1
|
Olesińska-Mönch M, Deo C. Small-molecule photoswitches for fluorescence bioimaging: engineering and applications. Chem Commun (Camb) 2023; 59:660-669. [PMID: 36622788 DOI: 10.1039/d2cc05870g] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Fluorescence microscopy has revolutionised our understanding of biological systems, enabling the visualisation of biomolecular structures and dynamics in complex systems. The possibility to reversibly control the optical or biochemical properties of fluorophores can unlock advanced applications ranging from super-resolution microscopy to the design of multi-stimuli responsive and functional biosensors. In this Highlight, we review recent progress in small-molecule photoswitches applied to biological imaging with an emphasis on molecular engineering strategies and promising applications, while underlining the main challenges in their design and implementation.
Collapse
Affiliation(s)
- Magdalena Olesińska-Mönch
- Cell Biology and Biophysics Unit, European Molecular Biology Laboratory (EMBL), Heidelberg 69117, Germany.
| | - Claire Deo
- Cell Biology and Biophysics Unit, European Molecular Biology Laboratory (EMBL), Heidelberg 69117, Germany.
| |
Collapse
|
2
|
Nienhaus K, Nienhaus GU. Genetically encodable fluorescent protein markers in advanced optical imaging. Methods Appl Fluoresc 2022; 10. [PMID: 35767981 DOI: 10.1088/2050-6120/ac7d3f] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Accepted: 06/29/2022] [Indexed: 11/12/2022]
Abstract
Optical fluorescence microscopy plays a pivotal role in the exploration of biological structure and dynamics, especially on live specimens. Progress in the field relies, on the one hand, on technical advances in imaging and data processing and, on the other hand, on progress in fluorescent marker technologies. Among these, genetically encodable fluorescent proteins (FPs) are invaluable tools, as they allow facile labeling of live cells, tissues or organisms, as these produce the FP markers all by themselves after introduction of a suitable gene. Here we cover FP markers from the GFP family of proteins as well as tetrapyrrole-binding proteins, which further complement the FP toolbox in important ways. A broad range of FP variants have been endowed, by using protein engineering, with photophysical properties that are essential for specific fluorescence microscopy techniques, notably those offering nanoscale image resolution. We briefly introduce various advanced imaging methods and show how they utilize the distinct properties of the FP markers in exciting imaging applications, with the aim to guide researchers toward the design of powerful imaging experiments that are optimally suited to address their biological questions.
Collapse
Affiliation(s)
- Karin Nienhaus
- Institute of Applied Physics, Karlsruhe Institute of Technology, Wolfgang Gaede Str. 1, Karlsruhe, 76131, GERMANY
| | - Gerd Ulrich Nienhaus
- Karlsruhe Institute of Technology, Wolfgang Gaede Str. 1, Karlsruhe, 76131, GERMANY
| |
Collapse
|
3
|
Absolute measurement of cellular activities using photochromic single-fluorophore biosensors and intermittent quantification. Nat Commun 2022; 13:1850. [PMID: 35387971 PMCID: PMC8986857 DOI: 10.1038/s41467-022-29508-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2020] [Accepted: 03/18/2022] [Indexed: 11/20/2022] Open
Abstract
Genetically-encoded biosensors based on a single fluorescent protein are widely used to visualize analyte levels or enzymatic activities in cells, though usually to monitor relative changes rather than absolute values. We report photochromism-enabled absolute quantification (PEAQ) biosensing, a method that leverages the photochromic properties of biosensors to provide an absolute measure of the analyte concentration or activity. We develop proof-of-concept photochromic variants of the popular GCaMP family of Ca2+ biosensors, and show that these can be used to resolve dynamic changes in the absolute Ca2+ concentration in live cells. We also develop intermittent quantification, a technique that combines absolute aquisitions with fast fluorescence acquisitions to deliver fast but fully quantitative measurements. We also show how the photochromism-based measurements can be expanded to situations where the absolute illumination intensities are unknown. In principle, PEAQ biosensing can be applied to other biosensors with photochromic properties, thereby expanding the possibilities for fully quantitative measurements in complex and dynamic systems. Biosensors often report relative rather than absolute values. Here the authors report a method that utilises the photochromic properties of biosensors to provide an absolute measure of the analyte concentration or activity: photochromism-enabled absolute quantification (PEAQ) biosensing.
Collapse
|
4
|
Nienhaus K, Nienhaus GU. Fluorescent proteins of the EosFP clade: intriguing marker tools with multiple photoactivation modes for advanced microscopy. RSC Chem Biol 2021; 2:796-814. [PMID: 34458811 PMCID: PMC8341165 DOI: 10.1039/d1cb00014d] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Accepted: 03/27/2021] [Indexed: 02/04/2023] Open
Abstract
Optical fluorescence microscopy has taken center stage in the exploration of biological structure and dynamics, especially on live specimens, and super-resolution imaging methods continue to deliver exciting new insights into the molecular foundations of life. Progress in the field, however, crucially hinges on advances in fluorescent marker technology. Among these, fluorescent proteins (FPs) of the GFP family are advantageous because they are genetically encodable, so that live cells, tissues or organisms can produce these markers all by themselves. A subclass of them, photoactivatable FPs, allow for control of their fluorescence emission by light irradiation, enabling pulse-chase imaging and super-resolution microscopy. In this review, we discuss FP variants of the EosFP clade that have been optimized by amino acid sequence modification to serve as markers for various imaging techniques. In general, two different modes of photoactivation are found, reversible photoswitching between a fluorescent and a nonfluorescent state and irreversible green-to red photoconversion. First, we describe their basic structural and optical properties. We then summarize recent research aimed at elucidating the photochemical processes underlying photoactivation. Finally, we briefly introduce various advanced imaging methods facilitated by specific EosFP variants, and show some exciting sample applications.
Collapse
Affiliation(s)
- Karin Nienhaus
- Institute of Applied Physics, Karlsruhe Institute of Technology 76049 Karlsruhe Germany
| | - Gerd Ulrich Nienhaus
- Institute of Applied Physics, Karlsruhe Institute of Technology 76049 Karlsruhe Germany
- Institute of Nanotechnology, Karlsruhe Institute of Technology 76021 Karlsruhe Germany
- Institute of Biological and Chemical Systems, Karlsruhe Institute of Technology 76021 Karlsruhe Germany
- Department of Physics, University of Illinois at Urbana-Champaign Urbana IL 61801 USA
| |
Collapse
|
5
|
Fang C, Drobizhev M, Ng HL, Pantazis P. Editorial: Mechanisms of Fluorescent Proteins. Front Mol Biosci 2021; 8:701523. [PMID: 34124168 PMCID: PMC8187757 DOI: 10.3389/fmolb.2021.701523] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Key Words] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2021] [Accepted: 05/10/2021] [Indexed: 11/23/2022] Open
Affiliation(s)
- Chong Fang
- Department of Chemistry, Oregon State University, Corvallis, OR, United States
| | - Mikhail Drobizhev
- Department of Cell Biology and Neuroscience, Montana State University, Bozeman, MT, United States
| | - Ho Leung Ng
- Department of Biochemistry and Molecular Biophysics, Kansas State University, Manhattan, KS, United States
| | - Periklis Pantazis
- Department of Bioengineering, Imperial College London, London, United Kingdom
| |
Collapse
|
6
|
Poddar H, Heyes DJ, Schirò G, Weik M, Leys D, Scrutton NS. A guide to time-resolved structural analysis of light-activated proteins. FEBS J 2021; 289:576-595. [PMID: 33864718 DOI: 10.1111/febs.15880] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Revised: 04/03/2021] [Accepted: 04/13/2021] [Indexed: 01/08/2023]
Abstract
Dynamical changes in protein structures are essential for protein function and occur over femtoseconds to seconds timescales. X-ray free electron lasers have facilitated investigations of structural dynamics in proteins with unprecedented temporal and spatial resolution. Light-activated proteins are attractive targets for time-resolved structural studies, as the reaction chemistry and associated protein structural changes can be triggered by short laser pulses. Proteins with different light-absorbing centres have evolved to detect light and harness photon energy to bring about downstream chemical and biological output responses. Following light absorption, rapid chemical/small-scale structural changes are typically localised around the chromophore. These localised changes are followed by larger structural changes propagated throughout the photoreceptor/photocatalyst that enables the desired chemical and/or biological output response. Time-resolved serial femtosecond crystallography (SFX) and solution scattering techniques enable direct visualisation of early chemical change in light-activated proteins on timescales previously inaccessible, whereas scattering gives access to slower timescales associated with more global structural change. Here, we review how advances in time-resolved SFX and solution scattering techniques have uncovered mechanisms of photochemistry and its coupling to output responses. We also provide a prospective on how these time-resolved structural approaches might impact on other photoreceptors/photoenzymes that have not yet been studied by these methods.
Collapse
Affiliation(s)
- Harshwardhan Poddar
- Manchester Institute of Biotechnology, Department of Chemistry, University of Manchester, UK
| | - Derren J Heyes
- Manchester Institute of Biotechnology, Department of Chemistry, University of Manchester, UK
| | - Giorgio Schirò
- Institut de Biologie Structurale, Univ. Grenoble Alpes, CEA, CNRS, Grenoble, France
| | - Martin Weik
- Institut de Biologie Structurale, Univ. Grenoble Alpes, CEA, CNRS, Grenoble, France
| | - David Leys
- Manchester Institute of Biotechnology, Department of Chemistry, University of Manchester, UK
| | - Nigel S Scrutton
- Manchester Institute of Biotechnology, Department of Chemistry, University of Manchester, UK
| |
Collapse
|
7
|
Cleveland JD, Tucker CL. Photo-SNAP-tag, a Light-Regulated Chemical Labeling System. ACS Chem Biol 2020; 15:2212-2220. [PMID: 32623878 DOI: 10.1021/acschembio.0c00412] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Methods that allow labeling and tracking of proteins have been instrumental for understanding their function. Traditional methods for labeling proteins include fusion to fluorescent proteins or self-labeling chemical tagging systems such as SNAP-tag or Halo-tag. These latter approaches allow bright fluorophores or other chemical moieties to be attached to a protein of interest through a small fusion tag. In this work, we sought to improve the versatility of self-labeling chemical-tagging systems by regulating their activity with light. We used light-inducible dimerizers to reconstitute a split SNAP-tag (modified human O6-alkylguanine-DNA-alkyltransferase, hAGT) protein, allowing tight light-dependent control of chemical labeling. In addition, we generated a small split SNAP-tag fragment that can efficiently self-assemble with its complement fragment, allowing high labeling efficacy with a small tag. We envision these tools will extend the versatility and utility of the SNAP-tag chemical system for protein labeling applications.
Collapse
Affiliation(s)
- Joseph D. Cleveland
- Department of Pharmacology, University of Colorado School of Medicine, Aurora, Colorado 80045, United States
| | - Chandra L. Tucker
- Department of Pharmacology, University of Colorado School of Medicine, Aurora, Colorado 80045, United States
| |
Collapse
|
8
|
Woodhouse J, Nass Kovacs G, Coquelle N, Uriarte LM, Adam V, Barends TRM, Byrdin M, de la Mora E, Bruce Doak R, Feliks M, Field M, Fieschi F, Guillon V, Jakobs S, Joti Y, Macheboeuf P, Motomura K, Nass K, Owada S, Roome CM, Ruckebusch C, Schirò G, Shoeman RL, Thepaut M, Togashi T, Tono K, Yabashi M, Cammarata M, Foucar L, Bourgeois D, Sliwa M, Colletier JP, Schlichting I, Weik M. Photoswitching mechanism of a fluorescent protein revealed by time-resolved crystallography and transient absorption spectroscopy. Nat Commun 2020; 11:741. [PMID: 32029745 PMCID: PMC7005145 DOI: 10.1038/s41467-020-14537-0] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2018] [Accepted: 01/06/2020] [Indexed: 02/08/2023] Open
Abstract
Reversibly switchable fluorescent proteins (RSFPs) serve as markers in advanced fluorescence imaging. Photoswitching from a non-fluorescent off-state to a fluorescent on-state involves trans-to-cis chromophore isomerization and proton transfer. Whereas excited-state events on the ps timescale have been structurally characterized, conformational changes on slower timescales remain elusive. Here we describe the off-to-on photoswitching mechanism in the RSFP rsEGFP2 by using a combination of time-resolved serial crystallography at an X-ray free-electron laser and ns-resolved pump–probe UV-visible spectroscopy. Ten ns after photoexcitation, the crystal structure features a chromophore that isomerized from trans to cis but the surrounding pocket features conformational differences compared to the final on-state. Spectroscopy identifies the chromophore in this ground-state photo-intermediate as being protonated. Deprotonation then occurs on the μs timescale and correlates with a conformational change of the conserved neighbouring histidine. Together with a previous excited-state study, our data allow establishing a detailed mechanism of off-to-on photoswitching in rsEGFP2. rsEGFP2 is a reversibly photoswitchable fluorescent protein used in super-resolution light microscopy. Here the authors present the structure of an rsEGFP2 ground-state intermediate after excited state-decay that was obtained by nanosecond time-resolved serial femtosecond crystallography at an X-ray free electron laser, and time-resolved absorption spectroscopy measurements complement their structural analysis.
Collapse
Affiliation(s)
- Joyce Woodhouse
- Univ. Grenoble Alpes, CEA, CNRS, Institut de Biologie Structurale, F-38000, Grenoble, France
| | - Gabriela Nass Kovacs
- Max-Planck-Institut für medizinische Forschung, Jahnstrasse 29, 69120, Heidelberg, Germany
| | - Nicolas Coquelle
- Univ. Grenoble Alpes, CEA, CNRS, Institut de Biologie Structurale, F-38000, Grenoble, France.,Large-Scale Structures Group, Institut Laue Langevin, 71, avenue des Martyrs, 38042, Grenoble, cedex 9, France
| | - Lucas M Uriarte
- Univ. Lille, CNRS, UMR 8516, LASIR, Laboratoire de Spectrochimie Infrarouge et Raman, F59 000, Lille, France
| | - Virgile Adam
- Univ. Grenoble Alpes, CEA, CNRS, Institut de Biologie Structurale, F-38000, Grenoble, France
| | - Thomas R M Barends
- Max-Planck-Institut für medizinische Forschung, Jahnstrasse 29, 69120, Heidelberg, Germany
| | - Martin Byrdin
- Univ. Grenoble Alpes, CEA, CNRS, Institut de Biologie Structurale, F-38000, Grenoble, France
| | - Eugenio de la Mora
- Univ. Grenoble Alpes, CEA, CNRS, Institut de Biologie Structurale, F-38000, Grenoble, France
| | - R Bruce Doak
- Max-Planck-Institut für medizinische Forschung, Jahnstrasse 29, 69120, Heidelberg, Germany
| | - Mikolaj Feliks
- Department of Chemistry, University of Southern California, Los Angeles, USA
| | - Martin Field
- Univ. Grenoble Alpes, CEA, CNRS, Institut de Biologie Structurale, F-38000, Grenoble, France.,Laboratoire Chimie et Biologie des Métaux, BIG, CEA-Grenoble, Grenoble, France
| | - Franck Fieschi
- Univ. Grenoble Alpes, CEA, CNRS, Institut de Biologie Structurale, F-38000, Grenoble, France
| | - Virginia Guillon
- Univ. Grenoble Alpes, CEA, CNRS, Institut de Biologie Structurale, F-38000, Grenoble, France
| | - Stefan Jakobs
- Department of NanoBiophotonics, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - Yasumasa Joti
- Japan Synchrotron Radiation Research Institute, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo, 679-5198, Japan
| | - Pauline Macheboeuf
- Univ. Grenoble Alpes, CEA, CNRS, Institut de Biologie Structurale, F-38000, Grenoble, France
| | - Koji Motomura
- Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai, 980-8577, Japan
| | - Karol Nass
- Max-Planck-Institut für medizinische Forschung, Jahnstrasse 29, 69120, Heidelberg, Germany
| | | | - Christopher M Roome
- Max-Planck-Institut für medizinische Forschung, Jahnstrasse 29, 69120, Heidelberg, Germany
| | - Cyril Ruckebusch
- Univ. Lille, CNRS, UMR 8516, LASIR, Laboratoire de Spectrochimie Infrarouge et Raman, F59 000, Lille, France
| | - Giorgio Schirò
- Univ. Grenoble Alpes, CEA, CNRS, Institut de Biologie Structurale, F-38000, Grenoble, France
| | - Robert L Shoeman
- Max-Planck-Institut für medizinische Forschung, Jahnstrasse 29, 69120, Heidelberg, Germany
| | - Michel Thepaut
- Univ. Grenoble Alpes, CEA, CNRS, Institut de Biologie Structurale, F-38000, Grenoble, France
| | - Tadashi Togashi
- Japan Synchrotron Radiation Research Institute, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo, 679-5198, Japan
| | - Kensuke Tono
- Japan Synchrotron Radiation Research Institute, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo, 679-5198, Japan
| | | | - Marco Cammarata
- Department of Physics, UMR UR1-CNRS 6251, University of Rennes 1, Rennes, France
| | - Lutz Foucar
- Max-Planck-Institut für medizinische Forschung, Jahnstrasse 29, 69120, Heidelberg, Germany
| | - Dominique Bourgeois
- Univ. Grenoble Alpes, CEA, CNRS, Institut de Biologie Structurale, F-38000, Grenoble, France
| | - Michel Sliwa
- Univ. Lille, CNRS, UMR 8516, LASIR, Laboratoire de Spectrochimie Infrarouge et Raman, F59 000, Lille, France.
| | | | - Ilme Schlichting
- Max-Planck-Institut für medizinische Forschung, Jahnstrasse 29, 69120, Heidelberg, Germany.
| | - Martin Weik
- Univ. Grenoble Alpes, CEA, CNRS, Institut de Biologie Structurale, F-38000, Grenoble, France.
| |
Collapse
|
9
|
Optimizing the fluorescent protein toolbox and its use. Curr Opin Biotechnol 2019; 58:183-191. [DOI: 10.1016/j.copbio.2019.04.006] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2018] [Accepted: 04/24/2019] [Indexed: 01/07/2023]
|
10
|
Correlative cryo super-resolution light and electron microscopy on mammalian cells using fluorescent proteins. Sci Rep 2019; 9:1369. [PMID: 30718653 PMCID: PMC6362030 DOI: 10.1038/s41598-018-37728-8] [Citation(s) in RCA: 83] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2018] [Accepted: 12/12/2018] [Indexed: 11/22/2022] Open
Abstract
Sample fixation by vitrification is critical for the optimal structural preservation of biomolecules and subsequent high-resolution imaging by cryo-correlative light and electron microscopy (cryoCLEM). There is a large resolution gap between cryo fluorescence microscopy (cryoFLM), ~400-nm, and the sub-nanometre resolution achievable with cryo-electron microscopy (cryoEM), which hinders interpretation of cryoCLEM data. Here, we present a general approach to increase the resolution of cryoFLM using cryo-super-resolution (cryoSR) microscopy that is compatible with successive cryoEM investigation in the same region. We determined imaging parameters to avoid devitrification of the cryosamples without the necessity for cryoprotectants. Next, we examined the applicability of various fluorescent proteins (FPs) for single-molecule localisation cryoSR microscopy and found that all investigated FPs display reversible photoswitchable behaviour, and demonstrated cryoSR on lipid nanotubes labelled with rsEGFP2 and rsFastLime. Finally, we performed SR-cryoCLEM on mammalian cells expressing microtubule-associated protein-2 fused to rsEGFP2 and performed 3D cryo-electron tomography on the localised areas. The method we describe exclusively uses commercially available equipment to achieve a localisation precision of 30-nm. Furthermore, all investigated FPs displayed behaviour compatible with cryoSR microscopy, making this technique broadly available without requiring specialised equipment and will improve the applicability of this emerging technique for cellular and structural biology.
Collapse
|
11
|
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.
Collapse
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
| |
Collapse
|
12
|
Wang S, Ding M, Xue B, Hou Y, Sun Y. Spying on protein interactions in living cells with reconstituted scarlet light. Analyst 2018; 143:5161-5169. [PMID: 30255175 DOI: 10.1039/c8an01223g] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The BiFC (bimolecular fluorescence complementation) assay and BiFC combined with FRET (fluorescence resonance energy transfer) technique have become important tools for molecular interaction studies in live cells. However, the real detection and cellular imaging performances of most existing red fluorescent protein-derived BiFC assays still suffer from relatively low ensemble brightness, high cytotoxicity, the red fluorescent proteins being prone-to-aggregation or severe residual dimerization, inefficient complementation and slow maturation at 37 °C physiological temperature in live mammalian cells. We developed a BiFC assay based on a recently evolved truly monomeric red fluorescent protein (FP) mScarlet-I with excellent cellular performances such as low cytotoxicity, fast and efficient chromophore maturation and the highest in-cell brightness among all previously reported monomeric red fluorescent proteins. In this work, a classic β-Fos/β-Jun constitutive heterodimerization model and a rapamycin-inducible FRB/FKBP interaction system were used to establish and test the performance of the mScarlet-I-based BiFC assay in live mammalian cells. Furthermore, simply by adopting the large-Stokes-shift fluorescent protein mAmetrine as the donor, β-Jun-β-Fos-NFAT1 ternary protein complex formation could be readily and efficiently detected and visualized with minimal spectral cross-talk in live HeLa cells by combining live-cell sensitized-emission FRET measurement with the mScarlet-I-based BiFC assay. The currently established BiFC assay in this work was also shown to be able to detect and visualize various protein-protein interactions (PPIs) at different subcellular compartments with high specificity and sensitivity at 37 °C physiological temperature in live mammalian cells.
Collapse
Affiliation(s)
- Sheng Wang
- State Key Laboratory of Membrane Biology, Biomedical pioneering innovation center (BIOPIC), School of Life Sciences, Peking University, Beijing 100871, China.
| | | | | | | | | |
Collapse
|
13
|
Wang S, Chen X, Chang L, Ding M, Xue R, Duan H, Sun Y. GMars-T Enabling Multimodal Subdiffraction Structural and Functional Fluorescence Imaging in Live Cells. Anal Chem 2018; 90:6626-6634. [PMID: 29722976 DOI: 10.1021/acs.analchem.8b00418] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Fluorescent probes with multimodal and multilevel imaging capabilities are highly valuable as imaging with such probes not only can obtain new layers of information but also enable cross-validation of results under different experimental conditions. In recent years, the development of genetically encoded reversibly photoswitchable fluorescent proteins (RSFPs) has greatly promoted the application of various kinds of live-cell nanoscopy approaches, including reversible saturable optical fluorescence transitions (RESOLFT) and stochastic optical fluctuation imaging (SOFI). However, these two classes of live-cell nanoscopy approaches require different optical characteristics of specific RSFPs. In this work, we developed GMars-T, a monomeric bright green RSFP which can satisfy both RESOLFT and photochromic SOFI (pcSOFI) imaging in live cells. We further generated biosensor based on bimolecular fluorescence complementation (BiFC) of GMars-T which offers high specificity and sensitivity in detecting and visualizing various protein-protein interactions (PPIs) in different subcellular compartments under physiological conditions (e.g., 37 °C) in live mammalian cells. Thus, the newly developed GMars-T can serve as both structural imaging probe with multimodal super-resolution imaging capability and functional imaging probe for reporting PPIs with high specificity and sensitivity based on its derived biosensor.
Collapse
Affiliation(s)
- Sheng Wang
- State Key Laboratory of Membrane Biology, Biodynamic Optical Imaging Center (BIOPIC), School of Life Sciences , Peking University , Beijing 100871 , China
| | - Xuanze Chen
- State Key Laboratory of Membrane Biology, Biodynamic Optical Imaging Center (BIOPIC), School of Life Sciences , Peking University , Beijing 100871 , China.,Department of Biomedical Engineering, College of Engineering , Peking University , Beijing 100871 , China.,Cowin Venture Shanghai 200040 , China
| | - Lei Chang
- State Key Laboratory of Membrane Biology, Biodynamic Optical Imaging Center (BIOPIC), School of Life Sciences , Peking University , Beijing 100871 , China
| | - Miao Ding
- State Key Laboratory of Membrane Biology, Biodynamic Optical Imaging Center (BIOPIC), School of Life Sciences , Peking University , Beijing 100871 , China
| | - Ruiying Xue
- State Key Laboratory of Membrane Biology, Biodynamic Optical Imaging Center (BIOPIC), School of Life Sciences , Peking University , Beijing 100871 , China
| | - Haifeng Duan
- State Key Laboratory of Membrane Biology, Biodynamic Optical Imaging Center (BIOPIC), School of Life Sciences , Peking University , Beijing 100871 , China
| | - Yujie Sun
- State Key Laboratory of Membrane Biology, Biodynamic Optical Imaging Center (BIOPIC), School of Life Sciences , Peking University , Beijing 100871 , China
| |
Collapse
|
14
|
Glazachev YI, Orlova DY, Řezníčková P, Bártová E. Effective scheme of photolysis of GFP in live cell as revealed with confocal fluorescence microscopy. Phys Biol 2018; 15:036008. [PMID: 29493532 DOI: 10.1088/1478-3975/aab31e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
We proposed an effective kinetics scheme of photolysis of green fluorescent protein (GFP) observed in live cells with a commercial confocal fluorescence microscope. We investigated the photolysis of GFP-tagged heterochromatin protein, HP1β-GFP, in live nucleus with the pulse position modulation approach, which has several advantages over the classical pump-and-probe method. At the basis of the proposed scheme lies a process of photoswitching from the native fluorescence state to the intermediate fluorescence state, which has a lower fluorescence yield and recovers back to native state in the dark. This kinetics scheme includes four effective parameters (photoswitching, reverse switching, photodegradation rate constants, and relative brightness of the intermediate state) and covers the time scale from dozens of milliseconds to minutes of the experimental fluorescence kinetics. Additionally, the applicability of the scheme was demonstrated in the cases of continuous irradiation and the classical pump-and-probe approach using numerical calculations and analytical solutions. An interesting finding of experimental data analysis was that the overall photodegradation of GFP proceeds dominantly from the intermediate state, and demonstrated approximately the second-order reaction versus irradiation power. As a practical example, the proposed scheme elucidates the artifacts of fluorescence recovery after the photobleaching method, and allows us to propose some suggestions on how to diminish them.
Collapse
Affiliation(s)
- Yu I Glazachev
- Institute of Chemical Kinetics and Combustion, Siberian Branch of Russian academy of Science, Novosibirsk 630090, Russia. Author to whom any correspondence should be addressed
| | | | | | | |
Collapse
|
15
|
Matela G, Gao P, Guigas G, Eckert AF, Nienhaus K, Nienhaus GU. A far-red emitting fluorescent marker protein, mGarnet2, for microscopy and STED nanoscopy. Chem Commun (Camb) 2017; 53:979-982. [PMID: 28044150 DOI: 10.1039/c6cc09081h] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Here we present mGarnet2, a monomeric, far-red fluorescent marker protein derived from mRuby, with absorption and emission bands peaking at 598 and 671 nm, respectively. The protein shows excellent performance as a live-cell fusion marker for STED nanoscopy with 640 nm excitation and 780 nm depletion wavelengths.
Collapse
Affiliation(s)
- Gabriela Matela
- Institute of Applied Physics, Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany
| | - Peng Gao
- Institute of Applied Physics, Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany and Institute of Nanotechnology and Institute of Toxicology and Genetics, Karlsruhe Institute of Technology (KIT), Eggenstein-Leopoldshafen, Germany
| | - Gernot Guigas
- Institute of Applied Physics, Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany
| | - Antonia F Eckert
- Institute of Applied Physics, Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany
| | - Karin Nienhaus
- Institute of Applied Physics, Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany
| | - G U Nienhaus
- Institute of Applied Physics, Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany and Institute of Nanotechnology and Institute of Toxicology and Genetics, Karlsruhe Institute of Technology (KIT), Eggenstein-Leopoldshafen, Germany and Department of Physics, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.
| |
Collapse
|