spatial resolution. The method simultaneously images fluorescence lifetimes in 3D with multiple excitation lasers. Through quantitative analysis of triple-channel intensity and lifetime images, we demonstrated that Ca(2+) and cAMP levels of live embryos expressing dual FRET sensors can be monitored simultaneously at microscopic resolution. The method is compatible with a broad range of FRET sensors currently available for probing various cellular biochemical functions. It opens the door to imaging complex cellular circuitries in whole live organisms.
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20
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Optimizing fluorescent protein trios for 3-Way FRET imaging of protein interactions in living cells. Sci Rep 2015; 5:10270. [PMID: 26130463 PMCID: PMC4487001 DOI: 10.1038/srep10270] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2014] [Accepted: 04/07/2015] [Indexed: 12/29/2022] Open
Abstract
Powerful new methods have extended FRET microscopy to the imaging of three or more interacting proteins inside living cells. Here, we compared widely available fluorescent proteins to find the best trio for 3-Way FRET imaging. We focused on readily available cyan, yellow, and red proteins that have high quantum yields, large extinction coefficients and good photostability, which defined these candidate proteins: CyPet/mTFP1/mTurqoise2, mCitrine/YPet, and TagRFP/TagRFPt/mRuby2/mCherry. By taking advantage of the high structural similarity across the fluorescent proteins, we generated structurally similar, but photophysically distinct donor/acceptor and triple fluorophore fusion proteins and measured their FRET efficiencies inside living cells. Surprisingly, their published photophysical parameters and calculated Förster distances did not predict the best combinations of FPs. Using cycloheximide to inhibit protein synthesis, we found that the different FP maturation rates had a strong effect on the FRET efficiency. This effect was pronounced when comparing rapidly maturing yellow and slowly maturing red FPs. We found that red FPs with inferior photophysics gave superior FRET efficiencies because of faster maturation rates. Based on combined metrics for the FRET efficiency, fluorophore photophysics and fluorophore maturation we determined that Turqoise2, YPet and Cherry were the best available FPs for live cell 3-Way FRET measurements.
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21
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Spectral measurement of acceptor-to-donor extinction coefficient ratio in living cells. Micron 2014; 68:98-106. [PMID: 25464147 DOI: 10.1016/j.micron.2014.09.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2014] [Revised: 08/06/2014] [Accepted: 09/24/2014] [Indexed: 01/16/2023]
Abstract
This report presents a simple method named as sp-ECR to determine the molar extinction coefficient ratio (γ(λex)) of acceptor-to-donor in living cells at excitation wavelength λex, which is closely associated with the acceptor cross-excitation, the hardest issue of FRET quantification. sp-ECR determines γ(λex) by spectrally unmixing the emission spectrum of a donor-acceptor tandem construct under λex excitation without any additional references, such that this method can be performed under optimal imaging condition. We used sp-ECR to measure the γ(458) of Venus/Cerulean in living HepG2 cells on a confocal microscope, and the measured values were consistent with those obtained by lux-FRET method. We also used sp-ECR to measure the γ(458) values of Venus/Cerulean and YFP/CFP as well as YFP/GFP, the commonly used FRET FPs pairs in other two kinds of cancer cell lines on the confocal microscope, and found that the extinction coefficients of FPs depended on cell lines. After predetermining the γ(458) of Venus to ECFP, we used sp-ECR method to monitor the staurosporine (STS)-induced dynamical caspase-3 activation in single live A549 cells expressing SCAT3 by spectrally resolving the absolute FRET efficiency of SCAT3, and found that STS-induced caspase-3 activation in single cells is a very rapid process within 20 min.
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22
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Newman RH, Zhang J, Zhu H. Toward a systems-level view of dynamic phosphorylation networks. Front Genet 2014; 5:263. [PMID: 25177341 PMCID: PMC4133750 DOI: 10.3389/fgene.2014.00263] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2014] [Accepted: 07/16/2014] [Indexed: 11/13/2022] Open
Abstract
To better understand how cells sense and respond to their environment, it is important to understand the organization and regulation of the phosphorylation networks that underlie most cellular signal transduction pathways. These networks, which are composed of protein kinases, protein phosphatases and their respective cellular targets, are highly dynamic. Importantly, to achieve signaling specificity, phosphorylation networks must be regulated at several levels, including at the level of protein expression, substrate recognition, and spatiotemporal modulation of enzymatic activity. Here, we briefly summarize some of the traditional methods used to study the phosphorylation status of cellular proteins before focusing our attention on several recent technological advances, such as protein microarrays, quantitative mass spectrometry, and genetically-targetable fluorescent biosensors, that are offering new insights into the organization and regulation of cellular phosphorylation networks. Together, these approaches promise to lead to a systems-level view of dynamic phosphorylation networks.
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Affiliation(s)
- Robert H Newman
- Department of Biology, North Carolina Agricultural and Technical State University Greensboro, NC, USA
| | - Jin Zhang
- Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine Baltimore, MD, USA ; The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine Baltimore, MD, USA ; Department of Oncology, Johns Hopkins University School of Medicine Baltimore, MD, USA ; Department of Chemical and Biomolecular Engineering, Johns Hopkins University School of Medicine Baltimore, MD, USA
| | - Heng Zhu
- Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine Baltimore, MD, USA ; High-Throughput Biology Center, Institute for Basic Biomedical Sciences, Johns Hopkins University Baltimore, MD, USA
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23
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Rich TC, Webb KJ, Leavesley SJ. Can we decipher the information content contained within cyclic nucleotide signals? J Gen Physiol 2014; 143:17-27. [PMID: 24378904 PMCID: PMC3874573 DOI: 10.1085/jgp.201311095] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Affiliation(s)
- Thomas C. Rich
- Center for Lung Biology, Department of Pharmacology, Basic Medical Sciences Graduate Program, and Department of Pharmacology, College of Medicine; and Department of Chemical and Biomolecular Engineering, College of Engineering, University of South Alabama, Mobile, AL 36688
| | - Kristal J. Webb
- Center for Lung Biology, Department of Pharmacology, Basic Medical Sciences Graduate Program, and Department of Pharmacology, College of Medicine; and Department of Chemical and Biomolecular Engineering, College of Engineering, University of South Alabama, Mobile, AL 36688
| | - Silas J. Leavesley
- Center for Lung Biology, Department of Pharmacology, Basic Medical Sciences Graduate Program, and Department of Pharmacology, College of Medicine; and Department of Chemical and Biomolecular Engineering, College of Engineering, University of South Alabama, Mobile, AL 36688
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24
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Delvigne F, Goffin P. Microbial heterogeneity affects bioprocess robustness: Dynamic single-cell analysis contributes to understanding of microbial populations. Biotechnol J 2013; 9:61-72. [DOI: 10.1002/biot.201300119] [Citation(s) in RCA: 100] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2013] [Revised: 08/23/2013] [Accepted: 09/12/2013] [Indexed: 12/27/2022]
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25
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Hoppe AD, Scott BL, Welliver TP, Straight SW, Swanson JA. N-way FRET microscopy of multiple protein-protein interactions in live cells. PLoS One 2013; 8:e64760. [PMID: 23762252 PMCID: PMC3675202 DOI: 10.1371/journal.pone.0064760] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2013] [Accepted: 04/17/2013] [Indexed: 11/19/2022] Open
Abstract
Fluorescence Resonance Energy Transfer (FRET) microscopy has emerged as a powerful tool to visualize nanoscale protein-protein interactions while capturing their microscale organization and millisecond dynamics. Recently, FRET microscopy was extended to imaging of multiple donor-acceptor pairs, thereby enabling visualization of multiple biochemical events within a single living cell. These methods require numerous equations that must be defined on a case-by-case basis. Here, we present a universal multispectral microscopy method (N-Way FRET) to enable quantitative imaging for any number of interacting and non-interacting FRET pairs. This approach redefines linear unmixing to incorporate the excitation and emission couplings created by FRET, which cannot be accounted for in conventional linear unmixing. Experiments on a three-fluorophore system using blue, yellow and red fluorescent proteins validate the method in living cells. In addition, we propose a simple linear algebra scheme for error propagation from input data to estimate the uncertainty in the computed FRET images. We demonstrate the strength of this approach by monitoring the oligomerization of three FP-tagged HIV Gag proteins whose tight association in the viral capsid is readily observed. Replacement of one FP-Gag molecule with a lipid raft-targeted FP allowed direct observation of Gag oligomerization with no association between FP-Gag and raft-targeted FP. The N-Way FRET method provides a new toolbox for capturing multiple molecular processes with high spatial and temporal resolution in living cells.
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Affiliation(s)
- Adam D Hoppe
- Department of Chemistry and Biochemistry, South Dakota State University, Brookings, South Dakota, United States of America.
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