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Electron transfer in protein modifications: from detection to imaging. Sci China Chem 2023. [DOI: 10.1007/s11426-022-1417-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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2
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Harashima T, Egami Y, Homma K, Jono Y, Kaneko S, Fujii S, Ono T, Nishino T. Unique Electrical Signature of Phosphate for Specific Single-Molecule Detection of Peptide Phosphorylation. J Am Chem Soc 2022; 144:17449-17456. [DOI: 10.1021/jacs.2c05787] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Takanori Harashima
- Department of Chemistry, School of Science, Tokyo Institute of Technology, 2-12-1 W4-11 Ookayama, Meguro-ku, Tokyo 152-8551, Japan
| | - Yoshiyuki Egami
- Division of Applied Physics, Faculty of Engineering, Hokkaido University, Sapporo, Hokkaido 060-8628, Japan
| | - Kanji Homma
- Department of Chemistry, School of Science, Tokyo Institute of Technology, 2-12-1 W4-11 Ookayama, Meguro-ku, Tokyo 152-8551, Japan
| | - Yuki Jono
- Department of Chemistry, School of Science, Tokyo Institute of Technology, 2-12-1 W4-11 Ookayama, Meguro-ku, Tokyo 152-8551, Japan
| | - Satoshi Kaneko
- Department of Chemistry, School of Science, Tokyo Institute of Technology, 2-12-1 W4-11 Ookayama, Meguro-ku, Tokyo 152-8551, Japan
| | - Shintaro Fujii
- Department of Chemistry, School of Science, Tokyo Institute of Technology, 2-12-1 W4-11 Ookayama, Meguro-ku, Tokyo 152-8551, Japan
| | - Tomoya Ono
- Department of Electrical and Electronic Engineering, Kobe University, Kobe, Hyogo 657-8501, Japan
| | - Tomoaki Nishino
- Department of Chemistry, School of Science, Tokyo Institute of Technology, 2-12-1 W4-11 Ookayama, Meguro-ku, Tokyo 152-8551, Japan
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It Takes More than Two to Tango: Complex, Hierarchal, and Membrane-Modulated Interactions in the Regulation of Receptor Tyrosine Kinases. Cancers (Basel) 2022; 14:cancers14040944. [PMID: 35205690 PMCID: PMC8869822 DOI: 10.3390/cancers14040944] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Revised: 02/09/2022] [Accepted: 02/12/2022] [Indexed: 12/18/2022] Open
Abstract
The search for an understanding of how cell fate and motility are regulated is not a purely scientific undertaking, but it can also lead to rationally designed therapies against cancer. The discovery of tyrosine kinases about half a century ago, the subsequent characterization of certain transmembrane receptors harboring tyrosine kinase activity, and their connection to the development of human cancer ushered in a new age with the hope of finding a treatment for malignant diseases in the foreseeable future. However, painstaking efforts were required to uncover the principles of how these receptors with intrinsic tyrosine kinase activity are regulated. Developments in molecular and structural biology and biophysical approaches paved the way towards better understanding of these pathways. Discoveries in the past twenty years first resulted in the formulation of textbook dogmas, such as dimerization-driven receptor association, which were followed by fine-tuning the model. In this review, the role of molecular interactions taking place during the activation of receptor tyrosine kinases, with special attention to the epidermal growth factor receptor family, will be discussed. The fact that these receptors are anchored in the membrane provides ample opportunities for modulatory lipid-protein interactions that will be considered in detail in the second part of the manuscript. Although qualitative and quantitative alterations in lipids in cancer are not sufficient in their own right to drive the malignant transformation, they both contribute to tumor formation and also provide ways to treat cancer. The review will be concluded with a summary of these medical aspects of lipid-protein interactions.
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Cooperation and Interplay between EGFR Signalling and Extracellular Vesicle Biogenesis in Cancer. Cells 2020; 9:cells9122639. [PMID: 33302515 PMCID: PMC7764760 DOI: 10.3390/cells9122639] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Revised: 11/30/2020] [Accepted: 12/02/2020] [Indexed: 12/13/2022] Open
Abstract
Epidermal growth factor receptor (EGFR) takes centre stage in carcinogenesis throughout its entire cellular trafficking odyssey. When loaded in extracellular vesicles (EVs), EGFR is one of the key proteins involved in the transfer of information between parental cancer and bystander cells in the tumour microenvironment. To hijack EVs, EGFR needs to play multiple signalling roles in the life cycle of EVs. The receptor is involved in the biogenesis of specific EV subpopulations, it signals as an active cargo, and it can influence the uptake of EVs by recipient cells. EGFR regulates its own inclusion in EVs through feedback loops during disease progression and in response to challenges such as hypoxia, epithelial-to-mesenchymal transition and drugs. Here, we highlight how the spatiotemporal rules that regulate EGFR intracellular function intersect with and influence different EV biogenesis pathways and discuss key regulatory features and interactions of this interplay. We also elaborate on outstanding questions relating to EGFR-driven EV biogenesis and available methods to explore them. This mechanistic understanding will be key to unravelling the functional consequences of direct anti-EGFR targeted and indirect EGFR-impacting cancer therapies on the secretion of pro-tumoural EVs and on their effects on drug resistance and microenvironment subversion.
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Zhang Y, Li S, Ma XT, He XW, Li WY, Zhang YK. Carbon dots-embedded epitope imprinted polymer for targeted fluorescence imaging of cervical cancer via recognition of epidermal growth factor receptor. Mikrochim Acta 2020; 187:228. [PMID: 32170469 DOI: 10.1007/s00604-020-4198-7] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2019] [Accepted: 02/25/2020] [Indexed: 12/29/2022]
Abstract
A carbon dots-embedded epitope imprinted polymer (C-MIP) was fabricated for targeted fluorescence imaging of cervical cancer by specifically recognizing the epidermal growth factor receptor (EGFR). The core-shell C-MIP was prepared by a reverse microemulsion polymerization method. This method used silica nanoparticles embedded with carbon dots as carriers, acrylamide as the main functional monomer, and N-terminal nonapeptides of EGFR modified by palmitic acid as templates. A series of characterizations (transmission electron microscope, dynamic light scattering, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, zeta potential, and energy dispersive X-ray spectroscopy) prove the successful synthesis of C-MIP. The fluorescence of C-MIP is quenched by the epitopes of EGFR due to the specific recognition of epitopes of EGFR through their imprinted cavities (analytical excitation/emission wavelengths, 540 nm/610 nm). The linear range of fluorescence quenching is 2.0 to 15.0 μg mL-1 and the determination limit is 0.73 μg mL-1. The targeted imaging capabilities of C-MIP are demonstrated through in vitro and in vivo experiments. The laser confocal imaging results indicate that HeLa cells (over-expression EGFR) incubated with C-MIP show stronger fluorescence than that of MCF-7 cells (low-expression EGFR), revealing that C-MIP can target tumor cells overexpressing EGFR. The results of imaging experiments in tumor-bearing mice exhibit that C-MIP has a better imaging effect than C-NIP, which further proves the targeted imaging ability of C-MIP in vivo. Graphical abstract An oriented epitope imprinted polymer embedded with carbon dots was prepared for the determination of the epitopes of epidermal growth factor receptor and targeted fluorescence imaging of cervical cancer.
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Affiliation(s)
- Yue Zhang
- College of Chemistry, Research Center for Analytical Sciences, State Key Laboratory of Medicinal Chemical Biology, Tianjin Key Laboratory of Biosensing and Molecular Recognition, Nankai University, Tianjin, 300071, China
| | - Si Li
- College of Chemistry, Research Center for Analytical Sciences, State Key Laboratory of Medicinal Chemical Biology, Tianjin Key Laboratory of Biosensing and Molecular Recognition, Nankai University, Tianjin, 300071, China
| | - Xiao-Tong Ma
- College of Chemistry, Research Center for Analytical Sciences, State Key Laboratory of Medicinal Chemical Biology, Tianjin Key Laboratory of Biosensing and Molecular Recognition, Nankai University, Tianjin, 300071, China
| | - Xi-Wen He
- College of Chemistry, Research Center for Analytical Sciences, State Key Laboratory of Medicinal Chemical Biology, Tianjin Key Laboratory of Biosensing and Molecular Recognition, Nankai University, Tianjin, 300071, China
| | - Wen-You Li
- College of Chemistry, Research Center for Analytical Sciences, State Key Laboratory of Medicinal Chemical Biology, Tianjin Key Laboratory of Biosensing and Molecular Recognition, Nankai University, Tianjin, 300071, China.
| | - Yu-Kui Zhang
- College of Chemistry, Research Center for Analytical Sciences, State Key Laboratory of Medicinal Chemical Biology, Tianjin Key Laboratory of Biosensing and Molecular Recognition, Nankai University, Tianjin, 300071, China
- National Chromatographic Research and Analysis Center, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, 116023, China
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6
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Zhang S, Reinhard BM. Characterizing Large-Scale Receptor Clustering on the Single Cell Level: A Comparative Plasmon Coupling and Fluorescence Superresolution Microscopy Study. J Phys Chem B 2019; 123:5494-5505. [PMID: 31244098 DOI: 10.1021/acs.jpcb.9b05176] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Spatial clustering of cell membrane receptors has been indicated to play a regulatory role in signal initiation, and the distribution of receptors on the cell surface may represent a potential biomarker. To realize its potential for diagnostic purposes, scalable assays capable of mapping spatial receptor heterogeneity with high throughput are needed. In this work, we use gold nanoparticle (NP) labels with an average diameter of 72.17 ± 2.16 nm as bright markers for large-scale epidermal growth factor receptor (EGFR) clustering in hyperspectral plasmon coupling microscopy and compare the obtained clustering maps with those obtained through fluorescence superresolution microscopy (direct stochastic optical reconstruction microscopy, dSTORM). Our dSTORM experiments reveal average EGFR cluster sizes of 172 ± 99 and 150 ± 90 nm for MDA-MB-468 and HeLa, respectively. The cluster sizes decrease after EGFR activation. Hyperspectral imaging of the NP labels shows that differences in the EGFR cluster sizes are accompanied by differences in the average separations between electromagnetically coupled NPs. Because of the distance dependence of plasmon coupling, changes in the average interparticle separation result in significant spectral shifts. For the experimental conditions investigated in this work, hyperspectral plasmon coupling microscopy of NP labels identified the same trends in large-scale EGFR clustering as dSTORM, but the NP imaging approach provided the information in a fraction of the time. Both dSTORM and hyperspectral plasmon coupling microscopy confirm the cortical actin network as one structural component that determines the average size of EGFR clusters.
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Affiliation(s)
- Sandy Zhang
- Department of Chemistry and The Photonics Center , Boston University , Boston , Massachusetts 02215 , United States
| | - Björn M Reinhard
- Department of Chemistry and The Photonics Center , Boston University , Boston , Massachusetts 02215 , United States
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7
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Chen S, Imoukhuede PI. Multiplexing Angiogenic Receptor Quantification via Quantum Dots. Anal Chem 2019; 91:7603-7612. [DOI: 10.1021/acs.analchem.9b00238] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Affiliation(s)
- Si Chen
- Department of Bioengineering, University of Illinois at Urbana−Champaign, Urbana, Illinois 61801, United States
- Department of Biomedical Engineering, Washington University in Saint Louis, St. Louis, Missouri 63130, United States
| | - P. I. Imoukhuede
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana−Champaign, Urbana, Illinois 61801, United States
- Department of Biomedical Engineering, Washington University in Saint Louis, St. Louis, Missouri 63130, United States
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Komorowski M, Tawfik DS. The Limited Information Capacity of Cross-Reactive Sensors Drives the Evolutionary Expansion of Signaling. Cell Syst 2019; 8:76-85.e6. [PMID: 30660612 DOI: 10.1016/j.cels.2018.12.006] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2018] [Revised: 10/15/2018] [Accepted: 12/10/2018] [Indexed: 01/10/2023]
Abstract
Signaling systems expand by duplications of various components, be it receptors or downstream effectors. However, whether and how duplicated components contribute to higher signaling capacity is unclear, especially because in most cases, their specificities overlap. Using information theory, we found that augmentation of capacity by an increase in the copy number is strongly limited by logarithmic diminishing returns. Moreover, counter to conventional biochemical wisdom, refinements of the response mechanism, e.g., by cooperativity or allostery, do not increase the overall signaling capacity. However, signaling capacity nearly doubles when a promiscuous, non-cognate ligand becomes explicitly recognized via duplication and partial divergence of signaling components. Our findings suggest that expansion of signaling components via duplication and enlistment of promiscuously acting cues is virtually the only accessible evolutionary strategy to achieve overall high-signaling capacity despite overlapping specificities and molecular noise. This mode of expansion also explains the highly cross-wired architecture of signaling pathways.
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Affiliation(s)
- Michał Komorowski
- Institute of Fundamental Technological Research, Polish Academy of Sciences, Warsaw 02-106, Poland.
| | - Dan S Tawfik
- Weizmann Institute of Science, The Department of Biomolecular Sciences, Rehovot 7610001, Israel
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9
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Claus J, Patel G, Autore F, Colomba A, Weitsman G, Soliman TN, Roberts S, Zanetti-Domingues LC, Hirsch M, Collu F, George R, Ortiz-Zapater E, Barber PR, Vojnovic B, Yarden Y, Martin-Fernandez ML, Cameron A, Fraternali F, Ng T, Parker PJ. Inhibitor-induced HER2-HER3 heterodimerisation promotes proliferation through a novel dimer interface. eLife 2018; 7:e32271. [PMID: 29712619 PMCID: PMC5929906 DOI: 10.7554/elife.32271] [Citation(s) in RCA: 48] [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: 09/25/2017] [Accepted: 03/21/2018] [Indexed: 12/13/2022] Open
Abstract
While targeted therapy against HER2 is an effective first-line treatment in HER2+ breast cancer, acquired resistance remains a clinical challenge. The pseudokinase HER3, heterodimerisation partner of HER2, is widely implicated in the resistance to HER2-mediated therapy. Here, we show that lapatinib, an ATP-competitive inhibitor of HER2, is able to induce proliferation cooperatively with the HER3 ligand neuregulin. This counterintuitive synergy between inhibitor and growth factor depends on their ability to promote atypical HER2-HER3 heterodimerisation. By stabilising a particular HER2 conformer, lapatinib drives HER2-HER3 kinase domain heterocomplex formation. This dimer exists in a head-to-head orientation distinct from the canonical asymmetric active dimer. The associated clustering observed for these dimers predisposes to neuregulin responses, affording a proliferative outcome. Our findings provide mechanistic insights into the liabilities involved in targeting kinases with ATP-competitive inhibitors and highlight the complex role of protein conformation in acquired resistance.
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Affiliation(s)
- Jeroen Claus
- Protein Phosphorylation LaboratoryThe Francis Crick InstituteLondonUnited Kingdom
| | - Gargi Patel
- Richard Dimbleby Department of Cancer Research, Randall Division and Division of Cancer StudiesKings College LondonLondonUnited Kingdom
- Sussex Cancer CentreBrighton and Sussex University HospitalsBrightonUnited States
| | - Flavia Autore
- Randall Division of Cell & Molecular BiophysicsKings College LondonLondonUnited Kingdom
| | - Audrey Colomba
- Protein Phosphorylation LaboratoryThe Francis Crick InstituteLondonUnited Kingdom
| | - Gregory Weitsman
- Richard Dimbleby Department of Cancer Research, Randall Division and Division of Cancer StudiesKings College LondonLondonUnited Kingdom
| | - Tanya N Soliman
- Protein Phosphorylation LaboratoryThe Francis Crick InstituteLondonUnited Kingdom
| | - Selene Roberts
- Central Laser Facility, Research Complex at Harwell, Science and Technology Facilities CouncilRutherford Appleton LaboratoryDidcotUnited Kingdom
| | - Laura C Zanetti-Domingues
- Central Laser Facility, Research Complex at Harwell, Science and Technology Facilities CouncilRutherford Appleton LaboratoryDidcotUnited Kingdom
| | - Michael Hirsch
- Central Laser Facility, Research Complex at Harwell, Science and Technology Facilities CouncilRutherford Appleton LaboratoryDidcotUnited Kingdom
| | - Francesca Collu
- Randall Division of Cell & Molecular BiophysicsKings College LondonLondonUnited Kingdom
| | - Roger George
- The Structural Biology Science Technology PlatformThe Francis Crick InstituteLondonUnited Kingdom
| | - Elena Ortiz-Zapater
- Department of Asthma, Allergy and Respiratory ScienceKing’s College London, Guy’s HospitalLondonUnited Kingdom
| | - Paul R Barber
- Randall Division of Cell & Molecular BiophysicsKings College LondonLondonUnited Kingdom
- UCL Cancer InstituteUniversity College LondonLondonUnited Kingdom
| | - Boris Vojnovic
- Randall Division of Cell & Molecular BiophysicsKings College LondonLondonUnited Kingdom
- Department of OncologyCancer Research UK and Medical Research Council Oxford Institute for Radiation OncologyOxfordUnited Kingdom
| | - Yosef Yarden
- Department of Biological RegulationWeizmann Institute of ScienceRehovotIsrael
| | - Marisa L Martin-Fernandez
- Central Laser Facility, Research Complex at Harwell, Science and Technology Facilities CouncilRutherford Appleton LaboratoryDidcotUnited Kingdom
| | - Angus Cameron
- Protein Phosphorylation LaboratoryThe Francis Crick InstituteLondonUnited Kingdom
- Barts Cancer InstituteQueen Mary University of LondonLondonUnited Kingdom
| | - Franca Fraternali
- Randall Division of Cell & Molecular BiophysicsKings College LondonLondonUnited Kingdom
| | - Tony Ng
- Richard Dimbleby Department of Cancer Research, Randall Division and Division of Cancer StudiesKings College LondonLondonUnited Kingdom
- UCL Cancer InstituteUniversity College LondonLondonUnited Kingdom
- Breast Cancer Now Research Unit, Department of Research OncologyGuy’s Hospital King’s College London School of MedicineLondonUnited Kingdom
| | - Peter J Parker
- Protein Phosphorylation LaboratoryThe Francis Crick InstituteLondonUnited Kingdom
- School of Cancer and Pharmaceutical SciencesKing’s College London, Guy’s CampusLondonUnited Kingdom
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Volpe A, Man F, Lim L, Khoshnevisan A, Blower J, Blower PJ, Fruhwirth GO. Radionuclide-fluorescence Reporter Gene Imaging to Track Tumor Progression in Rodent Tumor Models. J Vis Exp 2018:57088. [PMID: 29608157 PMCID: PMC5931757 DOI: 10.3791/57088] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Metastasis is responsible for most cancer deaths. Despite extensive research, the mechanistic understanding of the complex processes governing metastasis remains incomplete. In vivo models are paramount for metastasis research, but require refinement. Tracking spontaneous metastasis by non-invasive in vivo imaging is now possible, but remains challenging as it requires long-time observation and high sensitivity. We describe a longitudinal combined radionuclide and fluorescence whole-body in vivo imaging approach for tracking tumor progression and spontaneous metastasis. This reporter gene methodology employs the sodium iodide symporter (NIS) fused to a fluorescent protein (FP). Cancer cells are engineered to stably express NIS-FP followed by selection based on fluorescence-activated cell sorting. Corresponding tumor models are established in mice. NIS-FP expressing cancer cells are tracked non-invasively in vivo at the whole-body level by positron emission tomography (PET) using the NIS radiotracer [18F]BF4-. PET is currently the most sensitive in vivo imaging technology available at this scale and enables reliable and absolute quantification. Current methods either rely on large cohorts of animals that are euthanized for metastasis assessment at varying time points, or rely on barely quantifiable 2D imaging. The advantages of the described method are: (i) highly sensitive non-invasive in vivo 3D PET imaging and quantification, (ii) automated PET tracer production, (iii) a significant reduction in required animal numbers due to repeat imaging options, (iv) the acquisition of paired data from subsequent imaging sessions providing better statistical data, and (v) the intrinsic option for ex vivo confirmation of cancer cells in tissues by fluorescence microscopy or cytometry. In this protocol, we describe all steps required for routine NIS-FP-afforded non-invasive in vivo cancer cell tracking using PET/CT and ex vivo confirmation of in vivo results. This protocol has applications beyond cancer research whenever in vivo localization, expansion and long-time monitoring of a cell population is of interest.
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Affiliation(s)
- Alessia Volpe
- Department of Imaging Chemistry and Biology, School of Biomedical Engineering and Imaging Sciences, King's College London
| | - Francis Man
- Department of Imaging Chemistry and Biology, School of Biomedical Engineering and Imaging Sciences, King's College London
| | - Lindsay Lim
- Department of Imaging Chemistry and Biology, School of Biomedical Engineering and Imaging Sciences, King's College London
| | - Alex Khoshnevisan
- Department of Imaging Chemistry and Biology, School of Biomedical Engineering and Imaging Sciences, King's College London
| | - Julia Blower
- Department of Imaging Chemistry and Biology, School of Biomedical Engineering and Imaging Sciences, King's College London
| | - Philip J Blower
- Department of Imaging Chemistry and Biology, School of Biomedical Engineering and Imaging Sciences, King's College London
| | - Gilbert O Fruhwirth
- Department of Imaging Chemistry and Biology, School of Biomedical Engineering and Imaging Sciences, King's College London;
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Dahmke IN, Verch A, Hermannsdörfer J, Peckys DB, Weatherup RS, Hofmann S, de Jonge N. Graphene Liquid Enclosure for Single-Molecule Analysis of Membrane Proteins in Whole Cells Using Electron Microscopy. ACS NANO 2017; 11:11108-11117. [PMID: 29023096 DOI: 10.1021/acsnano.7b05258] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Membrane proteins govern many important functions in cells via dynamic oligomerization into active complexes. However, analytical methods to study their distribution and functional state in relation to the cellular structure are currently limited. Here, we introduce a technique for studying single-membrane proteins within their native context of the intact plasma membrane. SKBR3 breast cancer cells were grown on silicon microchips with thin silicon nitride windows. The cells were fixed, and the epidermal growth factor receptor ErbB2 was specifically labeled with quantum dot (QD) nanoparticles. For correlative fluorescence- and liquid-phase electron microscopy, we enclosed the liquid samples by chemical vapor deposited (CVD) graphene films. Depending on the local cell thickness, QD labels were imaged with a spatial resolution of 2 nm at a low electron dose. The distribution and stoichiometric assembly of ErbB2 receptors were determined at several different cellular locations, including tunneling nanotubes, where we found higher levels of homodimerization at the connecting sites. This experimental approach is applicable to a wide range of cell lines and membrane proteins and particularly suitable for studies involving both inter- and intracellular heterogeneity in protein distribution and expression.
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Affiliation(s)
- Indra N Dahmke
- INM - Leibniz Institute for New Materials , D-66123 Saarbrücken, Germany
| | - Andreas Verch
- INM - Leibniz Institute for New Materials , D-66123 Saarbrücken, Germany
| | | | - Diana B Peckys
- Department of Biophysics, Saarland University , D-66421 Homburg, Germany
| | - Robert S Weatherup
- Engineering Department, University of Cambridge , Cambridge CB3 0FA, United Kingdom
| | - Stephan Hofmann
- Engineering Department, University of Cambridge , Cambridge CB3 0FA, United Kingdom
| | - Niels de Jonge
- INM - Leibniz Institute for New Materials , D-66123 Saarbrücken, Germany
- Department of Physics, Saarland University , D-66123 Saarbrücken, Germany
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Oreopoulos J, Gray-Owen SD, Yip CM. High Density or Urban Sprawl: What Works Best in Biology? ACS NANO 2017; 11:1131-1135. [PMID: 28112892 DOI: 10.1021/acsnano.7b00061] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
With new approaches in imaging-from new tools or reagents to processing algorithms-come unique opportunities and challenges to our understanding of biological processes, structures, and dynamics. Although innovations in super-resolution imaging are affording novel perspectives into how molecules structurally associate and localize in response to, or in order to initiate, specific signaling events in the cell, questions arise as to how to interpret these observations in the context of biological function. Just as each neighborhood in a city has its own unique vibe, culture, and indeed density, recent work has shown that membrane receptor behavior and action is governed by their localization and association state. There is tremendous potential in developing strategies for tracking how the populations of these molecular neighborhoods change dynamically.
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Affiliation(s)
- John Oreopoulos
- Institute of Biomaterials and Biomedical Engineering, University of Toronto , Toronto M5S 3G9, Canada
| | - Scott D Gray-Owen
- Department of Molecular Genetics, University of Toronto , Toronto M5S 1A8, Canada
| | - Christopher M Yip
- Institute of Biomaterials and Biomedical Engineering, University of Toronto , Toronto M5S 3G9, Canada
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13
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Wong F, Coban O, Weitsman G, Ng T. Integrating imaging, exosome and protein network rewiring information to track early tumour evolution of resistance mechanisms. CONVERGENT SCIENCE PHYSICAL ONCOLOGY 2017. [DOI: 10.1088/2057-1739/aa5cbd] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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