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Wei Y, Zhao M, He T, Chen N, Rao L, Chen L, Zhang Y, Yang Y, Yuan Q. Quantitatively Lighting up the Spatial Organization of CD47/SIRPα Immune Checkpoints on the Cellular Membrane with Single-Molecule Localization Microscopy. ACS NANO 2023; 17:21626-21638. [PMID: 37878521 DOI: 10.1021/acsnano.3c06709] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2023]
Abstract
Immunotherapy including immune checkpoint inhibition has reinvigorated the current cancer treatment field. The development of efficient cancer immunotherapies depends on a thorough understanding of the status of immune checkpoints and how they interact. However, the distribution and spatial organization changes of immune checkpoints during their interactions at the single-molecule level remain difficult to directly visualize due to the lack of in situ imaging techniques with appropriate spatial and stoichiometric resolution. Herein, we report the direct visualization and quantification of the spatial distribution and organization of CD47 on the bladder tumor cell membrane and SIRPα on the macrophage membrane by using a single-molecule localization imaging technique called quantitative direct stochastic optical reconstruction microscopy (QdSTORM). Results showed that a portion of CD47 and SIRPα was present on cell membranes as heterogeneous clusters of varying sizes and densities prior to activation. Quantitative analyses of the reconstructed super-resolution images and theoretical simulation revealed that CD47 and SIRPα were reorganized into larger clusters upon binding to each other. Furthermore, we found that blocking the immune checkpoint interaction with small-molecule inhibitors or antibodies significantly impacted the spatial clustering behavior of CD47 on bladder tumor cells, demonstrating the promise of our QdSTORM strategy in elucidating the molecular mechanisms underlying immunotherapy. This work offers a promising strategy to advance our understanding of immune checkpoint state and interactions while also contributing to the fields including signal regulation and cancer therapy.
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Affiliation(s)
- Yurong Wei
- College of Chemistry and Molecular Sciences, Key Laboratory of Biomedical Polymers of Ministry of Education, Institute of Molecular Medicine, Renmin Hospital of Wuhan University, School of Microelectronics, Wuhan University, Wuhan 430072, P. R. China
| | - Min Zhao
- College of Chemistry and Molecular Sciences, Key Laboratory of Biomedical Polymers of Ministry of Education, Institute of Molecular Medicine, Renmin Hospital of Wuhan University, School of Microelectronics, Wuhan University, Wuhan 430072, P. R. China
| | - Tianpei He
- College of Chemistry and Molecular Sciences, Key Laboratory of Biomedical Polymers of Ministry of Education, Institute of Molecular Medicine, Renmin Hospital of Wuhan University, School of Microelectronics, Wuhan University, Wuhan 430072, P. R. China
| | - Na Chen
- College of Chemistry and Molecular Sciences, Key Laboratory of Biomedical Polymers of Ministry of Education, Institute of Molecular Medicine, Renmin Hospital of Wuhan University, School of Microelectronics, Wuhan University, Wuhan 430072, P. R. China
| | - Li Rao
- Hubei International Scientific and Technological Cooperation Base of Pesticide and Green Synthesis, Key Laboratory of Pesticide & Chemical Biology of Ministry of Education, College of Chemistry, Central China Normal University, Wuhan 430079, P. R. China
| | - Long Chen
- Department of Computer and Information Science, Faculty of Science and Technology, University of Macau, Macau 999078, P. R. China
| | - Yun Zhang
- CAS Key Laboratory of Design and Assembly of Functional Nanostructures, and Fujian Provincial Key Laboratory of Nanomaterials, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350025, P. R. China
| | - Yanbing Yang
- College of Chemistry and Molecular Sciences, Key Laboratory of Biomedical Polymers of Ministry of Education, Institute of Molecular Medicine, Renmin Hospital of Wuhan University, School of Microelectronics, Wuhan University, Wuhan 430072, P. R. China
| | - Quan Yuan
- College of Chemistry and Molecular Sciences, Key Laboratory of Biomedical Polymers of Ministry of Education, Institute of Molecular Medicine, Renmin Hospital of Wuhan University, School of Microelectronics, Wuhan University, Wuhan 430072, P. R. China
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2
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Li Y, Wang J, Chen X, Czajkowsky DM, Shao Z. Quantitative Super-Resolution Microscopy Reveals the Relationship between CENP-A Stoichiometry and Centromere Physical Size. Int J Mol Sci 2023; 24:15871. [PMID: 37958853 PMCID: PMC10649757 DOI: 10.3390/ijms242115871] [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: 08/31/2023] [Revised: 10/09/2023] [Accepted: 10/16/2023] [Indexed: 11/15/2023] Open
Abstract
Centromeric chromatin is thought to play a critical role in ensuring the faithful segregation of chromosomes during mitosis. However, our understanding of this role is presently limited by our poor understanding of the structure and composition of this unique chromatin. The nucleosomal variant, CENP-A, localizes to narrow regions within the centromere, where it plays a major role in centromeric function, effectively serving as a platform on which the kinetochore is assembled. Previous work found that, within a given cell, the number of microtubules within kinetochores is essentially unchanged between CENP-A-localized regions of different physical sizes. However, it is unknown if the amount of CENP-A is also unchanged between these regions of different sizes, which would reflect a strict structural correspondence between these two key characteristics of the centromere/kinetochore assembly. Here, we used super-resolution optical microscopy to image and quantify the amount of CENP-A and DNA within human centromere chromatin. We found that the amount of CENP-A within CENP-A domains of different physical sizes is indeed the same. Further, our measurements suggest that the ratio of CENP-A- to H3-containing nucleosomes within these domains is between 8:1 and 11:1. Thus, our results not only identify an unexpectedly strict relationship between CENP-A and microtubules stoichiometries but also that the CENP-A centromeric domain is almost exclusively composed of CENP-A nucleosomes.
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Affiliation(s)
- Yaqian Li
- State Key Laboratory of Systems Medicine for Cancer, School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China; (Y.L.); (Z.S.)
| | - Jiabin Wang
- School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China;
| | - Xuecheng Chen
- Shanghai Center for Systems Biomedicine, Shanghai Jiao Tong University, Shanghai 200240, China;
| | - Daniel M. Czajkowsky
- State Key Laboratory of Systems Medicine for Cancer, School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China; (Y.L.); (Z.S.)
| | - Zhifeng Shao
- State Key Laboratory of Systems Medicine for Cancer, School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China; (Y.L.); (Z.S.)
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3
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Prokop S, Ábrányi-Balogh P, Barti B, Vámosi M, Zöldi M, Barna L, Urbán GM, Tóth AD, Dudok B, Egyed A, Deng H, Leggio GM, Hunyady L, van der Stelt M, Keserű GM, Katona I. PharmacoSTORM nanoscale pharmacology reveals cariprazine binding on Islands of Calleja granule cells. Nat Commun 2021; 12:6505. [PMID: 34764251 PMCID: PMC8586358 DOI: 10.1038/s41467-021-26757-z] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2021] [Accepted: 09/30/2021] [Indexed: 12/25/2022] Open
Abstract
Immunolabeling and autoradiography have traditionally been applied as the methods-of-choice to visualize and collect molecular information about physiological and pathological processes. Here, we introduce PharmacoSTORM super-resolution imaging that combines the complementary advantages of these approaches and enables cell-type- and compartment-specific nanoscale molecular measurements. We exploited rational chemical design for fluorophore-tagged high-affinity receptor ligands and an enzyme inhibitor; and demonstrated broad PharmacoSTORM applicability for three protein classes and for cariprazine, a clinically approved antipsychotic and antidepressant drug. Because the neurobiological substrate of cariprazine has remained elusive, we took advantage of PharmacoSTORM to provide in vivo evidence that cariprazine predominantly binds to D3 dopamine receptors on Islands of Calleja granule cell axons but avoids dopaminergic terminals. These findings show that PharmacoSTORM helps to quantify drug-target interaction sites at the nanoscale level in a cell-type- and subcellular context-dependent manner and within complex tissue preparations. Moreover, the results highlight the underappreciated neuropsychiatric significance of the Islands of Calleja in the ventral forebrain.
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Affiliation(s)
- Susanne Prokop
- Momentum Laboratory of Molecular Neurobiology, Institute of Experimental Medicine, Budapest, Hungary
- School of Ph.D. Studies, Semmelweis University, Budapest, Hungary
| | - Péter Ábrányi-Balogh
- Medicinal Chemistry Research Group, Research Centre for Natural Sciences, Budapest, Hungary
| | - Benjámin Barti
- Momentum Laboratory of Molecular Neurobiology, Institute of Experimental Medicine, Budapest, Hungary
- School of Ph.D. Studies, Semmelweis University, Budapest, Hungary
- Department of Psychological and Brain Sciences, Indiana University, Bloomington, IN, USA
| | - Márton Vámosi
- Momentum Laboratory of Molecular Neurobiology, Institute of Experimental Medicine, Budapest, Hungary
| | - Miklós Zöldi
- Momentum Laboratory of Molecular Neurobiology, Institute of Experimental Medicine, Budapest, Hungary
- School of Ph.D. Studies, Semmelweis University, Budapest, Hungary
- Department of Psychological and Brain Sciences, Indiana University, Bloomington, IN, USA
| | - László Barna
- Nikon Center of Excellence for Neuronal Imaging, Institute of Experimental Medicine, Budapest, Hungary
| | - Gabriella M Urbán
- Momentum Laboratory of Molecular Neurobiology, Institute of Experimental Medicine, Budapest, Hungary
| | - András Dávid Tóth
- Department of Physiology, Faculty of Medicine, Semmelweis University, Budapest, Hungary
- MTA-SE Laboratory of Molecular Physiology, Eötvös Loránd Research Network, Budapest, Hungary
| | - Barna Dudok
- Momentum Laboratory of Molecular Neurobiology, Institute of Experimental Medicine, Budapest, Hungary
- Department of Neurosurgery, Stanford University, Stanford, CA, USA
| | - Attila Egyed
- Medicinal Chemistry Research Group, Research Centre for Natural Sciences, Budapest, Hungary
| | - Hui Deng
- Department of Molecular Physiology, Leiden Institute of Chemistry, Leiden University & Oncode Institute, Leiden, the Netherlands
| | - Gian Marco Leggio
- Department of Biomedical and Biotechnological Sciences, Section of Pharmacology, University of Catania, Catania, Italy
| | - László Hunyady
- Department of Physiology, Faculty of Medicine, Semmelweis University, Budapest, Hungary
- MTA-SE Laboratory of Molecular Physiology, Eötvös Loránd Research Network, Budapest, Hungary
| | - Mario van der Stelt
- Department of Molecular Physiology, Leiden Institute of Chemistry, Leiden University & Oncode Institute, Leiden, the Netherlands
| | - György M Keserű
- Medicinal Chemistry Research Group, Research Centre for Natural Sciences, Budapest, Hungary
| | - István Katona
- Momentum Laboratory of Molecular Neurobiology, Institute of Experimental Medicine, Budapest, Hungary.
- Department of Psychological and Brain Sciences, Indiana University, Bloomington, IN, USA.
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4
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Prada JP, Wangorsch G, Kucka K, Lang I, Dandekar T, Wajant H. A systems-biology model of the tumor necrosis factor (TNF) interactions with TNF receptor 1 and 2. Bioinformatics 2021; 37:669-676. [PMID: 32991680 DOI: 10.1093/bioinformatics/btaa844] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2019] [Revised: 07/07/2020] [Accepted: 09/15/2020] [Indexed: 01/28/2023] Open
Abstract
MOTIVATION Clustering enables TNF receptors to stimulate intracellular signaling. The differential soluble ligand-induced clustering behavior of TNF receptor 1 (TNFR1) and TNFR2 was modeled. A structured, rule-based model implemented ligand-independent pre-ligand binding assembly domain (PLAD)-mediated homotypic low affinity interactions of unliganded and liganded TNF receptors. RESULTS Soluble TNF initiates TNFR1 signaling but not TNFR2 signaling despite receptor binding unless it is secondarily oligomerized. We consider high affinity binding of TNF to signaling-incompetent pre-assembled dimeric TNFR1 and TNFR2 molecules and secondary clustering of liganded dimers to signaling competent ligand-receptor clusters. Published receptor numbers, affinities and measured different activities of clustered receptors validated model simulations for a large range of receptor and ligand concentrations. Different PLAD-PLAD affinities and different activities of receptor clusters explain the observed differences in the TNF receptor stimulating activities of soluble TNF. AVAILABILITY AND IMPLEMENTATION All scripts and data are in manuscript and supplement at Bioinformatics online. SUPPLEMENTARY INFORMATION Supplementary data are available at Bioinformatics online.
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Affiliation(s)
- Juan Pablo Prada
- Department of Bioinformatics, Biocenter, University of Würzburg, Würzburg 97074, Germany
| | - Gaby Wangorsch
- Department of Bioinformatics, Biocenter, University of Würzburg, Würzburg 97074, Germany
| | - Kirstin Kucka
- Division of Molecular Internal Medicine, Department of Internal Medicine II, University Hospital Würzburg, Würzburg 97080, Germany
| | - Isabell Lang
- Division of Molecular Internal Medicine, Department of Internal Medicine II, University Hospital Würzburg, Würzburg 97080, Germany
| | - Thomas Dandekar
- Department of Bioinformatics, Biocenter, University of Würzburg, Würzburg 97074, Germany.,Department of Structural and Computational Biology, European Molecular Biology Laboratory (EMBL), 69012 Heidelberg, Germany
| | - Harald Wajant
- Division of Molecular Internal Medicine, Department of Internal Medicine II, University Hospital Würzburg, Würzburg 97080, Germany
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5
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Fluorescence-Based TNFR1 Biosensor for Monitoring Receptor Structural and Conformational Dynamics and Discovery of Small Molecule Modulators. Methods Mol Biol 2021; 2248:121-137. [PMID: 33185872 DOI: 10.1007/978-1-0716-1130-2_9] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Inhibition of tumor necrosis factor receptor 1 (TNFR1) is a billion-dollar industry for treatment of autoimmune and inflammatory diseases. As current therapeutics of anti-TNF leads to dangerous side effects due to global inhibition of the ligand, receptor-specific inhibition of TNFR1 signaling is an intensely pursued strategy. To monitor directly the structural changes of the receptor in living cells, we engineered a fluorescence resonance energy transfer (FRET) biosensor by fusing green and red fluorescent proteins to TNFR1. Expression of the FRET biosensor in living cells allows for detection of receptor-receptor interactions and receptor structural dynamics. Using the TNFR1 FRET biosensor, in conjunction with a high-precision and high-throughput fluorescence lifetime detection technology, we developed a time-resolved FRET-based high-throughput screening platform to discover small molecules that directly target and modulate TNFR1 functions. Using this method in screening multiple pharmaceutical libraries, we have discovered a competitive inhibitor that disrupts receptor-receptor interactions, and allosteric modulators that alter the structural states of the receptor. This enables scientists to conduct high-throughput screening through a biophysical approach, with relevance to compound perturbation of receptor structure, for the discovery of novel lead compounds with high specificity for modulation of TNFR1 signaling.
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6
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Maß L, Holtmannspötter M, Zachgo S. Dual-color 3D-dSTORM colocalization and quantification of ROXY1 and RNAPII variants throughout the transcription cycle in root meristem nuclei. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2020; 104:1423-1436. [PMID: 32896918 DOI: 10.1111/tpj.14986] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Revised: 08/04/2020] [Accepted: 08/17/2020] [Indexed: 06/11/2023]
Abstract
To unravel the function of a protein of interest, it is crucial to asses to what extent it associates via direct interactions or by overlapping expression with other proteins. ROXY1, a land plant-specific glutaredoxin, exerts a function in Arabidopsis flower development and interacts with TGA transcription factors in the nucleus. We detected a novel ROXY1 function in the root meristem. Root cells that lack chlorophyll reducing plant-specific background problems that can hamper colocalization 3D microscopy. Thus far, a super-resolution three-dimensional stochastic optical reconstruction microscopy (3D-dSTORM) approach has mainly been applied in animal studies. We established 3D-dSTORM using the roxy1 mutant complemented with green fluorescence protein-ROXY1 and investigated its colocalization with three distinct RNAPII isoforms. To quantify the colocalization results, 3D-dSTORM was coupled with the coordinate-based colocalization method. Interestingly, ROXY1 proteins colocalize with different RNA polymerase II (RNAPII) isoforms that are active at distinct transcription cycle steps. Our colocalization data provide new insights on nuclear glutaredoxin activities suggesting that ROXY1 is not only required in early transcription initiation events via interaction with transcription factors but likely also participates throughout further transcription processes until late termination steps. Furthermore, we showed the applicability of the combined approaches to detect and quantify responses to altered growth conditions, exemplified by analysis of H2 O2 treatment, causing a dissociation of ROXY1 and RNAPII isoforms. We envisage that the powerful dual-color 3D-dSTORM/coordinate-based colocalization combination offers plant cell biologists the opportunity to colocalize and quantify root meristem proteins at an increased, unprecedented resolution level <50 nm, which will enable the detection of novel subcellular protein associations and functions.
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Affiliation(s)
- Lucia Maß
- Botany Department, School of Biology and Chemistry, Osnabrück University, Osnabrück, 49076, Germany
| | - Michael Holtmannspötter
- Integrated Bioimaging Facility iBiOs, School of Biology and Chemistry, Osnabrück University, Osnabrück, 49076, Germany
- Center of Cellular Nanoanalytics Osnabrück, School of Biology and Chemistry, Osnabrück University, Osnabrück, 49076, Germany
| | - Sabine Zachgo
- Botany Department, School of Biology and Chemistry, Osnabrück University, Osnabrück, 49076, Germany
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7
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Vunnam N, Szymonski S, Hirsova P, Gores GJ, Sachs JN, Hackel BJ. Noncompetitive Allosteric Antagonism of Death Receptor 5 by a Synthetic Affibody Ligand. Biochemistry 2020; 59:3856-3868. [PMID: 32941010 PMCID: PMC7658720 DOI: 10.1021/acs.biochem.0c00529] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Fatty acid-induced upregulation of death receptor 5 (DR5) and its cognate ligand, tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), promotes hepatocyte lipoapoptosis, which is a key mechanism in the progression of fatty liver disease. Accordingly, inhibition of DR5 signaling represents an attractive strategy for treating fatty liver disease. Ligand competition strategies are prevalent in tumor necrosis factor receptor antagonism, but recent studies have suggested that noncompetitive inhibition through perturbation of the receptor conformation may be a compelling alternative. To this end, we used yeast display and a designed combinatorial library to identify a synthetic 58-amino acid affibody ligand that specifically binds DR5. Biophysical and biochemical studies show that the affibody neither blocks TRAIL binding nor prevents the receptor-receptor interaction. Live-cell fluorescence lifetime measurements indicate that the affibody induces a conformational change in transmembrane dimers of DR5 and favors an inactive state of the receptor. The affibody inhibits apoptosis in TRAIL-treated Huh-7 cells, an in vitro model of fatty liver disease. Thus, this lead affibody serves as a potential drug candidate, with a unique mechanism of action, for fatty liver disease.
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Affiliation(s)
- Nagamani Vunnam
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN
| | - Sophia Szymonski
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN
| | - Petra Hirsova
- Division of Gastroenterology and Hepatology, Mayo Clinic, Rochester, MN
| | - Gregory J. Gores
- Division of Gastroenterology and Hepatology, Mayo Clinic, Rochester, MN
| | - Jonathan N. Sachs
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN
| | - Benjamin J. Hackel
- Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, MN
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8
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Su Z, Wu Y. A computational model for understanding the oligomerization mechanisms of TNF receptor superfamily. Comput Struct Biotechnol J 2020; 18:258-270. [PMID: 32021664 PMCID: PMC6994755 DOI: 10.1016/j.csbj.2019.12.016] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2019] [Revised: 12/29/2019] [Accepted: 12/31/2019] [Indexed: 01/07/2023] Open
Abstract
By recognizing members in the tumor necrosis factor (TNF) receptor superfamily, TNF ligand proteins function as extracellular cytokines to activate various signaling pathways involved in inflammation, proliferation, and apoptosis. Most ligands in TNF superfamily are trimeric and can simultaneously bind to three receptors on cell surfaces. It has been experimentally observed that the formation of these molecular complexes further triggers the oligomerization of TNF receptors, which in turn regulate the intracellular signaling processes by providing transient compartmentalization in the membrane proximal regions of cytoplasm. In order to decode the molecular mechanisms of oligomerization in TNF receptor superfamily, we developed a new computational method that can physically simulate the spatial-temporal process of binding between TNF ligands and their receptors. The simulations show that the TNF receptors can be organized into hexagonal oligomers. The formation of this spatial pattern is highly dependent not only on the molecular properties such as the affinities of trans and cis binding, but also on the cellular factors such as the concentration of TNF ligands in the extracellular area or the density of TNF receptors on cell surfaces. Moreover, our model suggests that if TNF receptors are pre-organized into dimers before ligand binding, these lateral interactions between receptor monomers can play a positive role in stabilizing the ligand-receptor interactions, as well as in regulating the kinetics of receptor oligomerization. Altogether, this method throws lights on the mechanisms of TNF ligand-receptor interactions in cellular environments.
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9
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Karathanasis C, Medler J, Fricke F, Smith S, Malkusch S, Widera D, Fulda S, Wajant H, van Wijk SJL, Dikic I, Heilemann M. Single-molecule imaging reveals the oligomeric state of functional TNFα-induced plasma membrane TNFR1 clusters in cells. Sci Signal 2020; 13:13/614/eaax5647. [PMID: 31937565 DOI: 10.1126/scisignal.aax5647] [Citation(s) in RCA: 51] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Ligand-induced tumor necrosis factor receptor 1 (TNFR1) activation controls nuclear factor κ-light-chain-enhancer of activated B cells (NF-κB) signaling, cell proliferation, programmed cell death, and survival and is crucially involved in inflammation, autoimmune disorders, and cancer progression. Despite the relevance of TNFR1 clustering for signaling, oligomerization of ligand-free and ligand-activated TNFR1 remains controversial. At present, models range from ligand-independent receptor predimerization to ligand-induced oligomerization. Here, we used quantitative, single-molecule superresolution microscopy to study TNFR1 assembly directly in native cellular settings and at physiological cell surface abundance. In the absence of its ligand TNFα, TNFR1 assembled into monomeric and dimeric receptor units. Upon binding of TNFα, TNFR1 clustered predominantly not only into trimers but also into higher-order oligomers. A functional mutation in the preligand assembly domain of TNFR1 resulted in only monomeric TNFR1, which exhibited impaired ligand binding. In contrast, a form of TNFR1 with a mutation in the ligand-binding CRD2 subdomain retained the monomer-to-dimer ratio of the unliganded wild-type TNFR1 but exhibited no ligand binding. These results underscore the importance of ligand-independent TNFR1 dimerization in NF-κB signaling.
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Affiliation(s)
- Christos Karathanasis
- Institute of Physical and Theoretical Chemistry, Goethe University, Max-von-Laue-Strasse 7, 60438 Frankfurt am Main, Germany
| | - Juliane Medler
- Division of Molecular Internal Medicine, Department of Internal Medicine II, University Hospital Würzburg, Auverahaus, Grombühlstrasse 12, 97080 Würzburg, Germany
| | - Franziska Fricke
- Institute of Physical and Theoretical Chemistry, Goethe University, Max-von-Laue-Strasse 7, 60438 Frankfurt am Main, Germany
| | - Sonja Smith
- Institute for Experimental Cancer Research in Paediatrics, Goethe University, Komturstrasse 3a, 60528 Frankfurt am Main, Germany
| | - Sebastian Malkusch
- Institute of Physical and Theoretical Chemistry, Goethe University, Max-von-Laue-Strasse 7, 60438 Frankfurt am Main, Germany
| | - Darius Widera
- Stem Cell Biology and Regenerative Medicine Group, School of Pharmacy, University of Reading, RG6 6UB Reading, UK
| | - Simone Fulda
- Institute for Experimental Cancer Research in Paediatrics, Goethe University, Komturstrasse 3a, 60528 Frankfurt am Main, Germany.,German Cancer Consortium (DKTK), Heidelberg, Germany.,German Cancer Research Centre (DKFZ), Heidelberg, Germany
| | - Harald Wajant
- Division of Molecular Internal Medicine, Department of Internal Medicine II, University Hospital Würzburg, Auverahaus, Grombühlstrasse 12, 97080 Würzburg, Germany
| | - Sjoerd J L van Wijk
- Institute for Experimental Cancer Research in Paediatrics, Goethe University, Komturstrasse 3a, 60528 Frankfurt am Main, Germany.
| | - Ivan Dikic
- Institute of Biochemistry II, Goethe University Medical School, Theodor-Stern-Kai 7, 60590 Frankfurt am Main, Germany. .,Buchmann Institute for Molecular Life Sciences (BMLS), Goethe University, Max-von-Laue-Strasse 15, 60438 Frankfurt am Main, Germany
| | - Mike Heilemann
- Institute of Physical and Theoretical Chemistry, Goethe University, Max-von-Laue-Strasse 7, 60438 Frankfurt am Main, Germany.
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10
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Su Z, Wu Y. Computational simulations of TNF receptor oligomerization on plasma membrane. Proteins 2019; 88:698-709. [PMID: 31710744 DOI: 10.1002/prot.25854] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2019] [Revised: 10/30/2019] [Accepted: 11/05/2019] [Indexed: 12/21/2022]
Abstract
The interactions between tumor necrosis factors (TNFs) and their corresponding receptors (TNFRs) play a pivotal role in inflammatory responses. Upon ligand binding, TNFR receptors were found to form oligomers on cell surfaces. However, the underlying mechanism of oligomerization is not fully understood. In order to tackle this problem, molecular dynamics (MD) simulations have been applied to the complex between TNF receptor-1 (TNFR1) and its ligand TNF-α as a specific test system. The simulations on both all-atom (AA) and coarse-grained (CG) levels achieved the similar results that the extracellular domains of TNFR1 can undergo large fluctuations on plasma membrane, while the dynamics of TNFα-TNFR1 complex is much more constrained. Using the CG model with the Martini force field, we are able to simulate the systems that contain multiple TNFα-TNFR1 complexes with the timescale of microseconds. We found that complexes can aggregate into oligomers on the plasma membrane through the lateral interactions between receptors at the end of the CG simulations. We suggest that this spatial organization is essential to the efficiency of signal transduction for ligands that belong to the TNF superfamily. We further show that the aggregation of two complexes is initiated by the association between the N-terminal domains of TNFR1 receptors. Interestingly, the cis-interfaces between N-terminal regions of two TNF receptors have been observed in the previous X-ray crystallographic experiment. Therefore, we provide supportive evidence that cis-interface is of functional importance in triggering the receptor oligomerization. Taken together, our study brings insights to understand the molecular mechanism of TNF signaling.
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Affiliation(s)
- Zhaoqian Su
- Department of Systems and Computational Biology, Albert Einstein College of Medicine, Bronx, New York
| | - Yinghao Wu
- Department of Systems and Computational Biology, Albert Einstein College of Medicine, Bronx, New York
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11
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Matveeva A, Fichtner M, McAllister K, McCann C, Sturrock M, Longley DB, Prehn JHM. Heterogeneous responses to low level death receptor activation are explained by random molecular assembly of the Caspase-8 activation platform. PLoS Comput Biol 2019; 15:e1007374. [PMID: 31553717 PMCID: PMC6779275 DOI: 10.1371/journal.pcbi.1007374] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2019] [Revised: 10/07/2019] [Accepted: 09/03/2019] [Indexed: 01/29/2023] Open
Abstract
Ligand binding to death receptors activates apoptosis in cancer cells. Stimulation of death receptors results in the formation of intracellular multiprotein platforms that either activate the apoptotic initiator Caspase-8 to trigger cell death, or signal through kinases to initiate inflammatory and cell survival signalling. Two of these platforms, the Death-Inducing Signalling Complex (DISC) and the RIPoptosome, also initiate necroptosis by building filamentous scaffolds that lead to the activation of mixed lineage kinase domain-like pseudokinase. To explain cell decision making downstream of death receptor activation, we developed a semi-stochastic model of DISC/RIPoptosome formation. The model is a hybrid of a direct Gillespie stochastic simulation algorithm for slow assembly of the RIPoptosome and a deterministic model of downstream caspase activation. The model explains how alterations in the level of death receptor-ligand complexes, their clustering properties and intrinsic molecular fluctuations in RIPoptosome assembly drive heterogeneous dynamics of Caspase-8 activation. The model highlights how kinetic proofreading leads to heterogeneous cell responses and results in fractional cell killing at low levels of receptor stimulation. It reveals that the noise in Caspase-8 activation-exclusively caused by the stochastic molecular assembly of the DISC/RIPoptosome platform-has a key function in extrinsic apoptotic stimuli recognition.
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Affiliation(s)
- Anna Matveeva
- Centre for Systems Medicine, Royal College of Surgeons in Ireland, Dublin, Ireland
- Department of Physiology and Medical Physics, Royal College of Surgeons in Ireland, Dublin, Ireland
| | - Michael Fichtner
- Centre for Systems Medicine, Royal College of Surgeons in Ireland, Dublin, Ireland
- Department of Physiology and Medical Physics, Royal College of Surgeons in Ireland, Dublin, Ireland
| | - Katherine McAllister
- Centre for Cancer Research and Cell Biology, Queen’s University, Belfast, United Kingdom
| | - Christopher McCann
- Centre for Cancer Research and Cell Biology, Queen’s University, Belfast, United Kingdom
| | - Marc Sturrock
- Centre for Systems Medicine, Royal College of Surgeons in Ireland, Dublin, Ireland
- Department of Physiology and Medical Physics, Royal College of Surgeons in Ireland, Dublin, Ireland
| | - Daniel B. Longley
- Centre for Cancer Research and Cell Biology, Queen’s University, Belfast, United Kingdom
| | - Jochen H. M. Prehn
- Centre for Systems Medicine, Royal College of Surgeons in Ireland, Dublin, Ireland
- Department of Physiology and Medical Physics, Royal College of Surgeons in Ireland, Dublin, Ireland
- * E-mail:
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12
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Lo CH, Schaaf TM, Grant BD, Lim CKW, Bawaskar P, Aldrich CC, Thomas DD, Sachs JN. Noncompetitive inhibitors of TNFR1 probe conformational activation states. Sci Signal 2019; 12:12/592/eaav5637. [PMID: 31363069 DOI: 10.1126/scisignal.aav5637] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Tumor necrosis factor receptor 1 (TNFR1) is a central mediator of the inflammatory pathway and is associated with several autoimmune diseases such as rheumatoid arthritis. A revision to the canonical model of TNFR1 activation suggests that activation involves conformational rearrangements of preassembled receptor dimers. Here, we identified small-molecule allosteric inhibitors of TNFR1 activation and probed receptor dimerization and function. Specifically, we used a fluorescence lifetime-based high-throughput screen and biochemical, biophysical, and cellular assays to identify small molecules that noncompetitively inhibited the receptor without reducing ligand affinity or disrupting receptor dimerization. We also found that residues in the ligand-binding loop that are critical to the dynamic coupling between the extracellular and the transmembrane domains played a key gatekeeper role in the conformational dynamics associated with signal propagation. Last, using a simple structure-activity relationship analysis, we demonstrated that these newly found molecules could be further optimized for improved potency and specificity. Together, these data solidify and deepen the new model for TNFR1 activation.
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Affiliation(s)
- Chih Hung Lo
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN 55455, USA
| | - Tory M Schaaf
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA
| | | | - Colin Kin-Wye Lim
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN 55455, USA
| | - Prachi Bawaskar
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA
| | - Courtney C Aldrich
- Department of Medicinal Chemistry, University of Minnesota, Minneapolis, MN 55455, USA
| | - David D Thomas
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA.,Photonic Pharma LLC, Minneapolis, MN 55410, USA
| | - Jonathan N Sachs
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN 55455, USA.
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13
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Oppelt A, Kaschek D, Huppelschoten S, Sison-Young R, Zhang F, Buck-Wiese M, Herrmann F, Malkusch S, Krüger CL, Meub M, Merkt B, Zimmermann L, Schofield A, Jones RP, Malik H, Schilling M, Heilemann M, van de Water B, Goldring CE, Park BK, Timmer J, Klingmüller U. Model-based identification of TNFα-induced IKKβ-mediated and IκBα-mediated regulation of NFκB signal transduction as a tool to quantify the impact of drug-induced liver injury compounds. NPJ Syst Biol Appl 2018; 4:23. [PMID: 29900006 PMCID: PMC5995845 DOI: 10.1038/s41540-018-0058-z] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2017] [Revised: 04/16/2018] [Accepted: 05/04/2018] [Indexed: 02/07/2023] Open
Abstract
Drug-induced liver injury (DILI) has become a major problem for patients and for clinicians, academics and the pharmaceutical industry. To date, existing hepatotoxicity test systems are only poorly predictive and the underlying mechanisms are still unclear. One of the factors known to amplify hepatotoxicity is the tumor necrosis factor alpha (TNFα), especially due to its synergy with commonly used drugs such as diclofenac. However, the exact mechanism of how diclofenac in combination with TNFα induces liver injury remains elusive. Here, we combined time-resolved immunoblotting and live-cell imaging data of HepG2 cells and primary human hepatocytes (PHH) with dynamic pathway modeling using ordinary differential equations (ODEs) to describe the complex structure of TNFα-induced NFκB signal transduction and integrated the perturbations of the pathway caused by diclofenac. The resulting mathematical model was used to systematically identify parameters affected by diclofenac. These analyses showed that more than one regulatory module of TNFα-induced NFκB signal transduction is affected by diclofenac, suggesting that hepatotoxicity is the integrated consequence of multiple changes in hepatocytes and that multiple factors define toxicity thresholds. Applying our mathematical modeling approach to other DILI-causing compounds representing different putative DILI mechanism classes enabled us to quantify their impact on pathway activation, highlighting the potential of the dynamic pathway model as a quantitative tool for the analysis of DILI compounds.
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Affiliation(s)
- Angela Oppelt
- 1Division Systems Biology of Signal Transduction, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Daniel Kaschek
- 2Institute of Physics, University of Freiburg, Freiburg, Germany
| | - Suzanna Huppelschoten
- 3Division of Toxicology, Leiden Academic Centre for Drug Research, Leiden University, Leiden, The Netherlands
| | - Rowena Sison-Young
- 4MRC Centre for Drug Safety Science, Department of Molecular and Clinical Pharmacology, University of Liverpool, Liverpool, UK
| | - Fang Zhang
- 4MRC Centre for Drug Safety Science, Department of Molecular and Clinical Pharmacology, University of Liverpool, Liverpool, UK
| | - Marie Buck-Wiese
- 1Division Systems Biology of Signal Transduction, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Franziska Herrmann
- 1Division Systems Biology of Signal Transduction, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Sebastian Malkusch
- 5Institute of Physical and Theoretical Chemistry, Single Molecule Biophysics, Johann Wolfgang Goethe-University, Frankfurt, Germany
| | - Carmen L Krüger
- 5Institute of Physical and Theoretical Chemistry, Single Molecule Biophysics, Johann Wolfgang Goethe-University, Frankfurt, Germany
| | - Mara Meub
- 5Institute of Physical and Theoretical Chemistry, Single Molecule Biophysics, Johann Wolfgang Goethe-University, Frankfurt, Germany
| | - Benjamin Merkt
- 2Institute of Physics, University of Freiburg, Freiburg, Germany
| | - Lea Zimmermann
- 1Division Systems Biology of Signal Transduction, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Amy Schofield
- 4MRC Centre for Drug Safety Science, Department of Molecular and Clinical Pharmacology, University of Liverpool, Liverpool, UK
| | - Robert P Jones
- 4MRC Centre for Drug Safety Science, Department of Molecular and Clinical Pharmacology, University of Liverpool, Liverpool, UK.,6North Western Hepatobiliary Unit, Aintree University Hospital NHS Foundation Trust, Liverpool, UK
| | - Hassan Malik
- 6North Western Hepatobiliary Unit, Aintree University Hospital NHS Foundation Trust, Liverpool, UK
| | - Marcel Schilling
- 1Division Systems Biology of Signal Transduction, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Mike Heilemann
- 5Institute of Physical and Theoretical Chemistry, Single Molecule Biophysics, Johann Wolfgang Goethe-University, Frankfurt, Germany.,7Bioquant, University of Heidelberg, Heidelberg, Germany
| | - Bob van de Water
- 3Division of Toxicology, Leiden Academic Centre for Drug Research, Leiden University, Leiden, The Netherlands
| | - Christopher E Goldring
- 4MRC Centre for Drug Safety Science, Department of Molecular and Clinical Pharmacology, University of Liverpool, Liverpool, UK
| | - B Kevin Park
- 4MRC Centre for Drug Safety Science, Department of Molecular and Clinical Pharmacology, University of Liverpool, Liverpool, UK
| | - Jens Timmer
- 2Institute of Physics, University of Freiburg, Freiburg, Germany.,8BIOSS Centre for Biological Signalling Studies, University of Freiburg, Freiburg, Germany
| | - Ursula Klingmüller
- 1Division Systems Biology of Signal Transduction, German Cancer Research Center (DKFZ), Heidelberg, Germany
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14
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Krüger CL, Zeuner MT, Cottrell GS, Widera D, Heilemann M. Quantitative single-molecule imaging of TLR4 reveals ligand-specific receptor dimerization. Sci Signal 2017; 10:10/503/eaan1308. [DOI: 10.1126/scisignal.aan1308] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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15
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Death Receptor 5 Activation Is Energetically Coupled to Opening of the Transmembrane Domain Dimer. Biophys J 2017; 113:381-392. [PMID: 28746849 DOI: 10.1016/j.bpj.2017.05.038] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2017] [Revised: 05/17/2017] [Accepted: 05/22/2017] [Indexed: 01/01/2023] Open
Abstract
The precise mechanism by which binding of tumor necrosis factor ligands to the extracellular domain of their corresponding receptors transmits signals across the plasma membrane has remained elusive. Recent studies have proposed that activation of several tumor necrosis factor receptors, including Death Receptor 5, involves a scissorlike opening of the disulfide-linked transmembrane (TM) dimer. Using time-resolved fluorescence resonance energy transfer, we provide, to our knowledge, the first direct biophysical evidence that Death Receptor 5 TM-dimers open in response to ligand binding. Then, to probe the importance of the closed-to-open TM domain transition in the overall energetics of receptor activation, we designed point-mutants (alanine to phenylalanine) in the predicted, tightly packed TM domain dimer interface. We hypothesized that the bulky residues should destabilize the closed conformation and eliminate the ∼3 kcal/mol energy barrier to TM domain opening and the ∼2 kcal/mol energy difference between the closed and open states, thus oversensitizing the receptor. To test this, we used all-atom molecular dynamics simulations of the isolated TM domain in explicit lipid bilayers coupled to thermodynamic potential of mean force calculations. We showed that single point mutants at the interface altered the energy landscape as predicted, but were not enough to completely eliminate the barrier to opening. However, the computational model did predict that a double mutation at i, i+4 positions at the center of the TM domain dimer eliminates the barrier and stabilizes the open conformation relative to the closed. We tested these mutants in cells with time-resolved fluorescence resonance energy transfer and death assays, and show remarkable agreement with the calculations. The single mutants had a small effect on TM domain separation and cell death, whereas the double mutant significantly increased the TM domain separation and more than doubled the sensitivity of cells to ligand stimulation.
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16
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Carrington B, Myers WK, Horanyi P, Calmiano M, Lawson ADG. Natural Conformational Sampling of Human TNFα Visualized by Double Electron-Electron Resonance. Biophys J 2017; 113:371-380. [PMID: 28746848 PMCID: PMC5529296 DOI: 10.1016/j.bpj.2017.06.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2017] [Revised: 05/05/2017] [Accepted: 06/06/2017] [Indexed: 12/20/2022] Open
Abstract
Double electron-electron resonance in conjunction with site-directed spin labeling has been used to probe natural conformational sampling of the human tumor necrosis factor α trimer. We suggest a previously unreported, predeoligomerization conformation of the trimer that has been shown to be sampled at low frequency. A model of this trimeric state has been constructed based on crystal structures using the double-electron-electron-resonance distances. The model shows one of the protomers to be rotated and tilted outward at the tip end, leading to a breaking of the trimerous symmetry and distortion at a receptor-binding interface. The new structure offers opportunities to modulate the biological activity of tumor necrosis factor α through stabilization of the distorted trimer with small molecules.
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Affiliation(s)
| | - William K Myers
- Department of Inorganic Chemistry, University of Oxford, Oxford, United Kingdom
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17
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Khan AO, Simms VA, Pike JA, Thomas SG, Morgan NV. CRISPR-Cas9 Mediated Labelling Allows for Single Molecule Imaging and Resolution. Sci Rep 2017; 7:8450. [PMID: 28814796 PMCID: PMC5559501 DOI: 10.1038/s41598-017-08493-x] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2017] [Accepted: 06/29/2017] [Indexed: 12/25/2022] Open
Abstract
Single molecule imaging approaches like dSTORM and PALM resolve structures at 10–20 nm, and allow for unique insights into protein stoichiometry and spatial relationships. However, key obstacles remain in developing highly accurate quantitative single molecule approaches. The genomic tagging of PALM fluorophores through CRISPR-Cas9 offers an excellent opportunity for generating stable cell lines expressing a defined single molecule probe at endogenous levels, without the biological disruption and variability inherent to transfection. A fundamental question is whether these comparatively low levels of expression can successfully satisfy the stringent labelling demands of super-resolution SMLM. Here we apply CRISPR-Cas9 gene editing to tag a cytoskeletal protein (α-tubulin) and demonstrate a relationship between expression level and the subsequent quality of PALM imaging, and that spatial resolutions comparable to dSTORM can be achieved with CRISPR-PALM. Our approach shows a relationship between choice of tag and the total expression of labelled protein, which has important implications for the development of future PALM tags. CRISPR-PALM allows for nanoscopic spatial resolution and the unique quantitative benefits of single molecule localization microscopy through endogenous expression, as well as the capacity for super-resolved live cell imaging.
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Affiliation(s)
- Abdullah O Khan
- Institute of Cardiovascular Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham, UK
| | - Victoria A Simms
- Institute of Cardiovascular Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham, UK
| | - Jeremy A Pike
- Centre of Membrane Proteins and Receptors (COMPARE), Universities of Birmingham and Nottingham, Midlands, UK
| | - Steven G Thomas
- Institute of Cardiovascular Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham, UK. .,Centre of Membrane Proteins and Receptors (COMPARE), Universities of Birmingham and Nottingham, Midlands, UK.
| | - Neil V Morgan
- Institute of Cardiovascular Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham, UK.
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18
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NF-κB signaling and cell-fate decision induced by a fast-dissociating tumor necrosis factor mutant. Biochem Biophys Res Commun 2017; 489:287-292. [DOI: 10.1016/j.bbrc.2017.05.149] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2017] [Accepted: 05/25/2017] [Indexed: 11/22/2022]
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19
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Lo CH, Vunnam N, Lewis AK, Chiu TL, Brummel BE, Schaaf TM, Grant BD, Bawaskar P, Thomas DD, Sachs JN. An Innovative High-Throughput Screening Approach for Discovery of Small Molecules That Inhibit TNF Receptors. SLAS DISCOVERY 2017; 22:950-961. [PMID: 28530838 DOI: 10.1177/2472555217706478] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Tumor necrosis factor receptor 1 (TNFR1) is a transmembrane receptor that binds tumor necrosis factor or lymphotoxin-alpha and plays a critical role in regulating the inflammatory response. Upregulation of these ligands is associated with inflammatory and autoimmune diseases. Current treatments reduce symptoms by sequestering free ligands, but this can cause adverse side effects by unintentionally inhibiting ligand binding to off-target receptors. Hence, there is a need for new small molecules that specifically target the receptors, rather than the ligands. Here, we developed a TNFR1 FRET biosensor expressed in living cells to screen compounds from the NIH Clinical Collection. We used an innovative high-throughput fluorescence lifetime screening platform that has exquisite spatial and temporal resolution to identify two small-molecule compounds, zafirlukast and triclabendazole, that inhibit the TNFR1-induced IκBα degradation and NF-κB activation. Biochemical and computational docking methods were used to show that zafirlukast disrupts the interactions between TNFR1 pre-ligand assembly domain (PLAD), whereas triclabendazole acts allosterically. Importantly, neither compound inhibits ligand binding, proving for the first time that it is possible to inhibit receptor activation by targeting TNF receptor-receptor interactions. This strategy should be generally applicable to other members of the TNFR superfamily, as well as to oligomeric receptors in general.
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Affiliation(s)
- Chih Hung Lo
- 1 Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN, USA
| | - Nagamani Vunnam
- 1 Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN, USA
| | - Andrew K Lewis
- 1 Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN, USA
| | - Ting-Lan Chiu
- 1 Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN, USA
| | - Benjamin E Brummel
- 1 Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN, USA
| | - Tory M Schaaf
- 2 Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN, USA
| | | | - Prachi Bawaskar
- 2 Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN, USA
| | - David D Thomas
- 2 Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN, USA.,4 Photonic Pharma LLC, Minneapolis, MN, USA
| | - Jonathan N Sachs
- 1 Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN, USA
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20
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Valley CC, Lewis AK, Sachs JN. Piecing it together: Unraveling the elusive structure-function relationship in single-pass membrane receptors. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2017; 1859:1398-1416. [PMID: 28089689 DOI: 10.1016/j.bbamem.2017.01.016] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/04/2016] [Revised: 01/06/2017] [Accepted: 01/09/2017] [Indexed: 12/17/2022]
Abstract
The challenge of crystallizing single-pass plasma membrane receptors has remained an obstacle to understanding the structural mechanisms that connect extracellular ligand binding to cytosolic activation. For example, the complex interplay between receptor oligomerization and conformational dynamics has been, historically, only inferred from static structures of isolated receptor domains. A fundamental challenge in the field of membrane receptor biology, then, has been to integrate experimentally observable dynamics of full-length receptors (e.g. diffusion and conformational flexibility) into static structural models of the disparate domains. In certain receptor families, e.g. the ErbB receptors, structures have led somewhat linearly to a putative model of activation. In other families, e.g. the tumor necrosis factor (TNF) receptors, structures have produced divergent hypothetical mechanisms of activation and transduction. Here, we discuss in detail these and other related receptors, with the goal of illuminating the current challenges and opportunities in building comprehensive models of single-pass receptor activation. The deepening understanding of these receptors has recently been accelerated by new experimental and computational tools that offer orthogonal perspectives on both structure and dynamics. As such, this review aims to contextualize those technological developments as we highlight the elegant and complex conformational communication between receptor domains. 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)
| | - Andrew K Lewis
- Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, Minnesota, USA
| | - Jonathan N Sachs
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, Minnesota, USA.
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21
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Lewis AK, Valley CC, Peery SL, Brummel B, Braun AR, Karim CB, Sachs JN. Death Receptor 5 Networks Require Membrane Cholesterol for Proper Structure and Function. J Mol Biol 2016; 428:4843-4855. [PMID: 27720987 DOI: 10.1016/j.jmb.2016.10.001] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2016] [Revised: 09/16/2016] [Accepted: 10/02/2016] [Indexed: 12/13/2022]
Abstract
Death receptor 5 (DR5) is an apoptosis-inducing member of the tumor necrosis factor receptor superfamily, whose activity has been linked to membrane cholesterol content. Upon ligand binding, DR5 forms large clusters within the plasma membrane that have often been assumed to be manifestations of receptor co-localization in cholesterol-rich membrane domains. However, we have recently shown that DR5 clusters are more than just randomly aggregated receptors. Instead, these are highly structured networks held together by receptor dimers. These dimers are stabilized by specific transmembrane helix-helix interactions, including a disulfide bond in the long isoform of the receptor. The complex relationships among DR5 network formation, transmembrane helix dimerization, membrane cholesterol, and receptor activity has not been established. It is unknown whether the membrane itself plays an active role in driving DR5 transmembrane helix interactions or in the formation of the networks. We show that cholesterol depletion in cells does not inhibit the formation of DR5 networks. However, the networks that form in cholesterol-depleted cells fail to induce caspase cleavage. These results suggest a potential structural difference between active and inactive networks. As evidence, we show that cholesterol is necessary for the covalent dimerization of DR5 transmembrane domains. Molecular simulations and experiments in synthetic vesicles on the DR5 transmembrane dimer suggest that dimerization is facilitated by increased helicity in a thicker bilayer.
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Affiliation(s)
- Andrew K Lewis
- Department of Biomedical Engineering, University of Minnesota, Twin Cities, Minneapolis, MN 55455, USA
| | - Christopher C Valley
- Department of Biomedical Engineering, University of Minnesota, Twin Cities, Minneapolis, MN 55455, USA
| | - Stephen L Peery
- Department of Biomedical Engineering, University of Minnesota, Twin Cities, Minneapolis, MN 55455, USA
| | - Benjamin Brummel
- Department of Biomedical Engineering, University of Minnesota, Twin Cities, Minneapolis, MN 55455, USA
| | - Anthony R Braun
- Department of Biomedical Engineering, University of Minnesota, Twin Cities, Minneapolis, MN 55455, USA
| | - Christine B Karim
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Twin Cities, Minneapolis, MN 55455, USA
| | - Jonathan N Sachs
- Department of Biomedical Engineering, University of Minnesota, Twin Cities, Minneapolis, MN 55455, USA.
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22
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Zeuner MT, Krüger CL, Volk K, Bieback K, Cottrell GS, Heilemann M, Widera D. Biased signalling is an essential feature of TLR4 in glioma cells. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2016; 1863:3084-3095. [PMID: 27669113 DOI: 10.1016/j.bbamcr.2016.09.016] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2016] [Revised: 09/21/2016] [Accepted: 09/22/2016] [Indexed: 01/19/2023]
Abstract
A distinct feature of the Toll-like receptor 4 (TLR4) is its ability to trigger both MyD88-dependent and MyD88-independent signalling, culminating in activation of pro-inflammatory NF-κB and/or the antiviral IRF3. Although TLR4 agonists (lipopolysaccharides; LPSs) derived from different bacterial species have different endotoxic activity, the impact of LPS chemotype on the downstream signalling is not fully understood. Notably, different TLR4 agonists exhibit anti-tumoural activity in animal models of glioma, but the underlying molecular mechanisms are largely unknown. Thus, we investigated the impact of LPS chemotype on the signalling events in the human glioma cell line U251. We found that LPS of Escherichia coli origin (LPSEC) leads to NF-κB-biased downstream signalling compared to Salmonella minnesota-derived LPS (LPSSM). Exposure of U251 cells to LPSEC resulted in faster nuclear translocation of the NF-κB subunit p65, higher NF-κB-activity and expression of its targets genes, and higher amount of secreted IL-6 compared to LPSSM. Using super-resolution microscopy we showed that the biased agonism of TLR4 in glioma cells is neither a result of differential regulation of receptor density nor of formation of higher order oligomers. Consistent with previous reports, LPSEC-mediated NF-κB activation led to significantly increased U251 proliferation, whereas LPSSM-induced IRF3 activity negatively influenced their invasiveness. Finally, treatment with methyl-β-cyclodextrin (MCD) selectively increased LPSSM-induced nuclear translocation of p65 and NF-κB activity without affecting IRF3. Our data may explain how TLR4 agonists differently affect glioma cell proliferation and migration.
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Affiliation(s)
- Marie-Theres Zeuner
- Stem Cell Biology and Regenerative Medicine, School of Pharmacy, University of Reading, Reading, United Kingdom
| | - Carmen L Krüger
- Institute of Physical and Theoretical Chemistry, Goethe-University, Frankfurt, Germany
| | - Katharina Volk
- Department of Cell Biology, University of Bielefeld, Bielefeld, Germany
| | - Karen Bieback
- Institute of Transfusion Medicine and Immunology, Medical Faculty Mannheim, Heidelberg University, Heidelberg, Germany
| | - Graeme S Cottrell
- Cellular and Molecular Neuroscience, School of Pharmacy, University of Reading, Reading, United Kingdom
| | - Mike Heilemann
- Institute of Physical and Theoretical Chemistry, Goethe-University, Frankfurt, Germany
| | - Darius Widera
- Stem Cell Biology and Regenerative Medicine, School of Pharmacy, University of Reading, Reading, United Kingdom.
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23
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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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24
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Fricke F, Beaudouin J, Eils R, Heilemann M. One, two or three? Probing the stoichiometry of membrane proteins by single-molecule localization microscopy. Sci Rep 2015; 5:14072. [PMID: 26358640 PMCID: PMC4642553 DOI: 10.1038/srep14072] [Citation(s) in RCA: 103] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2015] [Accepted: 08/18/2015] [Indexed: 12/18/2022] Open
Abstract
Probing the oligomeric state of abundant molecules, such as membrane proteins in intact cells, is essential, but has not been straightforward. We address this challenge with a simple counting strategy that is capable of reporting the oligomeric state of dense, membrane-bound protein complexes. It is based on single-molecule localization microscopy to super-resolve protein structures in intact cells and basic quantitative evaluation. We validate our method with membrane-bound monomeric CD86 and dimeric cytotoxic T-lymphocyte-associated protein as model proteins and confirm their oligomeric states. We further detect oligomerization of CD80 and vesicular stomatitis virus glycoprotein and propose coexistence of monomers and dimers for CD80 and trimeric assembly of the viral protein at the cell membrane. This approach should prove valuable for researchers striving for reliable molecular counting in cells.
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Affiliation(s)
- Franziska Fricke
- Institute of Physical and Theoretical Chemistry, Goethe-University Frankfurt, Max-von-Laue-Str. 7, 60438 Frankfurt am Main, Germany
| | - Joel Beaudouin
- Department for Bioinformatics and Functional Genomics, Bioquant and Institute of Pharmacy and Molecular Biotechnology, University of Heidelberg, and Division of Theoretical Bioinformatics, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 267, 69120 Heidelberg, Germany
| | - Roland Eils
- Department for Bioinformatics and Functional Genomics, Bioquant and Institute of Pharmacy and Molecular Biotechnology, University of Heidelberg, and Division of Theoretical Bioinformatics, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 267, 69120 Heidelberg, Germany
| | - Mike Heilemann
- Institute of Physical and Theoretical Chemistry, Goethe-University Frankfurt, Max-von-Laue-Str. 7, 60438 Frankfurt am Main, Germany
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Hennig S, van de Linde S, Bergmann S, Huser T, Sauer M. Quantitative Super-Resolution Microscopy of Nanopipette-Deposited Fluorescent Patterns. ACS NANO 2015; 9:8122-30. [PMID: 26173009 DOI: 10.1021/acsnano.5b02220] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
We describe a method for the deposition of minute amounts of fluorophore-labeled oligonucleotides with high local precision in conductive and transparent solid layers of poly(vinyl alcohol) (PVA) doped with glycerin and cysteamine (PVA-G-C layers). Deposition of negatively charged fluorescent molecules was accomplished with a setup based on a scanning ion conductance microscope (SICM) using nanopipettes with tip diameters of ∼100 nm by using the ion flux flowing between two electrodes through the nanopipette. To investigate the precision of the local deposition process, we performed in situ super-resolution microscopy by direct stochastic optical reconstruction microscopy (dSTORM). Exploiting the single-molecule sensitivity and reliability of dSTORM, we determine the number of fluorescent molecules deposited in single spots. The correlation of applied charge and number of deposited molecules enables the quantification of delivered molecules by measuring the charge during the delivery process. We demonstrate the reproducible deposition of 3-168 fluorescent molecules in single spots and the creation of fluorescent structures. The fluorescent structures are highly stable and can be reused several times.
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Affiliation(s)
- Simon Hennig
- Biomolecular Photonics, Department of Physics, University of Bielefeld , Universitätsstraße 25, 33615 Bielefeld, Germany
| | - Sebastian van de Linde
- Department of Biotechnology & Biophysics, Biozentrum, Julius Maximilians University Würzburg , Am Hubland, 97075 Würzburg, Germany
| | - Stephan Bergmann
- Biomolecular Photonics, Department of Physics, University of Bielefeld , Universitätsstraße 25, 33615 Bielefeld, Germany
| | - Thomas Huser
- Biomolecular Photonics, Department of Physics, University of Bielefeld , Universitätsstraße 25, 33615 Bielefeld, Germany
- Department of Internal Medicine, NSF Center for Biophotonics, University of California, Davis , 2700 Stockton Boulevard, Suite 1400, Sacramento, California 95817, United States
| | - Markus Sauer
- Department of Biotechnology & Biophysics, Biozentrum, Julius Maximilians University Würzburg , Am Hubland, 97075 Würzburg, Germany
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Burgert A, Letschert S, Doose S, Sauer M. Artifacts in single-molecule localization microscopy. Histochem Cell Biol 2015; 144:123-31. [PMID: 26138928 DOI: 10.1007/s00418-015-1340-4] [Citation(s) in RCA: 76] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/13/2015] [Indexed: 01/11/2023]
Abstract
Single-molecule localization microscopy provides subdiffraction resolution images with virtually molecular resolution. Through the availability of commercial instruments and open-source reconstruction software, achieving super resolution is now public domain. However, despite its conceptual simplicity, localization microscopy remains prone to user errors. Using direct stochastic optical reconstruction microscopy, we investigate the impact of irradiation intensity, label density and photoswitching behavior on the distribution of membrane proteins in reconstructed super-resolution images. We demonstrate that high emitter densities in combination with inappropriate photoswitching rates give rise to the appearance of artificial membrane clusters. Especially, two-dimensional imaging of intrinsically three-dimensional membrane structures like microvilli, filopodia, overlapping membranes and vesicles with high local emitter densities is prone to generate artifacts. To judge the quality and reliability of super-resolution images, the single-molecule movies recorded to reconstruct the images have to be carefully investigated especially when investigating membrane organization and cluster analysis.
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Affiliation(s)
- Anne Burgert
- Department of Biotechnology and Biophysics, University Würzburg, Am Hubland, 97074, Würzburg, Germany
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27
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The Histochemistry and Cell Biology pandect: the year 2014 in review. Histochem Cell Biol 2015; 143:339-68. [PMID: 25744491 DOI: 10.1007/s00418-015-1313-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/16/2015] [Indexed: 02/07/2023]
Abstract
This review encompasses a brief synopsis of the articles published in 2014 in Histochemistry and Cell Biology. Out of the total of 12 issues published in 2014, two special issues were devoted to "Single-Molecule Super-Resolution Microscopy." The present review is divided into 11 categories, providing an easy format for readers to quickly peruse topics of particular interest to them.
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28
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Schubert V, Weisshart K. Abundance and distribution of RNA polymerase II in Arabidopsis interphase nuclei. JOURNAL OF EXPERIMENTAL BOTANY 2015; 66:1687-98. [PMID: 25740920 PMCID: PMC4357323 DOI: 10.1093/jxb/erv091] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
RNA polymerase II (RNAPII) is responsible for the transcription of most eukaryotic protein-coding genes. Analysing the topological distribution and quantification of RNAPII can contribute to understanding its function in interphase nuclei. Previously it was shown that RNAPII molecules in plant nuclei form reticulate structures within euchromatin of differentiated Arabidopsis thaliana nuclei rather than being organized in distinct 'transcription factories' as observed in mammalian nuclei. Immunosignal intensity measurements based on specific antibody labelling in maximum intensity projections of image stacks acquired by structured illumination microscopy (SIM) suggested a relative proportional increase of RNAPII in endopolyploid plant nuclei. Here, photoactivated localization microscopy (PALM) was applied to determine the absolute number and distribution of active and inactive RNAPII molecules in differentiated A. thaliana nuclei. The proportional increase of RNAPII during endopolyploidization is confirmed, but it is also shown that PALM measurements are more reliable than those based on SIM in terms of quantification. The single molecule localization results show that, although RNAPII molecules are globally dispersed within plant euchromatin, they also aggregate within smaller distances as described for mammalian transcription factories.
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Affiliation(s)
- Veit Schubert
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK) Gatersleben, D-06466 Stadt Seeland, Germany
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Fricke F, Dietz MS, Heilemann M. Single-Molecule Methods to Study Membrane Receptor Oligomerization. Chemphyschem 2014; 16:713-21. [DOI: 10.1002/cphc.201402765] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2014] [Indexed: 11/06/2022]
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30
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Polarization of excitation light influences molecule counting in single-molecule localization microscopy. Histochem Cell Biol 2014; 143:11-9. [DOI: 10.1007/s00418-014-1267-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/18/2014] [Indexed: 11/27/2022]
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Roth J, Heilemann M. In this special issue. Histochem Cell Biol 2014; 142:3-4. [PMID: 24898544 DOI: 10.1007/s00418-014-1231-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/20/2014] [Indexed: 10/25/2022]
Affiliation(s)
- Jürgen Roth
- University of Zurich, 8091, Zurich, Switzerland,
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