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Schneider F, Cespedes PF, Karedla N, Dustin ML, Fritzsche M. Quantifying biomolecular organisation in membranes with brightness-transit statistics. Nat Commun 2024; 15:7082. [PMID: 39152104 PMCID: PMC11329664 DOI: 10.1038/s41467-024-51435-1] [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: 03/05/2024] [Accepted: 08/07/2024] [Indexed: 08/19/2024] Open
Abstract
Cells crucially rely on the interactions of biomolecules at their plasma membrane to maintain homeostasis. Yet, a methodology to systematically quantify biomolecular organisation, measuring diffusion dynamics and oligomerisation, represents an unmet need. Here, we introduce the brightness-transit statistics (BTS) method based on fluorescence fluctuation spectroscopy and combine information from brightness and transit times to elucidate biomolecular diffusion and oligomerisation in both cell-free in vitro and in vitro systems incorporating living cells. We validate our approach in silico with computer simulations and experimentally using oligomerisation of EGFP tethered to supported lipid bilayers. We apply our pipeline to study the oligomerisation of CD40 ectodomain in vitro and endogenous CD40 on primary B cells. While we find a potential for CD40 to oligomerize in a concentration or ligand depended manner, we do not observe mobile oligomers on B cells. The BTS method combines sensitive analysis, quantification, and intuitive visualisation of dynamic biomolecular organisation.
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Affiliation(s)
- Falk Schneider
- Kennedy Institute for Rheumatology, Roosevelt Drive, University of Oxford, Oxford, OX3 7LF, United Kingdom.
- Translational Imaging Center, University of Southern California, Los Angeles, California, 90089, United States of America.
| | - Pablo F Cespedes
- Kennedy Institute for Rheumatology, Roosevelt Drive, University of Oxford, Oxford, OX3 7LF, United Kingdom
| | - Narain Karedla
- Kennedy Institute for Rheumatology, Roosevelt Drive, University of Oxford, Oxford, OX3 7LF, United Kingdom
- Rosalind Franklin Institute, Harwell Campus, Didcot, OX11 0FA, United Kingdom
| | - Michael L Dustin
- Kennedy Institute for Rheumatology, Roosevelt Drive, University of Oxford, Oxford, OX3 7LF, United Kingdom
| | - Marco Fritzsche
- Kennedy Institute for Rheumatology, Roosevelt Drive, University of Oxford, Oxford, OX3 7LF, United Kingdom.
- Rosalind Franklin Institute, Harwell Campus, Didcot, OX11 0FA, United Kingdom.
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2
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Yang GS, Wagenknecht-Wiesner A, Yin B, Suresh P, London E, Baird BA, Bag N. Lipid-driven interleaflet coupling of plasma membrane order regulates FcεRI signaling in mast cells. Biophys J 2024; 123:2256-2270. [PMID: 37533258 PMCID: PMC11331041 DOI: 10.1016/j.bpj.2023.07.027] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2022] [Revised: 07/28/2023] [Accepted: 07/31/2023] [Indexed: 08/04/2023] Open
Abstract
Interleaflet coupling-the influence of one leaflet on the properties of the opposing leaflet-is a fundamental plasma membrane organizational principle. This coupling is proposed to participate in maintaining steady-state biophysical properties of the plasma membrane, which in turn regulates some transmembrane signaling processes. A prominent example is antigen (Ag) stimulation of signaling by clustering transmembrane receptors for immunoglobulin E (IgE), FcεRI. This transmembrane signaling depends on the stabilization of ordered regions in the inner leaflet for sorting of intracellular signaling components. The resting inner leaflet has a lipid composition that is generally less ordered than the outer leaflet and that does not spontaneously phase separate in model membranes. We propose that interleaflet coupling can mediate ordering and disordering of the inner leaflet, which is poised in resting cells to reorganize upon stimulation. To test this in live cells, we first established a straightforward approach to evaluate induced changes in membrane order by measuring inner leaflet diffusion of lipid probes by imaging fluorescence correlation spectroscopy, by imaging fluorescence correlation spectroscopy (ImFCS), before and after methyl-α-cyclodexrin (mαCD)-catalyzed exchange of outer leaflet lipids (LEX) with exogenous order- or disorder-promoting phospholipids. We examined the functional impact of LEX by monitoring two Ag-stimulated responses: recruitment of cytoplasmic Syk kinase to the inner leaflet and exocytosis of secretory granules (degranulation). Based on the ImFCS data in resting cells, we observed global increase or decrease of inner leaflet order when outer leaflet is exchanged with order- or disorder-promoting lipids, respectively. We find that the degree of both stimulated Syk recruitment and degranulation correlates positively with LEX-mediated changes of inner leaflet order in resting cells. Overall, our results show that resting-state lipid ordering of the outer leaflet influences the ordering of the inner leaflet, likely via interleaflet coupling. This imposed lipid reorganization modulates transmembrane signaling stimulated by Ag clustering of IgE-FcεRI.
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Affiliation(s)
- Gil-Suk Yang
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York
| | | | - Boyu Yin
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York
| | - Pavana Suresh
- Department of Biochemistry and Cell Biology, Stony Brook University, Stony Brook, New York
| | - Erwin London
- Department of Biochemistry and Cell Biology, Stony Brook University, Stony Brook, New York
| | - Barbara A Baird
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York
| | - Nirmalya Bag
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York; Department of Chemistry, Indian Institute of Technology, Kharagpur, India.
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3
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Tripathy A, Priyadarsinee S, Bag N. Evaluation of functional transbilayer coupling in live cells by controlled lipid exchange and imaging fluorescence correlation spectroscopy. Methods Enzymol 2024; 700:1-32. [PMID: 38971596 DOI: 10.1016/bs.mie.2024.04.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/08/2024]
Abstract
Biophysical coupling between the inner and outer leaflets, known as inter-leaflet or transbilayer coupling, is a fundamental organizational principle in the plasma membranes of live mammalian cells. Lipid-based interactions between the two leaflets are proposed to be a primary mechanism underlying transbilayer coupling. However, there are only a few experimental evidence supporting the existence of such interactions in live cells. This is seemingly due to the lack of experimental strategies to perturb the lipid composition in one leaflet and quantitative techniques to evaluate the biophysical properties of the opposite leaflet. The existing strategies often dependent on immobilization and clustering a component in one of the leaflets and technically demanding biophysical tools to evaluate the effects on the opposing leaflet. In the recent years, the London group developed a simple but elegant method, namely methyl-alpha-cyclodextrin catalyzed lipid exchange (LEX), to efficiently exchange outer leaflet lipids with an exogenous lipid of choice. Here, we adopted this method to perturb outer leaflet lipid composition. The corresponding changes in the inner leaflet is evaluated by comparing the diffusion of lipid probes localized in this leaflet in unperturbed and perturbed conditions. We employed highly multiplexed imaging fluorescence correlation spectroscopy (ImFCS), realized in a commercially available or home-built total internal reflection fluorescence microsocope equipped with a fast and sensitive camera, to determine diffusion coefficient of the lipid probes. Using the combination of LEX and ImFCS, we directly demonstrate lipid-based transbilayer coupling that does not require immobilization of membrane components in live mast cells in resting conditions. Overall, we present a relatively straightforward experimental strategy to evaluate transbilayer coupling quantitively in live cells.
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Affiliation(s)
- Arpita Tripathy
- Department of Chemistry, Indian Institute of Technology, Kharagpur, West Bengal, India
| | - Sudipti Priyadarsinee
- Department of Chemistry, Indian Institute of Technology, Kharagpur, West Bengal, India
| | - Nirmalya Bag
- Department of Chemistry, Indian Institute of Technology, Kharagpur, West Bengal, India.
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4
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Antarasen J, Wellnitz B, Kramer SN, Chatterjee S, Kisley L. Cross-correlation increases sampling in diffusion-based super-resolution optical fluctuation imaging. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.04.01.587586. [PMID: 38617244 PMCID: PMC11014504 DOI: 10.1101/2024.04.01.587586] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/16/2024]
Abstract
Correlation signal processing of optical three-dimensional (x, y, t) data can produce super-resolution images. The second order cross-correlation function XC 2 has been documented to produce super-resolution imaging with static and blinking emitters but not for diffusing emitters. Here, we both analytically and numerically demonstrate cross-correlation analysis for diffusing particles. We then expand our fluorescence correlation spectroscopy super-resolution optical fluctuation imaging (fcsSOFI) analysis to use cross-correlation as a post-processing computational technique to extract both dynamic and structural information of particle diffusion in nanoscale structures simultaneously. We further show how this method increases sampling rates and reduces aliasing for spatial information in both simulated and experimental data. Our work demonstrates how fcsSOFI with cross-correlation can be a powerful signal-processing tool to resolve the nanoscale dynamics and structure in samples relevant to biological and soft materials. TOC Graphic
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5
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Tang WH, Sim SR, Aik DYK, Nelanuthala AVS, Athilingam T, Röllin A, Wohland T. Deep learning reduces data requirements and allows real-time measurements in imaging FCS. Biophys J 2024; 123:655-666. [PMID: 38050354 PMCID: PMC10995408 DOI: 10.1016/j.bpj.2023.11.3403] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Revised: 11/18/2023] [Accepted: 11/30/2023] [Indexed: 12/06/2023] Open
Abstract
Imaging fluorescence correlation spectroscopy (FCS) is a powerful tool to extract information on molecular mobilities, actions, and interactions in live cells, tissues, and organisms. Nevertheless, several limitations restrict its applicability. First, FCS is data hungry, requiring 50,000 frames at 1-ms time resolution to obtain accurate parameter estimates. Second, the data size makes evaluation slow. Third, as FCS evaluation is model dependent, data evaluation is significantly slowed unless analytic models are available. Here, we introduce two convolutional neural networks-FCSNet and ImFCSNet-for correlation and intensity trace analysis, respectively. FCSNet robustly predicts parameters in 2D and 3D live samples. ImFCSNet reduces the amount of data required for accurate parameter retrieval by at least one order of magnitude and makes correct estimates even in moderately defocused samples. Both convolutional neural networks are trained on simulated data, are model agnostic, and allow autonomous, real-time evaluation of imaging FCS measurements.
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Affiliation(s)
- Wai Hoh Tang
- Department of Biological Sciences, National University of Singapore, Singapore, Singapore; NUS Centre for Bio-Imaging Sciences, National University of Singapore, Singapore, Singapore; Department of Statistics and Data Science, National University of Singapore, Singapore, Singapore; Institute of Digital Molecular Analytics and Science, National University of Singapore, Singapore, Singapore
| | - Shao Ren Sim
- Department of Biological Sciences, National University of Singapore, Singapore, Singapore; NUS Centre for Bio-Imaging Sciences, National University of Singapore, Singapore, Singapore
| | - Daniel Ying Kia Aik
- Department of Biological Sciences, National University of Singapore, Singapore, Singapore; NUS Centre for Bio-Imaging Sciences, National University of Singapore, Singapore, Singapore; Institute of Digital Molecular Analytics and Science, National University of Singapore, Singapore, Singapore; Department of Chemistry, National University of Singapore, Singapore, Singapore
| | - Ashwin Venkata Subba Nelanuthala
- Department of Biological Sciences, National University of Singapore, Singapore, Singapore; NUS Centre for Bio-Imaging Sciences, National University of Singapore, Singapore, Singapore
| | | | - Adrian Röllin
- Department of Statistics and Data Science, National University of Singapore, Singapore, Singapore
| | - Thorsten Wohland
- Department of Biological Sciences, National University of Singapore, Singapore, Singapore; NUS Centre for Bio-Imaging Sciences, National University of Singapore, Singapore, Singapore; Institute of Digital Molecular Analytics and Science, National University of Singapore, Singapore, Singapore; Department of Chemistry, National University of Singapore, Singapore, Singapore.
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6
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Sankaran J, Rice SA, Wohland T. Single Microcolony Diffusion Analysis in Pseudomonas aeruginosa Biofilms. Methods Mol Biol 2024; 2721:153-168. [PMID: 37819521 DOI: 10.1007/978-1-0716-3473-8_11] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/13/2023]
Abstract
Diffusion phenomena play an important role during various stages of biofilm development. Hence, quantification of the diffusion coefficient of molecules provides important information necessary to understand the variability in diffusion profiles at different biofilm stages. Imaging fluorescence correlation spectroscopy (FCS) enables the visualization of 3D diffusion profiles of biofilms. In this protocol, we explain how to grow biofilms for investigation using imaging FCS and how to acquire and analyze the data.
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Affiliation(s)
| | - Scott A Rice
- Singapore Centre for Environmental Life Science and Engineering, Singapore, Singapore
- University of Technology Sydney, Ultimo, NSW, Australia
- CSIRO, Agriculture and Food, Microbiomes for One Systems Health, Coopers Plains, QLD, Australia
| | - Thorsten Wohland
- Departments of Biological Sciences and Chemistry, National University of Singapore, Singapore, Singapore.
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Sankaran J, Wohland T. Current capabilities and future perspectives of FCS: super-resolution microscopy, machine learning, and in vivo applications. Commun Biol 2023; 6:699. [PMID: 37419967 PMCID: PMC10328937 DOI: 10.1038/s42003-023-05069-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2023] [Accepted: 06/23/2023] [Indexed: 07/09/2023] Open
Abstract
Fluorescence correlation spectroscopy (FCS) is a single molecule sensitive tool for the quantitative measurement of biomolecular dynamics and interactions. Improvements in biology, computation, and detection technology enable real-time FCS experiments with multiplexed detection even in vivo. These new imaging modalities of FCS generate data at the rate of hundreds of MB/s requiring efficient data processing tools to extract information. Here, we briefly review FCS's capabilities and limitations before discussing recent directions that address these limitations with a focus on imaging modalities of FCS, their combinations with super-resolution microscopy, new evaluation strategies, especially machine learning, and applications in vivo.
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Affiliation(s)
- Jagadish Sankaran
- Genome Institute of Singapore, Agency for Science, Technology and Research, Singapore, 138632, Singapore.
| | - Thorsten Wohland
- Department of Biological Sciences, National University of Singapore, Singapore, 117558, Singapore.
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8
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Chatterjee S, Kramer SN, Wellnitz B, Kim A, Kisley L. Spatially Resolving Size Effects on Diffusivity in Nanoporous Extracellular Matrix-like Materials with Fluorescence Correlation Spectroscopy Super-Resolution Optical Fluctuation Imaging. J Phys Chem B 2023; 127:4430-4440. [PMID: 37167609 DOI: 10.1021/acs.jpcb.3c00941] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
It is well documented that the nanoscale structures within porous microenvironments greatly impact the diffusion dynamics of molecules. However, how the interaction between the environment and molecules influences the diffusion dynamics has not been thoroughly explored. Here, we show that fluorescence correlation spectroscopy super-resolution optical fluctuation imaging (fcsSOFI) can be used to accurately measure the diffusion dynamics of molecules within varying matrices such as nanopatterned surfaces and porous agarose hydrogels. Our data demonstrate the robustness of fcsSOFI, where it is possible not only to quantify the diffusion speeds of molecules in heterogeneous media but also to recover the matrix structure with resolution on the order of 100 nm. Using dextran molecules of varying sizes, we show that the diffusion coefficient is sensitive to the change in the molecular hydrodynamic radius. fcsSOFI images further reveal that smaller dextran molecules can freely move through the small pores of the hydrogel and report the detailed porous structure and local diffusion heterogeneities not captured by the average diffusion coefficient. Conversely, bigger dextran molecules are confined and unable to freely move through the hydrogel, highlighting only the larger pore structures. These findings establish fcsSOFI as a powerful tool to characterize spatial and diffusion information of diverse macromolecules within biorelevant matrices.
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Affiliation(s)
- Surajit Chatterjee
- Department of Physics, Case Western Reserve University, Cleveland, Ohio 44106-7079, United States
| | - Stephanie N Kramer
- Department of Physics, Case Western Reserve University, Cleveland, Ohio 44106-7079, United States
| | - Benjamin Wellnitz
- Department of Physics, Case Western Reserve University, Cleveland, Ohio 44106-7079, United States
| | - Albert Kim
- Department of Physics, Case Western Reserve University, Cleveland, Ohio 44106-7079, United States
| | - Lydia Kisley
- Department of Physics, Case Western Reserve University, Cleveland, Ohio 44106-7079, United States
- Department of Chemistry, Case Western Reserve University, Cleveland, Ohio 44106-7079, United States
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9
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Incicco JJ, Roy D, Stuchell-Brereton MD, Soranno A. Fluorescence Correlation Spectroscopy and Phase Separation. Methods Mol Biol 2023; 2563:161-198. [PMID: 36227473 DOI: 10.1007/978-1-0716-2663-4_8] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
A quantitative understanding of the forces controlling the assembly and functioning of biomolecular condensates requires the identification of phase boundaries at which condensates form as well as the determination of tie-lines. Here, we describe in detail how Fluorescence Correlation Spectroscopy (FCS) provides a versatile approach to estimate phase boundaries of single-component and multicomponent solutions as well as insights about the transport properties of the condensate.
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Affiliation(s)
- Juan Jeremías Incicco
- Department of Biochemistry and Molecular Biophysics, Washington University in St Louis, St. Louis, MO, USA
- Center for Science and Engineering of Living Systems (CSELS), Washington University in St Louis, St. Louis, MO, USA
| | - Debjit Roy
- Department of Biochemistry and Molecular Biophysics, Washington University in St Louis, St. Louis, MO, USA
- Center for Science and Engineering of Living Systems (CSELS), Washington University in St Louis, St. Louis, MO, USA
| | - Melissa D Stuchell-Brereton
- Department of Biochemistry and Molecular Biophysics, Washington University in St Louis, St. Louis, MO, USA
- Center for Science and Engineering of Living Systems (CSELS), Washington University in St Louis, St. Louis, MO, USA
| | - Andrea Soranno
- Department of Biochemistry and Molecular Biophysics, Washington University in St Louis, St. Louis, MO, USA.
- Center for Science and Engineering of Living Systems (CSELS), Washington University in St Louis, St. Louis, MO, USA.
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10
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Balasubramanian H, Sankaran J, Pandey S, Goh CJH, Wohland T. The dependence of EGFR oligomerization on environment and structure: A camera-based N&B study. Biophys J 2022; 121:4452-4466. [PMID: 36335429 PMCID: PMC9748371 DOI: 10.1016/j.bpj.2022.11.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2022] [Revised: 09/30/2022] [Accepted: 11/01/2022] [Indexed: 11/06/2022] Open
Abstract
Number and brightness (N&B) analysis is a fluorescence spectroscopy technique to quantify oligomerization of the mobile fraction of proteins. Accurate results, however, rely on a good knowledge of nonfluorescent states of the fluorescent labels, especially of fluorescent proteins, which are widely used in biology. Fluorescent proteins have been characterized for confocal, but not camera-based, N&B, which allows, in principle, faster measurements over larger areas. Here, we calibrate camera-based N&B implemented on a total internal reflection fluorescence microscope for various fluorescent proteins by determining their propensity to be fluorescent. We then apply camera-based N&B in live CHO-K1 cells to determine the oligomerization state of the epidermal growth factor receptor (EGFR), a transmembrane receptor tyrosine kinase that is a crucial regulator of cell proliferation and survival with implications in many cancers. EGFR oligomerization in resting cells and its regulation by the plasma membrane microenvironment are still under debate. Therefore, we investigate the effects of extrinsic factors, including membrane organization, cytoskeletal structure, and ligand stimulation, and intrinsic factors, including mutations in various EGFR domains, on the receptor's oligomerization. Our results demonstrate that EGFR oligomerization increases with removal of cholesterol or sphingolipids or the disruption of GM3-EGFR interactions, indicating raft association. However, oligomerization is not significantly influenced by the cytoskeleton. Mutations in either I706/V948 residues or E685/E687/E690 residues in the kinase and juxtamembrane domains, respectively, lead to a decrease in oligomerization, indicating their necessity for EGFR dimerization. Finally, EGFR phosphorylation is oligomerization dependent, involving the extracellular domain (550-580 residues). Coupled with biochemical investigations, camera-based N&B indicates that EGFR oligomerization and phosphorylation are the outcomes of several molecular interactions involving the lipid content and structure of the cell membrane and multiple residues in the kinase, juxtamembrane, and extracellular domains.
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Affiliation(s)
- Harikrushnan Balasubramanian
- Department of Biological Sciences and NUS Centre for Bio-Imaging Sciences, National University of Singapore, Singapore, Singapore
| | - Jagadish Sankaran
- Department of Biological Sciences and NUS Centre for Bio-Imaging Sciences, National University of Singapore, Singapore, Singapore
| | - Shambhavi Pandey
- Department of Biological Sciences and NUS Centre for Bio-Imaging Sciences, National University of Singapore, Singapore, Singapore
| | - Corinna Jie Hui Goh
- Department of Biological Sciences and NUS Centre for Bio-Imaging Sciences, National University of Singapore, Singapore, Singapore
| | - Thorsten Wohland
- Department of Biological Sciences and NUS Centre for Bio-Imaging Sciences, National University of Singapore, Singapore, Singapore; Department of Chemistry, National University of Singapore, Singapore, Singapore.
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11
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Tantirimudalige SN, Raghuvamsi PV, Sharma KK, Wei Bao JC, Anand GS, Wohland T. The ganglioside GM1a functions as a coreceptor/attachment factor for dengue virus during infection. J Biol Chem 2022; 298:102570. [PMID: 36209827 PMCID: PMC9650044 DOI: 10.1016/j.jbc.2022.102570] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Revised: 09/29/2022] [Accepted: 10/01/2022] [Indexed: 11/09/2022] Open
Abstract
Dengue virus (DENV) is a flavivirus causing an estimated 390 million infections per year around the world. Despite the immense global health and economic impact of this virus, its true receptor(s) for internalization into live cells has not yet been identified, and no successful antivirals or treatments have been isolated to this date. This study aims to improve our understanding of virus entry routes by exploring the sialic acid-based cell surface molecule GM1a and its role in DENV infection. We studied the interaction of the virus with GM1a using fluorescence correlation spectroscopy, fluorescence crosscorrelation spectroscopy, imaging fluorescence correlation spectroscopy, amide hydrogen/deuterium exchange mass spectrometry, and isothermal titration calorimetry. Additionally, we explored the effect of this interaction on infectivity and movement of the virus during infection was explored using plaque assay and fluorescence-based imaging and single particle tracking. GM1a was deemed to interact with DENV at domain I (DI) and domain II (DII) of the E protein of the protein coat at quaternary contacts of a fully assembled virus, leading to a 10-fold and 7-fold increase in infectivity for DENV1 and DENV2 in mammalian cell systems, respectively. We determined that the interaction of the virus with GM1a triggers a speeding up of virus movement on live cell surfaces, possibly resulting from a reduction in rigidity of cellular rafts during infection. Collectively, our results suggest that GM1a functions as a coreceptor/attachment factor for DENV during infection in mammalian systems.
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Affiliation(s)
- Sarala Neomi Tantirimudalige
- Department of Biological Sciences, National University of Singapore, Singapore, Singapore; Centre for Bioimaging Sciences, National University of Singapore, Singapore, Singapore
| | - Palur Venkata Raghuvamsi
- Department of Biological Sciences, National University of Singapore, Singapore, Singapore; Bioinformatics Institute (A∗STAR), Singapore, Singapore
| | - Kamal Kant Sharma
- Department of Biological Sciences, National University of Singapore, Singapore, Singapore; Centre for Bioimaging Sciences, National University of Singapore, Singapore, Singapore
| | - Jonathan Chua Wei Bao
- Department of Biological Sciences, National University of Singapore, Singapore, Singapore
| | - Ganesh S Anand
- Department of Biological Sciences, National University of Singapore, Singapore, Singapore; Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania, USA
| | - Thorsten Wohland
- Department of Biological Sciences, National University of Singapore, Singapore, Singapore; Centre for Bioimaging Sciences, National University of Singapore, Singapore, Singapore; Department of Chemistry, National University of Singapore, Singapore, Singapore.
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12
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Sankaran J, Balasubramanian H, Tang WH, Ng XW, Röllin A, Wohland T. Simultaneous spatiotemporal super-resolution and multi-parametric fluorescence microscopy. Nat Commun 2021; 12:1748. [PMID: 33741958 PMCID: PMC7979808 DOI: 10.1038/s41467-021-22002-9] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2020] [Accepted: 02/15/2021] [Indexed: 11/29/2022] Open
Abstract
Super-resolution microscopy and single molecule fluorescence spectroscopy require mutually exclusive experimental strategies optimizing either temporal or spatial resolution. To achieve both, we implement a GPU-supported, camera-based measurement strategy that highly resolves spatial structures (~100 nm), temporal dynamics (~2 ms), and molecular brightness from the exact same data set. Simultaneous super-resolution of spatial and temporal details leads to an improved precision in estimating the diffusion coefficient of the actin binding polypeptide Lifeact and corrects structural artefacts. Multi-parametric analysis of epidermal growth factor receptor (EGFR) and Lifeact suggests that the domain partitioning of EGFR is primarily determined by EGFR-membrane interactions, possibly sub-resolution clustering and inter-EGFR interactions but is largely independent of EGFR-actin interactions. These results demonstrate that pixel-wise cross-correlation of parameters obtained from different techniques on the same data set enables robust physicochemical parameter estimation and provides biological knowledge that cannot be obtained from sequential measurements.
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Affiliation(s)
- Jagadish Sankaran
- Department of Biological Sciences and NUS Centre for Bio-Imaging Sciences, National University of Singapore, Singapore, Singapore
| | - Harikrushnan Balasubramanian
- Department of Biological Sciences and NUS Centre for Bio-Imaging Sciences, National University of Singapore, Singapore, Singapore
| | - Wai Hoh Tang
- Department of Statistics and Applied Probability, National University of Singapore, Singapore, Singapore
| | - Xue Wen Ng
- Department of Biological Sciences and NUS Centre for Bio-Imaging Sciences, National University of Singapore, Singapore, Singapore
- Department of Chemistry, National University of Singapore, Singapore, Singapore
| | - Adrian Röllin
- Department of Statistics and Applied Probability, National University of Singapore, Singapore, Singapore
| | - Thorsten Wohland
- Department of Biological Sciences and NUS Centre for Bio-Imaging Sciences, National University of Singapore, Singapore, Singapore.
- Department of Chemistry, National University of Singapore, Singapore, Singapore.
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13
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Hackl S, Ng XW, Lu D, Wohland T, Becker CFW. Cytoskeleton-dependent clustering of membrane-bound prion protein on the cell surface. J Biol Chem 2021; 296:100359. [PMID: 33539927 PMCID: PMC7988330 DOI: 10.1016/j.jbc.2021.100359] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2020] [Revised: 01/26/2021] [Accepted: 01/28/2021] [Indexed: 12/23/2022] Open
Abstract
Prion diseases are a group of neurodegenerative disorders that infect animals and humans with proteinaceous particles called prions. Prions consist of scrapie prion protein (PrPSc), a misfolded version of the cellular prion protein (PrPC). During disease progression, PrPSc replicates by interacting with PrPC and inducing its conversion to PrPSc. Attachment of PrPC to cellular membranes via a glycosylphosphatidylinositol (GPI) anchor is critical for the conversion of PrPC into PrPSc. However, the mechanisms governing PrPC conversion and replication on the membrane remain largely unclear. Here, a site-selectively modified PrP variant equipped with a fluorescent GPI anchor mimic (PrP-GPI) was employed to directly observe PrP at the cellular membrane in neuronal SH-SY5Y cells. PrP-GPI exhibits a cholesterol-dependent membrane accumulation and a cytoskeleton-dependent mobility. More specifically, inhibition of actin polymerization reduced the diffusion of PrP-GPI indicating protein clustering, which resembles the initial step of PrP aggregation and conversion into its pathogenic isoform. An intact actin cytoskeleton might therefore prevent conversion of PrPC into PrPSc and offer new therapeutic angles.
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Affiliation(s)
- Stefanie Hackl
- Institute of Biological Chemistry, Faculty of Chemistry, University of Vienna, Vienna, Austria
| | - Xue Wen Ng
- Departments of Biological Sciences and Chemistry and Centre for Bioimaging Sciences (CBIS), National University of Singapore (NUS), Singapore
| | - Danqin Lu
- Departments of Biological Sciences and Chemistry and Centre for Bioimaging Sciences (CBIS), National University of Singapore (NUS), Singapore; School of Chemistry and Molecular Engineering, East China Normal University, Shanghai, China
| | - Thorsten Wohland
- Departments of Biological Sciences and Chemistry and Centre for Bioimaging Sciences (CBIS), National University of Singapore (NUS), Singapore
| | - Christian F W Becker
- Institute of Biological Chemistry, Faculty of Chemistry, University of Vienna, Vienna, Austria.
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14
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Hobson CM, O'Brien ET, Falvo MR, Superfine R. Combined Selective Plane Illumination Microscopy and FRAP Maps Intranuclear Diffusion of NLS-GFP. Biophys J 2020; 119:514-524. [PMID: 32681822 DOI: 10.1016/j.bpj.2020.07.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Revised: 06/16/2020] [Accepted: 07/02/2020] [Indexed: 11/27/2022] Open
Abstract
Since its initial development in 1976, fluorescence recovery after photobleaching (FRAP) has been one of the most popular tools for studying diffusion and protein dynamics in living cells. Its popularity is derived from the widespread availability of confocal microscopes and the relative ease of the experiment and analysis. FRAP, however, is limited in its ability to resolve spatial heterogeneity. Here, we combine selective plane illumination microscopy (SPIM) and FRAP to create SPIM-FRAP, wherein we use a sheet of light to bleach a two-dimensional (2D) plane and subsequently image the recovery of the same image plane. This provides simultaneous quantification of diffusion or protein recovery for every pixel in a given 2D slice, thus moving FRAP measurements beyond these previous limitations. We demonstrate this technique by mapping both intranuclear diffusion of NLS-GFP and recovery of 53BP1-mCherry, a marker for DNA damage, in live MDA-MB-231 cells. SPIM-FRAP proves to be an order of magnitude faster than fluorescence-correlation-spectroscopy-based techniques for such measurements. We observe large length-scale (>∼500 nm) heterogeneity in the recovery times of NLS-GFP, which is validated against simulated data sets. 2D maps of NLS-GFP recovery times showed no pixel-by-pixel correlation with histone density, although slower diffusion was observed in nucleoli. Additionally, recovery of 53BP1-mCherry was observed to be slowed at sites of DNA damage. We finally developed a diffusion simulation for our SPIM-FRAP experiments to compare across techniques. Our measured diffusion coefficients are on the order of previously reported results, thus validating the quantitative accuracy of SPIM-FRAP relative to well-established methods. With the recent rise of accessibility of SPIM systems, SPIM-FRAP is set to provide a straightforward means of quantifying the spatial distribution of protein recovery or diffusion in living cells.
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Affiliation(s)
- Chad M Hobson
- Department of Physics and Astronomy, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina.
| | - E Timothy O'Brien
- Department of Physics and Astronomy, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - Michael R Falvo
- Department of Physics and Astronomy, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - Richard Superfine
- Department of Applied Physical Sciences, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina.
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15
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Gupta A, Phang IY, Wohland T. To Hop or not to Hop: Exceptions in the FCS Diffusion Law. Biophys J 2020; 118:2434-2447. [PMID: 32333863 PMCID: PMC7231916 DOI: 10.1016/j.bpj.2020.04.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2020] [Revised: 03/31/2020] [Accepted: 04/06/2020] [Indexed: 12/13/2022] Open
Abstract
Diffusion obstacles in membranes have not been directly visualized because of fast membrane dynamics and the occurrence of subresolution molecular complexes. To understand the obstacle characteristics, mobility-based methods are often used as an indirect way of assessing the membrane structure. Molecular movement in biological plasma membranes is often characterized by anomalous diffusion, but the exact underlying mechanisms are still elusive. Imaging total internal reflection fluorescence correlation spectroscopy (ITIR-FCS) is a well-established mobility-based method that provides spatially resolved diffusion coefficient maps and is combined with FCS diffusion law analysis to examine subresolution membrane organization. In recent years, although FCS diffusion law analysis has been instrumental in providing new insights into the membrane structure below the optical diffraction limit, there are certain exceptions and anomalies that require further clarification. To this end, we correlate the membrane structural features imaged by atomic force microscopy (AFM) with the dynamics measured using ITIR-FCS. We perform ITIR-FCS measurements on supported lipid bilayers (SLBs) of various lipid compositions to characterize the anomalous diffusion of lipid molecules in distinct obstacle configurations, along with the high-resolution imaging of the membrane structures with AFM. Furthermore, we validate our experimental results by performing simulations on image grids with experimentally determined obstacle configurations. This study demonstrates that FCS diffusion law analysis is a powerful tool to determine membrane heterogeneities implied from dynamics measurements. Our results corroborate the commonly accepted interpretations of imaging FCS diffusion law analysis, and we show that exceptions happen when domains reach the percolation threshold in a biphasic membrane and a network of domains behaves rather like a meshwork, resulting in hop diffusion.
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Affiliation(s)
- Anjali Gupta
- Department of Biological Sciences and NUS Centre for Bio-Imaging Sciences, National University of Singapore, Singapore, Singapore
| | - Inn Yee Phang
- Institute of Materials Research and Engineering, Singapore, Singapore
| | - Thorsten Wohland
- Department of Biological Sciences and NUS Centre for Bio-Imaging Sciences, National University of Singapore, Singapore, Singapore; Department of Chemistry, National University of Singapore, Singapore, Singapore.
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16
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Crul T, Csoboz B, Gombos I, Marton A, Peter M, Balogh G, Vizler C, Szente L, Vigh L. Modulation of Plasma Membrane Composition and Microdomain Organization Impairs Heat Shock Protein Expression in B16-F10 Mouse Melanoma Cells. Cells 2020; 9:cells9040951. [PMID: 32290618 PMCID: PMC7226980 DOI: 10.3390/cells9040951] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Revised: 03/30/2020] [Accepted: 04/06/2020] [Indexed: 11/23/2022] Open
Abstract
The heat shock response (HSR) regulates induction of stress/heat shock proteins (HSPs) to preserve proteostasis during cellular stress. Earlier, our group established that the plasma membrane (PM) acts as a sensor and regulator of HSR through changes in its microdomain organization. PM microdomains such as lipid rafts, dynamic nanoscale assemblies enriched in cholesterol and sphingomyelin, and caveolae, cholesterol-rich PM invaginations, constitute clustering platforms for proteins functional in signaling cascades. Here, we aimed to compare the effect of cyclodextrin (MβCD)- and nystatin-induced cholesterol modulations on stress-activated expression of the representative HSPs, HSP70, and HSP25 in mouse B16-F10 melanoma cells. Depletion of cholesterol levels with MβCD impaired the heat-inducibility of both HSP70 and HSP25. Sequestration of cholesterol with nystatin impaired the heat-inducibility of HSP25 but not of HSP70. Imaging fluorescent correlation spectroscopy marked a modulated lateral diffusion constant of fluorescently labelled cholesterol in PM during cholesterol deprived conditions. Lipidomics analysis upon MβCD treatment revealed, next to cholesterol reductions, decreased lysophosphatidylcholine and phosphatidic acid levels. These data not only highlight the involvement of PM integrity in HSR but also suggest that altered dynamics of specific cholesterol pools could represent a mechanism to fine tune HSP expression.
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Affiliation(s)
- Tim Crul
- Institute of Biochemistry, Biological Research Centre, Szeged 6726, Hungary
- Correspondence: ; Tel.: +36-62-599-652
| | - Balint Csoboz
- Institute of Biochemistry, Biological Research Centre, Szeged 6726, Hungary
- Institute of Medial Biology, University of Tromsø, Tromsø 9037, Norway
| | - Imre Gombos
- Institute of Biochemistry, Biological Research Centre, Szeged 6726, Hungary
| | - Annamaria Marton
- Institute of Biochemistry, Biological Research Centre, Szeged 6726, Hungary
| | - Maria Peter
- Institute of Biochemistry, Biological Research Centre, Szeged 6726, Hungary
| | - Gabor Balogh
- Institute of Biochemistry, Biological Research Centre, Szeged 6726, Hungary
| | - Csaba Vizler
- Institute of Biochemistry, Biological Research Centre, Szeged 6726, Hungary
| | - Lajos Szente
- Cyclolab Cyclodextrin R&D Laboratory Ltd., 1097 Budapest, Hungary
| | - Laszlo Vigh
- Institute of Biochemistry, Biological Research Centre, Szeged 6726, Hungary
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17
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Rehó B, Lau L, Mocsár G, Müller G, Fadel L, Brázda P, Nagy L, Tóth K, Vámosi G. Simultaneous Mapping of Molecular Proximity and Comobility Reveals Agonist-Enhanced Dimerization and DNA Binding of Nuclear Receptors. Anal Chem 2020; 92:2207-2215. [PMID: 31870146 DOI: 10.1021/acs.analchem.9b04902] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Single Plane Illumination Microscopy (SPIM) revolutionized time lapse imaging of live cells and organisms due to its high speed and reduced photodamage. Quantitative mapping of molecular (co)mobility by fluorescence (cross-)correlation spectroscopy (F(C)CS) in a SPIM has been introduced to reveal molecular diffusion and binding. A complementary aspect of interactions is proximity, which can be studied by Förster resonance energy transfer (FRET). Here, we extend SPIM-FCCS by alternating laser excitation, which reduces false positive cross-correlation and facilitates comapping of FRET. Thus, different aspects of interacting systems can be studied simultaneously, and molecular subpopulations can be discriminated by multiparameter analysis. After demonstrating the benefits of the method on the AP-1 transcription factor, the dimerization and DNA binding behavior of retinoic acid receptor (RAR) and retinoid X receptor (RXR) is revealed, and an extension of the molecular switch model of the nuclear receptor action is proposed. Our data imply that RAR agonist enhances RAR-RXR heterodimerization, and chromatin binding/dimerization are positively correlated. We also propose a ligand induced conformational change bringing the N-termini of RAR and RXR closer together. The RXR agonist increased homodimerization of RXR suggesting that RXR may act as an autonomous transcription factor.
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Affiliation(s)
- Bálint Rehó
- Department of Biophysics and Cell Biology, Doctoral School of Molecular Medicine, Faculty of Medicine , University of Debrecen , Egyetem tér 1 , H-4032 Debrecen , Hungary
| | - Lukas Lau
- Division Biophysics of Macromolecules , German Cancer Research Center , Im Neuenheimer Feld 280 , D-69120 Heidelberg , Germany
| | - Gábor Mocsár
- Department of Biophysics and Cell Biology, Doctoral School of Molecular Medicine, Faculty of Medicine , University of Debrecen , Egyetem tér 1 , H-4032 Debrecen , Hungary
| | - Gabriele Müller
- Division Biophysics of Macromolecules , German Cancer Research Center , Im Neuenheimer Feld 280 , D-69120 Heidelberg , Germany
| | - Lina Fadel
- Department of Biophysics and Cell Biology, Doctoral School of Molecular Medicine, Faculty of Medicine , University of Debrecen , Egyetem tér 1 , H-4032 Debrecen , Hungary
| | - Péter Brázda
- Department of Biochemistry and Molecular Biology, Faculty of Medicine , University of Debrecen , Egyetem tér 1 , H-4032 Debrecen , Hungary
| | - László Nagy
- Department of Biochemistry and Molecular Biology, Faculty of Medicine , University of Debrecen , Egyetem tér 1 , H-4032 Debrecen , Hungary.,Johns Hopkins University School of Medicine , Department of Medicine and Biological Chemistry, Institute for Fundamental Biomedical Research, Johns Hopkins All Children's Hospital , 600 Fifth Street South Saint Petersburg , Florida 33701-4634 , United States
| | - Katalin Tóth
- Division Biophysics of Macromolecules , German Cancer Research Center , Im Neuenheimer Feld 280 , D-69120 Heidelberg , Germany
| | - György Vámosi
- Department of Biophysics and Cell Biology, Doctoral School of Molecular Medicine, Faculty of Medicine , University of Debrecen , Egyetem tér 1 , H-4032 Debrecen , Hungary
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18
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Bag N, Holowka DA, Baird BA. Imaging FCS delineates subtle heterogeneity in plasma membranes of resting mast cells. Mol Biol Cell 2020; 31:709-723. [PMID: 31895009 PMCID: PMC7202073 DOI: 10.1091/mbc.e19-10-0559] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
A myriad of transient, nanoscopic lipid- and protein-based interactions confer a steady-state organization of the plasma membrane in resting cells that is poised to orchestrate assembly of key signaling components upon reception of an extracellular stimulus. Although difficult to observe directly in live cells, these subtle interactions can be discerned by their impact on the diffusion of membrane constituents. Here, we quantified the diffusion properties of a panel of structurally distinct lipid, lipid-anchored, and transmembrane (TM) probes in RBL mast cells by imaging fluorescence correlation spectroscopy (ImFCS). We developed a statistical analysis of data combined from many pixels over multiple cells to characterize differences in diffusion coefficients as small as 10%, which reflect differences in underlying interactions. We found that the distinctive diffusion properties of lipid probes can be explained by their dynamic partitioning into Lo-like proteolipid nanodomains, which encompass a major fraction of the membrane and whose physical properties are influenced by actin polymerization. Effects on diffusion of functional protein modules in both lipid-anchored and TM probes reflect additional complexity in steady state membrane organization. The contrast we observe between different probes diffusing through the same membrane milieu represents the dynamic resting steady state, which serves as a baseline for monitoring plasma membrane remodeling that occurs upon stimulation.
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Affiliation(s)
- Nirmalya Bag
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY 14853
| | - David A Holowka
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY 14853
| | - Barbara A Baird
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY 14853
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19
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Xia W, Ling B, Wang L, Gao F, Chen H. A near-infrared upconversion luminescence total internal reflection platform for quantitative image analysis. Chem Commun (Camb) 2020; 56:8440-8443. [DOI: 10.1039/d0cc03119d] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
A near-infrared upconversion luminescence total internal reflection platform was developed for quantitative image analysis of ClO−.
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Affiliation(s)
- Wanying Xia
- Anhui Key Laboratory of Chemo-Biosensing
- Key Laboratory of Functional Molecular Solids
- Ministry of Education
- College of Chemistry and Materials Science
- Anhui Normal University
| | - Bo Ling
- Anhui Key Laboratory of Chemo-Biosensing
- Key Laboratory of Functional Molecular Solids
- Ministry of Education
- College of Chemistry and Materials Science
- Anhui Normal University
| | - Lun Wang
- Anhui Key Laboratory of Chemo-Biosensing
- Key Laboratory of Functional Molecular Solids
- Ministry of Education
- College of Chemistry and Materials Science
- Anhui Normal University
| | - Feng Gao
- Anhui Key Laboratory of Chemo-Biosensing
- Key Laboratory of Functional Molecular Solids
- Ministry of Education
- College of Chemistry and Materials Science
- Anhui Normal University
| | - Hongqi Chen
- Anhui Key Laboratory of Chemo-Biosensing
- Key Laboratory of Functional Molecular Solids
- Ministry of Education
- College of Chemistry and Materials Science
- Anhui Normal University
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20
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Gupta A, Muralidharan S, Torta F, Wenk MR, Wohland T. Long acyl chain ceramides govern cholesterol and cytoskeleton dependence of membrane outer leaflet dynamics. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2019; 1862:183153. [PMID: 31857071 DOI: 10.1016/j.bbamem.2019.183153] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2019] [Accepted: 12/09/2019] [Indexed: 12/20/2022]
Abstract
The spatiotemporal dynamics of the plasma membrane is a consequence of fine-tuned interactions between membrane components. However, the precise identity of molecular factors that maintain this delicate balance, which is lost even in cell membrane derived mimics, remains elusive. Here, we use two cell lines, CHO-K1 and RBL-2H3, which show differences in outer membrane organization, dynamics, and cytoskeleton coupling, to investigate the underlying factors. To our surprise, knock-down of the cytoskeleton-interacting Immunoglobulin E receptor, which is abundant in RBL-2H3 but not in CHO-K1 cells, is not responsible for lipid confinement or cytoskeleton coupling. A subsequent lipidomic analysis of the two cell membranes revealed differences in total membrane ceramide content (C16 to C24). Analysis of the dynamics and organization of ceramide treated live cell membranes by imaging fluorescence correlation spectroscopy demonstrates that C24 and C16 saturated ceramides uniquely alter membrane dynamics by promoting the formation of cholesterol-independent domains and by elevating the inter-leaflet coupling.
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Affiliation(s)
- Anjali Gupta
- Department of Biological Sciences, National University of Singapore, 14 Science Drive 4, Singapore; NUS Centre for Bio-Imaging Sciences, National University of Singapore, 14 Science Drive 4, 117557, Singapore
| | - Sneha Muralidharan
- Department of Biological Sciences, National University of Singapore, 14 Science Drive 4, Singapore
| | - Federico Torta
- Department of Biochemistry, National University of Singapore, 3 Science Drive 3, 117543, Singapore
| | - Markus R Wenk
- Department of Biological Sciences, National University of Singapore, 14 Science Drive 4, Singapore; Department of Biochemistry, National University of Singapore, 3 Science Drive 3, 117543, Singapore
| | - Thorsten Wohland
- Department of Biological Sciences, National University of Singapore, 14 Science Drive 4, Singapore; NUS Centre for Bio-Imaging Sciences, National University of Singapore, 14 Science Drive 4, 117557, Singapore; Department of Chemistry, National University of Singapore, 3 Science Drive 3, 117543, Singapore.
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21
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Azbazdar Y, Ozalp O, Sezgin E, Veerapathiran S, Duncan AL, Sansom MSP, Eggeling C, Wohland T, Karaca E, Ozhan G. More Favorable Palmitic Acid Over Palmitoleic Acid Modification of Wnt3 Ensures Its Localization and Activity in Plasma Membrane Domains. Front Cell Dev Biol 2019; 7:281. [PMID: 31803740 PMCID: PMC6873803 DOI: 10.3389/fcell.2019.00281] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Accepted: 10/31/2019] [Indexed: 12/17/2022] Open
Abstract
While the lateral organization of plasma membrane components has been shown to control binding of Wnt ligands to their receptors preferentially in the ordered membrane domains, the role of posttranslational lipid modification of Wnt on this selective binding is unknown. Here, we identify that the canonical Wnt is presumably acylated by palmitic acid, a saturated 16-carbon fatty acid, at a conserved serine residue. Acylation of Wnt3 is dispensable for its secretion and binding to Fz8 while it is essential for Wnt3's proper binding and domain-like diffusion in the ordered membrane domains. We further unravel that non-palmitoylated Wnt3 is unable to activate Wnt/β-catenin signaling either in zebrafish embryos or in mammalian cells. Based on these results, we propose that the lipidation of canonical Wnt, presumably by a saturated fatty acid, determines its competence in interacting with the receptors in the appropriate domains of the plasma membrane, ultimately keeping the signaling activity under control.
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Affiliation(s)
- Yagmur Azbazdar
- Izmir Biomedicine and Genome Center (IBG), Dokuz Eylul University Health Campus, Inciralti-Balcova, Izmir, Turkey
- Izmir International Biomedicine and Genome Institute (IBG-Izmir), Dokuz Eylul University, Inciralti-Balcova, Izmir, Turkey
| | - Ozgun Ozalp
- Izmir Biomedicine and Genome Center (IBG), Dokuz Eylul University Health Campus, Inciralti-Balcova, Izmir, Turkey
- Izmir International Biomedicine and Genome Institute (IBG-Izmir), Dokuz Eylul University, Inciralti-Balcova, Izmir, Turkey
| | - Erdinc Sezgin
- MRC Human Immunology Unit, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, United Kingdom
| | - Sapthaswaran Veerapathiran
- Department of Biological Sciences and Center for BioImaging Sciences, National University of Singapore, Singapore, Singapore
| | - Anna L. Duncan
- Department of Biochemistry, University of Oxford, Oxford, United Kingdom
| | - Mark S. P. Sansom
- Department of Biochemistry, University of Oxford, Oxford, United Kingdom
| | - Christian Eggeling
- MRC Human Immunology Unit, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, United Kingdom
- Department of Super-Resolution Microscopy, Institute for Applied Optics and Biophysics, Friedrich-Schiller-University Jena, Jena, Germany
- Department of Biophysical Imaging, Leibniz Institute of Photonic Technology e.V., Jena, Germany
| | - Thorsten Wohland
- Department of Biological Sciences and Center for BioImaging Sciences, National University of Singapore, Singapore, Singapore
- Department of Chemistry, National University of Singapore, Singapore, Singapore
| | - Ezgi Karaca
- Izmir Biomedicine and Genome Center (IBG), Dokuz Eylul University Health Campus, Inciralti-Balcova, Izmir, Turkey
- Izmir International Biomedicine and Genome Institute (IBG-Izmir), Dokuz Eylul University, Inciralti-Balcova, Izmir, Turkey
| | - Gunes Ozhan
- Izmir Biomedicine and Genome Center (IBG), Dokuz Eylul University Health Campus, Inciralti-Balcova, Izmir, Turkey
- Izmir International Biomedicine and Genome Institute (IBG-Izmir), Dokuz Eylul University, Inciralti-Balcova, Izmir, Turkey
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22
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Gupta A, Sankaran J, Wohland T. Fluorescence correlation spectroscopy: The technique and its applications in soft matter. PHYSICAL SCIENCES REVIEWS 2019. [DOI: 10.1515/psr-2017-0104] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Abstract
Fluorescence correlation spectroscopy (FCS) is a well-established single-molecule method used for the quantitative spatiotemporal analysis of dynamic processes in a wide range of samples. It possesses single-molecule sensitivity but provides ensemble averaged molecular parameters such as mobility, concentration, chemical reaction kinetics, photophysical properties and interaction properties. These parameters have been utilized to characterize a variety of soft matter systems. This review provides an overview of the basic principles of various FCS modalities, their instrumentation, data analysis, and the applications of FCS to soft matter systems.
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23
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Gupta A, Marzinek JK, Jefferies D, Bond PJ, Harryson P, Wohland T. The disordered plant dehydrin Lti30 protects the membrane during water-related stress by cross-linking lipids. J Biol Chem 2019; 294:6468-6482. [PMID: 30819802 DOI: 10.1074/jbc.ra118.007163] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2018] [Revised: 02/14/2019] [Indexed: 12/13/2022] Open
Abstract
Dehydrins are intrinsically disordered proteins, generally expressed in plants as a response to embryogenesis and water-related stress. Their suggested functions are in membrane stabilization and cell protection. All dehydrins contain at least one copy of the highly conserved K-segment, proposed to be a membrane-binding motif. The dehydrin Lti30 (Arabidopsis thaliana) is up-regulated during cold and drought stress conditions and comprises six K-segments, each with two adjacent histidines. Lti30 interacts with the membrane electrostatically via pH-dependent protonation of the histidines. In this work, we seek a molecular understanding of the membrane interaction mechanism of Lti30 by determining the diffusion and molecular organization of Lti30 on model membrane systems by imaging total internal reflection- fluorescence correlation spectroscopy (ITIR-FCS) and molecular dynamics (MD) simulations. The dependence of the diffusion coefficient explored by ITIR-FCS together with MD simulations yields insights into Lti30 binding, domain partitioning, and aggregation. The effect of Lti30 on membrane lipid diffusion was studied on fluorescently labeled supported lipid bilayers of different lipid compositions at mechanistically important pH conditions. In parallel, we compared the mode of diffusion for short individual K-segment peptides. The results indicate that Lti30 binds the lipid bilayer via electrostatics, which restricts the mobility of lipids and bound protein molecules. At low pH, Lti30 binding induced lipid microdomain formation as well as protein aggregation, which could be correlated with one another. Moreover, at physiological pH, Lti30 forms nanoscale aggregates when proximal to the membrane suggesting that Lti30 may protect the cell by "cross-linking" the membrane lipids.
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Affiliation(s)
- Anjali Gupta
- From the Center for BioImaging Sciences and.,the Department of Biological Sciences, National University of Singapore, 14 Science Dr. 4, Singapore 117543, Singapore
| | - Jan K Marzinek
- the Bioinformatics Institute (A*STAR), 30 Biopolis St., 07-01 Matrix, Singapore 138671, Singapore
| | - Damien Jefferies
- the Bioinformatics Institute (A*STAR), 30 Biopolis St., 07-01 Matrix, Singapore 138671, Singapore.,the School of Chemistry, University of Southampton, Highfield, Southampton SO17 1BJ, United Kingdom
| | - Peter J Bond
- the Department of Biological Sciences, National University of Singapore, 14 Science Dr. 4, Singapore 117543, Singapore.,the Bioinformatics Institute (A*STAR), 30 Biopolis St., 07-01 Matrix, Singapore 138671, Singapore
| | - Pia Harryson
- the Department of Biochemistry and Biophysics, Arrhenius Laboratories for Natural Sciences, Stockholm University, SE-106 91 Stockholm, Sweden, and
| | - Thorsten Wohland
- From the Center for BioImaging Sciences and .,the Department of Biological Sciences, National University of Singapore, 14 Science Dr. 4, Singapore 117543, Singapore.,Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543, Singapore
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24
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Damirchi S, Maliheh AKK, Heidari T, Es'haghi Z, Chamsaz M. A comparison between digital camera and spectrophotometer for sensitive and selective kinetic determination of brilliant green in wastewaters. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2019; 206:232-239. [PMID: 30119003 DOI: 10.1016/j.saa.2018.08.011] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2018] [Revised: 07/29/2018] [Accepted: 08/04/2018] [Indexed: 06/08/2023]
Abstract
In this study, a simple and novel kinetic spectrophotometric method has been proposed for the sensitive and highly selective determination of Brilliant Green. The method is based on the interaction of Brilliant Green with Triton X-100 in micellar media at room temperature. As a result of this interaction, the peak wavelength (625 nm) is gradually shifted toward longer wavelength region (634 nm) and more intensive hyper chromic effect has been seen. As well as, variations in the red, blue and green (RGB) components of the images as a function of time were observed. The kinetic interaction of Brilliant Green with Triton X-100 was recorded, using UV-Vis Spectrophotometer-diode array detector and a digital camera. The fixed-time method was used for the construction of a calibration curves. Brilliant Green can be measured in the range of 1.0 to 12.0 mg L-1 and 1.0 to 10.0 mg L-1with the detection limit of 0.047 mg L-1 and 0.037 mg L-1 using spectrophotometer and digital camera, respectively. The proposed method has been successfully used to determine Brilliant Green in some wastewaters such as textile dye effluent and goldfish farming water in the presence of some triphenylmethan dyes as the interferences.
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Affiliation(s)
- Saeed Damirchi
- Department of Chemistry, Faculty of Sciences, Ferdowsi University of Mashhad, Mashhad, Iran
| | | | - Tahereh Heidari
- Department of Chemistry, Faculty of Sciences, Ferdowsi University of Mashhad, Mashhad, Iran.
| | - Zarrin Es'haghi
- Department of Chemistry, Faculty of Sciences, Payame Noor University, PO Box 19395-3697, Tehran, Iran
| | - Mahmoud Chamsaz
- Department of Chemistry, Faculty of Sciences, Ferdowsi University of Mashhad, Mashhad, Iran
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25
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Schneider F, Waithe D, Lagerholm BC, Shrestha D, Sezgin E, Eggeling C, Fritzsche M. Statistical Analysis of Scanning Fluorescence Correlation Spectroscopy Data Differentiates Free from Hindered Diffusion. ACS NANO 2018; 12:8540-8546. [PMID: 30028588 PMCID: PMC6117752 DOI: 10.1021/acsnano.8b04080] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2018] [Accepted: 07/20/2018] [Indexed: 05/28/2023]
Abstract
Cells rely on versatile diffusion dynamics in their plasma membrane. Quantification of this often heterogeneous diffusion is essential to the understanding of cell regulation and function. Yet such measurements remain a major challenge in cell biology, usually due to low sampling throughput, a necessity for dedicated equipment, sophisticated fluorescent label strategies, and limited sensitivity. Here, we introduce a robust, broadly applicable statistical analysis pipeline for large scanning fluorescence correlation spectroscopy data sets, which uncovers the nanoscale heterogeneity of the plasma membrane in living cells by differentiating free from hindered diffusion modes of fluorescent lipid and protein analogues.
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Affiliation(s)
- Falk Schneider
- MRC
Human Immunology Unit, Wolfson Imaging Centre Oxford, and MRC Centre for Computational Biology, Weatherall Institute of Molecular Medicine, University
of Oxford, Headley Way, Oxford OX3 9DS, United Kingdom
| | - Dominic Waithe
- MRC
Human Immunology Unit, Wolfson Imaging Centre Oxford, and MRC Centre for Computational Biology, Weatherall Institute of Molecular Medicine, University
of Oxford, Headley Way, Oxford OX3 9DS, United Kingdom
| | - B. Christoffer Lagerholm
- MRC
Human Immunology Unit, Wolfson Imaging Centre Oxford, and MRC Centre for Computational Biology, Weatherall Institute of Molecular Medicine, University
of Oxford, Headley Way, Oxford OX3 9DS, United Kingdom
| | - Dilip Shrestha
- MRC
Human Immunology Unit, Wolfson Imaging Centre Oxford, and MRC Centre for Computational Biology, Weatherall Institute of Molecular Medicine, University
of Oxford, Headley Way, Oxford OX3 9DS, United Kingdom
| | - Erdinc Sezgin
- MRC
Human Immunology Unit, Wolfson Imaging Centre Oxford, and MRC Centre for Computational Biology, Weatherall Institute of Molecular Medicine, University
of Oxford, Headley Way, Oxford OX3 9DS, United Kingdom
| | - Christian Eggeling
- MRC
Human Immunology Unit, Wolfson Imaging Centre Oxford, and MRC Centre for Computational Biology, Weatherall Institute of Molecular Medicine, University
of Oxford, Headley Way, Oxford OX3 9DS, United Kingdom
- Institute of Applied
Optics, Friedrich-Schiller-University and
Leibniz Institute of Photonic Technology, Helmholtzweg 4, 07743 Jena, Germany
| | - Marco Fritzsche
- MRC
Human Immunology Unit, Wolfson Imaging Centre Oxford, and MRC Centre for Computational Biology, Weatherall Institute of Molecular Medicine, University
of Oxford, Headley Way, Oxford OX3 9DS, United Kingdom
- Kennedy
Institute for Rheumatology, University of
Oxford, Roosevelt Drive, Oxford OX3 7LF, United Kingdom
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26
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Damirchi S, Heidari T. Evaluation of digital camera as a portable colorimetric sensor for low-cost determination of inorganic arsenic (III) in industrial wastewaters by chemical hydride generation assisted-Fe(III) − 1, 10-phenanthroline as a green color agent. JOURNAL OF THE IRANIAN CHEMICAL SOCIETY 2018. [DOI: 10.1007/s13738-018-1443-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
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27
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Buchholz J, Krieger J, Bruschini C, Burri S, Ardelean A, Charbon E, Langowski J. Widefield High Frame Rate Single-Photon SPAD Imagers for SPIM-FCS. Biophys J 2018; 114:2455-2464. [PMID: 29753448 DOI: 10.1016/j.bpj.2018.04.029] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2017] [Revised: 04/06/2018] [Accepted: 04/13/2018] [Indexed: 11/24/2022] Open
Abstract
Photon-counting sensors based on standard complementary metal-oxide-semiconductor single-photon avalanche diodes (SPADs) represent an emerging class of imagers that enable the counting and/or timing of single photons at zero readout noise (better than high-speed electron-multiplying charge-coupling devices) and over large arrays. They have seen substantial progress over the last 15 years, increasing their spatial resolution, timing accuracy, and sensitivity while reducing spurious signals such as afterpulsing and dark counts. They are increasingly being applied for time-resolved applications with the added advantage of enabling real-time options such as autocorrelation. We report in this study on the use of such a state-of-the-art 512 × 128 SPAD array, capable of a time resolution of 10-5-10-6 s for full frames while retaining acceptable photosensitivity thanks to the use of dedicated microlenses, in a selective plane illumination-fluorescence correlation spectroscopy setup. The latter allows us to perform thousands of fluorescence-correlation spectroscopy measurements simultaneously in a two-dimensional slice of the sample. This high-speed SPAD imager enables the measurement of molecular motion of small fluorescent particles such as single chemical dye molecules. Inhomogeneities in the molecular detection efficiency were compensated for by means of a global fit of the auto- and cross-correlation curves, which also made a calibration-free measurement of various samples possible. The afterpulsing effect could also be mitigated, making the measurement of the diffusion of Alexa-488 possible, and the overall result quality was further improved by spatial binning. The particle concentrations in the focus tend to be overestimated by a factor of 1.7 compared to a confocal setup; a calibration is thus required if absolute concentrations need to be measured. The first high-speed selective plane illumination-fluorescence correlation spectroscopy in vivo measurements to our knowledge were also recorded: although two-component fit models could not be employed because of noise, the diffusion of eGFP oligomers in HeLa cells could be measured. Sensitivity and noise will be further improved in the next generation of SPAD-based widefield sensors, which are currently under testing.
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Affiliation(s)
- Jan Buchholz
- German Cancer Research Center, Heidelberg, Germany
| | - Jan Krieger
- German Cancer Research Center, Heidelberg, Germany
| | | | - Samuel Burri
- École polytechnique fédérale de Lausanne, Lausanne, Switzerland
| | - Andrei Ardelean
- École polytechnique fédérale de Lausanne, Lausanne, Switzerland
| | - Edoardo Charbon
- École polytechnique fédérale de Lausanne, Lausanne, Switzerland
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28
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Ng J, Kamm RD, Wohland T, Kraut RS. Evidence from ITIR-FCS Diffusion Studies that the Amyloid-Beta (Aβ) Peptide Does Not Perturb Plasma Membrane Fluidity in Neuronal Cells. J Mol Biol 2018; 430:3439-3453. [PMID: 29746852 DOI: 10.1016/j.jmb.2018.04.030] [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] [Received: 02/28/2018] [Revised: 04/27/2018] [Accepted: 04/29/2018] [Indexed: 10/17/2022]
Abstract
The amyloid-beta (Aβ) peptide, commonly found in elevated levels in the brains of patients with Alzheimer's disease (AD) and in the cerebrospinal fluid of individuals presenting mild cognitive impairment, is thought to be one of the major factors resulting in the onset of AD. Although observed and studied at the molecular level for several decades, the exact disease pathology of AD is still not totally clear. One way in which Aβ is thought to affect neurons is by influencing cell membrane fluidity, which could result in abnormal synaptic or signaling function. The effects of Aβ on the fluidity of biological membranes have been studied using numerous membrane models such as artificial lipid bilayers and vesicles, living cells and membranes extracted from animal models of AD, yet there is still no consensus as to what effects Aβ has, if any, on membrane fluidity. As one of the most precise and accurate means of assaying membrane dynamics, we have thus chosen fluorescence correlation spectroscopy to investigate the issue, using fluorescent membrane-targeted probes on living cells treated with Aβ(1-42) oligomers and observing possible changes in membrane diffusion. Effects of Aβ on viability in different cell types varied from no detectable effect to extensive cell death by 72 h post-exposure. However, there was no change in the fluidity of either ordered membrane domains or the bulk membrane in any of these cells within this period. Our conclusion from these results is that perturbation of membrane fluidity is not likely to be a factor in acute Aβ-induced cytotoxicity.
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Affiliation(s)
- Justin Ng
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, S637551, Singapore; Singapore-MIT Alliance for Research and Technology, BioSyM IRG, 1 Create Way, S138602, Singapore
| | - Roger D Kamm
- Singapore-MIT Alliance for Research and Technology, BioSyM IRG, 1 Create Way, S138602, Singapore
| | - Thorsten Wohland
- Singapore-MIT Alliance for Research and Technology, BioSyM IRG, 1 Create Way, S138602, Singapore; Department of Biological Sciences and Chemistry, National University of Singapore, 14 Science Drive 4, S117543, Singapore
| | - Rachel S Kraut
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, S637551, Singapore; Singapore-MIT Alliance for Research and Technology, BioSyM IRG, 1 Create Way, S138602, Singapore.
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29
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Veerapathiran S, Wohland T. The imaging FCS diffusion law in the presence of multiple diffusive modes. Methods 2017; 140-141:140-150. [PMID: 29203404 DOI: 10.1016/j.ymeth.2017.11.016] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2017] [Revised: 11/24/2017] [Accepted: 11/28/2017] [Indexed: 01/21/2023] Open
Abstract
The cellular plasma membrane is the barrier over which cells exchange materials and communicate with their surroundings, and thus plays the central role in cellular sensing and metabolism. Therefore, the investigation of plasma membrane organization and dynamics is required for understanding of cellular functions. The plasma membrane is a heterogeneous matrix. The presence of structures such as lipid and protein domains and the cytoskeleton meshwork poses a hindrance to the free diffusion of membrane associated biomolecules. However, these domains and the cytoskeleton meshwork barriers are below the optical diffraction limit with potentially short lifetimes and are not easily detected even in super-resolution microscopy. Therefore, dynamic measurements are often used to indirectly prove the existence of domains and barriers by analyzing the mode of diffusion of probe molecules. One of these tools is the Fluorescence Correlation Spectroscopy (FCS) diffusion law. The FCS diffusion law is a plot of diffusion time (τd) versus observation area. For at least three different diffusive modes - free, domain confined, and meshwork hindered hop diffusion - the expected plots have been characterized, typically by its y-intercept (τ0) when fit with a linear model, and have been verified in many cases. However, a description of τ0 has only been given for pure diffusive modes. But in many experimental cases it is not evident that a protein will undergo only one kind of diffusion, and thus the interpretation of the τ0 value is problematic. Here, we therefore address the question about the absolute value of τ0 in the case of complex diffusive modes, i.e. when either one molecule is domain confined and cytoskeleton hindered or when two molecules exhibit different diffusive behavior at the same position in a sample. In addition, we investigate how τ0 changes when the diffusive mode of a probe alters upon disruption of domains or the cytoskeleton by drug treatments. By a combination of experimental studies and simulations, we show that τ0 is not influenced equally by the different diffusive modes as typically found in cellular environments, and that it is the relative change of τ0 rather than its absolute value that provides information on the mode of diffusion.
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Affiliation(s)
- Sapthaswaran Veerapathiran
- Department of Biological Sciences and NUS Centre for Bio-Imaging Sciences, National University of Singapore, 14 Science Drive 4, 117557 Singapore, Singapore
| | - Thorsten Wohland
- Department of Biological Sciences and NUS Centre for Bio-Imaging Sciences, National University of Singapore, 14 Science Drive 4, 117557 Singapore, Singapore; Department of Chemistry, National University of Singapore, 3 Science Drive 3, 117543 Singapore, Singapore.
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30
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Zhang B, Liu H, Huang X, Dong C, Ren J. Size Distribution of Nanoparticles in Solution Characterized by Combining Resonance Light Scattering Correlation Spectroscopy with the Maximum Entropy Method. Anal Chem 2017; 89:12609-12616. [DOI: 10.1021/acs.analchem.7b04166] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Bocheng Zhang
- School of Chemistry & Chemical Engineering, State Key Laboratory of Metal Matrix Composites, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, P. R. China
| | - Heng Liu
- School of Chemistry & Chemical Engineering, State Key Laboratory of Metal Matrix Composites, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, P. R. China
| | - Xiangyi Huang
- School of Chemistry & Chemical Engineering, State Key Laboratory of Metal Matrix Composites, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, P. R. China
| | - Chaoqing Dong
- School of Chemistry & Chemical Engineering, State Key Laboratory of Metal Matrix Composites, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, P. R. China
| | - Jicun Ren
- School of Chemistry & Chemical Engineering, State Key Laboratory of Metal Matrix Composites, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, P. R. China
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31
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Sezgin E, Azbazdar Y, Ng XW, Teh C, Simons K, Weidinger G, Wohland T, Eggeling C, Ozhan G. Binding of canonical Wnt ligands to their receptor complexes occurs in ordered plasma membrane environments. FEBS J 2017. [PMID: 28626941 PMCID: PMC5599997 DOI: 10.1111/febs.14139] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
While the cytosolic events of Wnt/β‐catenin signaling (canonical Wnt signaling) pathway have been widely studied, only little is known about the molecular mechanisms involved in Wnt binding to its receptors at the plasma membrane. Here, we reveal the influence of the immediate plasma membrane environment on the canonical Wnt–receptor interaction. While the receptors are distributed both in ordered and disordered environments, Wnt binding to its receptors selectively occurs in more ordered membrane environments which appear to cointernalize with the Wnt‐receptor complex. Moreover, Wnt/β‐catenin signaling is significantly reduced when the membrane order is disturbed by specific inhibitors of certain lipids that prefer to localize at the ordered environments. Similarly, a reduction in Wnt signaling activity is observed in Niemann–Pick Type C disease cells where trafficking of ordered membrane lipid components to the plasma membrane is genetically impaired. We thus conclude that ordered plasma membrane environments are essential for binding of canonical Wnts to their receptor complexes and downstream signaling activity.
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Affiliation(s)
- Erdinc Sezgin
- MRC Human Immunology Unit, Weatherall Institute of Molecular Medicine, University of Oxford, UK
| | - Yagmur Azbazdar
- Izmir International Biomedicine and Genome Institute (iBG-izmir), Dokuz Eylul University, Izmir, Turkey.,Department of Medical Biology and Genetics, Dokuz Eylul University Medical School, Izmir, Turkey
| | - Xue W Ng
- Department of Chemistry and Center for BioImaging Sciences, National University of Singapore, Singapore
| | - Cathleen Teh
- Institute of Molecular and Cell Biology, Agency for Science, Technology and Research, Singapore, Singapore
| | - Kai Simons
- Max Planck Institute of Cell Biology and Genetics, Dresden, Germany
| | - Gilbert Weidinger
- Institute of Biochemistry and Molecular Biology, Ulm University, Germany
| | - Thorsten Wohland
- Department of Chemistry and Center for BioImaging Sciences, National University of Singapore, Singapore
| | - Christian Eggeling
- MRC Human Immunology Unit, Weatherall Institute of Molecular Medicine, University of Oxford, UK
| | - Gunes Ozhan
- Izmir International Biomedicine and Genome Institute (iBG-izmir), Dokuz Eylul University, Izmir, Turkey.,Department of Medical Biology and Genetics, Dokuz Eylul University Medical School, Izmir, Turkey
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32
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3D Protein Dynamics in the Cell Nucleus. Biophys J 2017; 112:133-142. [PMID: 28076804 DOI: 10.1016/j.bpj.2016.11.3196] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2016] [Revised: 11/15/2016] [Accepted: 11/21/2016] [Indexed: 11/20/2022] Open
Abstract
The three-dimensional (3D) architecture of the cell nucleus plays an important role in protein dynamics and in regulating gene expression. However, protein dynamics within the 3D nucleus are poorly understood. Here, we present, to our knowledge, a novel combination of 1) single-objective based light-sheet microscopy, 2) photoconvertible proteins, and 3) fluorescence correlation microscopy, to quantitatively measure 3D protein dynamics in the nucleus. We are able to acquire >3400 autocorrelation functions at multiple spatial positions within a nucleus, without significant photobleaching, allowing us to make reliable estimates of diffusion dynamics. Using this tool, we demonstrate spatial heterogeneity in Polymerase II dynamics in live U2OS cells. Further, we provide detailed measurements of human-Yes-associated protein diffusion dynamics in a human gastric cancer epithelial cell line.
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33
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Ng XW, Teh C, Korzh V, Wohland T. The Secreted Signaling Protein Wnt3 Is Associated with Membrane Domains In Vivo: A SPIM-FCS Study. Biophys J 2017; 111:418-429. [PMID: 27463143 DOI: 10.1016/j.bpj.2016.06.021] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2016] [Revised: 06/10/2016] [Accepted: 06/16/2016] [Indexed: 10/21/2022] Open
Abstract
Wnt3 is a morphogen that activates the Wnt signaling pathway and regulates a multitude of biological processes ranging from cell proliferation and cell fate specification to differentiation over embryonic induction to neural patterning. Recent studies have shown that the palmitoylation of Wnt3 by Porcupine, a membrane-bound O-acyltransferase, plays a significant role in the intracellular membrane trafficking of Wnt3 and subsequently, its secretion in live zebrafish embryos, where chemical inhibition of Porcupine reduced the membrane-bound and secreted fractions of Wnt3 and eventually led to defective brain development. However, the membrane distribution of Wnt3 in cells remains not fully understood. Here, we determine the membrane organization of functionally active Wnt3-EGFP in cerebellar cells of live transgenic zebrafish embryos and the role of palmitoylation in its organization using single plane illumination microscopy-fluorescence correlation spectroscopy (SPIM-FCS), a multiplexed modality of FCS, which generates maps of molecular dynamics, concentration, and interaction of biomolecules. The FCS diffusion law was applied to SPIM-FCS data to study the subresolution membrane organization of Wnt3. We find that at the plasma membrane in vivo, Wnt3 is associated with cholesterol-dependent domains. This association reduces with increasing concentrations of Porcupine inhibitor (C59), confirming the importance of palmitoylation of Wnt3 for its association with cholesterol-dependent domains. Reduction of membrane cholesterol also results in a decrease of Wnt3 association with cholesterol-dependent domains in live zebrafish. This demonstrates for the first time, to our knowledge, in live vertebrate embryos that Wnt3 is associated with cholesterol-dependent domains.
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Affiliation(s)
- Xue Wen Ng
- Department of Chemistry, National University of Singapore, Singapore, Singapore; Center for BioImaging Sciences, National University of Singapore, Singapore, Singapore
| | - Cathleen Teh
- Institute of Molecular and Cell Biology, Agency for Science, Technology and Research, Singapore, Singapore
| | - Vladimir Korzh
- Institute of Molecular and Cell Biology, Agency for Science, Technology and Research, Singapore, Singapore; Department of Biological Sciences, National University of Singapore, Singapore, Singapore
| | - Thorsten Wohland
- Department of Chemistry, National University of Singapore, Singapore, Singapore; Center for BioImaging Sciences, National University of Singapore, Singapore, Singapore; Department of Biological Sciences, National University of Singapore, Singapore, Singapore.
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34
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Macháň R, Foo YH, Wohland T. On the Equivalence of FCS and FRAP: Simultaneous Lipid Membrane Measurements. Biophys J 2017; 111:152-61. [PMID: 27410743 DOI: 10.1016/j.bpj.2016.06.001] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2016] [Revised: 06/02/2016] [Accepted: 06/02/2016] [Indexed: 10/21/2022] Open
Abstract
Fluorescence correlation spectroscopy (FCS) and fluorescence recovery after photobleaching (FRAP) are widely used methods to determine diffusion coefficients. However, they often do not yield the same results. With the advent of camera-based imaging FCS, which measures the diffusion coefficient in each pixel of an image, and proper bleaching corrections, it is now possible to measure the diffusion coefficient by FRAP and FCS in the exact same images. We thus performed simultaneous FCS and FRAP measurements on supported lipid bilayers and live cell membranes to test how far the two methods differ in their results and whether the methodological differences, in particular the high bleach intensity in FRAP, the bleach corrections, and the fitting procedures in the two methods explain observed differences. Overall, we find that the FRAP bleach intensity does not measurably influence the diffusion in the samples, but that bleach correction and fitting introduce large uncertainties in FRAP. We confirm our results by simulations.
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Affiliation(s)
- Radek Macháň
- Department of Biological Sciences and Centre for BioImaging Sciences, National University of Singapore, Singapore
| | - Yong Hwee Foo
- Mechanobiology Institute, National University of Singapore, Singapore
| | - Thorsten Wohland
- Department of Biological Sciences and Centre for BioImaging Sciences, National University of Singapore, Singapore; Department of Chemistry, National University of Singapore, Singapore.
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35
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Li J, Dong C, Ren J. Strategies to reduce detection volume of fluorescence correlation spectroscopy (FCS) to realize physiological concentration measurements. Trends Analyt Chem 2017. [DOI: 10.1016/j.trac.2017.02.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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36
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Huang S, Lim SY, Gupta A, Bag N, Wohland T. Plasma membrane organization and dynamics is probe and cell line dependent. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2016; 1859:1483-1492. [PMID: 27998689 DOI: 10.1016/j.bbamem.2016.12.009] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2016] [Revised: 12/03/2016] [Accepted: 12/08/2016] [Indexed: 01/01/2023]
Abstract
The action and interaction of membrane receptor proteins take place within the plasma membrane. The plasma membrane, however, is not a passive matrix. It rather takes an active role and regulates receptor distribution and function by its composition and the interaction of its lipid components with embedded and surrounding proteins. Furthermore, it is not a homogenous fluid but contains lipid and protein domains of various sizes and characteristic lifetimes which are important in regulating receptor function and signaling. The precise lateral organization of the plasma membrane, the differences between the inner and outer leaflet, and the influence of the cytoskeleton are still debated. Furthermore, there is a lack of comparisons of the organization and dynamics of the plasma membrane of different cell types. Therefore, we used four different specific membrane markers to test the lateral organization, the differences between the inner and outer membrane leaflet, and the influence of the cytoskeleton of up to five different cell lines, including Chinese hamster ovary (CHO-K1), Human cervical carcinoma (HeLa), neuroblastoma (SH-SY5Y), fibroblast (WI-38) and rat basophilic leukemia (RBL-2H3) cells by Imaging Total Internal Reflection (ITIR)-Fluorescence Correlation Spectroscopy (FCS). We measure diffusion in the temperature range of 298-310K to measure the Arrhenius activation energy (EArr) of diffusion and apply the FCS diffusion law to obtain information on the spatial organization of the probe molecules on the various cell membranes. Our results show clear differences of the FCS diffusion law and EArr for the different probes in dependence of their localization. These differences are similar in the outer and inner leaflet of the membrane. However, these values can differ significantly between different cell lines raising the question how molecular plasma membrane events measured in different cell lines can be compared. This article is part of a Special Issue entitled: Interactions between membrane receptors in cellular membranes edited by Kalina Hristova.
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Affiliation(s)
- Shuangru Huang
- Department of Biological Sciences, National University of Singapore, 14 Science Drive 4, Singapore; NUS Centre for Bio-Imaging Sciences, National University of Singapore, 14 Science Drive 4, Singapore
| | - Shi Ying Lim
- NUS Centre for Bio-Imaging Sciences, National University of Singapore, 14 Science Drive 4, Singapore; Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore
| | - Anjali Gupta
- Department of Biological Sciences, National University of Singapore, 14 Science Drive 4, Singapore; NUS Centre for Bio-Imaging Sciences, National University of Singapore, 14 Science Drive 4, Singapore
| | - Nirmalya Bag
- NUS Centre for Bio-Imaging Sciences, National University of Singapore, 14 Science Drive 4, Singapore; Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore
| | - Thorsten Wohland
- Department of Biological Sciences, National University of Singapore, 14 Science Drive 4, Singapore; NUS Centre for Bio-Imaging Sciences, National University of Singapore, 14 Science Drive 4, Singapore; Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore.
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37
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Plasma Membrane Organization of Epidermal Growth Factor Receptor in Resting and Ligand-Bound States. Biophys J 2016; 109:1925-36. [PMID: 26536269 DOI: 10.1016/j.bpj.2015.09.007] [Citation(s) in RCA: 56] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2015] [Revised: 08/24/2015] [Accepted: 09/08/2015] [Indexed: 12/21/2022] Open
Abstract
The spatial arrangement of the epidermal growth factor receptor (EGFR) on the cellular plasma membrane is one of the prime factors that control its downstream signaling pathways and related functions. However, the molecular organization, which spans the scale from nanometers to micrometer-size clusters, has not been resolved in detail, mainly due to a lack of techniques with the required spatiotemporal resolution. Therefore, we used imaging total internal reflection-fluorescence correlation spectroscopy to investigate EGFR dynamics on live CHO-K1 plasma membranes in resting and ligand-bound states. In combination with the fluorescence correlation spectroscopy diffusion law, this provides information on the subresolution organization of EGFR on cell membranes. We found that overall EGFR organization is sensitive to both cholesterol and the actin cytoskeleton. EGFR in the resting state is partly trapped in cholesterol-containing domains, whereas another fraction exhibits cholesterol independent trapping on the membrane. Disruption of the cytoskeleton leads to a broader range of EGFR diffusion coefficients and a reduction of hop diffusion. In the ligand-bound state we found a dose-dependent behavior. At 10 ng/mL EGF the EGFR is endocytosed and recycled to the membrane, whereas diffusion and organization do not change significantly. At 100 ng/mL EGF the EGFR forms clusters, which are subsequently internalized, whereas outside the clusters diffusivity increases and the organization of the receptor remains unchanged. After disruption of cholesterol-containing domains or actin cytoskeleton, EGF induces microscopic EGFR clusters on the membrane and endocytosis is inhibited.
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38
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Bag N, Ng XW, Sankaran J, Wohland T. Spatiotemporal mapping of diffusion dynamics and organization in plasma membranes. Methods Appl Fluoresc 2016; 4:034003. [PMID: 28355150 DOI: 10.1088/2050-6120/4/3/034003] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Imaging fluorescence correlation spectroscopy (FCS) and the related FCS diffusion law have been applied in recent years to investigate the diffusion modes of lipids and proteins in membranes. These efforts have provided new insights into the membrane structure below the optical diffraction limit, new information on the existence of lipid domains, and on the influence of the cytoskeleton on membrane dynamics. However, there has been no systematic study to evaluate how domain size, domain density, and the probe partition coefficient affect the resulting imaging FCS diffusion law parameters. Here, we characterize the effects of these factors on the FCS diffusion law through simulations and experiments on lipid bilayers and live cells. By segmenting images into smaller 7 × 7 pixel areas, we can evaluate the FCS diffusion law on areas smaller than 2 µm and thus provide detailed maps of information on the membrane structure and heterogeneity at this length scale. We support and extend this analysis by deriving a mathematical expression to calculate the mean squared displacement (MSDACF) from the autocorrelation function of imaging FCS, and demonstrate that the MSDACF plots depend on the existence of nanoscopic domains. Based on the results, we derive limits for the detection of domains depending on their size, density, and relative viscosity in comparison to the surroundings. Finally, we apply these measurements to bilayers and live cells using imaging total internal reflection FCS and single plane illumination microscopy FCS.
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Affiliation(s)
- Nirmalya Bag
- Department of Biological Sciences, National University of Singapore, 14 Science Drive 4, Singapore 117543, Singapore. NUS Centre for Bio-Imaging Sciences, National University of Singapore, 14 Science Drive 4, Singapore 117557, Singapore
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39
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Cooper JT, Harris JM. Spatially Multiplexed Imaging: Fluorescence Correlation Spectroscopy for Efficient Measurement of Molecular Diffusion at Solid-Liquid Interfaces. APPLIED SPECTROSCOPY 2016; 70:695-701. [PMID: 26887989 DOI: 10.1177/0003702816631312] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/08/2015] [Accepted: 08/02/2015] [Indexed: 06/05/2023]
Abstract
Fluorescence correlation spectroscopy (FCS) has become an important technique for the characterization of molecular dynamics, especially at interfaces. Fluorescence correlation spectroscopy provides both temporal and spatial resolution for measuring fast processes at equilibrium through analysis of noise in fluorescence intensities from the statistical fluctuations in a small number of molecules. The small molecular populations produce very low-level fluorescence signals, where time-averaging the fluorescence autocorrelation function is needed to generate reasonable signal-to-noise (S/N) ratios. Recently imaging cameras have been adapted to FCS measurements of molecular dynamics at interfaces (membranes and surfaces) through the use of electron-multiplying charge-coupled device (EM-CCD) detectors for acquisition of fluorescence from addressable areas on the detector. This approach provides a major advantage over traditional focused-spot FCS by allowing electronic control over the location and area of the acquired region on the sample surface. Imaging-FCS can also provide a spatial multiplexing advantage through its ability to measure intensity data from larger areas in parallel with no loss of time resolution. In this work, this multiplexing advantage is exploited to determine molecular diffusion rates from the simultaneous measurement of multiple areas on a surface, the autocorrelation traces from which are averaged to improve the S/N ratio. As proof of concept, the diffusion of 1,1'-dioctadecyl-3,3,3'3'-tetramethylindocarbocyanine perchlorate (DiI) on a C18-modified interface was measured using this multiplexed method and compared to autocorrelation data acquired from a single spot. Due to the slow thermal recovery of the EM-CCD that inhibits fast time-averaging, spatial multiplexing in imaging-FCS provides an eightyfold time savings to reach the same S/N ratio as multiple (time-averaged) measurements from a single spot.
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Affiliation(s)
- Justin T Cooper
- Department of Chemistry, University of Utah, Salt Lake City, Utah, USA
| | - Joel M Harris
- Department of Chemistry, University of Utah, Salt Lake City, Utah, USA
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40
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Siraj N, El-Zahab B, Hamdan S, Karam TE, Haber LH, Li M, Fakayode SO, Das S, Valle B, Strongin RM, Patonay G, Sintim HO, Baker GA, Powe A, Lowry M, Karolin JO, Geddes CD, Warner IM. Fluorescence, Phosphorescence, and Chemiluminescence. Anal Chem 2015; 88:170-202. [PMID: 26575092 DOI: 10.1021/acs.analchem.5b04109] [Citation(s) in RCA: 80] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Affiliation(s)
- Noureen Siraj
- Department of Chemistry, Louisiana State University , Baton Rouge, Louisiana 70803, United States
| | - Bilal El-Zahab
- Department of Mechanical and Materials Engineering, Florida International University , Miami, Florida 33174, United States
| | - Suzana Hamdan
- Department of Chemistry, Louisiana State University , Baton Rouge, Louisiana 70803, United States
| | - Tony E Karam
- Department of Chemistry, Louisiana State University , Baton Rouge, Louisiana 70803, United States
| | - Louis H Haber
- Department of Chemistry, Louisiana State University , Baton Rouge, Louisiana 70803, United States
| | - Min Li
- Process Development Center, Albemarle Corporation , Baton Rouge, Louisiana 70805, United States
| | - Sayo O Fakayode
- Department of Chemistry, Winston-Salem State University , Winston-Salem, North Carolina 27110, United States
| | - Susmita Das
- Department of Civil Engineering, Adamas Institute of Technology , Barasat, Kolkata 700126, West Bengal India
| | - Bertha Valle
- Department of Chemistry, Texas Southern University , Houston, Texas 77004, United States
| | - Robert M Strongin
- Department of Chemistry, Portland State University , Portland, Oregon 97207, United States
| | - Gabor Patonay
- Department of Chemistry, Georgia State University , Atlanta, Georgia 30302-4098, United States
| | - Herman O Sintim
- Department of Chemistry and Biochemistry, University of Maryland , College Park, Maryland 20742, United States
| | - Gary A Baker
- Department of Chemistry, University of Missouri Columbia , Columbia, Missouri 65211-7600, United States
| | - Aleeta Powe
- Department of Chemistry, University of Louisville , Louisville, Kentucky 40208, United States
| | - Mark Lowry
- Department of Chemistry, Portland State University , Portland, Oregon 97207, United States
| | - Jan O Karolin
- Institute of Fluorescence, University of Maryland Baltimore County , Baltimore, Maryland 21202, United States
| | - Chris D Geddes
- Institute of Fluorescence, University of Maryland Baltimore County , Baltimore, Maryland 21202, United States
| | - Isiah M Warner
- Department of Chemistry, Louisiana State University , Baton Rouge, Louisiana 70803, United States
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41
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Abstract
The local structure and composition of the outer membrane of an animal cell are important factors in the control of many membrane processes and mechanisms. These include signaling, sorting, and exo- and endocytic processes that are occurring all the time in a living cell. Paradoxically, not only are the local structure and composition of the membrane matters of much debate and discussion, the mechanisms that govern its genesis remain highly controversial. Here, we discuss a swathe of new technological advances that may be applied to understand the local structure and composition of the membrane of a living cell from the molecular scale to the scale of the whole membrane.
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Affiliation(s)
- Thomas S van Zanten
- National Centre for Biological Sciences (TIFR), Bellary Road, Bangalore, 560065, India
| | - Satyajit Mayor
- National Centre for Biological Sciences (TIFR), Bellary Road, Bangalore, 560065, India
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42
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Imaging fluorescence (cross-) correlation spectroscopy in live cells and organisms. Nat Protoc 2015; 10:1948-74. [DOI: 10.1038/nprot.2015.100] [Citation(s) in RCA: 127] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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43
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Yin J, Zhang A, Dong C, Ren J. An aptamer-based single particle method for sensitive detection of thrombin using fluorescent quantum dots as labeling probes. Talanta 2015; 144:13-9. [PMID: 26452786 DOI: 10.1016/j.talanta.2015.05.034] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2015] [Revised: 05/10/2015] [Accepted: 05/12/2015] [Indexed: 01/28/2023]
Abstract
In this study, an aptamer-based single particle method was developed for the thrombin detection in human serum samples using fluorescence correlation spectroscopy (FCS). In this method, quantum dots (QDs) were used as the fluorescent probes and thrombin-binding aptamer (TBA) was used as molecular recognition unit. When two QDs probes labeled with TBA (QD-TBA1 and QD-TBA2) are mixed in a sample containing thrombin targets, the binding of targets will cause QDs to form dimers (or oligomers) with bigger sizes, which leads to the nearly double increase in the characteristic diffusion time of QDs in the detection volume of FCS. FCS method can detect the change in the characteristic diffusion time of QDs. Firstly, the diffusion and blinking behaviors of QD-TBA probes in the presence of thrombin were investigated by FCS and total internal reflection fluorescence microscopy (TIRFM) imaging system, and the experimental results documented that QD-TBAs were bound together with "one-by-one" structure when thrombin were added into the solution. And then, the assay conditions were optimized in order to improve the sensitivity and specificity of this method. Under the optimized conditions, the linear range of the method is from 5.0 nM to 500 nM of thrombin, and the limit of detection is about 2.6 nM. Finally, this method was applied to homogeneous determination of thrombin in human serum samples.
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Affiliation(s)
- Jinjin Yin
- School of Chemistry and Chemical Engineering, State Key Laboratory of Metal Matrix Composites, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, PR China
| | - Aidi Zhang
- School of Chemistry and Chemical Engineering, State Key Laboratory of Metal Matrix Composites, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, PR China
| | - Chaoqing Dong
- School of Chemistry and Chemical Engineering, State Key Laboratory of Metal Matrix Composites, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, PR China
| | - Jicun Ren
- School of Chemistry and Chemical Engineering, State Key Laboratory of Metal Matrix Composites, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, PR China.
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44
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Pernuš A, Langowski J. Imaging Fos-Jun transcription factor mobility and interaction in live cells by single plane illumination-fluorescence cross correlation spectroscopy. PLoS One 2015; 10:e0123070. [PMID: 25875593 PMCID: PMC4397054 DOI: 10.1371/journal.pone.0123070] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2014] [Accepted: 02/27/2015] [Indexed: 11/20/2022] Open
Abstract
We collected mobility and interaction maps of c-Fos-eGFP and c-Jun-mRFP1 transcription factors within living cell nuclei. c-Fos dimerizes with c-Jun to form the transcription activator protein-1 (AP-1) which binds to the specific recognition site. To monitor this process, we used fluorescence cross-correlation spectroscopy on a single plane illumination microscope (SPIM-FCCS), which provides diffusion coefficient and protein-protein interaction data in the whole image plane simultaneously, instead of just one point on conventional confocal FCS. We find a strong correlation between diffusional mobility and interaction: regions of strong interaction show slow mobility. Controls containing either an eGFP-mRFP dimer, separately expressing eGFP and mRPF, or c-Fos-eGFP and c-Jun-mRFP1 mutants lacking dimerization and DNA-binding domains, showed no such correlation. These results extend our earlier findings from confocal FCCS to include spatial information.
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Affiliation(s)
- Agata Pernuš
- Division Biophysics of Macromolecules, DKFZ, Heidelberg, Germany
| | - Jörg Langowski
- Division Biophysics of Macromolecules, DKFZ, Heidelberg, Germany
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45
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Huang H, Simsek MF, Jin W, Pralle A. Effect of receptor dimerization on membrane lipid raft structure continuously quantified on single cells by camera based fluorescence correlation spectroscopy. PLoS One 2015; 10:e0121777. [PMID: 25811483 PMCID: PMC4374828 DOI: 10.1371/journal.pone.0121777] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2014] [Accepted: 02/10/2015] [Indexed: 02/07/2023] Open
Abstract
Membrane bound cell signaling is modulated by the membrane ultra-structure, which itself may be affected by signaling. However, measuring the interaction of membrane proteins with membrane structures in intact cells in real-time poses considerable challenges. In this paper we present a non-destructive fluorescence method that quantifies these interactions in single cells, and is able to monitor the same cell continuously to observe small changes. This approach combines total internal fluorescence microscopy with fluorescence correlation spectroscopy to measure the protein's diffusion and molecular concentration in different sized areas simultaneously. It correctly differentiates proteins interacting with membrane fences from proteins interacting with cholesterol-stabilized domains, or lipid rafts. This method detects small perturbations of the membrane ultra-structure or of a protein's tendency to dimerize. Through continuous monitoring of single cells, we demonstrate how dimerization of GPI-anchored proteins increases their association with the structural domains. Using a dual-color approach we study the effect of dimerization of one GPI-anchored protein on another type of GPI-anchored protein expressed in the same cell. Scans over the cell surface reveal a correlation between cholesterol stabilized domains and membrane cytoskeleton.
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Affiliation(s)
- Heng Huang
- Department of Physics, University at Buffalo the State University of New York, Buffalo, New York, United States of America
| | - M. Fethullah Simsek
- Department of Physics, University at Buffalo the State University of New York, Buffalo, New York, United States of America
| | - Weixiang Jin
- Department of Physics, University at Buffalo the State University of New York, Buffalo, New York, United States of America
| | - Arnd Pralle
- Department of Physics, University at Buffalo the State University of New York, Buffalo, New York, United States of America
- Department of Biophysics and Physiology, University at Buffalo the State University of New York, Buffalo, New York, United States of America
- * E-mail:
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46
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Cooper J, Harris JM. Fluorescence-Correlation Spectroscopy Study of Molecular Transport within Reversed-Phase Chromatographic Particles Compared to Planar Model Surfaces. Anal Chem 2014; 86:11766-72. [DOI: 10.1021/ac503250a] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Justin Cooper
- Department of Chemistry, University of Utah, 315 South 1400
East, Salt Lake City, Utah 84112-0805, United States
| | - Joel M. Harris
- Department of Chemistry, University of Utah, 315 South 1400
East, Salt Lake City, Utah 84112-0805, United States
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47
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Dong C, Liu H, Ren J. Assessing the blinking state of fluorescent quantum dots in free solution by combining fluorescence correlation spectroscopy with ensemble spectroscopic methods. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2014; 30:12969-12976. [PMID: 25290853 DOI: 10.1021/la503055v] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
The current method for investigating the blinking behavior is to immobilize quantum dots (QDs) in the matrix and then apply a fluorescent technique to monitor the fluorescent trajectories of individual QDs. So far, no method can be used to directly assess the blinking state of ensemble QDs in free solution. In this study, a new method was described to characterize the blinking state of the QDs in free solution by combining single molecule fluorescence correlation spectroscopy (FCS) with ensemble spectroscopic methods. Its principle is based on the observation that the apparent concentration of bright QDs obtained by FCS is less than its actual concentration measured by ensemble spectroscopic method due to the QDs blinking. We proposed a blinking index (Kblink) for characterizing the blinking state of QDs, and Kblink is defined as the ratio of the actual concentration (Cb,actual) measured by the ensemble spectroscopic method to the apparent concentration (Cb,app) of QDs obtained by FCS. The effects of certain factors such as laser intensity, growth process, and ligands on blinking of QDs were investigated. The Kblink data of QDs obtained were successfully used to characterize the blinking state of QDs and explain certain experimental results.
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Affiliation(s)
- Chaoqing Dong
- School of Chemistry & Chemical Engineering, State Key Laboratory of Metal Matrix Composites, Shanghai Jiao Tong University , 800 Dongchuan Road, Shanghai 200240, P. R. China
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48
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Weidemann T, Mücksch J, Schwille P. Fluorescence fluctuation microscopy: a diversified arsenal of methods to investigate molecular dynamics inside cells. Curr Opin Struct Biol 2014; 28:69-76. [DOI: 10.1016/j.sbi.2014.07.008] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2014] [Accepted: 07/11/2014] [Indexed: 11/26/2022]
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49
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Cooper JT, Harris JM. Imaging Fluorescence-Correlation Spectroscopy for Measuring Fast Surface Diffusion at Liquid/Solid Interfaces. Anal Chem 2014; 86:7618-26. [DOI: 10.1021/ac5014354] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Justin T. Cooper
- Department
of Chemistry, University of Utah, 315 South 1400 East, Salt Lake City, Utah 84112-0805, United States
| | - Joel M. Harris
- Department
of Chemistry, University of Utah, 315 South 1400 East, Salt Lake City, Utah 84112-0805, United States
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50
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Singh AP, Wohland T. Applications of imaging fluorescence correlation spectroscopy. Curr Opin Chem Biol 2014; 20:29-35. [DOI: 10.1016/j.cbpa.2014.04.006] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2014] [Revised: 04/10/2014] [Accepted: 04/11/2014] [Indexed: 11/16/2022]
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