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Baumgart F, Arnold AM, Rossboth BK, Brameshuber M, Schütz GJ. What we talk about when we talk about nanoclusters. Methods Appl Fluoresc 2018; 7:013001. [PMID: 30412469 DOI: 10.1088/2050-6120/aaed0f] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Superresolution microscopy results have sparked the idea that many membrane proteins are not randomly distributed across the plasma membrane but are instead arranged in nanoclusters. Frequently, these new results seemed to confirm older data based on biochemical and electron microscopy experiments. Recently, however, it was recognized that multiple countings of the very same fluorescently labeled protein molecule can be easily confused with true protein clusters. Various strategies have been developed, which are intended to solve the problem of discriminating true protein clusters from imaging artifacts. We believe that there is currently no perfect algorithm for this problem; instead, different approaches have different strengths and weaknesses. In this review, we discuss single molecule localization microscopy in view of its ability to detect nanoclusters of membrane proteins. To capture the different views on nanoclustering, we chose an unconventional style for this article: we placed its scientific content in the setting of a fictive conference, where five researchers from different fields discuss the problem of detecting and quantifying nanoclusters. Using this style, we feel that the different approaches common for different research areas can be well illustrated. Similarities to a short story by Raymond Carver are not unintentional.
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Mechanistic insights into GLUT1 activation and clustering revealed by super-resolution imaging. Proc Natl Acad Sci U S A 2018; 115:7033-7038. [PMID: 29915035 DOI: 10.1073/pnas.1803859115] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
The glucose transporter GLUT1, a plasma membrane protein that mediates glucose homeostasis in mammalian cells, is responsible for constitutive uptake of glucose into many tissues and organs. Many studies have focused on its vital physiological functions and close relationship with diseases. However, the molecular mechanisms of its activation and transport are not clear, and its detailed distribution pattern on cell membranes also remains unknown. To address these, we first investigated the distribution and assembly of GLUT1 at a nanometer resolution by super-resolution imaging. On HeLa cell membranes, the transporter formed clusters with an average diameter of ∼250 nm, the majority of which were regulated by lipid rafts, as well as being restricted in size by both the cytoskeleton and glycosylation. More importantly, we found that the activation of GLUT1 by azide or MβCD did not increase its membrane expression but induced the decrease of the large clusters. The results suggested that sporadic distribution of GLUT1 may facilitate the transport of glucose, implying a potential association between the distribution and activation. Collectively, our work characterized the clustering distribution of GLUT1 and linked its spatial structural organization to the functions, which would provide insights into the activation mechanism of the transporter.
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Hausmann M, Ilić N, Pilarczyk G, Lee JH, Logeswaran A, Borroni AP, Krufczik M, Theda F, Waltrich N, Bestvater F, Hildenbrand G, Cremer C, Blank M. Challenges for Super-Resolution Localization Microscopy and Biomolecular Fluorescent Nano-Probing in Cancer Research. Int J Mol Sci 2017; 18:E2066. [PMID: 28956810 PMCID: PMC5666748 DOI: 10.3390/ijms18102066] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2017] [Revised: 09/21/2017] [Accepted: 09/23/2017] [Indexed: 11/17/2022] Open
Abstract
Understanding molecular interactions and regulatory mechanisms in tumor initiation, progression, and treatment response are key requirements towards advanced cancer diagnosis and novel treatment procedures in personalized medicine. Beyond decoding the gene expression, malfunctioning and cancer-related epigenetic pathways, investigations of the spatial receptor arrangements in membranes and genome organization in cell nuclei, on the nano-scale, contribute to elucidating complex molecular mechanisms in cells and tissues. By these means, the correlation between cell function and spatial organization of molecules or molecular complexes can be studied, with respect to carcinogenesis, tumor sensitivity or tumor resistance to anticancer therapies, like radiation or antibody treatment. Here, we present several new applications for bio-molecular nano-probes and super-resolution, laser fluorescence localization microscopy and their potential in life sciences, especially in biomedical and cancer research. By means of a tool-box of fluorescent antibodies, green fluorescent protein (GFP) tagging, or specific oligonucleotides, we present tumor relevant re-arrangements of Erb-receptors in membranes, spatial organization of Smad specific ubiquitin protein ligase 2 (Smurf2) in the cytosol, tumor cell characteristic heterochromatin organization, and molecular re-arrangements induced by radiation or antibody treatment. The main purpose of this article is to demonstrate how nano-scaled distance measurements between bio-molecules, tagged by appropriate nano-probes, can be applied to elucidate structures and conformations of molecular complexes which are characteristic of tumorigenesis and treatment responses. These applications open new avenues towards a better interpretation of the spatial organization and treatment responses of functionally relevant molecules, at the single cell level, in normal and cancer cells, offering new potentials for individualized medicine.
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Affiliation(s)
- Michael Hausmann
- Kirchhoff-Institute for Physics, University of Heidelberg, Im Neuenheimer Feld 227, 69120 Heidelberg, Germany.
| | - Nataša Ilić
- Laboratory of Molecular and Cellular Cancer Biology, Faculty of Medicine, Bar-Ilan University, 8 Henrietta Szold ST, Safed 1311502, Israel.
| | - Götz Pilarczyk
- Kirchhoff-Institute for Physics, University of Heidelberg, Im Neuenheimer Feld 227, 69120 Heidelberg, Germany.
| | - Jin-Ho Lee
- Kirchhoff-Institute for Physics, University of Heidelberg, Im Neuenheimer Feld 227, 69120 Heidelberg, Germany.
| | - Abiramy Logeswaran
- Kirchhoff-Institute for Physics, University of Heidelberg, Im Neuenheimer Feld 227, 69120 Heidelberg, Germany.
| | - Aurora Paola Borroni
- Laboratory of Molecular and Cellular Cancer Biology, Faculty of Medicine, Bar-Ilan University, 8 Henrietta Szold ST, Safed 1311502, Israel.
| | - Matthias Krufczik
- Kirchhoff-Institute for Physics, University of Heidelberg, Im Neuenheimer Feld 227, 69120 Heidelberg, Germany.
| | - Franziska Theda
- Kirchhoff-Institute for Physics, University of Heidelberg, Im Neuenheimer Feld 227, 69120 Heidelberg, Germany.
| | - Nadine Waltrich
- Kirchhoff-Institute for Physics, University of Heidelberg, Im Neuenheimer Feld 227, 69120 Heidelberg, Germany.
| | - Felix Bestvater
- German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany.
| | - Georg Hildenbrand
- Kirchhoff-Institute for Physics, University of Heidelberg, Im Neuenheimer Feld 227, 69120 Heidelberg, Germany.
- Department of Radiation Oncology, Universitätsmedizin Mannheim, University of Heidelberg, Theodor-Kutzer-Ufer 3-5, 68159 Mannheim, Germany.
| | - Christoph Cremer
- Institute of Molecular Biology, Ackermannweg 4, 55128 Mainz, Germany.
| | - Michael Blank
- Laboratory of Molecular and Cellular Cancer Biology, Faculty of Medicine, Bar-Ilan University, 8 Henrietta Szold ST, Safed 1311502, Israel.
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Malkusch S, Heilemann M. Extracting quantitative information from single-molecule super-resolution imaging data with LAMA - LocAlization Microscopy Analyzer. Sci Rep 2016; 6:34486. [PMID: 27703238 PMCID: PMC5050494 DOI: 10.1038/srep34486] [Citation(s) in RCA: 75] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2016] [Accepted: 09/14/2016] [Indexed: 11/30/2022] Open
Abstract
Super-resolution fluorescence microscopy revolutionizes cell biology research and provides novel insights on how proteins are organized at the nanoscale and in the cellular context. In order to extract a maximum of information, specialized tools for image analysis are necessary. Here, we introduce the LocAlization Microscopy Analyzer (LAMA), a comprehensive software tool that extracts quantitative information from single-molecule super-resolution imaging data. LAMA allows characterizing cellular structures by their size, shape, intensity, distribution, as well as the degree of colocalization with other structures. LAMA is freely available, platform-independent and designed to provide direct access to individual analysis of super-resolution data.
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Affiliation(s)
- Sebastian Malkusch
- Single Molecule Biophysics, Institute of Physical and Theoretical Chemistry, Goethe-University Frankfurt, Germany
| | - Mike Heilemann
- Single Molecule Biophysics, Institute of Physical and Theoretical Chemistry, Goethe-University Frankfurt, Germany
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Mateos-Gil P, Letschert S, Doose S, Sauer M. Super-Resolution Imaging of Plasma Membrane Proteins with Click Chemistry. Front Cell Dev Biol 2016; 4:98. [PMID: 27668214 PMCID: PMC5016519 DOI: 10.3389/fcell.2016.00098] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2016] [Accepted: 08/24/2016] [Indexed: 12/30/2022] Open
Abstract
Besides its function as a passive cell wall, the plasma membrane (PM) serves as a platform for different physiological processes such as signal transduction and cell adhesion, determining the ability of cells to communicate with the exterior, and form tissues. Therefore, the spatial distribution of PM components, and the molecular mechanisms underlying it, have important implications in various biological fields including cell development, neurobiology, and immunology. The existence of confined compartments in the plasma membrane that vary on many length scales from protein multimers to micrometer-size domains with different protein and lipid composition is today beyond all questions. As much as the physiology of cells is controlled by the spatial organization of PM components, the study of distribution, size, and composition remains challenging. Visualization of the molecular distribution of PM components has been impeded mainly due to two problems: the specific labeling of lipids and proteins without perturbing their native distribution and the diffraction-limit of fluorescence microscopy restricting the resolution to about half the wavelength of light. Here, we present a bioorthogonal chemical reporter strategy based on click chemistry and metabolic labeling for efficient and specific visualization of PM proteins and glycans with organic fluorophores in combination with super-resolution fluorescence imaging by direct stochastic optical reconstruction microscopy (dSTORM) with single-molecule sensitivity.
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Affiliation(s)
- Pablo Mateos-Gil
- Department of Biotechnology and Biophysics, Julius Maximilian University of Würzburg Würzburg, Germany
| | - Sebastian Letschert
- Department of Biotechnology and Biophysics, Julius Maximilian University of Würzburg Würzburg, Germany
| | - Sören Doose
- Department of Biotechnology and Biophysics, Julius Maximilian University of Würzburg Würzburg, Germany
| | - Markus Sauer
- Department of Biotechnology and Biophysics, Julius Maximilian University of Würzburg Würzburg, Germany
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Mattila PK, Batista FD, Treanor B. Dynamics of the actin cytoskeleton mediates receptor cross talk: An emerging concept in tuning receptor signaling. J Cell Biol 2016; 212:267-80. [PMID: 26833785 PMCID: PMC4748574 DOI: 10.1083/jcb.201504137] [Citation(s) in RCA: 92] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Recent evidence implicates the actin cytoskeleton in the control of receptor signaling. This may be of particular importance in the context of immune receptors, such as the B cell receptor, where dysregulated signaling can result in autoimmunity and malignancy. Here, we discuss the role of the actin cytoskeleton in controlling receptor compartmentalization, dynamics, and clustering as a means to regulate receptor signaling through controlling the interactions with protein partners. We propose that the actin cytoskeleton is a point of integration for receptor cross talk through modulation of protein dynamics and clustering. We discuss the implication of this cross talk via the cytoskeleton for both ligand-induced and low-level constitutive (tonic) signaling necessary for immune cell survival.
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Affiliation(s)
- Pieta K Mattila
- Institute of Biomedicine, MediCity, University of Turku, 20520 Turku, Finland
| | - Facundo D Batista
- Lymphocyte Interaction Laboratory, The Francis Crick Institute, Cancer Research UK, London WC2A 3LY, England, UK
| | - Bebhinn Treanor
- Department of Biological Sciences, University of Toronto Scarborough, Toronto, Ontario M5T 1C6, Canada
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