1
|
Fritze JS, Stiehler FF, Wolfrum U. Pathogenic Variants in USH1G/SANS Alter Protein Interaction with Pre-RNA Processing Factors PRPF6 and PRPF31 of the Spliceosome. Int J Mol Sci 2023; 24:17608. [PMID: 38139438 PMCID: PMC10744108 DOI: 10.3390/ijms242417608] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2023] [Revised: 12/08/2023] [Accepted: 12/12/2023] [Indexed: 12/24/2023] Open
Abstract
Pre-mRNA splicing is an essential process orchestrated by the spliceosome, a dynamic complex assembled stepwise on pre-mRNA. We have previously identified that USH1G protein SANS regulates pre-mRNA splicing by mediating the intranuclear transfer of the spliceosomal U4/U6.U5 tri-snRNP complex. During this process, SANS interacts with the U4/U6 and U5 snRNP-specific proteins PRPF31 and PRPF6 and regulates splicing, which is disturbed by variants of USH1G/SANS causative for human Usher syndrome (USH), the most common form of hereditary deaf-blindness. Here, we aim to gain further insights into the molecular interaction of the splicing molecules PRPF31 and PRPF6 to the CENTn domain of SANS using fluorescence resonance energy transfer assays in cells and in silico deep learning-based protein structure predictions. This demonstrates that SANS directly binds via two distinct conserved regions of its CENTn to the two PRPFs. In addition, we provide evidence that these interactions occur sequentially and a conformational change of an intrinsically disordered region to a short α-helix of SANS CENTn2 is triggered by the binding of PRPF6. Furthermore, we find that pathogenic variants of USH1G/SANS perturb the binding of SANS to both PRPFs, implying a significance for the USH1G pathophysiology.
Collapse
Affiliation(s)
| | | | - Uwe Wolfrum
- Institute of Molecular Physiology, Johannes Gutenberg University Mainz, 55128 Mainz, Germany; (J.S.F.)
| |
Collapse
|
2
|
Semalti P, Sharma V, Devi M, Prathap P, Upadhyay NK, Sharma SN. Surface engineering of colloidal quaternary chalcogenide Cu 2ZnSnS 4 nanocrystals: a potential low-cost photocatalyst for water remediation. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2023; 30:79774-79788. [PMID: 36997778 DOI: 10.1007/s11356-023-26603-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/17/2022] [Accepted: 03/18/2023] [Indexed: 06/19/2023]
Abstract
Colloidal route synthesis of quaternary compound CZTS (Cu2ZnSnS4) has been anticipated with an inimitable combination of coordinating ligands and solvents using the hot injection technique. CZTS is recognized as one of the worthiest materials for photo-voltaic/catalytic applications due to its exclusive properties (viz., non-toxic, economical, direct bandgap, high absorbance coefficient, etc.). This paper demonstrates the formation of crystalline, single-phased, monodispersed, and electrically passivated CZTS nanoparticles using a distinctive combination of ligands viz. oleic acid (OA)-trioctylphosphine (TOP) and butylamine (BA)-trioctylphosphine (TOP). Detailed optical, structural, and electrochemical studies were done for all CZTS nanoparticles, and the most efficient composition was found using ligands butylamine and TOP. CZTS nanocrystals were rendered hydrophilic via surface-ligand engineering, which was used for photocatalysis studies of organic pollutants. Malachite green (MG) and rhodamine 6G (Rh) for water remediation have great commercial prospects. The unique selling proposition of this work is the rapid synthesis time (~ 45 min) of colloidal CZTS nanocrystals, cost-effective ligand-exchange process, and negligible material wastage (~ 200 µl per 10 ml of pollutant) during photocatalytic experiments.
Collapse
Affiliation(s)
- Pooja Semalti
- CSIR-National Physical Laboratory, Dr. K.S. Krishnan Marg, New Delhi, 110012, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India
| | - Vikash Sharma
- CSIR-National Physical Laboratory, Dr. K.S. Krishnan Marg, New Delhi, 110012, India
| | - Meenakshi Devi
- CSIR-National Physical Laboratory, Dr. K.S. Krishnan Marg, New Delhi, 110012, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India
| | - Pathi Prathap
- CSIR-National Physical Laboratory, Dr. K.S. Krishnan Marg, New Delhi, 110012, India
| | | | - Shailesh Narain Sharma
- CSIR-National Physical Laboratory, Dr. K.S. Krishnan Marg, New Delhi, 110012, India.
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India.
| |
Collapse
|
3
|
Feng W, Huang Y, Zhao Y, Tian W, Yan H. Water-Soluble Cationic Eu 3+-Metallopolymer with High Quantum Yield and Sensitivity for Intracellular Temperature Sensing. ACS APPLIED MATERIALS & INTERFACES 2023; 15:17211-17221. [PMID: 36859768 DOI: 10.1021/acsami.3c00478] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Lanthanide-based (Ln3+) luminescent materials are ideal candidates for use in fluorescence intracellular temperature sensing. However, it remains a great challenge to obtain a Ln3+-ratiometric fluorescence thermometer with high sensitivity and quantum yield in an aqueous environment. Herein, a cationic Eu3+-metallopolymer was synthesized via the coordination of Eu(TTA)3·2H2O with an AIE active amphipathic polymer backbone that contains APTMA ((3-acrylamidopropyl) trimethylammonium) and NIPAM (N-isopropylacrylamide) units, which can self-assemble into nanoparticles in water solution with APTMA and NIPAM as the hydrophilic shell. This polymer exhibited highly efficient dual-emissive white-light emission (Φ = 34.3%). Particularly, when the temperature rises, the NIPAM units will transform from hydrophilic to hydrophobic in the spherical core of the nanoparticle, while the VTPE units are moved from inside the nanoparticle to the shell, activating its nonradiative transition channel and thereby decreasing its energy transfer to Eu3+ centers, endowing the Eu3+-metallopolymer with an extremely high temperature sensing sensitivity within the physiological temperature range. Finally, the real-time monitoring of the intracellular temperature variation is further conducted.
Collapse
Affiliation(s)
- Weixu Feng
- Xi'an Key Laboratory of Hybrid Luminescent Materials and Photonic Device, School of Chemistry and Chemical engineering, Northwestern Polytechnical University, Xi'an 710129, Shaanxi, China
- Research & Development Institute of Northwestern Polytechnical University in Shenzhen, Shenzhen 518057, China
| | - Yujuan Huang
- Xi'an Key Laboratory of Hybrid Luminescent Materials and Photonic Device, School of Chemistry and Chemical engineering, Northwestern Polytechnical University, Xi'an 710129, Shaanxi, China
| | - Yan Zhao
- Xi'an Key Laboratory of Hybrid Luminescent Materials and Photonic Device, School of Chemistry and Chemical engineering, Northwestern Polytechnical University, Xi'an 710129, Shaanxi, China
| | - Wei Tian
- Xi'an Key Laboratory of Hybrid Luminescent Materials and Photonic Device, School of Chemistry and Chemical engineering, Northwestern Polytechnical University, Xi'an 710129, Shaanxi, China
| | - Hongxia Yan
- Xi'an Key Laboratory of Hybrid Luminescent Materials and Photonic Device, School of Chemistry and Chemical engineering, Northwestern Polytechnical University, Xi'an 710129, Shaanxi, China
| |
Collapse
|
4
|
Hu Z, Li Y, Figueroa-Miranda G, Musal S, Li H, Martínez-Roque MA, Hu Q, Feng L, Mayer D, Offenhäusser A. Aptamer based biosensor platforms for neurotransmitters analysis. Trends Analyt Chem 2023. [DOI: 10.1016/j.trac.2023.117021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/16/2023]
|
5
|
Unraveling the hidden temporal range of fast β 2-adrenergic receptor mobility by time-resolved fluorescence. Commun Biol 2022; 5:176. [PMID: 35228644 PMCID: PMC8885909 DOI: 10.1038/s42003-022-03106-4] [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: 06/02/2021] [Accepted: 02/02/2022] [Indexed: 12/29/2022] Open
Abstract
G-protein-coupled receptors (GPCRs) are hypothesized to possess molecular mobility over a wide temporal range. Until now the temporal range has not been fully accessible due to the crucially limited temporal range of available methods. This in turn, may lead relevant dynamic constants to remain masked. Here, we expand this dynamic range by combining fluorescent techniques using a spot confocal setup. We decipher mobility constants of β2-adrenergic receptor over a wide time range (nanosecond to second). Particularly, a translational mobility (10 µm²/s), one order of magnitude faster than membrane associated lateral mobility that explains membrane protein turnover and suggests a wider picture of the GPCR availability on the plasma membrane. And a so far elusive rotational mobility (1-200 µs) which depicts a previously overlooked dynamic component that, despite all complexity, behaves largely as predicted by the Saffman-Delbrück model. The mobility of the β2-adrenergic receptor, from the nanosecond to the second range, is revealed by combining several fluorescent spectroscopy techniques. These data also show a previously hidden mobility of this GPCR.
Collapse
|
6
|
Gallardo-Villagrán M, Paulus L, Charissoux JL, Leger DY, Vergne-Salle P, Therrien B, Liagre B. Ruthenium-based assemblies incorporating tetrapyridylporphyrin panels: a photosensitizer delivery strategy for the treatment of rheumatoid arthritis by photodynamic therapy. Dalton Trans 2022; 51:9673-9680. [DOI: 10.1039/d2dt00917j] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Ruthenium-based assemblies containing tetrapyridylporphyrin derivatives in their structures have been evaluated as photosensitizers to treat rheumatoid arthritis by photodynamic therapy.
Collapse
Affiliation(s)
- Manuel Gallardo-Villagrán
- Institut de Chimie, Université de Neuchâtel, Avenue de Bellevaux 51, CH-2000 Neuchâtel, Switzerland
- Université de Limoges, Laboratoire PEIRENE UR 22722, Faculté de Pharmacie, F-87025 Limoges, France
| | - Lucie Paulus
- Université de Limoges, Laboratoire PEIRENE UR 22722, Faculté de Pharmacie, F-87025 Limoges, France
| | - Jean-Louis Charissoux
- Service d'Orthopédie-Traumatologie, CHRU Dupuytren, 2 avenue Martin Luther King, 87042 Limoges Cedex, France
| | - David Yannick Leger
- Université de Limoges, Laboratoire PEIRENE UR 22722, Faculté de Pharmacie, F-87025 Limoges, France
| | - Pascale Vergne-Salle
- Service de Rhumatologie, CHRU Dupuytren 2, 16 rue Bernard Descottes, 87042 Limoges Cedex, France
| | - Bruno Therrien
- Institut de Chimie, Université de Neuchâtel, Avenue de Bellevaux 51, CH-2000 Neuchâtel, Switzerland
| | - Bertrand Liagre
- Université de Limoges, Laboratoire PEIRENE UR 22722, Faculté de Pharmacie, F-87025 Limoges, France
| |
Collapse
|
7
|
Li Y, Zhou Y, Yao Y, Gao T, Yan P, Li H. White-light emission from the quadruple-stranded dinuclear Eu( iii) helicate decorated with pendent tetraphenylethylene (TPE). NEW J CHEM 2021. [DOI: 10.1039/d1nj00700a] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The hybrid film doped with a quadruple-stranded Eu3+ helicate displayed tuneable emission and white light.
Collapse
Affiliation(s)
- Yuying Li
- Key Laboratory of Functional Inorganic Material Chemistry
- Ministry of Education
- P. R. China
- School of Chemistry and Materials Science
- Heilongjiang University
| | - Yanyan Zhou
- Key Laboratory of Functional Inorganic Material Chemistry
- Ministry of Education
- P. R. China
- School of Chemistry and Materials Science
- Heilongjiang University
| | - Yuan Yao
- Key Laboratory of Functional Inorganic Material Chemistry
- Ministry of Education
- P. R. China
- School of Chemistry and Materials Science
- Heilongjiang University
| | - Ting Gao
- Key Laboratory of Functional Inorganic Material Chemistry
- Ministry of Education
- P. R. China
- School of Chemistry and Materials Science
- Heilongjiang University
| | - Pengfei Yan
- Key Laboratory of Functional Inorganic Material Chemistry
- Ministry of Education
- P. R. China
- School of Chemistry and Materials Science
- Heilongjiang University
| | - Hongfeng Li
- Key Laboratory of Functional Inorganic Material Chemistry
- Ministry of Education
- P. R. China
- School of Chemistry and Materials Science
- Heilongjiang University
| |
Collapse
|
8
|
Bednarkiewicz A, Chan EM, Prorok K. Enhancing FRET biosensing beyond 10 nm with photon avalanche nanoparticles. NANOSCALE ADVANCES 2020; 2:4863-4872. [PMID: 36132913 PMCID: PMC9417941 DOI: 10.1039/d0na00404a] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Accepted: 08/12/2020] [Indexed: 05/24/2023]
Abstract
Förster Resonance Energy Transfer (FRET) between donor (D) and acceptor (A) molecules is a phenomenon commonly exploited to study or visualize biological interactions at the molecular level. However, commonly used organic D and A molecules often suffer from photobleaching and spectral bleed-through, and their spectral properties hinder quantitative analysis. Lanthanide-doped upconverting nanoparticles (UCNPs) as alternative D species offer significant improvements in terms of photostability, spectral purity and background-free luminescence detection, but they bring new challenges related to multiple donor ions existing in a single large size UCNP and the need for nanoparticle biofunctionalization. Considering the relatively short Förster distance (typically below 5-7 nm), it becomes a non-trivial task to assure sufficiently strong D-A interaction, which translates directly to the sensitivity of such bio-sensors. In this work we propose a solution to these issues, which employs the photon avalanche (PA) phenomenon in lanthanide-doped materials. Using theoretical modelling, we predict that these PA systems would be highly susceptible to the presence of A and that the estimated sensitivity range extends to distances 2 to 4 times longer (i.e. 10-25 nm) than those typically found in conventional FRET systems. This promises high sensitivity, low background and spectral or temporal biosensing, and provides the basis for a radically novel approach to combine luminescence imaging and self-normalized bio-molecular interaction sensing.
Collapse
Affiliation(s)
- Artur Bednarkiewicz
- Institute of Low Temperature and Structure Research, Polish Academy of Sciences Okolna 2 50-422 Wroclaw Poland
| | - Emory M Chan
- The Molecular Foundry, Lawrence Berkeley National Laboratory Berkeley CA 94720 USA
| | - Katarzyna Prorok
- Institute of Low Temperature and Structure Research, Polish Academy of Sciences Okolna 2 50-422 Wroclaw Poland
| |
Collapse
|
9
|
Kinashi K, Tsuchida H, Sakai W, Tsutsumi N. Theoretical Limit of the Color-Change Sensitivity of a Composite Resin Dosimeter Film Based on Spiropyran/BaFCl : Eu 2+/Polystyrene. ChemistryOpen 2020; 9:623-627. [PMID: 32489767 PMCID: PMC7253063 DOI: 10.1002/open.202000071] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2020] [Revised: 05/05/2020] [Indexed: 11/08/2022] Open
Abstract
The theoretical limit of the color-change sensitivity of a composite resin dosimeter film based on 6-nitro BIPS/BaFCl : Eu2+/polystyrene under X-ray exposure has been estimated. Each photophysical and photochemical process occurring inside the composite resin dosimeter was quantitatively determined, and the obtained values were used to estimate the theoretical limit of the color-change sensitivity for the composite resin dosimeter. The values obtained were 70.6 % for the X-ray absorption efficiency, 13 % for the fluorescence quantum yield, 73.5 % for the UV absorption efficiency and 37.6 % for the photochemical quantum yield. Assuming that the figure-of-merit is their product, its value is estimated to be 2.5 %, which contributes to the chromaticity difference and leads to a color-change sensitivity of 100 mGy. The figure-of-merit of a structurally optimized composite dosimeter was estimated to be 1.9 times that of the dosimeter without structural optimization, which showed a sensitivity of 100 mGy. We predicted that the structurally optimized composite resin dosimeter film, which eliminates optical losses due to the structure, will be able to detect X-ray exposure doses on the order of approximately 28 mGy.
Collapse
Affiliation(s)
- Kenji Kinashi
- Faculty of Materials Science and EngineeringKyoto Institute of Technology MatsugasakiSakyo, Kyoto606-8585Japan
| | - Hayato Tsuchida
- Master's Program of Innovative MaterialsGraduate School of Science and TechnologyKyoto Institute of Technology MatsugasakiSakyo, Kyoto606-8585Japan
| | - Wataru Sakai
- Faculty of Materials Science and EngineeringKyoto Institute of Technology MatsugasakiSakyo, Kyoto606-8585Japan
| | - Naoto Tsutsumi
- Faculty of Materials Science and EngineeringKyoto Institute of Technology MatsugasakiSakyo, Kyoto606-8585Japan
| |
Collapse
|
10
|
Rastogi A, Pandey FP, Hegde G, Manohar R. Time-resolved fluorescence and UV absorbance study on Elaeis guineensis/oil palm leaf based carbon nanoparticles doped in nematic liquid crystals. J Mol Liq 2020. [DOI: 10.1016/j.molliq.2020.112773] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
|
11
|
Baibakov M, Patra S, Claude JB, Wenger J. Long-Range Single-Molecule Förster Resonance Energy Transfer between Alexa Dyes in Zero-Mode Waveguides. ACS OMEGA 2020; 5:6947-6955. [PMID: 32258931 PMCID: PMC7114734 DOI: 10.1021/acsomega.0c00322] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/23/2020] [Accepted: 03/05/2020] [Indexed: 06/11/2023]
Abstract
Zero-mode waveguide (ZMW) nano-apertures milled in metal films were proposed to improve the Förster resonance energy transfer (FRET) efficiency and enable single-molecule FRET detection beyond the 10 nm barrier, overcoming the restrictions of diffraction-limited detection in a homogeneous medium. However, the earlier ZMW demonstrations were limited to the Atto 550-Atto 647N fluorophore pair, asking the question whether the FRET enhancement observation was an artifact related to this specific set of fluorescent dyes. Here, we use Alexa Fluor 546 and Alexa Fluor 647 to investigate single-molecule FRET at large donor-acceptor separations exceeding 10 nm inside ZMWs. These Alexa fluorescent dyes feature a markedly different chemical structure, surface charge, and hydrophobicity as compared to their Atto counterparts. Our single molecule data on Alexa 546-Alexa 647 demonstrate enhanced FRET efficiencies at large separations exceeding 10 nm, extending the spatial range available for FRET and confirming the earlier conclusions. By showing that the FRET enhancement inside a ZMW does not depend on the set of fluorescent dyes, this report is an important step to establish the relevance of ZMWs to extend the sensitivity and detection range of FRET, while preserving its ability to work on regular fluorescent dye pairs.
Collapse
Affiliation(s)
- Mikhail Baibakov
- Aix Marseille Univ, CNRS, Centrale
Marseille, Institut Fresnel, 13013 Marseille, France
| | - Satyajit Patra
- Aix Marseille Univ, CNRS, Centrale
Marseille, Institut Fresnel, 13013 Marseille, France
| | - Jean-Benoît Claude
- Aix Marseille Univ, CNRS, Centrale
Marseille, Institut Fresnel, 13013 Marseille, France
| | - Jérôme Wenger
- Aix Marseille Univ, CNRS, Centrale
Marseille, Institut Fresnel, 13013 Marseille, France
| |
Collapse
|
12
|
Paten JA, Martin CL, Wanis JT, Siadat SM, Figueroa-Navedo AM, Ruberti JW, Deravi LF. Molecular Interactions between Collagen and Fibronectin: A Reciprocal Relationship that Regulates De Novo Fibrillogenesis. Chem 2019. [DOI: 10.1016/j.chempr.2019.05.011] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
|
13
|
Baibakov M, Patra S, Claude JB, Moreau A, Lumeau J, Wenger J. Extending Single-Molecule Förster Resonance Energy Transfer (FRET) Range beyond 10 Nanometers in Zero-Mode Waveguides. ACS NANO 2019; 13:8469-8480. [PMID: 31283186 DOI: 10.1021/acsnano.9b04378] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Single-molecule Förster resonance energy transfer (smFRET) is widely used to monitor conformations and interaction dynamics at the molecular level. However, conventional smFRET measurements are ineffective at donor-acceptor distances exceeding 10 nm, impeding the studies on biomolecules of larger size. Here, we show that zero-mode waveguide (ZMW) apertures can be used to overcome the 10 nm barrier in smFRET. Using an optimized ZMW structure, we demonstrate smFRET between standard commercial fluorophores up to 13.6 nm distance with a significantly improved FRET efficiency. To further break into the classical FRET range limit, ZMWs are combined with molecular constructs featuring multiple acceptor dyes to achieve high FRET efficiencies together with high fluorescence count rates. As we discuss general guidelines for quantitative smFRET measurements inside ZMWs, the technique can be readily applied for monitoring conformations and interactions on large molecular complexes with enhanced brightness.
Collapse
Affiliation(s)
- Mikhail Baibakov
- Aix Marseille Univ, CNRS, Centrale Marseille , Institut Fresnel , 13013 Marseille , France
| | - Satyajit Patra
- Aix Marseille Univ, CNRS, Centrale Marseille , Institut Fresnel , 13013 Marseille , France
| | - Jean-Benoît Claude
- Aix Marseille Univ, CNRS, Centrale Marseille , Institut Fresnel , 13013 Marseille , France
| | - Antonin Moreau
- Aix Marseille Univ, CNRS, Centrale Marseille , Institut Fresnel , 13013 Marseille , France
| | - Julien Lumeau
- Aix Marseille Univ, CNRS, Centrale Marseille , Institut Fresnel , 13013 Marseille , France
| | - Jérôme Wenger
- Aix Marseille Univ, CNRS, Centrale Marseille , Institut Fresnel , 13013 Marseille , France
| |
Collapse
|
14
|
Yokota H. Fluorescence microscopy for visualizing single-molecule protein dynamics. Biochim Biophys Acta Gen Subj 2019; 1864:129362. [PMID: 31078674 DOI: 10.1016/j.bbagen.2019.05.005] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2018] [Revised: 04/26/2019] [Accepted: 05/07/2019] [Indexed: 01/06/2023]
Abstract
BACKGROUND Single-molecule fluorescence imaging (smFI) has evolved into a valuable method used in biophysical and biochemical studies as it can observe the real-time behavior of individual protein molecules, enabling understanding of their detailed dynamic features. smFI is also closely related to other state-of-the-art microscopic methods, optics, and nanomaterials in that smFI and these technologies have developed synergistically. SCOPE OF REVIEW This paper provides an overview of the recently developed single-molecule fluorescence microscopy methods, focusing on critical techniques employed in higher-precision measurements in vitro and fluorescent nanodiamond, an emerging promising fluorophore that will improve single-molecule fluorescence microscopy. MAJOR CONCLUSIONS smFI will continue to improve regarding the photostability of fluorophores and will develop via combination with other techniques based on nanofabrication, single-molecule manipulation, and so on. GENERAL SIGNIFICANCE Quantitative, high-resolution single-molecule studies will help establish an understanding of protein dynamics and complex biomolecular systems.
Collapse
Affiliation(s)
- Hiroaki Yokota
- Biophotonics Laboratory, Graduate School for the Creation of New Photonics Industries, Kurematsu-cho, Nishi-ku, Hamamatsu, Shizuoka 431-1202, Japan.
| |
Collapse
|
15
|
Park S, Kim H, Lim SC, Lim K, Lee ES, Oh KT, Choi HG, Youn YS. Gold nanocluster-loaded hybrid albumin nanoparticles with fluorescence-based optical visualization and photothermal conversion for tumor detection/ablation. J Control Release 2019; 304:7-18. [PMID: 31028785 DOI: 10.1016/j.jconrel.2019.04.036] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2018] [Revised: 04/02/2019] [Accepted: 04/23/2019] [Indexed: 12/29/2022]
Abstract
Gold nanoclusters (AuNCs) are viewed as effective hyperthermal agents for the treatment of tumors. Whereas AuNCs formed by the agglomeration of several to tens of gold atoms (<1-2 nm) possess significant fluorescence, they have a negligible hyperthermal effect, while AuNCs comprised of spherical gold nanoparticles (AuNPs > a few nanometers) have a marked hyperthermic effect but lose their inherent fluorescence and obstruct the intensity of neighboring fluorescent dyes due to Forster resonance energy transfer (FRET). To achieve both hyperthermia and fluorescence-based optical visualization, we generated hybrid albumin nanoparticles containing AuNCs (~88 nm) comprising AuNPs (~4.5 nm). We generated a series of formulated AuNCs and optimized the size, morphology, NIR absorbance (600-900 nm), hyperthermal activity, and fluorescence spectral characters of the resulting hybrid albumin nanoparticles (AuNCs/BSA-NPs) by considering the interparticle distance between the AuNPs and Cy5.5. Among these, AuNCs/BSA-NPs (formula D) had a strong hyperthermic effect and had well-preserved fluorescence intensity (from the attached Cy5.5) due to localized surface plasmon resonance (LSPR) and a reduction in FRET. These AuNCs/BSA-NPs were able to elevate the surface tumor temperature of HCT116-bearing mice to >50 °C following 808 nm laser irradiation (1.5 W/cm2, 10 min), which remarkably suppressed tumor growth (17.8 ± 16.9 mm3vs. PBS and AuNCs/BSA-NPs (formula E): ~1850 and ~1250 mm3, respectively). Also, Cy5.5-modified AuNCs/BSA-NPs (formula D) showed good performance in optical fluorescence imaging of target tumors in HCT116 tumor-bearing mice. Together, our results indicate that the interparticle distance between albumin or Cy5.5 and AuNPs/AuNCs can be optimized to achieve both hyperthermia and fluorescence emission by striking a balance between LSPR and FRET effects. We believe that the AuNC/BSA-NPs formulation presented here can serve as a potential platform for both optically visualizing and treating colon cancers.
Collapse
Affiliation(s)
- Sanghyun Park
- School of Pharmacy, Sungkyunkwan University, 2066 Seobu-ro, Jangan-gu, Gyeonggi-do, Suwon 16419, Republic of Korea
| | - Hanju Kim
- School of Pharmacy, Sungkyunkwan University, 2066 Seobu-ro, Jangan-gu, Gyeonggi-do, Suwon 16419, Republic of Korea
| | - Su Chan Lim
- School of Pharmacy, Sungkyunkwan University, 2066 Seobu-ro, Jangan-gu, Gyeonggi-do, Suwon 16419, Republic of Korea
| | - Kyungseop Lim
- School of Pharmacy, Sungkyunkwan University, 2066 Seobu-ro, Jangan-gu, Gyeonggi-do, Suwon 16419, Republic of Korea
| | - Eun Seong Lee
- Division of Biotechnology, The Catholic University of Korea, 43 Jibong-ro, Gyeonggi-do, Bucheon-si 14662, Republic of Korea
| | - Kyung Taek Oh
- College of Pharmacy, Chung-Ang University, 84 Heukseok-ro, Dongjak-gu, Seoul 06974, Republic of Korea
| | - Han-Gon Choi
- College of Pharmacy, Hanyang University, 55 Hanyangdaehak-ro, Sangnok-gu, Ansan 15588, Republic of Korea
| | - Yu Seok Youn
- School of Pharmacy, Sungkyunkwan University, 2066 Seobu-ro, Jangan-gu, Gyeonggi-do, Suwon 16419, Republic of Korea.
| |
Collapse
|
16
|
FRET-based assay using a three-way junction DNA substrate to identify inhibitors of human cytomegalovirus pUL89 endonuclease activity. Eur J Pharm Sci 2019; 127:29-37. [DOI: 10.1016/j.ejps.2018.10.016] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2018] [Revised: 10/15/2018] [Accepted: 10/16/2018] [Indexed: 02/06/2023]
|
17
|
Mujoo H, Reynolds JNJ, Tucker IG. A real-time in vitro assay to evaluate the release of macromolecules from liposomes. Drug Test Anal 2017; 10:1025-1032. [PMID: 29088510 DOI: 10.1002/dta.2332] [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] [Received: 07/19/2017] [Revised: 10/18/2017] [Accepted: 10/19/2017] [Indexed: 12/22/2022]
Abstract
The availability of a real-time assay to experimentally investigate the release of encapsulated proteins would be beneficial given the interest in the use of liposomes as a drug delivery vehicle. Although simple assays for small molecular weight substances exist, assays to evaluate macromolecules do not. Here we describe a method that detects the release of model macromolecules from liposomes in real time. The assay employs the intermolecular distance-dependent phenomenon of fluorescence resonance energy transfer (FRET) between the fluorophore donor, fluorescein (FITC), and fluorescent quencher, QSY® 9. The macromolecular species were conjugated to the markers fluorescein (44kDa dextran) and QSY® 9 (67 kDa bovine serum albumin, BSA). Following confirmation of quenching between FITC-Dex and QSY® 9-BSA, liposomes were loaded with the macromolecular markers and subjected to various treatments (high-pressure extrusion and Triton X solubilisation) to cause release from liposomes. An increase in FITC fluorescence was observed when liposomes were subjected to extrusion cycles. Surprisingly, the addition of Triton X did not cause an increase in fluorescence probably because the FRET pair became associated with mixed micelles. This assay method should be useful in studies to investigate the mechanisms by which macromolecules are released from liposomes, particularly when liposomes are exposed to release-triggers (eg, temperature change, pH change, ultrasound). Such understanding will underpin the formulation of triggered liposomal delivery systems for macromolecules.
Collapse
Affiliation(s)
- Himang Mujoo
- School of Pharmacy, University of Otago, Dunedin, New Zealand
| | - John N J Reynolds
- Department of Anatomy, The Brain Health Research Centre, University of Otago, Dunedin, New Zealand
| | - Ian G Tucker
- School of Pharmacy, University of Otago, Dunedin, New Zealand
| |
Collapse
|
18
|
Osad'ko IS. Dependence of FRET efficiency on distance in single donor-acceptor pairs. J Chem Phys 2015; 142:125102. [PMID: 25833609 DOI: 10.1063/1.4915279] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Possibility to create single donor-acceptor (D-A) pairs by attaching dye molecules to various sites of DNA strands with control of the inter-dye distance R enables one to measure average Förster resonance energy transfer (FRET) efficiency E as a function of R. Triplet states of the dyes influence the dependence E(R) considerably. Two types of FRET efficiency are considered: E = EA and E = ED. The efficiency EA(R) = JA(R)/[JA(R) + JD(R)] depends on the donor and the acceptor average intensities JD(R) and JA(R) measured in D- and A-fluorescence, whereas the efficiency ED(R) = 1 - JD(R)/JD(∞) depends only on the intensity of D-fluorescence, so-called the donor quenching method. The shape of the functions ED (R) and EA (R) depends strongly on whether the dyes have blinking fluorescence. FRET efficiencies ED (R) and EA (R) undergo the influence of many experimental factors and therefore, differ considerably from pure FRET efficiencies ED (s) (R) and EA (s) (R). Pure FRET efficiencies ED,A (s) (R) are calculated with the help of rate equations for D-A pairs, whose molecules have triplet states. It is shown how the calculated efficiencies ED,A (s) (R) can be compared to FRET efficiencies measured with the help of the intensities ID,A(R) corrected by cross talk and background light.
Collapse
Affiliation(s)
- I S Osad'ko
- Institute for Spectroscopy, RAS, 142190 Moscow, Russia
| |
Collapse
|
19
|
Ng KK, Zheng G. Molecular Interactions in Organic Nanoparticles for Phototheranostic Applications. Chem Rev 2015; 115:11012-42. [PMID: 26244706 DOI: 10.1021/acs.chemrev.5b00140] [Citation(s) in RCA: 353] [Impact Index Per Article: 39.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Kenneth K Ng
- Princess Margaret Cancer Centre and Techna Institute, University Health Network , Toronto, Ontario M5G 2C4, Canada
| | - Gang Zheng
- Princess Margaret Cancer Centre and Techna Institute, University Health Network , Toronto, Ontario M5G 2C4, Canada
| |
Collapse
|
20
|
Ghosh S, Das NK, Anand U, Mukherjee S. Photostable Copper Nanoclusters: Compatible Förster Resonance Energy-Transfer Assays and a Nanothermometer. J Phys Chem Lett 2015; 6:1293-8. [PMID: 26262990 DOI: 10.1021/acs.jpclett.5b00378] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
To address the concern of material chemists over the issue of stability and photoluminescent (PL) characteristics of Cu nanoclusters (NCs), herein we present an efficient protocol discussing PL Cu NCs (Cu/HSA) having blue emission and high photostability. These PL NCs were illustrated as efficient probes for Förster resonance energy transfer (FRET) with a compatible fluorophore (Coumarin 153). Our spectroscopic results were well complemented by our molecular docking calculations, which also favored our proposed mechanism for Cu NC formation. The beneficial aspect and uniqueness of these nontoxic Cu/HSA NCs highlights their temperature-dependent PL reversibility as well as the reversible FRET with Coumarin 153, which enables them to be used as a nanothermometer and a PL marker for sensitive biological samples.
Collapse
Affiliation(s)
- Subhadip Ghosh
- Department of Chemistry, Indian Institute of Science Education and Research Bhopal, Indore By-Pass Road, Bhauri, Bhopal 462 066, Madhya Pradesh, India
| | - Nirmal Kumar Das
- Department of Chemistry, Indian Institute of Science Education and Research Bhopal, Indore By-Pass Road, Bhauri, Bhopal 462 066, Madhya Pradesh, India
| | - Uttam Anand
- Department of Chemistry, Indian Institute of Science Education and Research Bhopal, Indore By-Pass Road, Bhauri, Bhopal 462 066, Madhya Pradesh, India
| | - Saptarshi Mukherjee
- Department of Chemistry, Indian Institute of Science Education and Research Bhopal, Indore By-Pass Road, Bhauri, Bhopal 462 066, Madhya Pradesh, India
| |
Collapse
|
21
|
Hevekerl H, Widengren J. Determination of molecular stoichiometry without reference samples by analyzing fluorescence blinking with and without excitation synchronization. Methods Appl Fluoresc 2015; 3:025001. [PMID: 29148486 DOI: 10.1088/2050-6120/3/2/025001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Stoichiometry of molecular complexes plays a crucial role in biology. Moreover, for quantitative fluorescence studies, it is often useful to know the number of fluorophores labeled onto the molecules studied. In this work, we propose an approach to determine the number of independent fluorescence emitters on fluorescent molecules based on fluorescence blinking caused by photo-induced triplet state formation, photo-isomerization or charge transfer. The fluorescence blinking is measured under two different excitation regimes, on the same setup, and in one and the same sample. By comparing the fluorescence fluctuations under continuous excitation using Fluorescence Correlation Spectroscopy (FCS), when all the fluorophores are blinking independently of each other, with those occurring under square-pulsed excitation using Transient State (TRAST) spectroscopy, when all fluorophores are blinking in a synchronized manner, the number of fluorophores per molecule can be determined. No calibration sample is needed and the approach is independent of experimental conditions and of the specific environment of the molecules under study.The approach was experimentally validated by labeling double stranded DNA (dsDNA) with different concentrations of the intercalating dye YOYO-1 Iodide. The sample was then measured consecutively by TRAST and FCS and the number of fluorophores per molecule was calculated. The determined numbers were found to agree well with the number of fluorophores per dsDNA, as determined from FCS measurements using additional calibration samples.
Collapse
Affiliation(s)
- Heike Hevekerl
- Experimental Biomolecular Physics, Department of Applied Physics, Royal Institute of Technology, Stockholm, Sweden
| | | |
Collapse
|
22
|
Spielmann T, Xu L, Gad AKB, Johansson S, Widengren J. Transient state microscopy probes patterns of altered oxygen consumption in cancer cells. FEBS J 2014; 281:1317-1332. [PMID: 24418170 DOI: 10.1111/febs.12709] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2013] [Revised: 12/06/2013] [Accepted: 01/01/2014] [Indexed: 11/30/2022]
Abstract
Altered cellular metabolism plays an important role in many diseases, not least in many forms of cancer, where cellular metabolic pathways requiring lower oxygen consumption are often favored (the so-called Warburg effect). In this work, we have applied fluorescence-based transient state imaging and have exploited the environment sensitivity of long-lived dark states of fluorophores, in particular triplet state decay rates, to image the oxygen consumption of living cells. Our measurements can resolve differences in oxygen concentrations between different regions of individual cells, between different cell types, and also based on what metabolic pathways the cells use. In MCF-7 breast cancer cells, higher oxygen consumption can be detected when they rely on glutamine instead of glucose as their main metabolite, predominantly undergoing oxidative phosphorylation rather than glycolysis. By use of the high triplet yield dye Eosin Y the irradiance requirements during the measurements can be kept low. This reduces the instrumentation requirements, and harmful biological effects from high excitation doses can be avoided. Taken together, our imaging approach is widely applicable and capable of detecting subtle changes in oxygen consumption in live cells, stemming from the Warburg effect or reflecting other differences in the cellular metabolism. This may lead to new diagnostic means as well as advance our understanding of the interplay between cellular metabolism and major disease categories, such as cancer.
Collapse
Affiliation(s)
- Thiemo Spielmann
- Experimental Biomolecular Physics, Department of Applied Physics, Royal Institute of Technology, Stockholm, Sweden
| | | | | | | | | |
Collapse
|
23
|
Ibrahim B, Henze R, Gruenert G, Egbert M, Huwald J, Dittrich P. Spatial rule-based modeling: a method and its application to the human mitotic kinetochore. Cells 2013; 2:506-44. [PMID: 24709796 PMCID: PMC3972674 DOI: 10.3390/cells2030506] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2013] [Revised: 06/05/2013] [Accepted: 06/25/2013] [Indexed: 12/23/2022] Open
Abstract
A common problem in the analysis of biological systems is the combinatorial explosion that emerges from the complexity of multi-protein assemblies. Conventional formalisms, like differential equations, Boolean networks and Bayesian networks, are unsuitable for dealing with the combinatorial explosion, because they are designed for a restricted state space with fixed dimensionality. To overcome this problem, the rule-based modeling language, BioNetGen, and the spatial extension, SRSim, have been developed. Here, we describe how to apply rule-based modeling to integrate experimental data from different sources into a single spatial simulation model and how to analyze the output of that model. The starting point for this approach can be a combination of molecular interaction data, reaction network data, proximities, binding and diffusion kinetics and molecular geometries at different levels of detail. We describe the technique and then use it to construct a model of the human mitotic inner and outer kinetochore, including the spindle assembly checkpoint signaling pathway. This allows us to demonstrate the utility of the procedure, show how a novel perspective for understanding such complex systems becomes accessible and elaborate on challenges that arise in the formulation, simulation and analysis of spatial rule-based models.
Collapse
Affiliation(s)
- Bashar Ibrahim
- Bio Systems Analysis Group, Institute of Computer Science, Jena Centre for Bioinformatics and Friedrich Schiller University Jena, Ernst-Abbe-Platz 2, D-0007743 Jena, Germany.
| | - Richard Henze
- Bio Systems Analysis Group, Institute of Computer Science, Jena Centre for Bioinformatics and Friedrich Schiller University Jena, Ernst-Abbe-Platz 2, D-0007743 Jena, Germany.
| | - Gerd Gruenert
- Bio Systems Analysis Group, Institute of Computer Science, Jena Centre for Bioinformatics and Friedrich Schiller University Jena, Ernst-Abbe-Platz 2, D-0007743 Jena, Germany.
| | - Matthew Egbert
- Bio Systems Analysis Group, Institute of Computer Science, Jena Centre for Bioinformatics and Friedrich Schiller University Jena, Ernst-Abbe-Platz 2, D-0007743 Jena, Germany.
| | - Jan Huwald
- Bio Systems Analysis Group, Institute of Computer Science, Jena Centre for Bioinformatics and Friedrich Schiller University Jena, Ernst-Abbe-Platz 2, D-0007743 Jena, Germany.
| | - Peter Dittrich
- Bio Systems Analysis Group, Institute of Computer Science, Jena Centre for Bioinformatics and Friedrich Schiller University Jena, Ernst-Abbe-Platz 2, D-0007743 Jena, Germany.
| |
Collapse
|
24
|
Nuin E, Jiménez MC, Sastre G, Andreu I, Miranda MA. Drug-Drug Interactions within Protein Cavities Probed by Triplet-Triplet Energy Transfer. J Phys Chem Lett 2013; 4:1603-7. [PMID: 26282966 DOI: 10.1021/jz400640s] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
A new direct and noninvasive methodology based on transient absorption spectroscopy has been developed to probe the feasibility of drug-drug interactions within a common protein binding site. The simultaneous presence of (R)-cinacalcet (CIN) and (S)-propranolol (PPN) within human or bovine α1-acid glycoproteins (AAGs) is revealed by detection of (3)CIN* as the only transient species after laser flash photolysis of CIN/PPN/AAG mixtures at 308 nm. This is the result of triplet-triplet energy transfer from (3)PPN* to CIN, which requires close contact between the two drugs within the same biological compartment. Similar results are obtained with nabumetone and CIN as donor/acceptor partners. This new methodology can, in principle, be extended to a variety of drug/drug/biomolecule combinations.
Collapse
Affiliation(s)
- Edurne Nuin
- †Departamento de Química-Instituto de Tecnología Química UPV-CSIC, Universidad Politécnica de Valencia, Camino de Vera s/n, Valencia, Spain
| | - M Consuelo Jiménez
- †Departamento de Química-Instituto de Tecnología Química UPV-CSIC, Universidad Politécnica de Valencia, Camino de Vera s/n, Valencia, Spain
| | - Germán Sastre
- †Departamento de Química-Instituto de Tecnología Química UPV-CSIC, Universidad Politécnica de Valencia, Camino de Vera s/n, Valencia, Spain
| | - Inmaculada Andreu
- ‡Unidad mixta de investigación IIS La Fe-UPV, Hospital La Fe, Avda. Campanar 21, 46009 Valencia, Spain
| | - Miguel A Miranda
- †Departamento de Química-Instituto de Tecnología Química UPV-CSIC, Universidad Politécnica de Valencia, Camino de Vera s/n, Valencia, Spain
| |
Collapse
|
25
|
Walczewska-Szewc K, Bojarski P, d'Auria S. Extending the range of FRET--the Monte Carlo study of the antenna effect. J Mol Model 2013; 19:4195-201. [PMID: 23512181 PMCID: PMC3778230 DOI: 10.1007/s00894-013-1810-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2012] [Accepted: 02/20/2013] [Indexed: 01/17/2023]
Abstract
The problem of extending the utilizable range of Förster resonance energy transfer (FRET) is of great current interest, due to the demand of conformation studies of larger biological structures at distances exceeding typical limiting distance of 100 Å. One of the ways to address this issue is the use of so-called antenna effect. In the present work, the influence of the antenna effect on the FRET efficiency is investigated by the Monte Carlo analysis. The previously published results Bojarski et al. (J Phys Chem B 115:10120–10125, 2011) indicate that using a simple model of donor linked with a protein labeled with multiple acceptors, significantly increases the transfer efficiency in comparison with donor–single acceptor system. The effect is stronger if the transition moments of acceptors are mutually parallel. In this work, to extend the scope of possible biological systems to be analyzed, different distributions of donor–acceptors distance are analyzed, as well as the size and shape of the attached molecule.
Collapse
|
26
|
Torregrosa-Hetland CJ, Villanueva J, Garcia-Martínez V, Expósito-Romero G, Francés MDM, Gutiérrez LM. Cortical F-actin affects the localization and dynamics of SNAP-25 membrane clusters in chromaffin cells. Int J Biochem Cell Biol 2012; 45:583-92. [PMID: 23220175 DOI: 10.1016/j.biocel.2012.11.021] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2012] [Revised: 10/22/2012] [Accepted: 11/28/2012] [Indexed: 10/27/2022]
Abstract
It has been proposed recently that the F-actin cytoskeleton organizes the relative disposition of the SNARE proteins and calcium channels that form part of the secretory machinery in chromaffin cells, a neurosecretory model. To test this idea, we used confocal microscopy do determine if DsRed-SNAP-25 microdomains, which define the final sites of exocytosis along with syntaxin-1, preferentially remain in contact with F-actin cortical structures labelled by lifeact-EGFP. A quantitative analysis showed that in cells over-expressing these constructs there is a preferential colocalization, rather than a random distribution of SNAP-25 patches. To analyze the possible interactions between these proteins, we designed FRET experiments and tested whether treatment with agents that affect F-actin mobility would modify SNAP-25 movement. The significant FRET efficiencies detected suggest that direct molecular interactions occur, whereas dynamic experiments using TIRFM revealed that attenuation of cortical F-actin movement clearly diminishes the mobility of SNAP-25 clusters. Taken together, these data can be explained by a model that associates components of the secretory machinery to the F-actin cortex through flexible links.
Collapse
Affiliation(s)
- Cristina J Torregrosa-Hetland
- Instituto de Neurociencias de Alicante, Universidad Miguel Hernández-Consejo Superior de Investigaciones Científicas, Sant Joan d'Alacant, Carretera Nacional 332 s/n, 03550 Alicante, Spain
| | | | | | | | | | | |
Collapse
|
27
|
Preus S, Wilhelmsson LM. Advances in quantitative FRET-based methods for studying nucleic acids. Chembiochem 2012; 13:1990-2001. [PMID: 22936620 DOI: 10.1002/cbic.201200400] [Citation(s) in RCA: 98] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2012] [Indexed: 01/02/2023]
Abstract
Förster resonance energy transfer (FRET) is a powerful tool for monitoring molecular distances and interactions at the nanoscale level. The strong dependence of transfer efficiency on probe separation makes FRET perfectly suited for "on/off" experiments. To use FRET to obtain quantitative distances and three-dimensional structures, however, is more challenging. This review summarises recent studies and technological advances that have improved FRET as a quantitative molecular ruler in nucleic acid systems, both at the ensemble and at the single-molecule levels.
Collapse
Affiliation(s)
- Søren Preus
- Department of Chemistry, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen, Denmark
| | | |
Collapse
|