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Anderson M, Padgett CM, Dargatz CJ, Nichols CR, Vittalam KR, DeVore NM. Engineering a Yellow Thermostable Fluorescent Protein by Rational Design. ACS OMEGA 2023; 8:436-443. [PMID: 36643458 PMCID: PMC9835079 DOI: 10.1021/acsomega.2c05005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Accepted: 11/29/2022] [Indexed: 06/17/2023]
Abstract
Thermal green protein (TGP) is an extremely stable, highly soluble synthetic green fluorescent protein. The quantum yield of TGP is lower than the closest related natural fluorescent protein, monomeric Azami-Green. We improved the thermal recovery of TGP through the introduction of a chromophore mutation, Q66E. Furthermore, we developed a yellow thermal protein (YTP) via mutation of histidine 193 to tyrosine. Incorporation of Q66E into YTP (YTP-E) improved chemostability and pH stability. Both YTP and YTP-E have superior thermostability compared to TGP or TGP-E. These proteins offer a new option for green or yellow fluorescence under harsh chemical or thermal conditions.
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Affiliation(s)
- Matthew
R. Anderson
- Department
of Chemistry and Biochemistry, Missouri
State University, 901 South National Ave, Springfield, Missouri65897, United States
| | - Caitlin M. Padgett
- Department
of Chemistry and Biochemistry, Missouri
State University, 901 South National Ave, Springfield, Missouri65897, United States
| | - Cammi J. Dargatz
- Department
of Chemistry and Biochemistry, Missouri
State University, 901 South National Ave, Springfield, Missouri65897, United States
| | - Calysta R. Nichols
- Department
of Chemistry and Biochemistry, Missouri
State University, 901 South National Ave, Springfield, Missouri65897, United States
| | - Keerti R. Vittalam
- Department
of Chemistry and Biochemistry, Missouri
State University, 901 South National Ave, Springfield, Missouri65897, United States
- Greenwood
Laboratory School, 1024
E. Harrison, Springfield, Missouri65897, United
States
| | - Natasha M. DeVore
- Department
of Chemistry and Biochemistry, Missouri
State University, 901 South National Ave, Springfield, Missouri65897, United States
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2
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Optogenetic Imaging of Protein Activity Using Two-Photon Fluorescence Lifetime Imaging Microscopy. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2021; 1293:295-308. [PMID: 33398821 DOI: 10.1007/978-981-15-8763-4_18] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Spatiotemporal dynamics of cellular proteins, including protein-protein interactions and conformational changes, is essential for understanding cellular functions such as synaptic plasticity, cell motility, and cell division. One of the best ways to understand the mechanisms of signal transduction is to visualize protein activity with high spatiotemporal resolution in living cells within tissues. Optogenetic probes such as fluorescent proteins, in combination with Förster Resonance Energy Transfer (FRET) techniques, enable the measurement of protein-protein interactions and conformational changes in response to signaling events in living cells. Of the various FRET detection systems, two-photon fluorescence lifetime imaging microscopy (2pFLIM) is one of the methods best suited to monitoring FRET in subcellular compartments of living cells located deep within tissues, such as brain slices. This review will introduce the principle of 2pFLIM-FRET and the use of chromoproteins for imaging intracellular protein activities and protein-protein interactions. Also, we will discuss two examples of 2pFLIM-FRET application: imaging actin polymerization in synapses of hippocampal neurons in brain sections and detecting small GTPase Cdc42 activity in astrocytes.
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3
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ShadowR: a novel chromoprotein with reduced non-specific binding and improved expression in living cells. Sci Rep 2019; 9:12072. [PMID: 31427680 PMCID: PMC6700193 DOI: 10.1038/s41598-019-48604-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2019] [Accepted: 08/08/2019] [Indexed: 01/08/2023] Open
Abstract
Here we developed an orange light-absorbing chromoprotein named ShadowR as a novel acceptor for performing fluorescence lifetime imaging microscopy-based Förster resonance energy transfer (FLIM-FRET) measurement in living cells. ShadowR was generated by replacing hydrophobic amino acids located at the surface of the chromoprotein Ultramarine with hydrophilic amino acids in order to reduce non-specific interactions with cytosolic proteins. Similar to Ultramarine, ShadowR shows high absorption capacity and no fluorescence. However, it exhibits reduced non-specific binding to cytosolic proteins and is highly expressed in HeLa cells. Using tandem constructs and a LOVTRAP system, we showed that ShadowR can be used as a FRET acceptor in combination with donor mRuby2 or mScarlet in HeLa cells. Thus, ShadowR is a useful, novel FLIM-FRET acceptor.
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4
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Wang S, Shuai Y, Sun C, Xue B, Hou Y, Su X, Sun Y. Lighting Up Live Cells with Smart Genetically Encoded Fluorescence Probes from GMars Family. ACS Sens 2018; 3:2269-2277. [PMID: 30346738 DOI: 10.1021/acssensors.8b00449] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
As a special kind of delicate light-controllable genetically encoded optical device, reversibly photoswitchable fluorescent proteins (RSFPs) have been widely applied in many fields, especially various kinds of advanced nanoscopy approaches in recent years. However, there are still necessities for exploring novel RSFPs with specific biochemical or photophysical properties not only for bioimaging or biosensing applications but also for fluorescent protein (FP) mechanisms study and further knowledge-based molecular sensors or optical actuators' rational design and evolution. Besides previously reported GMars-Q and GMars-T variants, herein, we reported the development and applications of other RSFPs from GMars family, especially some featured RSFPs with desired optical properties. In the current work, in vitro FP purification, spectra measurements, and live-cell RESOLFT nanoscopy approaches were applied to characterize the basic properties and test the imaging performances of the selected RSFPs. As demonstrated, GMars variants such as GMars-A, GMars-G, or remarkable photofatigue-resistant GMars-L were found with beneficial properties to be capable of parallelized RESOLFT nanoscopy in living cells, while other featured GMars variants such as dark GMars-P may be a good candidate for further biosensor or actuator design and applications.
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Affiliation(s)
- Sheng Wang
- Biomedical Pioneering Innovation Center (BIOPIC), School of Life Sciences, Peking University, Beijing 100871, China
- State Key Laboratory of Membrane Biology, Peking University, Beijing 100871, China
| | - Yao Shuai
- Biomedical Pioneering Innovation Center (BIOPIC), School of Life Sciences, Peking University, Beijing 100871, China
- State Key Laboratory of Protein and Plant Gene Research, Peking University, Beijing 100871, China
| | - Chaoying Sun
- Biomedical Pioneering Innovation Center (BIOPIC), School of Life Sciences, Peking University, Beijing 100871, China
- State Key Laboratory of Membrane Biology, Peking University, Beijing 100871, China
| | - Boxin Xue
- Biomedical Pioneering Innovation Center (BIOPIC), School of Life Sciences, Peking University, Beijing 100871, China
- State Key Laboratory of Membrane Biology, Peking University, Beijing 100871, China
| | - Yingping Hou
- Biomedical Pioneering Innovation Center (BIOPIC), School of Life Sciences, Peking University, Beijing 100871, China
- State Key Laboratory of Membrane Biology, Peking University, Beijing 100871, China
| | - Xiaodong Su
- Biomedical Pioneering Innovation Center (BIOPIC), School of Life Sciences, Peking University, Beijing 100871, China
- State Key Laboratory of Protein and Plant Gene Research, Peking University, Beijing 100871, China
| | - Yujie Sun
- Biomedical Pioneering Innovation Center (BIOPIC), School of Life Sciences, Peking University, Beijing 100871, China
- State Key Laboratory of Membrane Biology, Peking University, Beijing 100871, China
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5
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ShadowY: a dark yellow fluorescent protein for FLIM-based FRET measurement. Sci Rep 2017; 7:6791. [PMID: 28754922 PMCID: PMC5533704 DOI: 10.1038/s41598-017-07002-4] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2017] [Accepted: 06/20/2017] [Indexed: 01/30/2023] Open
Abstract
Fluorescence lifetime imaging microscopy (FLIM)-based Förster resonance energy transfer (FRET) measurement (FLIM-FRET) is one of the powerful methods for imaging of intracellular protein activities such as protein–protein interactions and conformational changes. Here, using saturation mutagenesis, we developed a dark yellow fluorescent protein named ShadowY that can serve as an acceptor for FLIM-FRET. ShadowY is spectrally similar to the previously reported dark YFP but has a much smaller quantum yield, greater extinction coefficient, and superior folding property. When ShadowY was paired with mEGFP or a Clover mutant (CloverT153M/F223R) and applied to a single-molecule FRET sensor to monitor a light-dependent conformational change of the light-oxygen-voltage domain 2 (LOV2) in HeLa cells, we observed a large FRET signal change with low cell-to-cell variability, allowing for precise measurement of individual cell responses. In addition, an application of ShadowY to a separate-type Ras FRET sensor revealed an EGF-dependent large FRET signal increase. Thus, ShadowY in combination with mEGFP or CloverT153M/F223R is a promising FLIM-FRET acceptor.
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6
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Nakahata Y, Nabekura J, Murakoshi H. Dual observation of the ATP-evoked small GTPase activation and Ca 2+ transient in astrocytes using a dark red fluorescent protein. Sci Rep 2016; 6:39564. [PMID: 28004840 PMCID: PMC5177924 DOI: 10.1038/srep39564] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2016] [Accepted: 11/23/2016] [Indexed: 11/22/2022] Open
Abstract
Intracellular signal transduction involves a number of biochemical reactions, which largely consist of protein-protein interactions and protein conformational changes. Monitoring Förster resonance energy transfer (FRET) by fluorescence lifetime imaging microscopy (FLIM), called FLIM-FRET, is one of the best ways to visualize such protein dynamics. Here, we attempted to apply dark red fluorescent proteins with significantly smaller quantum yields. Application of the dark mCherry mutants to single-molecule FRET sensors revealed that these dark mCherry mutants are a good acceptor in a pair with mRuby2. Because the FRET measurement between mRuby2 and dark mCherry requires only the red region of wavelengths, it facilitates dual observation with other signaling sensors such as genetically encoded Ca2+ sensors. Taking advantage of this approach, we attempted dual observation of Ca2+ and Rho GTPase (RhoA and Cdc42) activities in astrocytes and found that ATP triggers both RhoA and Cdc42 activation. In early phase, while Cdc42 activity is independent of Ca2+ transient evoked by ATP, RhoA activity is Ca2+ dependent. Moreover, the transient Ca2+ upregulation triggers long-lasting Cdc42 and RhoA activities, thereby converting short-term Ca2+ signaling to long-term signaling. Thus, the new FRET pair should be useful for dual observation of intracellular biochemical reactions.
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Affiliation(s)
- Yoshihisa Nakahata
- Division of Homeostatic Development, National Institute for Physiological Sciences, Okazaki, Aichi 444-8585, Japan
| | - Junichi Nabekura
- Division of Homeostatic Development, National Institute for Physiological Sciences, Okazaki, Aichi 444-8585, Japan
- Department of Physiological Sciences, The Graduate University for Advanced Studies (SOKENDAI), Okazaki, Aichi 444-8585, Japan
- Core Research for Evolutional Science and Technology, Japan Science and Technology Agency (JST), Kawaguchi, Saitama 332-0012, Japan
| | - Hideji Murakoshi
- Department of Physiological Sciences, The Graduate University for Advanced Studies (SOKENDAI), Okazaki, Aichi 444-8585, Japan
- Supportive Center for Brain Research, National Institute for Physiological Sciences, Okazaki, Aichi 444-8585, Japan
- Precursory Research for Embryonic Science and Technology, Japan Science and Technology Agency (JST), Kawaguchi, Saitama 332-0012, Japan
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7
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A Guide to Fluorescent Protein FRET Pairs. SENSORS 2016; 16:s16091488. [PMID: 27649177 PMCID: PMC5038762 DOI: 10.3390/s16091488] [Citation(s) in RCA: 272] [Impact Index Per Article: 34.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/21/2016] [Revised: 08/23/2016] [Accepted: 08/25/2016] [Indexed: 12/20/2022]
Abstract
Förster or fluorescence resonance energy transfer (FRET) technology and genetically encoded FRET biosensors provide a powerful tool for visualizing signaling molecules in live cells with high spatiotemporal resolution. Fluorescent proteins (FPs) are most commonly used as both donor and acceptor fluorophores in FRET biosensors, especially since FPs are genetically encodable and live-cell compatible. In this review, we will provide an overview of methods to measure FRET changes in biological contexts, discuss the palette of FP FRET pairs developed and their relative strengths and weaknesses, and note important factors to consider when using FPs for FRET studies.
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8
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Murakoshi H, Shibata ACE, Nakahata Y, Nabekura J. A dark green fluorescent protein as an acceptor for measurement of Förster resonance energy transfer. Sci Rep 2015; 5:15334. [PMID: 26469148 PMCID: PMC4606784 DOI: 10.1038/srep15334] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2015] [Accepted: 09/23/2015] [Indexed: 01/31/2023] Open
Abstract
Measurement of Förster resonance energy transfer by fluorescence lifetime imaging microscopy (FLIM-FRET) is a powerful method for visualization of intracellular signaling activities such as protein-protein interactions and conformational changes of proteins. Here, we developed a dark green fluorescent protein (ShadowG) that can serve as an acceptor for FLIM-FRET. ShadowG is spectrally similar to monomeric enhanced green fluorescent protein (mEGFP) and has a 120-fold smaller quantum yield. When FRET from mEGFP to ShadowG was measured using an mEGFP-ShadowG tandem construct with 2-photon FLIM-FRET, we observed a strong FRET signal with low cell-to-cell variability. Furthermore, ShadowG was applied to a single-molecule FRET sensor to monitor a conformational change of CaMKII and of the light oxygen voltage (LOV) domain in HeLa cells. These sensors showed reduced cell-to-cell variability of both the basal fluorescence lifetime and response signal. In contrast to mCherry- or dark-YFP-based sensors, our sensor allowed for precise measurement of individual cell responses. When ShadowG was applied to a separate-type Ras FRET sensor, it showed a greater response signal than did the mCherry-based sensor. Furthermore, Ras activation and translocation of its effector ERK2 into the nucleus could be observed simultaneously. Thus, ShadowG is a promising FLIM-FRET acceptor.
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Affiliation(s)
- Hideji Murakoshi
- Supportive Center for Brain Research, National Institute for Physiological Sciences, Okazaki, Aichi 444-8585, Japan
- Department of Physiological Sciences, SOKENDAI (The Graduate University for Advanced Studies), Okazaki, Aichi 444-8585, Japan
- Precursory Research for Embryonic Science and Technology, Japan Science and Technology Agency (JST), Kawaguchi, Saitama 332-0012, Japan
| | - Akihiro C. E. Shibata
- Supportive Center for Brain Research, National Institute for Physiological Sciences, Okazaki, Aichi 444-8585, Japan
| | - Yoshihisa Nakahata
- Division of Homeostatic Development, National Institute for Physiological Sciences, Okazaki, Aichi 444-8585, Japan
| | - Junichi Nabekura
- Department of Physiological Sciences, SOKENDAI (The Graduate University for Advanced Studies), Okazaki, Aichi 444-8585, Japan
- Division of Homeostatic Development, National Institute for Physiological Sciences, Okazaki, Aichi 444-8585, Japan
- Core Research for Evolutional Science and Technology, Japan Science and Technology Agency (JST), Kawaguchi, Saitama 332-0012, Japan
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9
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Close DW, Don Paul C, Langan PS, Wilce MC, Traore DA, Halfmann R, Rocha RC, Waldo GS, Payne RJ, Rucker JB, Prescott M, Bradbury AR. Thermal green protein, an extremely stable, nonaggregating fluorescent protein created by structure-guided surface engineering. Proteins 2015; 83:1225-37. [PMID: 25287913 PMCID: PMC4592778 DOI: 10.1002/prot.24699] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2014] [Revised: 09/16/2014] [Accepted: 09/27/2014] [Indexed: 01/27/2023]
Abstract
In this article, we describe the engineering and X-ray crystal structure of Thermal Green Protein (TGP), an extremely stable, highly soluble, non-aggregating green fluorescent protein. TGP is a soluble variant of the fluorescent protein eCGP123, which despite being highly stable, has proven to be aggregation-prone. The X-ray crystal structure of eCGP123, also determined within the context of this paper, was used to carry out rational surface engineering to improve its solubility, leading to TGP. The approach involved simultaneously eliminating crystal lattice contacts while increasing the overall negative charge of the protein. Despite intentional disruption of lattice contacts and introduction of high entropy glutamate side chains, TGP crystallized readily in a number of different conditions and the X-ray crystal structure of TGP was determined to 1.9 Å resolution. The structural reasons for the enhanced stability of TGP and eCGP123 are discussed. We demonstrate the utility of using TGP as a fusion partner in various assays and significantly, in amyloid assays in which the standard fluorescent protein, EGFP, is undesirable because of aberrant oligomerization.
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Affiliation(s)
- Devin W. Close
- Bioscience Division, Los Alamos National Laboratory, Los Alamos, NM, USA
- Center for Integrated Nanotechnologies, Los Alamos National Laboratory, Los Alamos, NM, USA
| | - Craig Don Paul
- Department of Biochemistry and Molecular Biology, Monash University, Clayton Campus, Melbourne, Victoria, Australia
| | - Patricia S. Langan
- Bioscience Division, Los Alamos National Laboratory, Los Alamos, NM, USA
| | - Matthew C.J. Wilce
- Department of Biochemistry and Molecular Biology, Monash University, Clayton Campus, Melbourne, Victoria, Australia
| | - Daouda A.K. Traore
- Department of Biochemistry and Molecular Biology, Monash University, Clayton Campus, Melbourne, Victoria, Australia
| | - Randal Halfmann
- Department of Biochemistry, UT Southwestern Medical Center, Dallas, TX, USA
| | - Reginaldo C. Rocha
- Center for Integrated Nanotechnologies, Los Alamos National Laboratory, Los Alamos, NM, USA
| | - Geoffery S. Waldo
- Bioscience Division, Los Alamos National Laboratory, Los Alamos, NM, USA
| | | | | | - Mark Prescott
- Department of Biochemistry and Molecular Biology, Monash University, Clayton Campus, Melbourne, Victoria, Australia
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Don Paul C, Traore DAK, Olsen S, Devenish RJ, Close DW, Bell TDM, Bradbury A, Wilce MCJ, Prescott M. X-Ray Crystal Structure and Properties of Phanta, a Weakly Fluorescent Photochromic GFP-Like Protein. PLoS One 2015; 10:e0123338. [PMID: 25923520 PMCID: PMC4414407 DOI: 10.1371/journal.pone.0123338] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2014] [Accepted: 03/02/2015] [Indexed: 01/07/2023] Open
Abstract
Phanta is a reversibly photoswitching chromoprotein (ΦF, 0.003), useful for pcFRET, that was isolated from a mutagenesis screen of the bright green fluorescent eCGP123 (ΦF, 0.8). We have investigated the contribution of substitutions at positions His193, Thr69 and Gln62, individually and in combination, to the optical properties of Phanta. Single amino acid substitutions at position 193 resulted in proteins with very low ΦF, indicating the importance of this position in controlling the fluorescence efficiency of the variant proteins. The substitution Thr69Val in Phanta was important for supressing the formation of a protonated chromophore species observed in some His193 substituted variants, whereas the substitution Gln62Met did not significantly contribute to the useful optical properties of Phanta. X-ray crystal structures for Phanta (2.3 Å), eCGP123T69V (2.0 Å) and eCGP123H193Q (2.2 Å) in their non-photoswitched state were determined, revealing the presence of a cis-coplanar chromophore. We conclude that changes in the hydrogen-bonding network supporting the cis-chromophore, and its contacts with the surrounding protein matrix, are responsible for the low fluorescence emission of eCGP123 variants containing a His193 substitution.
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Affiliation(s)
- Craig Don Paul
- Department of Neuro- and Sensory Physiology, University Medicine, Göttingen, 37073, Göttingen, Germany
| | - Daouda A. K. Traore
- Department of Biochemistry and Molecular Biology, School of Biomedical Sciences, Monash University, Clayton campus, Victoria, 3800, Australia
| | - Seth Olsen
- School of Mathematics and Physics, The University of Queensland, Brisbane, Queensland, 4072, Australia
| | - Rodney J. Devenish
- Department of Biochemistry and Molecular Biology, School of Biomedical Sciences, Monash University, Clayton campus, Victoria, 3800, Australia
| | - Devin W. Close
- Bioscience Division, Los Alamos National Laboratory, Los Alamos, NM, 87545, United States of America
| | - Toby D. M. Bell
- School of Chemistry, Monash University, Clayton campus, Victoria, 3800, Australia
| | - Andrew Bradbury
- Bioscience Division, Los Alamos National Laboratory, Los Alamos, NM, 87545, United States of America
| | - Matthew C. J. Wilce
- Department of Biochemistry and Molecular Biology, School of Biomedical Sciences, Monash University, Clayton campus, Victoria, 3800, Australia
- * E-mail: (MP); (MCJW)
| | - Mark Prescott
- Department of Biochemistry and Molecular Biology, School of Biomedical Sciences, Monash University, Clayton campus, Victoria, 3800, Australia
- * E-mail: (MP); (MCJW)
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11
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Ebrecht R, Don Paul C, Wouters FS. Fluorescence lifetime imaging microscopy in the medical sciences. PROTOPLASMA 2014; 251:293-305. [PMID: 24390249 DOI: 10.1007/s00709-013-0598-4] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/04/2013] [Accepted: 12/12/2013] [Indexed: 06/03/2023]
Abstract
The steady improvement in the imaging of cellular processes in living tissue over the last 10-15 years through the use of various fluorophores including organic dyes, fluorescent proteins and quantum dots, has made observing biological events common practice. Advances in imaging and recording technology have made it possible to exploit a fluorophore's fluorescence lifetime. The fluorescence lifetime is an intrinsic parameter that is unique for each fluorophore, and that is highly sensitive to its immediate environment and/or the photophysical coupling to other fluorophores by the phenomenon Förster resonance energy transfer (FRET). The fluorescence lifetime has become an important tool in the construction of optical bioassays for various cellular activities and reactions. The measurement of the fluorescence lifetime is possible in two formats; time domain or frequency domain, each with their own advantages. Fluorescence lifetime imaging applications have now progressed to a state where, besides their utility in cell biological research, they can be employed as clinical diagnostic tools. This review highlights the multitude of fluorophores, techniques and clinical applications that make use of fluorescence lifetime imaging microscopy (FLIM).
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Affiliation(s)
- René Ebrecht
- Department of Neuro- and Sensory Physiology, University Medicine Göttingen, 37073, Göttingen, Germany
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12
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Adam V. Phototransformable fluorescent proteins: which one for which application? Histochem Cell Biol 2014; 142:19-41. [PMID: 24522394 DOI: 10.1007/s00418-014-1190-5] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/24/2014] [Indexed: 01/10/2023]
Abstract
In these last two decades , fluorescent proteins (FPs) have become highly valued imaging tools for cell biology, owing to their compatibility with living samples, their low levels of invasiveness and the possibility to specifically fuse them to a variety of proteins of interest. Remarkably, the recent development of phototransformable fluorescent proteins (PTFPs) has made it possible to conceive optical imaging experiments that were unimaginable only a few years ago. For example, it is nowadays possible to monitor intra- or intercellular trafficking, to optically individualize single cells in tissues or to observe single molecules in live cells. The tagging specificity brought by these genetically encoded highlighters leads to constant progress in the engineering of increasingly powerful, versatile and non-cytotoxic FPs. This review is focused on the recent developments of PTFPs and highlights their contribution to studies within cells, tissues and even living organisms. The aspects of single-molecule localization microscopy, intracellular tracking of photoactivated molecules, applications of PTFPs in biotechnology/optobiology and complementarities between PTFPs and other microscopy techniques are particularly discussed.
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Affiliation(s)
- Virgile Adam
- Institut de Biologie Structurale (IBS), Univ. Grenoble Alpes, F-38000, Grenoble, France,
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13
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Abstract
An engineered fluorescent protein exhibits visibly striking photochromism and thermochromism under ambient conditions.
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Affiliation(s)
- Y. Shen
- Department of Chemistry
- University of Alberta
- Edmonton, Canada
| | - M. D. Wiens
- Department of Chemistry
- University of Alberta
- Edmonton, Canada
| | - R. E. Campbell
- Department of Chemistry
- University of Alberta
- Edmonton, Canada
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