1
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Kumari R, Ven K, Chastney M, Kokate SB, Peränen J, Aaron J, Kogan K, Almeida-Souza L, Kremneva E, Poincloux R, Chew TL, Gunning PW, Ivaska J, Lappalainen P. Focal adhesions contain three specialized actin nanoscale layers. Nat Commun 2024; 15:2547. [PMID: 38514695 PMCID: PMC10957975 DOI: 10.1038/s41467-024-46868-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2024] [Accepted: 03/13/2024] [Indexed: 03/23/2024] Open
Abstract
Focal adhesions (FAs) connect inner workings of cell to the extracellular matrix to control cell adhesion, migration and mechanosensing. Previous studies demonstrated that FAs contain three vertical layers, which connect extracellular matrix to the cytoskeleton. By using super-resolution iPALM microscopy, we identify two additional nanoscale layers within FAs, specified by actin filaments bound to tropomyosin isoforms Tpm1.6 and Tpm3.2. The Tpm1.6-actin filaments, beneath the previously identified α-actinin cross-linked actin filaments, appear critical for adhesion maturation and controlled cell motility, whereas the adjacent Tpm3.2-actin filament layer beneath seems to facilitate adhesion disassembly. Mechanistically, Tpm3.2 stabilizes ACF-7/MACF1 and KANK-family proteins at adhesions, and hence targets microtubule plus-ends to FAs to catalyse their disassembly. Tpm3.2 depletion leads to disorganized microtubule network, abnormally stable FAs, and defects in tail retraction during migration. Thus, FAs are composed of distinct actin filament layers, and each may have specific roles in coupling adhesions to the cytoskeleton, or in controlling adhesion dynamics.
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Affiliation(s)
- Reena Kumari
- HiLIFE Institute of Biotechnology, University of Helsinki, FI-00014, Helsinki, Finland
| | - Katharina Ven
- HiLIFE Institute of Biotechnology, University of Helsinki, FI-00014, Helsinki, Finland
| | - Megan Chastney
- Turku Bioscience Centre, University of Turku and Åbo Akademi University, FI-20520, Turku, Finland
| | - Shrikant B Kokate
- HiLIFE Institute of Biotechnology, University of Helsinki, FI-00014, Helsinki, Finland
| | - Johan Peränen
- HiLIFE Institute of Biotechnology, University of Helsinki, FI-00014, Helsinki, Finland
| | - Jesse Aaron
- Advanced Imaging Center, HHMI Janelia Research Campus, Ashburn, VA, 20147, USA
| | - Konstantin Kogan
- HiLIFE Institute of Biotechnology, University of Helsinki, FI-00014, Helsinki, Finland
| | - Leonardo Almeida-Souza
- HiLIFE Institute of Biotechnology, University of Helsinki, FI-00014, Helsinki, Finland
- Faculty of Biological and Environmental Sciences, University of Helsinki, Helsinki, Finland
| | - Elena Kremneva
- HiLIFE Institute of Biotechnology, University of Helsinki, FI-00014, Helsinki, Finland
| | - Renaud Poincloux
- Institut de Pharmacologie et de Biologie Structurale, Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Teng-Leong Chew
- Advanced Imaging Center, HHMI Janelia Research Campus, Ashburn, VA, 20147, USA
| | - Peter W Gunning
- School of Biomedical Sciences, UNSW Sydney, Wallace Wurth Building, Sydney, NSW 2052, Australia
| | - Johanna Ivaska
- Turku Bioscience Centre, University of Turku and Åbo Akademi University, FI-20520, Turku, Finland
- Department of Life Technologies, University of Turku, FI-20520, Turku, Finland
- InFLAMES Research Flagship Center, University of Turku, Turku, Finland
- Foundation for the Finnish Cancer Institute, Tukholmankatu 8, FI-00014, Helsinki, Finland
| | - Pekka Lappalainen
- HiLIFE Institute of Biotechnology, University of Helsinki, FI-00014, Helsinki, Finland.
- Faculty of Biological and Environmental Sciences, University of Helsinki, Helsinki, Finland.
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2
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Xu T, Verhagen MP, Teeuwssen M, Sun W, Joosten R, Sacchetti A, Ewing-Graham PC, Jansen MPHM, Boere IA, Bryce NS, Zeng J, Treutlein HR, Hook J, Hardeman EC, Gunning PW, Fodde R. Tropomyosin1 isoforms underlie epithelial to mesenchymal plasticity, metastatic dissemination, and resistance to chemotherapy in high-grade serous ovarian cancer. Cell Death Differ 2024; 31:360-377. [PMID: 38365970 PMCID: PMC10923901 DOI: 10.1038/s41418-024-01267-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2023] [Revised: 02/01/2024] [Accepted: 02/06/2024] [Indexed: 02/18/2024] Open
Abstract
Phenotypic plasticity, defined as the ability of individual cells with stable genotypes to exert different phenotypes upon exposure to specific environmental cues, represent the quintessential hallmark of the cancer cell en route from the primary lesion to distant organ sites where metastatic colonization will occur. Phenotypic plasticity is driven by a broad spectrum of epigenetic mechanisms that allow for the reversibility of epithelial-to-mesenchymal and mesenchymal-to-epithelial transitions (EMT/MET). By taking advantage of the co-existence of epithelial and quasi-mesenchymal cells within immortalized cancer cell lines, we have analyzed the role of EMT-related gene isoforms in the regulation of epithelial mesenchymal plasticity (EMP) in high grade serous ovarian cancer. When compared with colon cancer, a distinct spectrum of downstream targets characterizes quasi-mesenchymal ovarian cancer cells, likely to reflect the different modalities of metastasis formation between these two types of malignancy, i.e. hematogenous in colon and transcoelomic in ovarian cancer. Moreover, upstream RNA-binding proteins differentially expressed between epithelial and quasi-mesenchymal subpopulations of ovarian cancer cells were identified that underlie differential regulation of EMT-related isoforms. In particular, the up- and down-regulation of RBM24 and ESRP1, respectively, represent a main regulator of EMT in ovarian cancer cells. To validate the functional and clinical relevance of our approach, we selected and functionally analyzed the Tropomyosin 1 gene (TPM1), encoding for a protein that specifies the functional characteristics of individual actin filaments in contractile cells, among the ovarian-specific downstream AS targets. The low-molecular weight Tpm1.8/9 isoforms are specifically expressed in patient-derived ascites and promote invasion through activation of EMT and Wnt signaling, together with a broad spectrum of inflammation-related pathways. Moreover, Tpm1.8/9 expression confers resistance to taxane- and platinum-based chemotherapy. Small molecule inhibitors that target the Tpm1 isoforms support targeting Tpm1.8/9 as therapeutic targets for the development of future tailor-made clinical interventions.
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Affiliation(s)
- Tong Xu
- Department of Pathology, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Mathijs P Verhagen
- Department of Pathology, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Miriam Teeuwssen
- Department of Pathology, Erasmus University Medical Center, Rotterdam, The Netherlands
- Elisabeth-TweeSteden Ziekenhuis (ETZ), Tilburg, The Netherlands
| | - Wenjie Sun
- Institut Curie, Laboratory of Genetics and Developmental Biology, Paris, France
| | - Rosalie Joosten
- Department of Pathology, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Andrea Sacchetti
- Department of Pathology, Erasmus University Medical Center, Rotterdam, The Netherlands
| | | | - Maurice P H M Jansen
- Department of Medical Oncology, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Ingrid A Boere
- Department of Medical Oncology, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Nicole S Bryce
- School of Biomedical Sciences, Faculty of Medicine and Health, The University of New South Wales, Sydney, New South Wales, Australia
- The Victor Chang Cardiac Research Institute, Darlinghurst, NSW, Australia
| | - Jun Zeng
- Computist Bio-NanoTech, Scoresby, VIC, 3179, Australia
| | - Herbert R Treutlein
- Computist Bio-NanoTech, Scoresby, VIC, 3179, Australia
- Sanoosa Pty. Ltd, Moonee Ponds, VIC, 3039, Australia
| | - Jeff Hook
- School of Biomedical Sciences, Faculty of Medicine and Health, The University of New South Wales, Sydney, New South Wales, Australia
| | - Edna C Hardeman
- School of Biomedical Sciences, Faculty of Medicine and Health, The University of New South Wales, Sydney, New South Wales, Australia
| | - Peter W Gunning
- School of Biomedical Sciences, Faculty of Medicine and Health, The University of New South Wales, Sydney, New South Wales, Australia
| | - Riccardo Fodde
- Department of Pathology, Erasmus University Medical Center, Rotterdam, The Netherlands.
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3
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Mann Z, Lim F, Verma S, Nanavati BN, Davies JM, Begun J, Hardeman EC, Gunning PW, Subramanyam D, Yap AS, Duszyc K. Preexisting tissue mechanical hypertension at adherens junctions disrupts apoptotic extrusion in epithelia. Mol Biol Cell 2024; 35:br3. [PMID: 37903230 PMCID: PMC10881161 DOI: 10.1091/mbc.e23-08-0337] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2023] [Revised: 10/13/2023] [Accepted: 10/20/2023] [Indexed: 11/01/2023] Open
Abstract
Apical extrusion is a tissue-intrinsic process that allows epithelia to eliminate unfit or surplus cells. This is exemplified by the early extrusion of apoptotic cells, which is critical to maintain the epithelial barrier and prevent inflammation. Apoptotic extrusion is an active mechanical process, which involves mechanotransduction between apoptotic cells and their neighbors, as well as local changes in tissue mechanics. Here we report that the preexisting mechanical tension at adherens junctions (AJs) conditions the efficacy of apoptotic extrusion. Specifically, increasing baseline mechanical tension by overexpression of a phosphomimetic Myosin II regulatory light chain (MRLC) compromises apoptotic extrusion. This occurs when tension is increased in either the apoptotic cell or its surrounding epithelium. Further, we find that the proinflammatory cytokine, TNFα, stimulates Myosin II and increases baseline AJ tension to disrupt apical extrusion, causing apoptotic cells to be retained in monolayers. Importantly, reversal of mechanical tension with an inhibitory MRLC mutant or tropomyosin inhibitors is sufficient to restore apoptotic extrusion in TNFα-treated monolayers. Together, these findings demonstrate that baseline levels of tissue tension are important determinants of apoptotic extrusion, which can potentially be coopted by pathogenetic factors to disrupt the homeostatic response of epithelia to apoptosis.
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Affiliation(s)
- Zoya Mann
- Division of Cell and Developmental Biology, Institute for Molecular Bioscience, The University of Queensland, Brisbane, Australia 4072
| | - Fayth Lim
- Division of Cell and Developmental Biology, Institute for Molecular Bioscience, The University of Queensland, Brisbane, Australia 4072
| | - Suzie Verma
- Division of Cell and Developmental Biology, Institute for Molecular Bioscience, The University of Queensland, Brisbane, Australia 4072
| | - Bageshri N. Nanavati
- Division of Cell and Developmental Biology, Institute for Molecular Bioscience, The University of Queensland, Brisbane, Australia 4072
| | - Julie M. Davies
- Mater Research – The University of Queensland, Woolloongabba, Queensland, Australia 4102
| | - Jakob Begun
- Mater Research – The University of Queensland, Woolloongabba, Queensland, Australia 4102
- Department of Gastroenterology, Mater Hospital Brisbane, South Brisbane, Australia 4101
| | - Edna C. Hardeman
- School of Biomedical Sciences, Faculty of Medicine and Health, Univeristy of New South Wales Sydney, New South Wales, Australia 2052
| | - Peter W. Gunning
- School of Biomedical Sciences, Faculty of Medicine and Health, Univeristy of New South Wales Sydney, New South Wales, Australia 2052
| | - Deepa Subramanyam
- National Centre for Cell Science, Savitribai Phule Pune University, Pune 411007, India
| | - Alpha S. Yap
- Division of Cell and Developmental Biology, Institute for Molecular Bioscience, The University of Queensland, Brisbane, Australia 4072
| | - Kinga Duszyc
- Division of Cell and Developmental Biology, Institute for Molecular Bioscience, The University of Queensland, Brisbane, Australia 4072
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4
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Heydecker M, Shitara A, Chen D, Tran D, Masedunskas A, Tora M, Ebrahim S, Appaduray MA, Galeano Niño JL, Bhardwaj A, Narayan K, Hardeman EC, Gunning PW, Weigert R. Spatial and Temporal Coordination of Force-generating Actin-based Modules Drives Membrane Remodeling In Vivo. bioRxiv 2023:2023.12.04.569944. [PMID: 38168275 PMCID: PMC10760165 DOI: 10.1101/2023.12.04.569944] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2024]
Abstract
Membrane remodeling drives a broad spectrum of cellular functions, and it is regulated through mechanical forces exerted on the membrane by cytoplasmic complexes. Here, we investigate how actin filaments dynamically tune their structure to control the active transfer of membranes between cellular compartments with distinct compositions and biophysical properties. Using intravital subcellular microscopy in live rodents we show that: a lattice composed of linear filaments stabilizes the granule membrane after fusion with the plasma membrane; and a network of branched filaments linked to the membranes by Ezrin, a regulator of membrane tension, initiates and drives to completion the integration step. Our results highlight how the actin cytoskeleton tunes its structure to adapt to dynamic changes in the biophysical properties of membranes.
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5
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Wang D, Wang Y, Di X, Wang F, Wanninayaka A, Carnell M, Hardeman EC, Jin D, Gunning PW. Cortical tension drug screen links mitotic spindle integrity to Rho pathway. Curr Biol 2023; 33:4458-4469.e4. [PMID: 37875071 DOI: 10.1016/j.cub.2023.09.022] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2022] [Revised: 07/24/2023] [Accepted: 09/11/2023] [Indexed: 10/26/2023]
Abstract
Mechanical force generation plays an essential role in many cellular functions, including mitosis. Actomyosin contractile forces mediate changes in cell shape in mitosis and are implicated in mitotic spindle integrity via cortical tension. An unbiased screen of 150 small molecules that impact actin organization and 32 anti-mitotic drugs identified two molecular targets, Rho kinase (ROCK) and tropomyosin 3.1/2 (Tpm3.1/2), whose inhibition has the greatest impact on mitotic cortical tension. The converse was found for compounds that depolymerize microtubules. Tpm3.1/2 forms a co-polymer with mitotic cortical actin filaments, and its inhibition prevents rescue of multipolar spindles induced by anti-microtubule chemotherapeutics. We examined the role of mitotic cortical tension in this rescue mechanism. Inhibition of ROCK and Tpm3.1/2 and knockdown (KD) of cortical nonmuscle myosin 2A (NM2A), all of which reduce cortical tension, inhibited rescue of multipolar mitotic spindles, further implicating cortical tension in the rescue mechanism. GEF-H1 released from microtubules by depolymerization increased cortical tension through the RhoA pathway, and its KD also inhibited rescue of multipolar mitotic spindles. We conclude that microtubule depolymerization by anti-cancer drugs induces cortical-tension-based rescue to ensure integrity of the mitotic bipolar spindle mediated via the RhoA pathway. Central to this mechanism is the dependence of NM2A on Tpm3.1/2 to produce the functional engagement of actin filaments responsible for cortical tension.
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Affiliation(s)
- Dejiang Wang
- Institute for Biomedical Materials and Devices (IBMD), Faculty of Science, University of Technology Sydney, Sydney, NSW 2007, Australia; School of Biomedical Sciences, Faculty of Medicine and Health, UNSW Sydney, Sydney, NSW 2052, Australia
| | - Yao Wang
- School of Biomedical Sciences, Faculty of Medicine and Health, UNSW Sydney, Sydney, NSW 2052, Australia
| | - Xiangjun Di
- Institute for Biomedical Materials and Devices (IBMD), Faculty of Science, University of Technology Sydney, Sydney, NSW 2007, Australia
| | - Fan Wang
- School of Electrical and Data Engineering, Faculty of Engineering and Information Technology, University of Technology Sydney, Sydney, NSW 2007, Australia; School of Physics, Beihang University, Beijing 100191, P.R. China
| | - Amanda Wanninayaka
- School of Biomedical Sciences, Faculty of Medicine and Health, UNSW Sydney, Sydney, NSW 2052, Australia
| | - Michael Carnell
- Katharina Gaus Light Microscope Facility, Mark Wainwright Analytical Centre, UNSW Sydney, Sydney, NSW 2052, Australia
| | - Edna C Hardeman
- School of Biomedical Sciences, Faculty of Medicine and Health, UNSW Sydney, Sydney, NSW 2052, Australia
| | - Dayong Jin
- Institute for Biomedical Materials and Devices (IBMD), Faculty of Science, University of Technology Sydney, Sydney, NSW 2007, Australia; UTS-SUStech Joint Research Centre for Biomedical Materials & Devices, Department of Biomedical Engineering, Southern University of Science and Technology, Shenzhen 518055, P.R. China
| | - Peter W Gunning
- School of Biomedical Sciences, Faculty of Medicine and Health, UNSW Sydney, Sydney, NSW 2052, Australia.
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6
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Zhao X, Alibhai D, Walsh TG, Tarassova N, Englert M, Birol SZ, Li Y, Williams CM, Neal CR, Burkard P, Cross SJ, Aitken EW, Waller AK, Beltrán JB, Gunning PW, Hardeman EC, Agbani EO, Nieswandt B, Hers I, Ghevaert C, Poole AW. Highly efficient platelet generation in lung vasculature reproduced by microfluidics. Nat Commun 2023; 14:4026. [PMID: 37419900 PMCID: PMC10329040 DOI: 10.1038/s41467-023-39598-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2022] [Accepted: 06/20/2023] [Indexed: 07/09/2023] Open
Abstract
Platelets, small hemostatic blood cells, are derived from megakaryocytes. Both bone marrow and lung are principal sites of thrombopoiesis although underlying mechanisms remain unclear. Outside the body, however, our ability to generate large number of functional platelets is poor. Here we show that perfusion of megakaryocytes ex vivo through the mouse lung vasculature generates substantial platelet numbers, up to 3000 per megakaryocyte. Despite their large size, megakaryocytes are able repeatedly to passage through the lung vasculature, leading to enucleation and subsequent platelet generation intravascularly. Using ex vivo lung and an in vitro microfluidic chamber we determine how oxygenation, ventilation, healthy pulmonary endothelium and the microvascular structure support thrombopoiesis. We also show a critical role for the actin regulator Tropomyosin 4 in the final steps of platelet formation in lung vasculature. This work reveals the mechanisms of thrombopoiesis in lung vasculature and informs approaches to large-scale generation of platelets.
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Affiliation(s)
- Xiaojuan Zhao
- School of Physiology, Pharmacology and Neuroscience, Biomedical Sciences Building, University of Bristol, Bristol, BS8 1TD, UK.
| | - Dominic Alibhai
- Wolfson BioimagingFacility, Biomedical Sciences Building, University of Bristol, Bristol, BS8 1TD, UK
| | - Tony G Walsh
- School of Physiology, Pharmacology and Neuroscience, Biomedical Sciences Building, University of Bristol, Bristol, BS8 1TD, UK
| | - Nathalie Tarassova
- School of Physiology, Pharmacology and Neuroscience, Biomedical Sciences Building, University of Bristol, Bristol, BS8 1TD, UK
| | - Maximilian Englert
- University Hospital and Rudolf Virchow Center, University of Würzburg, Würzburg, D-97080, Germany
| | - Semra Z Birol
- School of Physiology, Pharmacology and Neuroscience, Biomedical Sciences Building, University of Bristol, Bristol, BS8 1TD, UK
| | - Yong Li
- School of Physiology, Pharmacology and Neuroscience, Biomedical Sciences Building, University of Bristol, Bristol, BS8 1TD, UK
| | - Christopher M Williams
- School of Physiology, Pharmacology and Neuroscience, Biomedical Sciences Building, University of Bristol, Bristol, BS8 1TD, UK
| | - Chris R Neal
- Wolfson BioimagingFacility, Biomedical Sciences Building, University of Bristol, Bristol, BS8 1TD, UK
| | - Philipp Burkard
- University Hospital and Rudolf Virchow Center, University of Würzburg, Würzburg, D-97080, Germany
| | - Stephen J Cross
- Wolfson BioimagingFacility, Biomedical Sciences Building, University of Bristol, Bristol, BS8 1TD, UK
| | - Elizabeth W Aitken
- School of Physiology, Pharmacology and Neuroscience, Biomedical Sciences Building, University of Bristol, Bristol, BS8 1TD, UK
| | - Amie K Waller
- University of Cambridge / NHS Blood and Transplant, Wellcome-MRC Cambridge Stem Cell Institute, Jeffrey Cheah Biomedical Centre, Cambridge Biomedical Campus, University of Cambridge, Cambridge, CB2 0AW, UK
| | - José Ballester Beltrán
- University of Cambridge / NHS Blood and Transplant, Wellcome-MRC Cambridge Stem Cell Institute, Jeffrey Cheah Biomedical Centre, Cambridge Biomedical Campus, University of Cambridge, Cambridge, CB2 0AW, UK
| | - Peter W Gunning
- School of Medical Sciences, University of New South Wales, Sydney, NSW, 2052, Australia
| | - Edna C Hardeman
- School of Medical Sciences, University of New South Wales, Sydney, NSW, 2052, Australia
| | - Ejaife O Agbani
- Cumming School of Medicine, University of Calgary, Calgary, AB, T2N 1N4, Canada
| | - Bernhard Nieswandt
- University Hospital and Rudolf Virchow Center, University of Würzburg, Würzburg, D-97080, Germany
| | - Ingeborg Hers
- School of Physiology, Pharmacology and Neuroscience, Biomedical Sciences Building, University of Bristol, Bristol, BS8 1TD, UK
| | - Cedric Ghevaert
- University of Cambridge / NHS Blood and Transplant, Wellcome-MRC Cambridge Stem Cell Institute, Jeffrey Cheah Biomedical Centre, Cambridge Biomedical Campus, University of Cambridge, Cambridge, CB2 0AW, UK
| | - Alastair W Poole
- School of Physiology, Pharmacology and Neuroscience, Biomedical Sciences Building, University of Bristol, Bristol, BS8 1TD, UK.
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7
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Hardeman EC, Heydecker M, Masedunskas A, Ebrahim S, Weigert R, Gunning PW. Intravital subcellular and single molecule imaging reveals multiple actin filament populations collaborate in the remodelling of the secretory granule membrane. Biophys J 2022. [DOI: 10.1016/j.bpj.2021.11.1268] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
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8
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Cagigas ML, Bryce NS, Ariotti N, Brayford S, Gunning PW, Hardeman EC. Correlative cryo-ET identifies actin/tropomyosin filaments that mediate cell-substrate adhesion in cancer cells and mechanosensitivity of cell proliferation. Nat Mater 2022; 21:120-128. [PMID: 34518666 DOI: 10.1038/s41563-021-01087-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Accepted: 07/23/2021] [Indexed: 05/26/2023]
Abstract
The actin cytoskeleton is the primary driver of cellular adhesion and mechanosensing due to its ability to generate force and sense the stiffness of the environment. At the cell's leading edge, severing of the protruding Arp2/3 actin network generates a specific actin/tropomyosin (Tpm) filament population that controls lamellipodial persistence. The interaction between these filaments and adhesion to the environment is unknown. Using cellular cryo-electron tomography we resolve the ultrastructure of the Tpm/actin copolymers and show that they specifically anchor to nascent adhesions and are essential for focal adhesion assembly. Re-expression of Tpm1.8/1.9 in transformed and cancer cells is sufficient to restore cell-substrate adhesions. We demonstrate that knock-out of Tpm1.8/1.9 disrupts the formation of dorsal actin bundles, hindering the recruitment of α-actinin and non-muscle myosin IIa, critical mechanosensors. This loss causes a force-generation and proliferation defect that is notably reversed when cells are grown on soft surfaces. We conclude that Tpm1.8/1.9 suppress the metastatic phenotype, which may explain why transformed cells naturally downregulate this Tpm subset during malignant transformation.
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Affiliation(s)
- Maria Lastra Cagigas
- School of Medical Sciences, Faculty of Medicine and Health, UNSW Sydney, Sydney, New South Wales, Australia
| | - Nicole S Bryce
- School of Medical Sciences, Faculty of Medicine and Health, UNSW Sydney, Sydney, New South Wales, Australia
| | - Nicholas Ariotti
- School of Medical Sciences, Faculty of Medicine and Health, UNSW Sydney, Sydney, New South Wales, Australia
- Electron Microscope Unit, Mark Wainwright Analytical Centre, UNSW Sydney, Sydney, New South Wales, Australia
| | - Simon Brayford
- School of Medical Sciences, Faculty of Medicine and Health, UNSW Sydney, Sydney, New South Wales, Australia
- Children's Cancer Institute, Lowy Cancer Research Centre, UNSW Sydney, Sydney, New South Wales, Australia
| | - Peter W Gunning
- School of Medical Sciences, Faculty of Medicine and Health, UNSW Sydney, Sydney, New South Wales, Australia.
| | - Edna C Hardeman
- School of Medical Sciences, Faculty of Medicine and Health, UNSW Sydney, Sydney, New South Wales, Australia
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9
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Chaichim C, Tomanic T, Stefen H, Paric E, Gamaroff L, Suchowerska AK, Gunning PW, Ke YD, Fath T, Power J. Overexpression of Tropomyosin Isoform Tpm3.1 Does Not Alter Synaptic Function in Hippocampal Neurons. Int J Mol Sci 2021; 22:ijms22179303. [PMID: 34502205 PMCID: PMC8430609 DOI: 10.3390/ijms22179303] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Revised: 08/23/2021] [Accepted: 08/24/2021] [Indexed: 11/16/2022] Open
Abstract
Tropomyosin (Tpm) has been regarded as the master regulator of actin dynamics. Tpms regulate the binding of the various proteins involved in restructuring actin. The actin cytoskeleton is the predominant cytoskeletal structure in dendritic spines. Its regulation is critical for spine formation and long-term activity-dependent changes in synaptic strength. The Tpm isoform Tpm3.1 is enriched in dendritic spines, but its role in regulating the synapse structure and function is not known. To determine the role of Tpm3.1, we studied the synapse structure and function of cultured hippocampal neurons from transgenic mice overexpressing Tpm3.1. We recorded hippocampal field excitatory postsynaptic potentials (fEPSPs) from brain slices to examine if Tpm3.1 overexpression alters long-term synaptic plasticity. Tpm3.1-overexpressing cultured neurons did not show a significantly altered dendritic spine morphology or synaptic activity. Similarly, we did not observe altered synaptic transmission or plasticity in brain slices. Furthermore, expression of Tpm3.1 at the postsynaptic compartment does not increase the local F-actin levels. The results suggest that although Tpm3.1 localises to dendritic spines in cultured hippocampal neurons, it does not have any apparent impact on dendritic spine morphology or function. This is contrary to the functional role of Tpm3.1 previously observed at the tip of growing neurites, where it increases the F-actin levels and impacts growth cone dynamics.
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Affiliation(s)
- Chanchanok Chaichim
- Translational Neuroscience Facility, School of Medical Sciences, University of New South Wales, Sydney, NSW 2052, Australia;
- Dementia Research Centre, Department of Biomedical Sciences, Faculty of Medicine, Health and Human Sciences, Macquarie University, Sydney, NSW 2109, Australia; (T.T.); (H.S.); (E.P.); (L.G.); (A.K.S.); (Y.D.K.)
| | - Tamara Tomanic
- Dementia Research Centre, Department of Biomedical Sciences, Faculty of Medicine, Health and Human Sciences, Macquarie University, Sydney, NSW 2109, Australia; (T.T.); (H.S.); (E.P.); (L.G.); (A.K.S.); (Y.D.K.)
| | - Holly Stefen
- Dementia Research Centre, Department of Biomedical Sciences, Faculty of Medicine, Health and Human Sciences, Macquarie University, Sydney, NSW 2109, Australia; (T.T.); (H.S.); (E.P.); (L.G.); (A.K.S.); (Y.D.K.)
| | - Esmeralda Paric
- Dementia Research Centre, Department of Biomedical Sciences, Faculty of Medicine, Health and Human Sciences, Macquarie University, Sydney, NSW 2109, Australia; (T.T.); (H.S.); (E.P.); (L.G.); (A.K.S.); (Y.D.K.)
| | - Lucy Gamaroff
- Dementia Research Centre, Department of Biomedical Sciences, Faculty of Medicine, Health and Human Sciences, Macquarie University, Sydney, NSW 2109, Australia; (T.T.); (H.S.); (E.P.); (L.G.); (A.K.S.); (Y.D.K.)
| | - Alexandra K. Suchowerska
- Dementia Research Centre, Department of Biomedical Sciences, Faculty of Medicine, Health and Human Sciences, Macquarie University, Sydney, NSW 2109, Australia; (T.T.); (H.S.); (E.P.); (L.G.); (A.K.S.); (Y.D.K.)
| | - Peter W. Gunning
- Cellular and Genetic Medicine Unit, School of Medical Sciences, University of New South Wales, Sydney, NSW 2052, Australia;
| | - Yazi D. Ke
- Dementia Research Centre, Department of Biomedical Sciences, Faculty of Medicine, Health and Human Sciences, Macquarie University, Sydney, NSW 2109, Australia; (T.T.); (H.S.); (E.P.); (L.G.); (A.K.S.); (Y.D.K.)
| | - Thomas Fath
- Dementia Research Centre, Department of Biomedical Sciences, Faculty of Medicine, Health and Human Sciences, Macquarie University, Sydney, NSW 2109, Australia; (T.T.); (H.S.); (E.P.); (L.G.); (A.K.S.); (Y.D.K.)
- Correspondence: (T.F.); (J.P.)
| | - John Power
- Translational Neuroscience Facility, School of Medical Sciences, University of New South Wales, Sydney, NSW 2052, Australia;
- Correspondence: (T.F.); (J.P.)
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10
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Xu X, Wang Y, Bryce N, Tang K, Meagher NS, Kang EY, Kelemen LE, Köbel M, Ramus SJ, Friedlander M, Ford CE, Hardeman EC, Gunning PW. Abstract 1045: Combined targeting of actin/tropomyosin and microtubules underlies a potential treatment strategy of epithelial ovarian cancer with cell-cycle dependent synergy. Cancer Res 2021. [DOI: 10.1158/1538-7445.am2021-1045] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Anti-microtubule agents are widely used to treat ovarian cancers in the first line and recurrent setting either in combination with platinum or as single agents. However, the majority of patients will experience a recurrence, and most will die with drug resistant disease. We investigated co-targeting the actin cytoskeleton in combination with anti-microtubule agents to increase efficacy of treatment in epithelial ovarian cancers and potentially overcome resistance mechanisms. We examined the presence of actin/tropomyosin 3.1 (Tpm3.1) filaments in a large cohort of clinical specimens from patients with epithelial ovarian cancer of all histotypes using immunohistochemistry. Combinatorial effects of an anti-Tpm3.1 compound (ATM) with both vinorelbine and paclitaxel were evaluated in three ovarian cancer cell lines using cell viability and apoptosis assays. The mechanisms of synergy of both combinations were established using live-cell imaging, fluorescent microscopy, and pathway analysis. We found that Tpm3.1 is abundant and overexpressed in 97% of ovarian cancers examined (558 of 577) representing all histotypes of epithelial ovarian cancer. High levels of Tpm3.1 were also present in all sites sampled and similar at primary diagnosis and at recurrence. ATM displayed both single agent activity as well as synergy with both anti-microtubule drugs to reduce cell viability in all ovarian cancer cell lines tested, including one with platinum resistance. Only vinorelbine, however, synergised with ATM in the induction of apoptosis. Vinorelbine-induced mitotic arrest was significantly prolonged by ATM with elevated activity of the spindle assembly checkpoint, leading to almost one third of total cells dying in mitosis. In contrast, ATM showed minor impact on paclitaxel-induced mitotic defects. Both combinations resulted in a substantial increase in cells arrested in the subsequent G1 phase with a large decrease of both cyclin D1 and E1 as compared to single agents. Upregulation of p21Cip and p27Kip were associated with both combinations. In summary, targeting Tpm3.1-associated actin filaments in combination with anti-microtubule drugs is a promising treatment strategy that should be tested in clinical trials and is potentially applicable to all histotypes of ovarian cancer.
Citation Format: Xing Xu, Yao Wang, Nicole Bryce, Katrina Tang, Nicola S. Meagher, Eun Young Kang, Linda E. Kelemen, Martin Köbel, Susan J. Ramus, Michael Friedlander, Caroline E. Ford, Edna C. Hardeman, Peter W. Gunning. Combined targeting of actin/tropomyosin and microtubules underlies a potential treatment strategy of epithelial ovarian cancer with cell-cycle dependent synergy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 1045.
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Affiliation(s)
- Xing Xu
- 1University of New South Wales, Sydney, Australia
| | - Yao Wang
- 1University of New South Wales, Sydney, Australia
| | - Nicole Bryce
- 1University of New South Wales, Sydney, Australia
| | | | | | | | | | - Martin Köbel
- 3University of Calgary, Calgary, Alberta, Canada
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11
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Rae J, Ferguson C, Ariotti N, Webb RI, Cheng HH, Mead JL, Riches JD, Hunter DJ, Martel N, Baltos J, Christopoulos A, Bryce NS, Cagigas ML, Fonseka S, Sayre ME, Hardeman EC, Gunning PW, Gambin Y, Hall TE, Parton RG. A robust method for particulate detection of a genetic tag for 3D electron microscopy. eLife 2021; 10:64630. [PMID: 33904409 PMCID: PMC8104959 DOI: 10.7554/elife.64630] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2020] [Accepted: 04/26/2021] [Indexed: 12/20/2022] Open
Abstract
Genetic tags allow rapid localization of tagged proteins in cells and tissues. APEX, an ascorbate peroxidase, has proven to be one of the most versatile and robust genetic tags for ultrastructural localization by electron microscopy (EM). Here, we describe a simple method, APEX-Gold, which converts the diffuse oxidized diaminobenzidine reaction product of APEX into a silver/gold particle akin to that used for immunogold labelling. The method increases the signal-to-noise ratio for EM detection, providing unambiguous detection of the tagged protein, and creates a readily quantifiable particulate signal. We demonstrate the wide applicability of this method for detection of membrane proteins, cytoplasmic proteins, and cytoskeletal proteins. The method can be combined with different EM techniques including fast freezing and freeze substitution, focussed ion beam scanning EM, and electron tomography. Quantitation of expressed APEX-fusion proteins is achievable using membrane vesicles generated by a cell-free expression system. These membrane vesicles possess a defined quantum of signal, which can act as an internal standard for determination of the absolute density of expressed APEX-fusion proteins. Detection of fusion proteins expressed at low levels in cells from CRISPR-edited mice demonstrates the high sensitivity of the APEX-Gold method.
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Affiliation(s)
- James Rae
- The University of Queensland, Institute for Molecular Bioscience, Queensland, Australia
| | - Charles Ferguson
- The University of Queensland, Institute for Molecular Bioscience, Queensland, Australia
| | - Nicholas Ariotti
- Mark Wainwright Analytical Centre, University of New South Wales, Sydney, Australia.,School of Medical Sciences, University of New South Wales, Sydney, Australia
| | - Richard I Webb
- The University of Queensland, Centre for Microscopy and Microanalysis, Queensland, Australia
| | - Han-Hao Cheng
- The University of Queensland, Centre for Microscopy and Microanalysis, Queensland, Australia
| | - James L Mead
- The University of Queensland, Centre for Microscopy and Microanalysis, Queensland, Australia.,Division Microrobotics and Control Engineering, Department of Computing Science, University of Oldenburg, Oldenburg, Germany
| | - James D Riches
- Queensland University of Technology, Queensland, Australia
| | - Dominic Jb Hunter
- The University of Queensland, Institute for Molecular Bioscience, Queensland, Australia.,EMBL Australia Node for Single Molecule Sciences, University of New South Wales, Sydney, Australia
| | - Nick Martel
- The University of Queensland, Institute for Molecular Bioscience, Queensland, Australia
| | - Joanne Baltos
- Monash Institute of Pharmaceutical Sciences, Monash University, Victoria, Australia
| | - Arthur Christopoulos
- Monash Institute of Pharmaceutical Sciences, Monash University, Victoria, Australia
| | - Nicole S Bryce
- School of Medical Sciences, University of New South Wales, Sydney, Australia
| | | | - Sachini Fonseka
- The University of Queensland, Institute for Molecular Bioscience, Queensland, Australia
| | - Marcel E Sayre
- The University of Queensland, Centre for Microscopy and Microanalysis, Queensland, Australia
| | - Edna C Hardeman
- School of Medical Sciences, University of New South Wales, Sydney, Australia
| | - Peter W Gunning
- School of Medical Sciences, University of New South Wales, Sydney, Australia
| | - Yann Gambin
- EMBL Australia Node for Single Molecule Sciences, University of New South Wales, Sydney, Australia
| | - Thomas E Hall
- The University of Queensland, Institute for Molecular Bioscience, Queensland, Australia
| | - Robert G Parton
- The University of Queensland, Institute for Molecular Bioscience, Queensland, Australia.,The University of Queensland, Centre for Microscopy and Microanalysis, Queensland, Australia
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12
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Janco M, Dedova I, Bryce NS, Hardeman EC, Gunning PW. Visualizing the in vitro assembly of tropomyosin/actin filaments using TIRF microscopy. Biophys Rev 2020; 12:879-885. [PMID: 32638329 PMCID: PMC7429660 DOI: 10.1007/s12551-020-00720-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2020] [Accepted: 07/02/2020] [Indexed: 12/23/2022] Open
Abstract
Tropomyosins are elongated alpha-helical proteins that form co-polymers with most actin filaments within a cell and play important roles in the structural and functional diversification of the actin cytoskeleton. How the assembly of tropomyosins along an actin filament is regulated and the kinetics of tropomyosin association with an actin filament is yet to be fully determined. A recent series of publications have used total internal reflection fluorescence (TIRF) microscopy in combination with advanced surface and protein chemistry to visualise the molecular assembly of actin/tropomyosin filaments in vitro. Here, we review the use of the in vitro TIRF assay in the determination of kinetic data on tropomyosin filament assembly. This sophisticated approach has enabled generation of real-time single-molecule data to fill the gap between in vitro bulk assays and in vivo assays of tropomyosin function. The in vitro TIRF assays provide a new foundation for future studies involving multiple actin-binding proteins that will more accurately reflect the physiological protein-protein interactions in cells.
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Affiliation(s)
- Miro Janco
- School of Medical Sciences, University of New South Wales, Sydney, NSW, 2052, Australia
| | - Irina Dedova
- School of Medical Sciences, University of New South Wales, Sydney, NSW, 2052, Australia
| | - Nicole S Bryce
- School of Medical Sciences, University of New South Wales, Sydney, NSW, 2052, Australia
| | - Edna C Hardeman
- School of Medical Sciences, University of New South Wales, Sydney, NSW, 2052, Australia
| | - Peter W Gunning
- School of Medical Sciences, University of New South Wales, Sydney, NSW, 2052, Australia.
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13
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Abouelezz A, Stefen H, Segerstråle M, Micinski D, Minkeviciene R, Lahti L, Hardeman EC, Gunning PW, Hoogenraad CC, Taira T, Fath T, Hotulainen P. Tropomyosin Tpm3.1 Is Required to Maintain the Structure and Function of the Axon Initial Segment. iScience 2020; 23:101053. [PMID: 32344377 PMCID: PMC7186529 DOI: 10.1016/j.isci.2020.101053] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2019] [Revised: 03/05/2020] [Accepted: 04/06/2020] [Indexed: 12/26/2022] Open
Abstract
The axon initial segment (AIS) is the site of action potential initiation and serves as a cargo transport filter and diffusion barrier that helps maintain neuronal polarity. The AIS actin cytoskeleton comprises actin patches and periodic sub-membranous actin rings. We demonstrate that tropomyosin isoform Tpm3.1 co-localizes with actin patches and that the inhibition of Tpm3.1 led to a reduction in the density of actin patches. Furthermore, Tpm3.1 showed a periodic distribution similar to sub-membranous actin rings but Tpm3.1 was only partially congruent with sub-membranous actin rings. Nevertheless, the inhibition of Tpm3.1 affected the uniformity of the periodicity of actin rings. Furthermore, Tpm3.1 inhibition led to reduced accumulation of AIS structural and functional proteins, disruption in sorting somatodendritic and axonal proteins, and a reduction in firing frequency. These results show that Tpm3.1 is necessary for the structural and functional maintenance of the AIS. Tropomyosin isoform Tpm3.1 co-localizes with the actin cytoskeleton in the AIS Tpm3.1 inhibition led to a less organized AIS actin cytoskeleton Perturbation of Tpm3.1 function reduced the accumulation of AIS scaffolding proteins Tpm3.1 inhibition compromised cargo sorting and rapidly reduced firing frequency
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Affiliation(s)
- Amr Abouelezz
- Minerva Foundation Institute for Medical Research, Biomedicum Helsinki 2U, Tukholmankatu 8, 00290 Helsinki, Finland; HiLIFE - Neuroscience Center, University of Helsinki, Haartmaninkatu 8, 00290 Helsinki, Finland
| | - Holly Stefen
- School of Medical Sciences, UNSW Sydney, Sydney, NSW 2052, Australia
| | - Mikael Segerstråle
- Faculty of Biological and Environmental Sciences, University of Helsinki, Viikinkaari 1, 00790 Helsinki, Finland
| | - David Micinski
- Minerva Foundation Institute for Medical Research, Biomedicum Helsinki 2U, Tukholmankatu 8, 00290 Helsinki, Finland
| | - Rimante Minkeviciene
- Minerva Foundation Institute for Medical Research, Biomedicum Helsinki 2U, Tukholmankatu 8, 00290 Helsinki, Finland
| | - Lauri Lahti
- Department of Computer Science, Aalto University School of Science, Espoo, Finland
| | - Edna C Hardeman
- School of Medical Sciences, UNSW Sydney, Sydney, NSW 2052, Australia
| | - Peter W Gunning
- School of Medical Sciences, UNSW Sydney, Sydney, NSW 2052, Australia
| | - Casper C Hoogenraad
- Cell Biology, Department of Biology, Faculty of Science, Utrecht University, Padualaan 8, 3584CH Utrecht, the Netherlands
| | - Tomi Taira
- Faculty of Veterinary Medicine, University of Helsinki, Agnes Sjöbergin katu 2, 00790 Helsinki, Finland
| | - Thomas Fath
- School of Medical Sciences, UNSW Sydney, Sydney, NSW 2052, Australia; Dementia Research Centre, Faculty of Medicine and Health Sciences, Macquarie University, Sydney, NSW 2109, Australia
| | - Pirta Hotulainen
- Minerva Foundation Institute for Medical Research, Biomedicum Helsinki 2U, Tukholmankatu 8, 00290 Helsinki, Finland.
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14
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Wang Y, Stear JH, Swain A, Xu X, Bryce NS, Carnell M, Alieva IB, Dugina VB, Cripe TP, Stehn J, Hardeman EC, Gunning PW. Drug Targeting the Actin Cytoskeleton Potentiates the Cytotoxicity of Low Dose Vincristine by Abrogating Actin-Mediated Repair of Spindle Defects. Mol Cancer Res 2020; 18:1074-1087. [PMID: 32269073 DOI: 10.1158/1541-7786.mcr-19-1122] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2019] [Revised: 03/09/2020] [Accepted: 04/03/2020] [Indexed: 11/16/2022]
Abstract
Antimicrotubule vinca alkaloids are widely used in the clinic but their toxicity is often dose limiting. Strategies that enhance their effectiveness at lower doses are needed. We show that combining vinca alkaloids with compounds that target a specific population of actin filaments containing the cancer-associated tropomyosin Tpm3.1 result in synergy against a broad range of tumor cell types. We discovered that low concentrations of vincristine alone induce supernumerary microtubule asters that form transient multi-polar spindles in early mitosis. Over time these asters can be reconstructed into functional bipolar spindles resulting in cell division and survival. These microtubule asters are organized by the nuclear mitotic apparatus protein (NuMA)-dynein-dynactin complex without involvement of centrosomes. However, anti-Tpm3.1 compounds at nontoxic concentrations inhibit this rescue mechanism resulting in delayed onset of anaphase, formation of multi-polar spindles, and apoptosis during mitosis. These findings indicate that drug targeting actin filaments containing Tpm3.1 potentiates the anticancer activity of low-dose vincristine treatment. IMPLICATIONS: Simultaneously inhibiting Tpm3.1-containing actin filaments and microtubules is a promising strategy to potentiate the anticancer activity of low-dose vincristine.
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Affiliation(s)
- Yao Wang
- Cellular and Genetic Medicine Unit, School of Medical Sciences, University of New South Wales, Sydney, New South Wales, Australia
| | - Jeffrey H Stear
- Cellular and Genetic Medicine Unit, School of Medical Sciences, University of New South Wales, Sydney, New South Wales, Australia
| | - Ashleigh Swain
- Cellular and Genetic Medicine Unit, School of Medical Sciences, University of New South Wales, Sydney, New South Wales, Australia
| | - Xing Xu
- Cellular and Genetic Medicine Unit, School of Medical Sciences, University of New South Wales, Sydney, New South Wales, Australia
| | - Nicole S Bryce
- Cellular and Genetic Medicine Unit, School of Medical Sciences, University of New South Wales, Sydney, New South Wales, Australia
| | - Michael Carnell
- Biomedical Imaging Facility, Mark Wainwright Analytical Center, University of New South Wales, Sydney, New South Wales, Australia
| | - Irina B Alieva
- Department of Electron Microscopy, A.N. Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russia
| | - Vera B Dugina
- Department of Mathematical Methods in Biology, A.N. Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russia
| | | | - Justine Stehn
- Cellular and Genetic Medicine Unit, School of Medical Sciences, University of New South Wales, Sydney, New South Wales, Australia
| | - Edna C Hardeman
- Cellular and Genetic Medicine Unit, School of Medical Sciences, University of New South Wales, Sydney, New South Wales, Australia
| | - Peter W Gunning
- Cellular and Genetic Medicine Unit, School of Medical Sciences, University of New South Wales, Sydney, New South Wales, Australia.
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15
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Kumari R, Jiu Y, Carman PJ, Tojkander S, Kogan K, Varjosalo M, Gunning PW, Dominguez R, Lappalainen P. Tropomodulins Control the Balance between Protrusive and Contractile Structures by Stabilizing Actin-Tropomyosin Filaments. Curr Biol 2020; 30:767-778.e5. [PMID: 32037094 DOI: 10.1016/j.cub.2019.12.049] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2019] [Revised: 11/06/2019] [Accepted: 12/16/2019] [Indexed: 02/08/2023]
Abstract
Eukaryotic cells have diverse protrusive and contractile actin filament structures, which compete with one another for a limited pool of actin monomers. Numerous actin-binding proteins regulate the dynamics of actin structures, including tropomodulins (Tmods), which cap the pointed end of actin filaments. In striated muscles, Tmods prevent actin filaments from overgrowing, whereas in non-muscle cells, their function has remained elusive. Here, we identify two Tmod isoforms, Tmod1 and Tmod3, as key components of contractile stress fibers in non-muscle cells. Individually, Tmod1 and Tmod3 can compensate for one another, but their simultaneous depletion results in disassembly of actin-tropomyosin filaments, loss of force-generating stress fibers, and severe defects in cell morphology. Knockout-rescue experiments reveal that Tmod's interaction with tropomyosin is essential for its role in the stabilization of actin-tropomyosin filaments in cells. Thus, in contrast to their role in muscle myofibrils, in non-muscle cells, Tmods bind actin-tropomyosin filaments to protect them from depolymerizing, not elongating. Furthermore, loss of Tmods shifts the balance from linear actin-tropomyosin filaments to Arp2/3 complex-nucleated branched networks, and this phenotype can be partially rescued by inhibiting the Arp2/3 complex. Collectively, the data reveal that Tmods are essential for the maintenance of contractile actomyosin bundles and that Tmod-dependent capping of actin-tropomyosin filaments is critical for the regulation of actin homeostasis in non-muscle cells.
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Affiliation(s)
- Reena Kumari
- HiLIFE Institute of Biotechnology, University of Helsinki, PO Box 56, 00014 Helsinki, Finland
| | - Yaming Jiu
- HiLIFE Institute of Biotechnology, University of Helsinki, PO Box 56, 00014 Helsinki, Finland; CAS Key Laboratory of Molecular Virology and Immunology, Institute Pasteur of Shanghai, Chinese Academy of Sciences, Life Science Research Building 320, Yueyang Road, Xuhui District, 200031 Shanghai, China; University of Chinese Academy of Sciences, Yuquan Road No.19(A), Shijingshan District, 100049 Beijing, China
| | - Peter J Carman
- Department of Physiology, Perelman School of Medicine, University of Pennsylvania, 728 Clinical Research Bldg, 415 Curie Boulevard, Philadelphia, PA 19104, USA; Graduate Group in Biochemistry and Molecular Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Sari Tojkander
- Department of Veterinary Biosciences, Faculty of Veterinary Medicine, University of Helsinki, Agnes Sjöberginkatu 2, 00014 Helsinki, Finland
| | - Konstantin Kogan
- HiLIFE Institute of Biotechnology, University of Helsinki, PO Box 56, 00014 Helsinki, Finland
| | - Markku Varjosalo
- HiLIFE Institute of Biotechnology, University of Helsinki, PO Box 56, 00014 Helsinki, Finland
| | - Peter W Gunning
- School of Medical Sciences, UNSW, Sydney, Wallace Wurth Building, Sydney, NSW 2052, Australia
| | - Roberto Dominguez
- Department of Physiology, Perelman School of Medicine, University of Pennsylvania, 728 Clinical Research Bldg, 415 Curie Boulevard, Philadelphia, PA 19104, USA
| | - Pekka Lappalainen
- HiLIFE Institute of Biotechnology, University of Helsinki, PO Box 56, 00014 Helsinki, Finland.
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16
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Affiliation(s)
- Edna C Hardeman
- School of Medical Sciences, University of New South Wales, Sydney, Australia.
| | - Peter W Gunning
- School of Medical Sciences, University of New South Wales, Sydney, Australia
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17
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Bryce NS, Failes TW, Stehn JR, Baker K, Zahler S, Arzhaeva Y, Bischof L, Lyons C, Dedova I, Arndt GM, Gaus K, Goult BT, Hardeman EC, Gunning PW, Lock JG. High-Content Imaging of Unbiased Chemical Perturbations Reveals that the Phenotypic Plasticity of the Actin Cytoskeleton Is Constrained. Cell Syst 2019; 9:496-507.e5. [PMID: 31606369 DOI: 10.1016/j.cels.2019.09.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2018] [Revised: 07/08/2019] [Accepted: 09/06/2019] [Indexed: 12/27/2022]
Abstract
Although F-actin has a large number of binding partners and regulators, the number of phenotypic states available to the actin cytoskeleton is unknown. Here, we quantified 74 features defining filamentous actin (F-actin) and cellular morphology in >25 million cells after treatment with a library of 114,400 structurally diverse compounds. After reducing the dimensionality of these data, only ∼25 recurrent F-actin phenotypes emerged, each defined by distinct quantitative features that could be machine learned. We identified 2,003 unknown compounds as inducers of actin-related phenotypes, including two that directly bind the focal adhesion protein, talin. Moreover, we observed that compounds with distinct molecular mechanisms could induce equivalent phenotypes and that initially divergent cellular responses could converge over time. These findings suggest a conceptual parallel between the actin cytoskeleton and gene regulatory networks, where the theoretical plasticity of interactions is nearly infinite, yet phenotypes in vivo are constrained into a limited subset of practicable configurations.
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Affiliation(s)
- Nicole S Bryce
- School of Medical Sciences, UNSW Sydney, Sydney, NSW 2052, Australia
| | - Tim W Failes
- Australian Cancer Research Foundation Drug Discovery Centre, Children's Cancer Institute, Lowy Cancer Research Centre, UNSW Sydney, Sydney, NSW 2052, Australia
| | - Justine R Stehn
- School of Medical Sciences, UNSW Sydney, Sydney, NSW 2052, Australia
| | - Karen Baker
- School of Biosciences, University of Kent, Canterbury, Kent CT2 7NJ, UK
| | - Stefan Zahler
- Department of Pharmacy, Ludwig-Maximilians-University, Munich, Germany
| | - Yulia Arzhaeva
- Quantitative Imaging Research Team, CSIRO Data 61, Marsfield, NSW, Australia
| | - Leanne Bischof
- Quantitative Imaging Research Team, CSIRO Data 61, Marsfield, NSW, Australia
| | - Ciaran Lyons
- School of Medical Sciences, UNSW Sydney, Sydney, NSW 2052, Australia
| | - Irina Dedova
- School of Medical Sciences, UNSW Sydney, Sydney, NSW 2052, Australia
| | - Greg M Arndt
- Australian Cancer Research Foundation Drug Discovery Centre, Children's Cancer Institute, Lowy Cancer Research Centre, UNSW Sydney, Sydney, NSW 2052, Australia
| | - Katharina Gaus
- School of Medical Sciences, UNSW Sydney, Sydney, NSW 2052, Australia; EMBL Australia Node in Single Molecule Science, UNSW Sydney, Sydney, NSW 2052, Australia; ARC Centre of Excellence in Advanced Molecular Imaging, UNSW Sydney, Sydney, NSW 2052, Australia
| | - Benjamin T Goult
- School of Biosciences, University of Kent, Canterbury, Kent CT2 7NJ, UK
| | - Edna C Hardeman
- School of Medical Sciences, UNSW Sydney, Sydney, NSW 2052, Australia
| | - Peter W Gunning
- School of Medical Sciences, UNSW Sydney, Sydney, NSW 2052, Australia
| | - John G Lock
- School of Medical Sciences, UNSW Sydney, Sydney, NSW 2052, Australia.
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18
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Janco M, Rynkiewicz MJ, Li L, Hook J, Eiffe E, Ghosh A, Böcking T, Lehman WJ, Hardeman EC, Gunning PW. Molecular integration of the anti-tropomyosin compound ATM-3507 into the coiled coil overlap region of the cancer-associated Tpm3.1. Sci Rep 2019; 9:11262. [PMID: 31375704 PMCID: PMC6677793 DOI: 10.1038/s41598-019-47592-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2019] [Accepted: 07/19/2019] [Indexed: 11/30/2022] Open
Abstract
Tropomyosins (Tpm) determine the functional capacity of actin filaments in an isoform-specific manner. The primary isoform in cancer cells is Tpm3.1 and compounds that target Tpm3.1 show promising results as anti-cancer agents both in vivo and in vitro. We have determined the molecular mechanism of interaction of the lead compound ATM-3507 with Tpm3.1-containing actin filaments. When present during co-polymerization of Tpm3.1 with actin, 3H-ATM-3507 is incorporated into the filaments and saturates at approximately one molecule per Tpm3.1 dimer and with an apparent binding affinity of approximately 2 µM. In contrast, 3H-ATM-3507 is poorly incorporated into preformed Tpm3.1/actin co-polymers. CD spectroscopy and thermal melts using Tpm3.1 peptides containing the C-terminus, the N-terminus, and a combination of the two forming the overlap junction at the interface of adjacent Tpm3.1 dimers, show that ATM-3507 shifts the melting temperature of the C-terminus and the overlap junction, but not the N-terminus. Molecular dynamic simulation (MDS) analysis predicts that ATM-3507 integrates into the 4-helix coiled coil overlap junction and in doing so, likely changes the lateral movement of Tpm3.1 across the actin surface resulting in an alteration of filament interactions with actin binding proteins and myosin motors, consistent with the cellular impact of ATM-3507.
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Affiliation(s)
- Miro Janco
- School of Medical Sciences, University of New South Wales Sydney, Sydney, NSW, 2052, Australia
| | - Michael J Rynkiewicz
- Department of Physiology & Biophysics, Boston University School of Medicine, 72 East Concord Street, Boston, MA, 02118, USA
| | - Liang Li
- School of Medical Sciences, University of New South Wales Sydney, Sydney, NSW, 2052, Australia
| | - Jeff Hook
- School of Medical Sciences, University of New South Wales Sydney, Sydney, NSW, 2052, Australia
| | - Eleanor Eiffe
- School of Medical Sciences, University of New South Wales Sydney, Sydney, NSW, 2052, Australia
| | - Anita Ghosh
- Department of Physiology & Biophysics, Boston University School of Medicine, 72 East Concord Street, Boston, MA, 02118, USA
| | - Till Böcking
- Single Molecule Science and ARC Centre of Excellence in Advanced Molecular Imaging, University of New South Wales Sydney, Sydney, NSW, 2052, Australia
| | - William J Lehman
- Department of Physiology & Biophysics, Boston University School of Medicine, 72 East Concord Street, Boston, MA, 02118, USA
| | - Edna C Hardeman
- School of Medical Sciences, University of New South Wales Sydney, Sydney, NSW, 2052, Australia
| | - Peter W Gunning
- School of Medical Sciences, University of New South Wales Sydney, Sydney, NSW, 2052, Australia.
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19
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Meiring JCM, Bryce NS, Niño JLG, Gabriel A, Tay SS, Hardeman EC, Biro M, Gunning PW. Tropomyosin concentration but not formin nucleators mDia1 and mDia3 determines the level of tropomyosin incorporation into actin filaments. Sci Rep 2019; 9:6504. [PMID: 31019238 PMCID: PMC6482184 DOI: 10.1038/s41598-019-42977-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2018] [Accepted: 04/11/2019] [Indexed: 12/31/2022] Open
Abstract
The majority of actin filaments in human cells exist as a co-polymer with tropomyosin, which determines the functionality of actin filaments in an isoform dependent manner. Tropomyosin isoforms are sorted to different actin filament populations and in yeast this process is determined by formins, however it remains unclear what process determines tropomyosin isoform sorting in mammalian cells. We have tested the roles of two major formin nucleators, mDia1 and mDia3, in the recruitment of specific tropomyosin isoforms in mammals. Despite observing poorer cell-cell attachments in mDia1 and mDia3 KD cells and an actin bundle organisation defect with mDia1 knock down; depletion of mDia1 and mDia3 individually and concurrently did not result in any significant impact on tropomyosin recruitment to actin filaments, as observed via immunofluorescence and measured via biochemical assays. Conversely, in the presence of excess Tpm3.1, the absolute amount of Tpm3.1-containing actin filaments is not fixed by actin filament nucleators but rather depends on the cell concentration of Tpm3.1. We conclude that mDia1 and mDia3 are not essential for tropomyosin recruitment and that tropomyosin incorporation into actin filaments is concentration dependent.
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Affiliation(s)
- Joyce C M Meiring
- Cellular and Genetic Medicine Unit, School of Medical Sciences, University of New South Wales, Sydney, NSW, 2052, Australia
| | - Nicole S Bryce
- Cellular and Genetic Medicine Unit, School of Medical Sciences, University of New South Wales, Sydney, NSW, 2052, Australia
| | - Jorge Luis Galeano Niño
- Single Molecule Science, School of Medical Sciences, University of New South Wales, Sydney, NSW, 2052, Australia
| | - Antje Gabriel
- Cellular and Genetic Medicine Unit, School of Medical Sciences, University of New South Wales, Sydney, NSW, 2052, Australia.,Pharmaceutical Biology, Center for Drug Research, Ludwig-Maximilians-Universität, Munich, Germany
| | - Szun S Tay
- Single Molecule Science, School of Medical Sciences, University of New South Wales, Sydney, NSW, 2052, Australia
| | - Edna C Hardeman
- Cellular and Genetic Medicine Unit, School of Medical Sciences, University of New South Wales, Sydney, NSW, 2052, Australia
| | - Maté Biro
- Single Molecule Science, School of Medical Sciences, University of New South Wales, Sydney, NSW, 2052, Australia
| | - Peter W Gunning
- Cellular and Genetic Medicine Unit, School of Medical Sciences, University of New South Wales, Sydney, NSW, 2052, Australia.
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20
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Bryce NS, Hardeman EC, Gunning PW, Lock JG. Chemical biology approaches targeting the actin cytoskeleton through phenotypic screening. Curr Opin Chem Biol 2019; 51:40-47. [PMID: 30901618 DOI: 10.1016/j.cbpa.2019.02.013] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2018] [Revised: 02/05/2019] [Accepted: 02/12/2019] [Indexed: 12/29/2022]
Abstract
The actin cytoskeleton is dysregulated in cancer, yet this critical cellular machinery has not translated as a druggable clinical target due to cardio-toxic side-effects. Many actin regulators are also considered undruggable, being structural proteins lacking clear functional sites suitable for targeted drug design. In this review, we discuss opportunities and challenges associated with drugging the actin cytoskeleton through its structural regulators, taking tropomyosins as a target example. In particular, we highlight emerging data acquisition and analysis trends driving phenotypic, imaging-based compound screening. Finally, we consider how the confluence of these trends is now bringing functionally integral machineries such as the actin cytoskeleton, and associated structural regulatory proteins, into an expanded repertoire of druggable targets with previously unexploited clinical potential.
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Affiliation(s)
- Nicole S Bryce
- School of Medical Sciences, UNSW Sydney, NSW 2052, Australia
| | - Edna C Hardeman
- School of Medical Sciences, UNSW Sydney, NSW 2052, Australia
| | - Peter W Gunning
- School of Medical Sciences, UNSW Sydney, NSW 2052, Australia.
| | - John G Lock
- School of Medical Sciences, UNSW Sydney, NSW 2052, Australia
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21
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Sao K, Jones TM, Doyle AD, Maity D, Schevzov G, Chen Y, Gunning PW, Petrie RJ. Myosin II governs intracellular pressure and traction by distinct tropomyosin-dependent mechanisms. Mol Biol Cell 2019; 30:1170-1181. [PMID: 30865560 PMCID: PMC6724525 DOI: 10.1091/mbc.e18-06-0355] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Two-dimensional (2D) substrate rigidity promotes myosin II activity to increase traction force in a process negatively regulated by tropomyosin (Tpm) 2.1. We recently discovered that actomyosin contractility can increase intracellular pressure and switch tumor cells from low-pressure lamellipodia to high-pressure lobopodial protrusions during three-dimensional (3D) migration. However, it remains unclear whether these myosin II–generated cellular forces are produced simultaneously, and by the same molecular machinery. Here we identify Tpm 1.6 as a positive regulator of intracellular pressure and confirm that Tpm 2.1 is a negative regulator of traction force. We find that Tpm 1.6 and 2.1 can control intracellular pressure and traction independently, suggesting these myosin II–dependent forces are generated by distinct mechanisms. Further, these tropomyosin-regulated mechanisms can be integrated to control complex cell behaviors on 2D and in 3D environments.
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Affiliation(s)
- Kimheak Sao
- Department of Biology, Drexel University, Philadelphia, PA 19104
| | - Tia M Jones
- Department of Biology, Drexel University, Philadelphia, PA 19104
| | - Andrew D Doyle
- National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD 20892
| | - Debonil Maity
- Department of Mechanical Engineering, Johns Hopkins University, Baltimore, MD 21218
| | - Galina Schevzov
- School of Medical Sciences, University of New South Wales, Sydney NSW 2052, Australia
| | - Yun Chen
- Department of Mechanical Engineering, Johns Hopkins University, Baltimore, MD 21218
| | - Peter W Gunning
- School of Medical Sciences, University of New South Wales, Sydney NSW 2052, Australia
| | - Ryan J Petrie
- Department of Biology, Drexel University, Philadelphia, PA 19104
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22
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Kim TH, Ly C, Christodoulides A, Nowell CJ, Gunning PW, Sloan EK, Rowat AC. Stress hormone signaling through β-adrenergic receptors regulates macrophage mechanotype and function. FASEB J 2019; 33:3997-4006. [PMID: 30509116 PMCID: PMC6404566 DOI: 10.1096/fj.201801429rr] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2018] [Accepted: 11/05/2018] [Indexed: 12/11/2022]
Abstract
Critical functions of immune cells require them to rapidly change their shape and generate forces in response to cues from their surrounding environment. However, little is known about how soluble factors that may be present in the microenvironment modulate key aspects of cellular mechanobiology-such as immune cell deformability and force generation-to impact functions such as phagocytosis and migration. Here we show that signaling by soluble stress hormones through β-adrenoceptors (β-AR) reduces the deformability of macrophages; this is dependent on changes in the organization of the actin cytoskeleton and is associated with functional changes in phagocytosis and migration. Pharmacologic interventions reveal that the impact of β-AR signaling on macrophage deformability is dependent on actin-related proteins 2/3, indicating that stress hormone signaling through β-AR shifts actin organization to favor branched structures rather than linear unbranched actin filaments. These findings show that through remodeling of the actin cytoskeleton, β-AR-mediated stress hormone signaling modulates macrophage mechanotype to impact functions that play a critical role in immune response.-Kim, T.-H., Ly, C., Christodoulides, A., Nowell, C. J., Gunning, P. W., Sloan, E. K., Rowat, A. C. Stress hormone signaling through β-adrenergic receptors regulates macrophage mechanotype and function.
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Affiliation(s)
- Tae-Hyung Kim
- Department of Integrative Biology and Physiology, University of California, Los Angeles, California, USA
- Cousins Center for Psychoneuroimmunology, Semel Institute for Neuroscience and Human Behavior, University of California, Los Angeles, California, USA
| | - Chau Ly
- Department of Integrative Biology and Physiology, University of California, Los Angeles, California, USA
- Department of Bioengineering, University of California, Los Angeles, California, USA
| | - Alexei Christodoulides
- Department of Integrative Biology and Physiology, University of California, Los Angeles, California, USA
| | - Cameron J. Nowell
- Drug Discovery Biology Theme, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia
| | - Peter W. Gunning
- School of Medical Sciences, University of New South Wales Sydney, Kensington, New South Wales, Australia
| | - Erica K. Sloan
- Cousins Center for Psychoneuroimmunology, Semel Institute for Neuroscience and Human Behavior, University of California, Los Angeles, California, USA
- UCLA Jonsson Comprehensive Cancer Center, University of California, Los Angeles, California, USA
- Drug Discovery Biology Theme, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia
- Division of Cancer Surgery, Peter MacCallum Cancer Centre, Melbourne, Victoria, Australia; and
- UCLA AIDS Institute, University of California, Los Angeles, California, USA
| | - Amy C. Rowat
- Department of Integrative Biology and Physiology, University of California, Los Angeles, California, USA
- Department of Bioengineering, University of California, Los Angeles, California, USA
- UCLA Jonsson Comprehensive Cancer Center, University of California, Los Angeles, California, USA
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23
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Ghosh A, Janco M, Böcking T, Gunning PW, Lehman W, Rynkiewicz MJ. Structure of the Tpm3.1 N-Terminus: A New Target for Anti-Cancer Treatment. Biophys J 2019. [DOI: 10.1016/j.bpj.2018.11.1382] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022] Open
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24
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Meiring JCM, Bryce NS, Cagigas ML, Benda A, Whan RM, Ariotti N, Parton RG, Stear JH, Hardeman EC, Gunning PW. Colocation of Tpm3.1 and myosin IIa heads defines a discrete subdomain in stress fibres. J Cell Sci 2019; 132:jcs.228916. [DOI: 10.1242/jcs.228916] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2018] [Accepted: 07/06/2019] [Indexed: 01/06/2023] Open
Abstract
Co-polymers of tropomyosin and actin make up a major fraction of the actin cytoskeleton. Tropomyosin isoforms determine the function of an actin filament by selectively enhancing or inhibiting the association of other actin binding proteins, altering the stability of an actin filament and regulating myosin activity in an isoform specific manner. Previous work has implicated specific roles for at least 5 different tropomyosin isoforms in stress fibres, as depletion of any of these 5 isoforms results in a loss of stress fibres. Despite this, most models of stress fibres continue to exclude tropomyosins. In this study we investigate tropomyosin organisation in stress fibres using super resolution light microscopy and electron microscopy with genetically tagged, endogenous tropomyosin. We show that tropomyosin isoforms are organised in subdomains within the overall domain of stress fibres. Tpm3.1/3.2 co-localises with non-muscle myosin IIa/IIb heads and are in register but do not overlap with non-muscle myosin IIa/IIb tails. Furthermore, perturbation of Tpm3.1/3.2 results in decreased myosin IIa in stress fibres, which is consistent with a role for Tpm3.1 in maintaining myosin IIa localisation in stress fibres.
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Affiliation(s)
- Joyce C. M. Meiring
- School of Medical Sciences, University of New South Wales, Sydney, NSW 2052, Australia
| | - Nicole S. Bryce
- School of Medical Sciences, University of New South Wales, Sydney, NSW 2052, Australia
| | - Maria Lastra Cagigas
- School of Medical Sciences, University of New South Wales, Sydney, NSW 2052, Australia
| | - Aleš Benda
- Biomedical Imaging Facility, Mark Wainwright Analytical Centre, University of New South Wales, Sydney, NSW 2052, Australia
| | - Renee M. Whan
- Biomedical Imaging Facility, Mark Wainwright Analytical Centre, University of New South Wales, Sydney, NSW 2052, Australia
| | - Nicholas Ariotti
- School of Medical Sciences, University of New South Wales, Sydney, NSW 2052, Australia
- Electron Microscope Unit, Mark Wainwright Analytical Centre, University of New South Wales, Sydney, NSW 2052, Australia
| | - Robert G. Parton
- Cell Biology and Molecular Medicine Division, Institute for Molecular Bioscience, University of Queensland, St Lucia, QLD 4072, Australia
- Centre for Microscopy and Microanalysis, University of Queensland, St Lucia, QLD 4072, Australia
| | - Jeffrey H. Stear
- School of Medical Sciences, University of New South Wales, Sydney, NSW 2052, Australia
| | - Edna C. Hardeman
- School of Medical Sciences, University of New South Wales, Sydney, NSW 2052, Australia
| | - Peter W. Gunning
- School of Medical Sciences, University of New South Wales, Sydney, NSW 2052, Australia
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25
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Abstract
The actin cytoskeleton provides not only the underpinning for cell architecture but also mechanical force and the ability to drive movement of cells and their organelles. It is tempting to think of it simply as a set of stable structural elements, but nothing could be further from the truth. The cells of our bodies are continually remodelling their architecture by responding to a range of imposed biomechanical forces and intracellular functional demands. Studies of the dynamic and functional properties of the actin cytoskeleton have been dominated by a focus on actin and the view that actin filaments are essentially 'generic'. However, the 'other' component of most actin filaments in animals - tropomyosin - is coming into prominence. With this discovery is the realisation that far from being generic, actin filaments have their own functional individuality provided to them by their associated tropomyosin. This is changing the way we understand and study the actin cytoskeleton and has delivered a new therapeutic opportunity in what had come to be considered a 'no-go zone'.
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Affiliation(s)
- Peter W Gunning
- School of Medical Sciences, University of New South Wales, Sydney, NSW, 2052, Australia.
| | - Edna C Hardeman
- School of Medical Sciences, University of New South Wales, Sydney, NSW, 2052, Australia.
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26
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Meiring JC, Bryce NS, Wang Y, Taft MH, Manstein DJ, Liu Lau S, Stear J, Hardeman EC, Gunning PW. Co-polymers of Actin and Tropomyosin Account for a Major Fraction of the Human Actin Cytoskeleton. Curr Biol 2018; 28:2331-2337.e5. [DOI: 10.1016/j.cub.2018.05.053] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2017] [Revised: 04/20/2018] [Accepted: 05/17/2018] [Indexed: 01/14/2023]
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27
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Masedunskas A, Appaduray MA, Lucas CA, Lastra Cagigas M, Heydecker M, Holliday M, Meiring JCM, Hook J, Kee A, White M, Thomas P, Zhang Y, Adelstein RS, Meckel T, Böcking T, Weigert R, Bryce NS, Gunning PW, Hardeman EC. Parallel assembly of actin and tropomyosin, but not myosin II, during de novo actin filament formation in live mice. J Cell Sci 2018; 131:jcs.212654. [PMID: 29487177 DOI: 10.1242/jcs.212654] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2017] [Accepted: 02/12/2018] [Indexed: 01/04/2023] Open
Abstract
Many actin filaments in animal cells are co-polymers of actin and tropomyosin. In many cases, non-muscle myosin II associates with these co-polymers to establish a contractile network. However, the temporal relationship of these three proteins in the de novo assembly of actin filaments is not known. Intravital subcellular microscopy of secretory granule exocytosis allows the visualisation and quantification of the formation of an actin scaffold in real time, with the added advantage that it occurs in a living mammal under physiological conditions. We used this model system to investigate the de novo assembly of actin, tropomyosin Tpm3.1 (a short isoform of TPM3) and myosin IIA (the form of non-muscle myosin II with its heavy chain encoded by Myh9) on secretory granules in mouse salivary glands. Blocking actin polymerization with cytochalasin D revealed that Tpm3.1 assembly is dependent on actin assembly. We used time-lapse imaging to determine the timing of the appearance of the actin filament reporter LifeAct-RFP and of Tpm3.1-mNeonGreen on secretory granules in LifeAct-RFP transgenic, Tpm3.1-mNeonGreen and myosin IIA-GFP (GFP-tagged MYH9) knock-in mice. Our findings are consistent with the addition of tropomyosin to actin filaments shortly after the initiation of actin filament nucleation, followed by myosin IIA recruitment.
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Affiliation(s)
| | | | | | | | - Marco Heydecker
- School of Medical Sciences, UNSW Sydney, NSW 2052, Australia.,Membrane Dynamics, Department of Biology, Technische Universität Darmstadt, Schnittspahnstrasse 3, 64287 Darmstadt, Germany
| | - Mira Holliday
- School of Medical Sciences, UNSW Sydney, NSW 2052, Australia
| | | | - Jeff Hook
- School of Medical Sciences, UNSW Sydney, NSW 2052, Australia
| | - Anthony Kee
- School of Medical Sciences, UNSW Sydney, NSW 2052, Australia
| | - Melissa White
- South Australian Genome Editing, Facility Robinson Research Institute, University of Adelaide, Adelaide, SA 5005, Australia
| | - Paul Thomas
- South Australian Genome Editing, Facility Robinson Research Institute, University of Adelaide, Adelaide, SA 5005, Australia
| | - Yingfan Zhang
- NHLBI, National Institutes of Health, Bethesda, MD 20892, USA
| | | | - Tobias Meckel
- Membrane Dynamics, Department of Biology, Technische Universität Darmstadt, Schnittspahnstrasse 3, 64287 Darmstadt, Germany
| | - Till Böcking
- School of Medical Sciences, UNSW Sydney, NSW 2052, Australia
| | - Roberto Weigert
- Laboratory of Cellular and Molecular Biology, CCR, National Cancer Institute, Bethesda, MD 20892, USA
| | - Nicole S Bryce
- School of Medical Sciences, UNSW Sydney, NSW 2052, Australia
| | - Peter W Gunning
- School of Medical Sciences, UNSW Sydney, NSW 2052, Australia
| | - Edna C Hardeman
- School of Medical Sciences, UNSW Sydney, NSW 2052, Australia
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28
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Kee AJ, Chagan J, Chan JY, Bryce NS, Lucas CA, Zeng J, Hook J, Treutlein H, Laybutt DR, Stehn JR, Gunning PW, Hardeman EC. On-target action of anti-tropomyosin drugs regulates glucose metabolism. Sci Rep 2018; 8:4604. [PMID: 29545590 PMCID: PMC5854615 DOI: 10.1038/s41598-018-22946-x] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2017] [Accepted: 03/01/2018] [Indexed: 01/09/2023] Open
Abstract
The development of novel small molecule inhibitors of the cancer-associated tropomyosin 3.1 (Tpm3.1) provides the ability to examine the metabolic function of specific actin filament populations. We have determined the ability of these anti-Tpm (ATM) compounds to regulate glucose metabolism in mice. Acute treatment (1 h) of wild-type (WT) mice with the compounds (TR100 and ATM1001) led to a decrease in glucose clearance due mainly to suppression of glucose-stimulated insulin secretion (GSIS) from the pancreatic islets. The impact of the drugs on GSIS was significantly less in Tpm3.1 knock out (KO) mice indicating that the drug action is on-target. Experiments in MIN6 β-cells indicated that the inhibition of GSIS by the drugs was due to disruption to the cortical actin cytoskeleton. The impact of the drugs on insulin-stimulated glucose uptake (ISGU) was also examined in skeletal muscle ex vivo. In the absence of drug, ISGU was decreased in KO compared to WT muscle, confirming a role of Tpm3.1 in glucose uptake. Both compounds suppressed ISGU in WT muscle, but in the KO muscle there was little impact of the drugs. Collectively, this data indicates that the ATM drugs affect glucose metabolism in vivo by inhibiting Tpm3.1's function with few off-target effects.
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Affiliation(s)
- Anthony J Kee
- School of Medical Sciences, UNSW Sydney, Sydney, NSW, 2052, Australia
| | - Jayshan Chagan
- School of Medical Sciences, UNSW Sydney, Sydney, NSW, 2052, Australia
| | - Jeng Yie Chan
- Garvan Institute of Medical Research, St Vincent's Hospital, UNSW Sydney, Sydney, NSW, Australia
| | - Nicole S Bryce
- School of Medical Sciences, UNSW Sydney, Sydney, NSW, 2052, Australia
| | - Christine A Lucas
- School of Medical Sciences, UNSW Sydney, Sydney, NSW, 2052, Australia
| | - Jun Zeng
- MedChemSoft Solutions, Level 3 Brandon Park Drive, Wheelers Hill, 3150, VIC, Australia
| | - Jeff Hook
- School of Medical Sciences, UNSW Sydney, Sydney, NSW, 2052, Australia
| | - Herbert Treutlein
- Sanoosa Pty. Ltd., 35 Collins Street, Melbourne, 3000, VIC, Australia
| | - D Ross Laybutt
- Garvan Institute of Medical Research, St Vincent's Hospital, UNSW Sydney, Sydney, NSW, Australia
| | - Justine R Stehn
- School of Medical Sciences, UNSW Sydney, Sydney, NSW, 2052, Australia
- Novogen Pty Ltd, 502/20 George St, Hornsby, NSW, 2077, Australia
| | - Peter W Gunning
- School of Medical Sciences, UNSW Sydney, Sydney, NSW, 2052, Australia
| | - Edna C Hardeman
- School of Medical Sciences, UNSW Sydney, Sydney, NSW, 2052, Australia.
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29
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Jeong S, Lim S, Schevzov G, Gunning PW, Helfman DM. Loss of Tpm4.1 leads to disruption of cell-cell adhesions and invasive behavior in breast epithelial cells via increased Rac1 signaling. Oncotarget 2018; 8:33544-33559. [PMID: 28431393 PMCID: PMC5464889 DOI: 10.18632/oncotarget.16825] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2016] [Accepted: 03/22/2017] [Indexed: 12/18/2022] Open
Abstract
Here we report the identification and characterization of a novel high molecular weight isoform of tropomyosin, Tpm4.1, expressed from the human TPM4 gene. Tpm4.1 expression is down-regulated in a subset of breast cancer cells compared with untransformed MCF10A breast epithelial cells and in highly metastatic breast cancer cell lines derived from poorly metastatic MDA-MD-231 cells. In addition, patients with invasive ductal breast carcinoma show decreased TPM4 expression compared with patients with ductal breast carcinoma in situ, and low TPM4 expression is associated with poor prognosis. Loss of Tpm4.1 using siRNA in MCF10A cells increases cell migration in wound-healing and Boyden chamber assays and invasion out of spheroids as well as disruption of cell-cell adhesions. Down-regulation of Tpm4.1 in MDA-MB-231 cells leads to disruption of actin organization and increased cell invasion and dissemination from spheroids into collagen gels. The down-regulation of Tpm4.1 induces Rac1-mediated alteration of myosin IIB localization, and pharmacologic inhibition of Rac1 or down-regulation of myosin IIB using siRNA inhibits the invasive phenotypes in MCF10A cells. Thus Tpm4.1 plays an important role in blocking invasive behaviors through Rac1-myosin IIB signaling and our findings suggest that decreased expression of Tpm4.1 might play a crucial role during tumor progression.
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Affiliation(s)
- SukYeong Jeong
- Department of Biological Sciences, Korean Advanced Institute of Science and Technology, Daejeon, Republic of Korea
| | - SunYoung Lim
- Department of Biological Sciences, Korean Advanced Institute of Science and Technology, Daejeon, Republic of Korea
| | - Galina Schevzov
- Oncology Research Unit, School of Medical Sciences, UNSW, Sydney, NSW, Australia
| | - Peter W Gunning
- Oncology Research Unit, School of Medical Sciences, UNSW, Sydney, NSW, Australia
| | - David M Helfman
- Department of Biological Sciences, Korean Advanced Institute of Science and Technology, Daejeon, Republic of Korea
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30
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Abstract
The differences between β- and γ-actin are deeper than those between the amino acid sequences of these two proteins.
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31
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Suchowerska AK, Fok S, Stefen H, Gunning PW, Hardeman EC, Power J, Fath T. Developmental Profiling of Tropomyosin Expression in Mouse Brain Reveals Tpm4.2 as the Major Post-synaptic Tropomyosin in the Mature Brain. Front Cell Neurosci 2017; 11:421. [PMID: 29311841 PMCID: PMC5743921 DOI: 10.3389/fncel.2017.00421] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2017] [Accepted: 12/14/2017] [Indexed: 12/14/2022] Open
Abstract
Nerve cell connections, formed in the developing brain of mammals, undergo a well-programmed process of maturation with changes in their molecular composition over time. The major structural element at the post-synaptic specialization is the actin cytoskeleton, which is composed of different populations of functionally distinct actin filaments. Previous studies, using ultrastructural and light imaging techniques have established the presence of different actin filament populations at the post-synaptic site. However, it remains unknown, how these different actin filament populations are defined and how their molecular composition changes over time. In the present study, we have characterized changes in a core component of actin filaments, the tropomyosin (Tpm) family of actin-associated proteins from embryonal stage to the adult stage. Using biochemical fractionation of mouse brain tissue, we identified the tropomyosin Tpm4.2 as the major post-synaptic Tpm. Furthermore, we found age-related differences in the composition of Tpms at the post-synaptic compartment. Our findings will help to guide future studies that aim to define the functional properties of actin filaments at different developmental stages in the mammalian brain.
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Affiliation(s)
- Alexandra K Suchowerska
- Neurodegeneration and Repair Unit, School of Medical Sciences, University of New South Wales, Sydney, NSW, Australia
| | - Sandra Fok
- Neurodegeneration and Repair Unit, School of Medical Sciences, University of New South Wales, Sydney, NSW, Australia
| | - Holly Stefen
- Neurodegeneration and Repair Unit, School of Medical Sciences, University of New South Wales, Sydney, NSW, Australia.,Neuron Culture Core Facility, University of New South Wales, SydneyNSW, Australia
| | - Peter W Gunning
- Cellular and Genetic Medicine Unit, School of Medical Sciences, University of New South Wales, Sydney, NSW, Australia
| | - Edna C Hardeman
- Cellular and Genetic Medicine Unit, School of Medical Sciences, University of New South Wales, Sydney, NSW, Australia
| | - John Power
- Translational Neuroscience Facility, School of Medical Sciences, University of New South Wales, Sydney, NSW, Australia
| | - Thomas Fath
- Neurodegeneration and Repair Unit, School of Medical Sciences, University of New South Wales, Sydney, NSW, Australia.,Neuron Culture Core Facility, University of New South Wales, SydneyNSW, Australia
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32
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Kee AJ, Bryce NS, Yang L, Polishchuk E, Schevzov G, Weigert R, Polishchuk R, Gunning PW, Hardeman EC. Cover Image, Volume 74, Issue 10. Cytoskeleton (Hoboken) 2017. [DOI: 10.1002/cm.21413] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Anthony J. Kee
- School of Medical Sciences; UNSW Sydney; Sydney NSW 2052 Australia
| | - Nicole S. Bryce
- School of Medical Sciences; UNSW Sydney; Sydney NSW 2052 Australia
| | - Lingyan Yang
- School of Medical Sciences; UNSW Sydney; Sydney NSW 2052 Australia
| | | | - Galina Schevzov
- School of Medical Sciences; UNSW Sydney; Sydney NSW 2052 Australia
| | - Roberto Weigert
- Laboratory of Cellular and Molecular Biology; Center for Cancer Research, National Cancer Institute; Bethesda Maryland 20892
| | | | - Peter W. Gunning
- School of Medical Sciences; UNSW Sydney; Sydney NSW 2052 Australia
| | - Edna C. Hardeman
- School of Medical Sciences; UNSW Sydney; Sydney NSW 2052 Australia
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33
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Nobis M, Herrmann D, Warren SC, Kadir S, Leung W, Killen M, Magenau A, Stevenson D, Lucas MC, Reischmann N, Vennin C, Conway JRW, Boulghourjian A, Zaratzian A, Law AM, Gallego-Ortega D, Ormandy CJ, Walters SN, Grey ST, Bailey J, Chtanova T, Quinn JMW, Baldock PA, Croucher PI, Schwarz JP, Mrowinska A, Zhang L, Herzog H, Masedunskas A, Hardeman EC, Gunning PW, Del Monte-Nieto G, Harvey RP, Samuel MS, Pajic M, McGhee EJ, Johnsson AKE, Sansom OJ, Welch HCE, Morton JP, Strathdee D, Anderson KI, Timpson P. A RhoA-FRET Biosensor Mouse for Intravital Imaging in Normal Tissue Homeostasis and Disease Contexts. Cell Rep 2017; 21:274-288. [PMID: 28978480 DOI: 10.1016/j.celrep.2017.09.022] [Citation(s) in RCA: 72] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2017] [Revised: 07/06/2017] [Accepted: 09/05/2017] [Indexed: 01/04/2023] Open
Abstract
The small GTPase RhoA is involved in a variety of fundamental processes in normal tissue. Spatiotemporal control of RhoA is thought to govern mechanosensing, growth, and motility of cells, while its deregulation is associated with disease development. Here, we describe the generation of a RhoA-fluorescence resonance energy transfer (FRET) biosensor mouse and its utility for monitoring real-time activity of RhoA in a variety of native tissues in vivo. We assess changes in RhoA activity during mechanosensing of osteocytes within the bone and during neutrophil migration. We also demonstrate spatiotemporal order of RhoA activity within crypt cells of the small intestine and during different stages of mammary gestation. Subsequently, we reveal co-option of RhoA activity in both invasive breast and pancreatic cancers, and we assess drug targeting in these disease settings, illustrating the potential for utilizing this mouse to study RhoA activity in vivo in real time.
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MESH Headings
- Animals
- Antineoplastic Agents/pharmacology
- Biosensing Techniques
- Bone and Bones/cytology
- Bone and Bones/metabolism
- Cell Movement/drug effects
- Dasatinib/pharmacology
- Erlotinib Hydrochloride/pharmacology
- Female
- Fluorescence Resonance Energy Transfer/instrumentation
- Fluorescence Resonance Energy Transfer/methods
- Gene Expression Regulation
- Intestine, Small/metabolism
- Intestine, Small/ultrastructure
- Intravital Microscopy/instrumentation
- Intravital Microscopy/methods
- Mammary Glands, Animal/blood supply
- Mammary Glands, Animal/drug effects
- Mammary Glands, Animal/ultrastructure
- Mammary Neoplasms, Experimental/blood supply
- Mammary Neoplasms, Experimental/drug therapy
- Mammary Neoplasms, Experimental/genetics
- Mammary Neoplasms, Experimental/ultrastructure
- Mechanotransduction, Cellular
- Mice
- Mice, Transgenic
- Neutrophils/metabolism
- Neutrophils/ultrastructure
- Osteocytes/metabolism
- Osteocytes/ultrastructure
- Pancreatic Neoplasms/blood supply
- Pancreatic Neoplasms/drug therapy
- Pancreatic Neoplasms/genetics
- Pancreatic Neoplasms/ultrastructure
- Time-Lapse Imaging/instrumentation
- Time-Lapse Imaging/methods
- rho GTP-Binding Proteins/genetics
- rho GTP-Binding Proteins/metabolism
- rhoA GTP-Binding Protein
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Affiliation(s)
- Max Nobis
- The Garvan Institute of Medical Research, St. Vincent's Clinical School, Faculty of Medicine, University of New South Wales, Sydney, NSW 2010, Australia
| | - David Herrmann
- The Garvan Institute of Medical Research, St. Vincent's Clinical School, Faculty of Medicine, University of New South Wales, Sydney, NSW 2010, Australia
| | - Sean C Warren
- The Garvan Institute of Medical Research, St. Vincent's Clinical School, Faculty of Medicine, University of New South Wales, Sydney, NSW 2010, Australia
| | - Shereen Kadir
- Cancer Research UK Beatson Institute, Switchback Road, Bearsden, Glasgow G611BD, UK
| | - Wilfred Leung
- The Garvan Institute of Medical Research, St. Vincent's Clinical School, Faculty of Medicine, University of New South Wales, Sydney, NSW 2010, Australia
| | - Monica Killen
- The Garvan Institute of Medical Research, St. Vincent's Clinical School, Faculty of Medicine, University of New South Wales, Sydney, NSW 2010, Australia
| | - Astrid Magenau
- The Garvan Institute of Medical Research, St. Vincent's Clinical School, Faculty of Medicine, University of New South Wales, Sydney, NSW 2010, Australia
| | - David Stevenson
- Cancer Research UK Beatson Institute, Switchback Road, Bearsden, Glasgow G611BD, UK
| | - Morghan C Lucas
- The Garvan Institute of Medical Research, St. Vincent's Clinical School, Faculty of Medicine, University of New South Wales, Sydney, NSW 2010, Australia
| | - Nadine Reischmann
- The Garvan Institute of Medical Research, St. Vincent's Clinical School, Faculty of Medicine, University of New South Wales, Sydney, NSW 2010, Australia
| | - Claire Vennin
- The Garvan Institute of Medical Research, St. Vincent's Clinical School, Faculty of Medicine, University of New South Wales, Sydney, NSW 2010, Australia
| | - James R W Conway
- The Garvan Institute of Medical Research, St. Vincent's Clinical School, Faculty of Medicine, University of New South Wales, Sydney, NSW 2010, Australia
| | - Alice Boulghourjian
- The Garvan Institute of Medical Research, St. Vincent's Clinical School, Faculty of Medicine, University of New South Wales, Sydney, NSW 2010, Australia
| | - Anaiis Zaratzian
- The Garvan Institute of Medical Research, St. Vincent's Clinical School, Faculty of Medicine, University of New South Wales, Sydney, NSW 2010, Australia
| | - Andrew M Law
- The Garvan Institute of Medical Research, St. Vincent's Clinical School, Faculty of Medicine, University of New South Wales, Sydney, NSW 2010, Australia
| | - David Gallego-Ortega
- The Garvan Institute of Medical Research, St. Vincent's Clinical School, Faculty of Medicine, University of New South Wales, Sydney, NSW 2010, Australia
| | - Christopher J Ormandy
- The Garvan Institute of Medical Research, St. Vincent's Clinical School, Faculty of Medicine, University of New South Wales, Sydney, NSW 2010, Australia
| | - Stacey N Walters
- The Garvan Institute of Medical Research, St. Vincent's Clinical School, Faculty of Medicine, University of New South Wales, Sydney, NSW 2010, Australia
| | - Shane T Grey
- The Garvan Institute of Medical Research, St. Vincent's Clinical School, Faculty of Medicine, University of New South Wales, Sydney, NSW 2010, Australia
| | - Jacqueline Bailey
- The Garvan Institute of Medical Research, St. Vincent's Clinical School, Faculty of Medicine, University of New South Wales, Sydney, NSW 2010, Australia
| | - Tatyana Chtanova
- The Garvan Institute of Medical Research, St. Vincent's Clinical School, Faculty of Medicine, University of New South Wales, Sydney, NSW 2010, Australia
| | - Julian M W Quinn
- The Garvan Institute of Medical Research, St. Vincent's Clinical School, Faculty of Medicine, University of New South Wales, Sydney, NSW 2010, Australia
| | - Paul A Baldock
- The Garvan Institute of Medical Research, St. Vincent's Clinical School, Faculty of Medicine, University of New South Wales, Sydney, NSW 2010, Australia
| | - Peter I Croucher
- The Garvan Institute of Medical Research, St. Vincent's Clinical School, Faculty of Medicine, University of New South Wales, Sydney, NSW 2010, Australia
| | - Juliane P Schwarz
- Cancer Research UK Beatson Institute, Switchback Road, Bearsden, Glasgow G611BD, UK
| | - Agata Mrowinska
- Cancer Research UK Beatson Institute, Switchback Road, Bearsden, Glasgow G611BD, UK
| | - Lei Zhang
- The Garvan Institute of Medical Research, St. Vincent's Clinical School, Faculty of Medicine, University of New South Wales, Sydney, NSW 2010, Australia
| | - Herbert Herzog
- The Garvan Institute of Medical Research, St. Vincent's Clinical School, Faculty of Medicine, University of New South Wales, Sydney, NSW 2010, Australia
| | - Andrius Masedunskas
- Neuromuscular and Regenerative Medicine Unit, University of New South Wales, Sydney, NSW 2010, Australia; Oncology Research Unit, School of Medical Sciences, University of New South Wales, Sydney, NSW 2010, Australia
| | - Edna C Hardeman
- Neuromuscular and Regenerative Medicine Unit, University of New South Wales, Sydney, NSW 2010, Australia
| | - Peter W Gunning
- Oncology Research Unit, School of Medical Sciences, University of New South Wales, Sydney, NSW 2010, Australia
| | - Gonzalo Del Monte-Nieto
- Developmental and Stem Cell Biology Division, Victor Chang Cardiac Research Institute, Sydney, NSW 2010, Australia; St. Vincent's Clinical School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW 2052, Australia
| | - Richard P Harvey
- Developmental and Stem Cell Biology Division, Victor Chang Cardiac Research Institute, Sydney, NSW 2010, Australia; St. Vincent's Clinical School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW 2052, Australia
| | - Michael S Samuel
- Centre for Cancer Biology, SA Pathology and University of South Australia School of Medicine, University of Adelaide, Adelaide, SA 5000, Australia
| | - Marina Pajic
- The Garvan Institute of Medical Research, St. Vincent's Clinical School, Faculty of Medicine, University of New South Wales, Sydney, NSW 2010, Australia
| | - Ewan J McGhee
- Cancer Research UK Beatson Institute, Switchback Road, Bearsden, Glasgow G611BD, UK
| | | | - Owen J Sansom
- Cancer Research UK Beatson Institute, Switchback Road, Bearsden, Glasgow G611BD, UK
| | - Heidi C E Welch
- Signalling Programme, Babraham Institute, Cambridge CB223AT, UK
| | - Jennifer P Morton
- Cancer Research UK Beatson Institute, Switchback Road, Bearsden, Glasgow G611BD, UK
| | - Douglas Strathdee
- Cancer Research UK Beatson Institute, Switchback Road, Bearsden, Glasgow G611BD, UK
| | | | - Paul Timpson
- The Garvan Institute of Medical Research, St. Vincent's Clinical School, Faculty of Medicine, University of New South Wales, Sydney, NSW 2010, Australia.
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Elam WA, Cao W, Kang H, Huehn A, Hocky GM, Prochniewicz E, Schramm AC, Negrón K, Garcia J, Bonello TT, Gunning PW, Thomas DD, Voth GA, Sindelar CV, De La Cruz EM. Phosphomimetic S3D cofilin binds but only weakly severs actin filaments. J Biol Chem 2017; 292:19565-19579. [PMID: 28939776 DOI: 10.1074/jbc.m117.808378] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2017] [Revised: 09/18/2017] [Indexed: 12/30/2022] Open
Abstract
Many biological processes, including cell division, growth, and motility, rely on rapid remodeling of the actin cytoskeleton and on actin filament severing by the regulatory protein cofilin. Phosphorylation of vertebrate cofilin at Ser-3 regulates both actin binding and severing. Substitution of serine with aspartate at position 3 (S3D) is widely used to mimic cofilin phosphorylation in cells and in vitro The S3D substitution weakens cofilin binding to filaments, and it is presumed that subsequent reduction in cofilin occupancy inhibits filament severing, but this hypothesis has remained untested. Here, using time-resolved phosphorescence anisotropy, electron cryomicroscopy, and all-atom molecular dynamics simulations, we show that S3D cofilin indeed binds filaments with lower affinity, but also with a higher cooperativity than wild-type cofilin, and severs actin weakly across a broad range of occupancies. We found that three factors contribute to the severing deficiency of S3D cofilin. First, the high cooperativity of S3D cofilin generates fewer boundaries between bare and decorated actin segments where severing occurs preferentially. Second, S3D cofilin only weakly alters filament bending and twisting dynamics and therefore does not introduce the mechanical discontinuities required for efficient filament severing at boundaries. Third, Ser-3 modification (i.e. substitution with Asp or phosphorylation) "undocks" and repositions the cofilin N terminus away from the filament axis, which compromises S3D cofilin's ability to weaken longitudinal filament subunit interactions. Collectively, our results demonstrate that, in addition to inhibiting actin binding, Ser-3 modification favors formation of a cofilin-binding mode that is unable to sufficiently alter filament mechanical properties and promote severing.
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Affiliation(s)
- W Austin Elam
- From the Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut 06520
| | - Wenxiang Cao
- From the Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut 06520
| | - Hyeran Kang
- From the Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut 06520
| | - Andrew Huehn
- From the Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut 06520
| | - Glen M Hocky
- the Department of Chemistry, University of Chicago, Chicago, Illinois 60637
| | - Ewa Prochniewicz
- the Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, Minnesota 55455, and
| | - Anthony C Schramm
- From the Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut 06520
| | - Karina Negrón
- From the Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut 06520
| | - Jean Garcia
- From the Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut 06520
| | - Teresa T Bonello
- the School of Medical Sciences, University of New South Wales, Sydney, New South Wales 2052, Australia
| | - Peter W Gunning
- the School of Medical Sciences, University of New South Wales, Sydney, New South Wales 2052, Australia
| | - David D Thomas
- the Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, Minnesota 55455, and
| | - Gregory A Voth
- the Department of Chemistry, University of Chicago, Chicago, Illinois 60637
| | - Charles V Sindelar
- From the Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut 06520
| | - Enrique M De La Cruz
- From the Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut 06520,
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35
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Kee AJ, Bryce NS, Yang L, Polishchuk E, Schevzov G, Weigert R, Polishchuk R, Gunning PW, Hardeman EC. ER/Golgi trafficking is facilitated by unbranched actin filaments containing Tpm4.2. Cytoskeleton (Hoboken) 2017; 74:379-389. [PMID: 28834398 DOI: 10.1002/cm.21405] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2017] [Revised: 07/31/2017] [Accepted: 08/16/2017] [Indexed: 01/14/2023]
Abstract
We have identified novel actin filaments defined by tropomyosin Tpm4.2 at the ER. EM analysis of mouse embryo fibroblasts (MEFs) isolated from mice expressing a mutant Tpm4.2 (Tpm4Plt53/Plt53 ), incapable of incorporating into actin filaments, revealed swollen ER structures compared with wild-type (WT) MEFs (Tpm4+/+ ). ER-to-Golgi, but not Golgi-to-ER trafficking was altered in the Tpm4Plt53/Plt53 MEFs following the transfection of the temperature sensitive ER-associated ts045-VSVg construct. Exogenous Tpm4.2 was able to rescue the ER-to-Golgi trafficking defect in the Tpm4Plt53/Plt53 cells. The treatment of WT MEFs with the myosin II inhibitor, blebbistatin, blocked the Tpm4.2-dependent ER-to-Golgi trafficking. The lack of an effect on ER-to-Golgi trafficking following treatment of MEFs with CK666 indicates that branched Arp2/3-containing actin filaments are not involved in anterograde vesicle trafficking. We propose that unbranched, Tpm4.2-containing filaments have an important role in maintaining ER/Golgi structure and that these structures, in conjunction with myosin II motors, mediate ER-to-Golgi trafficking.
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Affiliation(s)
- Anthony J Kee
- School of Medical Sciences, UNSW Sydney, Sydney, NSW 2052, Australia
| | - Nicole S Bryce
- School of Medical Sciences, UNSW Sydney, Sydney, NSW 2052, Australia
| | - Lingyan Yang
- School of Medical Sciences, UNSW Sydney, Sydney, NSW 2052, Australia
| | - Elena Polishchuk
- Telethon Institute of Genetics and Medicine, Naples 80131, Italy
| | - Galina Schevzov
- School of Medical Sciences, UNSW Sydney, Sydney, NSW 2052, Australia
| | - Roberto Weigert
- Laboratory of Cellular and Molecular Biology, Center for Cancer Research, National Cancer Institute, Bethesda, Maryland 20892
| | - Roman Polishchuk
- Telethon Institute of Genetics and Medicine, Naples 80131, Italy
| | - Peter W Gunning
- School of Medical Sciences, UNSW Sydney, Sydney, NSW 2052, Australia
| | - Edna C Hardeman
- School of Medical Sciences, UNSW Sydney, Sydney, NSW 2052, Australia
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36
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Desouza-Armstrong M, Gunning PW, Stehn JR. Cover Image, Volume 74, Issue 6. Cytoskeleton (Hoboken) 2017. [DOI: 10.1002/cm.21375] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Melissa Desouza-Armstrong
- Department of Anatomy, School of Medical Sciences, Faculty of Medicine; University of New South Wales; Sydney Australia
| | - Peter W. Gunning
- Department of Anatomy, School of Medical Sciences, Faculty of Medicine; University of New South Wales; Sydney Australia
| | - Justine R. Stehn
- Department of Anatomy, School of Medical Sciences, Faculty of Medicine; University of New South Wales; Sydney Australia
- Novogen Ltd. Hornsby; Sydney New South Wales 2077 Australia
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37
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Desouza-Armstrong M, Gunning PW, Stehn JR. Cover Image, Volume 74, Issue 6. Cytoskeleton (Hoboken) 2017. [DOI: 10.1002/cm.21376] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Melissa Desouza-Armstrong
- Department of Anatomy, School of Medical Sciences, Faculty of Medicine; University of New South Wales; Sydney Australia
| | - Peter W. Gunning
- Department of Anatomy, School of Medical Sciences, Faculty of Medicine; University of New South Wales; Sydney Australia
| | - Justine R. Stehn
- Department of Anatomy, School of Medical Sciences, Faculty of Medicine; University of New South Wales; Sydney Australia
- Novogen Ltd. Hornsby; Sydney New South Wales 2077 Australia
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38
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Currier MA, Stehn JR, Swain A, Chen D, Hook J, Eiffe E, Heaton A, Brown D, Nartker BA, Eaves DW, Kloss N, Treutlein H, Zeng J, Alieva IB, Dugina VB, Hardeman EC, Gunning PW, Cripe TP. Identification of Cancer-Targeted Tropomyosin Inhibitors and Their Synergy with Microtubule Drugs. Mol Cancer Ther 2017; 16:1555-1565. [PMID: 28522589 DOI: 10.1158/1535-7163.mct-16-0873] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2016] [Revised: 03/30/2017] [Accepted: 05/11/2017] [Indexed: 12/20/2022]
Abstract
Actin filaments, with their associated tropomyosin polymers, and microtubules are dynamic cytoskeletal systems regulating numerous cell functions. While antimicrotubule drugs are well-established, antiactin drugs have been more elusive. We previously targeted actin in cancer cells by inhibiting the function of a tropomyosin isoform enriched in cancer cells, Tpm3.1, using a first-in-class compound, TR100. Here, we screened over 200 other antitropomyosin analogues for anticancer and on-target activity using a series of in vitro cell-based and biochemical assays. ATM-3507 was selected as the new lead based on its ability to disable Tpm3.1-containing filaments, its cytotoxicity potency, and more favorable drug-like characteristics. We tested ATM-3507 and TR100 alone and in combination with antimicrotubule agents against neuroblastoma models in vitro and in vivo Both ATM-3507 and TR100 showed a high degree of synergy in vitro with vinca alkaloid and taxane antimicrotubule agents. In vivo, combination-treated animals bearing human neuroblastoma xenografts treated with antitropomyosin combined with vincristine showed minimal weight loss, a significant and profound regression of tumor growth and improved survival compared with control and either drug alone. Antitropomyosin combined with vincristine resulted in G2-M phase arrest, disruption of mitotic spindle formation, and cellular apoptosis. Our data suggest that small molecules targeting the actin cytoskeleton via tropomyosin sensitize cancer cells to antimicrotubule agents and are tolerated together in vivo This combination warrants further study. Mol Cancer Ther; 16(8); 1555-65. ©2017 AACR.
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Affiliation(s)
- Mark A Currier
- Center for Childhood Cancer and Blood Diseases, Nationwide Children's Hospital, Columbus, Ohio.,Division of Hematology/Oncology/Blood and Marrow Transplantation, Nationwide Children's Hospital, Columbus, Ohio
| | - Justine R Stehn
- School of Medical Sciences, University of New South Wales Australia, Sydney, New South Wales, Australia.,Novogen Pty Ltd, Hornsby, New South Wales, Australia
| | - Ashleigh Swain
- School of Medical Sciences, University of New South Wales Australia, Sydney, New South Wales, Australia
| | - Duo Chen
- Center for Childhood Cancer and Blood Diseases, Nationwide Children's Hospital, Columbus, Ohio
| | - Jeff Hook
- School of Medical Sciences, University of New South Wales Australia, Sydney, New South Wales, Australia
| | - Eleanor Eiffe
- Novogen Pty Ltd, Hornsby, New South Wales, Australia
| | - Andrew Heaton
- School of Medical Sciences, University of New South Wales Australia, Sydney, New South Wales, Australia.,Novogen Pty Ltd, Hornsby, New South Wales, Australia
| | - David Brown
- School of Medical Sciences, University of New South Wales Australia, Sydney, New South Wales, Australia.,Novogen Pty Ltd, Hornsby, New South Wales, Australia
| | - Brooke A Nartker
- Center for Childhood Cancer and Blood Diseases, Nationwide Children's Hospital, Columbus, Ohio
| | - David W Eaves
- Division of Oncology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio
| | - Nina Kloss
- School of Medical Sciences, University of New South Wales Australia, Sydney, New South Wales, Australia
| | | | - Jun Zeng
- MedChemSoft Solutions, Wheelers Hill, Victoria, Australia
| | - Irina B Alieva
- School of Medical Sciences, University of New South Wales Australia, Sydney, New South Wales, Australia.,Department of Electron Microscopy, A.N. Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russia
| | - Vera B Dugina
- School of Medical Sciences, University of New South Wales Australia, Sydney, New South Wales, Australia.,Mathematical Methods in Biology, A.N. Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russia
| | - Edna C Hardeman
- School of Medical Sciences, University of New South Wales Australia, Sydney, New South Wales, Australia
| | - Peter W Gunning
- School of Medical Sciences, University of New South Wales Australia, Sydney, New South Wales, Australia
| | - Timothy P Cripe
- Center for Childhood Cancer and Blood Diseases, Nationwide Children's Hospital, Columbus, Ohio. .,Division of Hematology/Oncology/Blood and Marrow Transplantation, Nationwide Children's Hospital, Columbus, Ohio
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39
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Desouza-Armstrong M, Gunning PW, Stehn JR. Tumor suppressor tropomyosin Tpm2.1 regulates sensitivity to apoptosis beyond anoikis characterized by changes in the levels of intrinsic apoptosis proteins. Cytoskeleton (Hoboken) 2017; 74:233-248. [PMID: 28378936 DOI: 10.1002/cm.21367] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2016] [Revised: 03/03/2017] [Accepted: 03/28/2017] [Indexed: 01/15/2023]
Abstract
The actin cytoskeleton is a polymer system that acts both as a sensor and mediator of apoptosis. Tropomyosins (Tpm) are a family of actin binding proteins that form co-polymers with actin and diversify actin filament function. Previous studies have shown that elevated expression of the tropomyosin isoform Tpm2.1 sensitized cells to apoptosis induced by cell detachment (anoikis) via an unknown mechanism. It is not yet known whether Tpm2.1 or other tropomyosin isoforms regulate sensitivity to apoptosis beyond anoikis. In this study, rat neuroepithelial cells overexpressing specific tropomyosin isoforms (Tpm1.7, Tpm2.1, Tpm3.1, and Tpm4.2) were screened for sensitivity to different classes of apoptotic stimuli, including both cytoskeletal and non-cytoskeletal targeting compounds. Results showed that elevated expression of tropomyosins in general inhibited apoptosis sensitivity to different stimuli. However, Tpm2.1 overexpression consistently enhanced sensitivity to anoikis as well as apoptosis induced by the actin targeting drug jasplakinolide (JASP). In contrast the cancer-associated isoform Tpm3.1 inhibited the induction of apoptosis by a range of agents. Treatment of Tpm2.1 overexpressing cells with JASP was accompanied by enhanced sensitivity to mitochondrial depolarization, a hallmark of intrinsic apoptosis. Moreover, Tpm2.1 overexpressing cells showed elevated levels of the apoptosis proteins Bak (proapoptotic), Mcl-1 (prosurvival), Bcl-2 (prosurvival) and phosphorylated p53 (Ser392). Finally, JASP treatment of Tpm2.1 cells caused significantly reduced Mcl-1, Bcl-2 and p53 (Ser392) levels relative to control cells. We therefore propose that Tpm2.1 regulates sensitivity to apoptosis beyond the scope of anoikis by modulating the expression of key intrinsic apoptosis proteins which primes the cell for death.
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Affiliation(s)
- Melissa Desouza-Armstrong
- Department of Anatomy, School of Medical Sciences, Faculty of Medicine, University of New South Wales, Sydney, Australia
| | - Peter W Gunning
- Department of Anatomy, School of Medical Sciences, Faculty of Medicine, University of New South Wales, Sydney, Australia
| | - Justine R Stehn
- Department of Anatomy, School of Medical Sciences, Faculty of Medicine, University of New South Wales, Sydney, Australia.,Novogen Ltd. Hornsby, Sydney, New South Wales, 2077, Australia
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40
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Gateva G, Kremneva E, Reindl T, Kotila T, Kogan K, Gressin L, Gunning PW, Manstein DJ, Michelot A, Lappalainen P. Tropomyosin Isoforms Specify Functionally Distinct Actin Filament Populations In Vitro. Curr Biol 2017; 27:705-713. [PMID: 28216317 PMCID: PMC5344678 DOI: 10.1016/j.cub.2017.01.018] [Citation(s) in RCA: 103] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2016] [Revised: 12/14/2016] [Accepted: 01/10/2017] [Indexed: 12/28/2022]
Abstract
Actin filaments assemble into a variety of networks to provide force for diverse cellular processes [1]. Tropomyosins are coiled-coil dimers that form head-to-tail polymers along actin filaments and regulate interactions of other proteins, including actin-depolymerizing factor (ADF)/cofilins and myosins, with actin [2, 3, 4, 5]. In mammals, >40 tropomyosin isoforms can be generated through alternative splicing from four tropomyosin genes. Different isoforms display non-redundant functions and partially non-overlapping localization patterns, for example within the stress fiber network [6, 7]. Based on cell biological studies, it was thus proposed that tropomyosin isoforms may specify the functional properties of different actin filament populations [2]. To test this hypothesis, we analyzed the properties of actin filaments decorated by stress-fiber-associated tropomyosins (Tpm1.6, Tpm1.7, Tpm2.1, Tpm3.1, Tpm3.2, and Tpm4.2). These proteins bound F-actin with high affinity and competed with α-actinin for actin filament binding. Importantly, total internal reflection fluorescence (TIRF) microscopy of fluorescently tagged proteins revealed that most tropomyosin isoforms cannot co-polymerize with each other on actin filaments. These isoforms also bind actin with different dynamics, which correlate with their effects on actin-binding proteins. The long isoforms Tpm1.6 and Tpm1.7 displayed stable interactions with actin filaments and protected filaments from ADF/cofilin-mediated disassembly, but did not activate non-muscle myosin IIa (NMIIa). In contrast, the short isoforms Tpm3.1, Tpm3.2, and Tpm4.2 displayed rapid dynamics on actin filaments and stimulated the ATPase activity of NMIIa, but did not efficiently protect filaments from ADF/cofilin. Together, these data provide experimental evidence that tropomyosin isoforms segregate to different actin filaments and specify functional properties of distinct actin filament populations. Stress-fiber-associated tropomyosin isoforms segregate to different actin filaments Tropomyosin isoforms bind F-actin with different dynamics Dynamic tropomyosin isoforms activate non-muscle myosin II Stable tropomyosin isoforms protect actin filaments from ADF/cofilin
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Affiliation(s)
- Gergana Gateva
- Institute of Biotechnology, University of Helsinki, P.O. Box 56, 00014 Helsinki, Finland
| | - Elena Kremneva
- Institute of Biotechnology, University of Helsinki, P.O. Box 56, 00014 Helsinki, Finland
| | - Theresia Reindl
- Institute for Biophysical Chemistry, Hannover Medical School, 30625 Hannover, Germany
| | - Tommi Kotila
- Institute of Biotechnology, University of Helsinki, P.O. Box 56, 00014 Helsinki, Finland
| | - Konstantin Kogan
- Institute of Biotechnology, University of Helsinki, P.O. Box 56, 00014 Helsinki, Finland
| | - Laurène Gressin
- Biosciences and Biotechnology Institute of Grenoble, LPCV/CNRS/CEA/UGA/INRA, 38054 Grenoble, France
| | - Peter W Gunning
- Oncology Research Unit, School of Medical Sciences, UNSW Australia, Sydney, NSW 2052, Australia
| | - Dietmar J Manstein
- Institute for Biophysical Chemistry, Hannover Medical School, 30625 Hannover, Germany
| | - Alphée Michelot
- Aix-Marseille University, CNRS, IBDM, 13284 Marseille, France
| | - Pekka Lappalainen
- Institute of Biotechnology, University of Helsinki, P.O. Box 56, 00014 Helsinki, Finland.
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Pleines I, Woods J, Chappaz S, Kew V, Foad N, Ballester-Beltrán J, Aurbach K, Lincetto C, Lane RM, Schevzov G, Alexander WS, Hilton DJ, Astle WJ, Downes K, Nurden P, Westbury SK, Mumford AD, Obaji SG, Collins PW, Delerue F, Ittner LM, Bryce NS, Holliday M, Lucas CA, Hardeman EC, Ouwehand WH, Gunning PW, Turro E, Tijssen MR, Kile BT. Mutations in tropomyosin 4 underlie a rare form of human macrothrombocytopenia. J Clin Invest 2017; 127:814-829. [PMID: 28134622 PMCID: PMC5330761 DOI: 10.1172/jci86154] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2015] [Accepted: 12/01/2016] [Indexed: 01/12/2023] Open
Abstract
Platelets are anuclear cells that are essential for blood clotting. They are produced by large polyploid precursor cells called megakaryocytes. Previous genome-wide association studies in nearly 70,000 individuals indicated that single nucleotide variants (SNVs) in the gene encoding the actin cytoskeletal regulator tropomyosin 4 (TPM4) exert an effect on the count and volume of platelets. Platelet number and volume are independent risk factors for heart attack and stroke. Here, we have identified 2 unrelated families in the BRIDGE Bleeding and Platelet Disorders (BPD) collection who carry a TPM4 variant that causes truncation of the TPM4 protein and segregates with macrothrombocytopenia, a disorder characterized by low platelet count. N-Ethyl-N-nitrosourea–induced (ENU-induced) missense mutations in Tpm4 or targeted inactivation of the Tpm4 locus led to gene dosage–dependent macrothrombocytopenia in mice. All other blood cell counts in Tpm4-deficient mice were normal. Insufficient TPM4 expression in human and mouse megakaryocytes resulted in a defect in the terminal stages of platelet production and had a mild effect on platelet function. Together, our findings demonstrate a nonredundant role for TPM4 in platelet biogenesis in humans and mice and reveal that truncating variants in TPM4 cause a previously undescribed dominant Mendelian platelet disorder.
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Affiliation(s)
- Irina Pleines
- Walter and Eliza Hall Institute of Medical Research, Parkville, Australia
- Department of Medical Biology, University of Melbourne, Parkville, Australia
| | - Joanne Woods
- Department of Haematology, University of Cambridge, Cambridge Biomedical Campus, Cambridge, United Kingdom
- NHS Blood and Transplant, Cambridge Biomedical Campus, Cambridge, United Kingdom
| | - Stephane Chappaz
- Walter and Eliza Hall Institute of Medical Research, Parkville, Australia
- Department of Medical Biology, University of Melbourne, Parkville, Australia
| | - Verity Kew
- Department of Haematology, University of Cambridge, Cambridge Biomedical Campus, Cambridge, United Kingdom
- NHS Blood and Transplant, Cambridge Biomedical Campus, Cambridge, United Kingdom
| | - Nicola Foad
- Department of Haematology, University of Cambridge, Cambridge Biomedical Campus, Cambridge, United Kingdom
- NHS Blood and Transplant, Cambridge Biomedical Campus, Cambridge, United Kingdom
| | - José Ballester-Beltrán
- Department of Haematology, University of Cambridge, Cambridge Biomedical Campus, Cambridge, United Kingdom
- NHS Blood and Transplant, Cambridge Biomedical Campus, Cambridge, United Kingdom
| | - Katja Aurbach
- Institute of Experimental Biomedicine, University Hospital and Rudolf Virchow Center, University of Wuerzburg, Wuerzburg, Germany
| | - Chiara Lincetto
- Department of Haematology, University of Cambridge, Cambridge Biomedical Campus, Cambridge, United Kingdom
- NHS Blood and Transplant, Cambridge Biomedical Campus, Cambridge, United Kingdom
| | - Rachael M. Lane
- Walter and Eliza Hall Institute of Medical Research, Parkville, Australia
| | - Galina Schevzov
- School of Medical Sciences, University of New South Wales, Sydney, Australia
| | - Warren S. Alexander
- Walter and Eliza Hall Institute of Medical Research, Parkville, Australia
- Department of Medical Biology, University of Melbourne, Parkville, Australia
| | - Douglas J. Hilton
- Walter and Eliza Hall Institute of Medical Research, Parkville, Australia
- Department of Medical Biology, University of Melbourne, Parkville, Australia
| | - William J. Astle
- Department of Haematology, University of Cambridge, Cambridge Biomedical Campus, Cambridge, United Kingdom
- NHS Blood and Transplant, Cambridge Biomedical Campus, Cambridge, United Kingdom
| | - Kate Downes
- Department of Haematology, University of Cambridge, Cambridge Biomedical Campus, Cambridge, United Kingdom
- NHS Blood and Transplant, Cambridge Biomedical Campus, Cambridge, United Kingdom
| | - Paquita Nurden
- Institut Hospitalo-Universitaire LIRYC, Plateforme Technologique d’Innovation Biomédicale, Hôpital Xavier Arnozan, Pessac, France
| | - Sarah K. Westbury
- School of Clinical Sciences, University of Bristol, Bristol, United Kingdom
| | - Andrew D. Mumford
- School of Cellular and Molecular Medicine, University of Bristol, Bristol, United Kingdom
| | - Samya G. Obaji
- Arthur Bloom Haemophilia Centre, School of Medicine, Cardiff University, Heath Park, Cardiff, United Kingdom
| | - Peter W. Collins
- Arthur Bloom Haemophilia Centre, School of Medicine, Cardiff University, Heath Park, Cardiff, United Kingdom
| | - NIHR BioResource
- NIHR BioResource–Rare Diseases, Cambridge University Hospitals, Cambridge Biomedical Campus, Cambridge, United Kingdom
| | - Fabien Delerue
- Transgenic Animal Unit, Mark Wainwright Analytical Centre, University of New South Wales, Sydney, Australia
| | - Lars M. Ittner
- Transgenic Animal Unit, Mark Wainwright Analytical Centre, University of New South Wales, Sydney, Australia
| | - Nicole S. Bryce
- School of Medical Sciences, University of New South Wales, Sydney, Australia
| | - Mira Holliday
- School of Medical Sciences, University of New South Wales, Sydney, Australia
| | - Christine A. Lucas
- School of Medical Sciences, University of New South Wales, Sydney, Australia
| | - Edna C. Hardeman
- School of Medical Sciences, University of New South Wales, Sydney, Australia
| | - Willem H. Ouwehand
- Department of Haematology, University of Cambridge, Cambridge Biomedical Campus, Cambridge, United Kingdom
- NHS Blood and Transplant, Cambridge Biomedical Campus, Cambridge, United Kingdom
- NIHR BioResource–Rare Diseases, Cambridge University Hospitals, Cambridge Biomedical Campus, Cambridge, United Kingdom
- Human Genetics, Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, United Kingdom
| | - Peter W. Gunning
- School of Medical Sciences, University of New South Wales, Sydney, Australia
| | - Ernest Turro
- Department of Haematology, University of Cambridge, Cambridge Biomedical Campus, Cambridge, United Kingdom
- NHS Blood and Transplant, Cambridge Biomedical Campus, Cambridge, United Kingdom
- Medical Research Council Biostatistics Unit, Cambridge Institute of Public Health, Cambridge, United Kingdom
| | - Marloes R. Tijssen
- Department of Haematology, University of Cambridge, Cambridge Biomedical Campus, Cambridge, United Kingdom
- NHS Blood and Transplant, Cambridge Biomedical Campus, Cambridge, United Kingdom
| | - Benjamin T. Kile
- Walter and Eliza Hall Institute of Medical Research, Parkville, Australia
- Department of Medical Biology, University of Melbourne, Parkville, Australia
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42
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Appaduray MA, Masedunskas A, Bryce NS, Lucas CA, Warren SC, Timpson P, Stear JH, Gunning PW, Hardeman EC. Recruitment Kinetics of Tropomyosin Tpm3.1 to Actin Filament Bundles in the Cytoskeleton Is Independent of Actin Filament Kinetics. PLoS One 2016; 11:e0168203. [PMID: 27977753 PMCID: PMC5158027 DOI: 10.1371/journal.pone.0168203] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2016] [Accepted: 11/28/2016] [Indexed: 12/23/2022] Open
Abstract
The actin cytoskeleton is a dynamic network of filaments that is involved in virtually every cellular process. Most actin filaments in metazoa exist as a co-polymer of actin and tropomyosin (Tpm) and the function of an actin filament is primarily defined by the specific Tpm isoform associated with it. However, there is little information on the interdependence of these co-polymers during filament assembly and disassembly. We addressed this by investigating the recovery kinetics of fluorescently tagged isoform Tpm3.1 into actin filament bundles using FRAP analysis in cell culture and in vivo in rats using intracellular intravital microscopy, in the presence or absence of the actin-targeting drug jasplakinolide. The mobile fraction of Tpm3.1 is between 50% and 70% depending on whether the tag is at the C- or N-terminus and whether the analysis is in vivo or in cultured cells. We find that the continuous dynamic exchange of Tpm3.1 is not significantly impacted by jasplakinolide, unlike tagged actin. We conclude that tagged Tpm3.1 may be able to undergo exchange in actin filament bundles largely independent of the assembly and turnover of actin.
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Affiliation(s)
- Mark A. Appaduray
- Cellular and Genetic Medicine Unit, School of Medical Sciences, UNSW Australia, Sydney, New South Wales, Australia
| | - Andrius Masedunskas
- Cellular and Genetic Medicine Unit, School of Medical Sciences, UNSW Australia, Sydney, New South Wales, Australia
| | - Nicole S. Bryce
- Cellular and Genetic Medicine Unit, School of Medical Sciences, UNSW Australia, Sydney, New South Wales, Australia
| | - Christine A. Lucas
- Cellular and Genetic Medicine Unit, School of Medical Sciences, UNSW Australia, Sydney, New South Wales, Australia
| | - Sean C. Warren
- The Kinghorn Cancer Center, Garvan Institute of Medical Research, Sydney, New South Wales, Australia
| | - Paul Timpson
- The Kinghorn Cancer Center, Garvan Institute of Medical Research, Sydney, New South Wales, Australia
| | - Jeffrey H. Stear
- Cellular and Genetic Medicine Unit, School of Medical Sciences, UNSW Australia, Sydney, New South Wales, Australia
| | - Peter W. Gunning
- Cellular and Genetic Medicine Unit, School of Medical Sciences, UNSW Australia, Sydney, New South Wales, Australia
| | - Edna C. Hardeman
- Cellular and Genetic Medicine Unit, School of Medical Sciences, UNSW Australia, Sydney, New South Wales, Australia
- * E-mail:
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43
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Nicovich PR, Janco M, Sobey T, Gajwani M, Obeidy P, Whan R, Gaus K, Gunning PW, Coster AC, Böcking T. Effect of surface chemistry on tropomyosin binding to actin filaments on surfaces. Cytoskeleton (Hoboken) 2016; 73:729-738. [PMID: 27783462 DOI: 10.1002/cm.21342] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2016] [Revised: 10/24/2016] [Accepted: 10/25/2016] [Indexed: 01/29/2023]
Abstract
Reconstitution of actin filaments on surfaces for observation of filament-associated protein dynamics by fluorescence microscopy is currently an exciting field in biophysics. Here we examine the effects of attaching actin filaments to surfaces on the binding and dissociation kinetics of a fluorescence-labeled tropomyosin, a rod-shaped protein that forms continuous strands wrapping around the actin filament. Two attachment modalities of the actin to the surface are explored: where the actin filament is attached to the surface at multiple points along its length; and where the actin filament is attached at one end and aligned parallel to the surface by buffer flow. To facilitate analysis of actin-binding protein dynamics, we have developed a software tool for the viewing, tracing and analysis of filaments and co-localized species in noisy fluorescence timelapse images. Our analysis shows that the interaction of tropomyosin with actin filaments is similar for both attachment modalities. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Philip R Nicovich
- ARC Centre of Excellence in Advanced Molecular Imaging and EMBL Australia Node in Single Molecule Science, School of Medical Sciences, University of New South Wales, Sydney, Australia
| | - Miro Janco
- ARC Centre of Excellence in Advanced Molecular Imaging and EMBL Australia Node in Single Molecule Science, School of Medical Sciences, University of New South Wales, Sydney, Australia
| | - Tom Sobey
- School of Medical Sciences, University of New South Wales, Sydney, Australia
| | - Mehul Gajwani
- ARC Centre of Excellence in Advanced Molecular Imaging and EMBL Australia Node in Single Molecule Science, School of Medical Sciences, University of New South Wales, Sydney, Australia
| | - Peyman Obeidy
- School of Medical Sciences, University of New South Wales, Sydney, Australia
| | - Renee Whan
- Biomedical Imaging Facility, University of New South Wales, Sydney, Australia
| | - Katharina Gaus
- ARC Centre of Excellence in Advanced Molecular Imaging and EMBL Australia Node in Single Molecule Science, School of Medical Sciences, University of New South Wales, Sydney, Australia
| | - Peter W Gunning
- School of Medical Sciences, University of New South Wales, Sydney, Australia
| | - Adelle Cf Coster
- School of Mathematics and Statistics, University of New South Wales, Sydney, Australia
| | - Till Böcking
- ARC Centre of Excellence in Advanced Molecular Imaging and EMBL Australia Node in Single Molecule Science, School of Medical Sciences, University of New South Wales, Sydney, Australia
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44
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Dugina V, Alieva I, Khromova N, Kireev I, Gunning PW, Kopnin P. Interaction of microtubules with the actin cytoskeleton via cross-talk of EB1-containing +TIPs and γ-actin in epithelial cells. Oncotarget 2016; 7:72699-72715. [PMID: 27683037 PMCID: PMC5341938 DOI: 10.18632/oncotarget.12236] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2016] [Accepted: 09/18/2016] [Indexed: 12/16/2022] Open
Abstract
Actin microfilaments and microtubules are both highly dynamic cytoskeleton components implicated in a wide range of intracellular processes as well as cell-cell and cell-substrate interactions. The interactions of actin filaments with the microtubule system play an important role in the assembly and maintenance of 3D cell structure. Here we demonstrate that cytoplasmic actins are differentially distributed in relation to the microtubule system. LSM, 3D-SIM, proximity ligation assay (PLA) and co-immunoprecipitation methods applied in combination with selective depletion of β- or γ-cytoplasmic actins revealed a selective interaction between microtubules and γ-, but not β-cytoplasmic actin via the microtubule +TIPs protein EB1. EB1-positive comet distribution analysis and quantification have shown more effective microtubule growth in the absence of β-actin. Our data represent the first demonstration that microtubule +TIPs protein EB1 interacts mainly with γ-cytoplasmic actin in epithelial cells.
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Affiliation(s)
- Vera Dugina
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russia
- School of Medical Science, The University of New South Wales, NSW, Sydney, Australia
| | - Irina Alieva
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russia
- School of Medical Science, The University of New South Wales, NSW, Sydney, Australia
| | | | - Igor Kireev
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russia
| | - Peter W. Gunning
- School of Medical Science, The University of New South Wales, NSW, Sydney, Australia
| | - Pavel Kopnin
- Blokhin Russian Cancer Research Center, Moscow, Russia
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45
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Knothe Tate ML, Gunning PW, Sansalone V. Emergence of Form from Function - Mechanical Engineering Approaches to Probe the Role of Stem Cell Mechanoadaptation in Sealing Cell Fate. Bioarchitecture 2016; 6:85-103. [PMID: 27739911 DOI: 10.1080/19490992.2016.1229729] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Stem cell "mechanomics" refers to the effect of mechanical cues on stem cell and matrix biology, where cell shape and fate are intrinsic manifestations of form and function. Before specialization, the stem cell itself serves as a sensor and actuator; its structure emerges from its local mechanical milieu as the cell adapts over time. Coupling of novel spatiotemporal imaging and computational methods allows for linking of the energy of adaptation to the structure, biology and mechanical function of the cell. Cutting edge imaging methods enable probing of mechanisms by which stem cells' emergent anisotropic architecture and fate commitment occurs. A novel cell-scale model provides a mechanistic framework to describe stem cell growth and remodeling through mechanical feedback; making use of a generalized virtual power principle, the model accounts for the rate of doing work or the rate of using energy to effect the work. This coupled approach provides a basis to elucidate mechanisms underlying the stem cell's innate capacity to adapt to mechanical stimuli as well as the role of mechanoadaptation in lineage commitment. An understanding of stem cell mechanoadaptation is key to deciphering lineage commitment, during prenatal development, postnatal wound healing, and engineering of tissues.
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Affiliation(s)
- Melissa L Knothe Tate
- a Graduate School of Biomedical Engineering , University of New South Wales , Sydney , Australia
| | - Peter W Gunning
- b School of Medical Sciences, University of New South Wales , Sydney , Australia
| | - Vittorio Sansalone
- c Université Paris-Est Créteil (UPEC), Laboratoire Modélisation et Simulation Multi Echelle , MSME UMR 8208 CNRS, France
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46
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Coombes JD, Schevzov G, Kan CY, Petti C, Maritz MF, Whittaker S, Mackenzie KL, Gunning PW. Ras Transformation Overrides a Proliferation Defect Induced by Tpm3.1 Knockout. Cell Mol Biol Lett 2016; 20:626-46. [PMID: 26274783 DOI: 10.1515/cmble-2015-0037] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2015] [Accepted: 07/30/2015] [Indexed: 12/16/2022] Open
Abstract
Extensive re-organisation of the actin cytoskeleton and changes in the expression of its binding proteins is a characteristic feature of cancer cells. Previously we have shown that the tropomyosin isoform Tpm3.1, an integral component of the actin cytoskeleton in tumor cells, is required for tumor cell survival. Our objective was to determine whether cancer cells devoid of Tpm3.1 would evade the tumorgenic effects induced by H-Ras transformation. The tropomyosin isoform (Tpm) expression profile of a range of cancer cell lines (21) demonstrates that Tpm3.1 is one of the most broadly expressed Tpm isoform. Consequently, the contribution of Tpm3.1 to the transformation process was functionally evaluated. Primary embryonic fibroblasts isolated from wild type (WT) and Tpm3.1 knockout (KO) mice were transduced with retroviral vectors expressing SV40 large T antigen and an oncogenic allele of the H-Ras gene, H-RasV12, to generate immortalized and transformed WT and KO MEFs respectively. We show that Tpm3.1 is required for growth factor-independent proliferation in the SV40 large T antigen immortalized MEFs, but this requirement is overcome by H-Ras transformation. Consistent with those findings, we found that Tpm3.1 was not required for anchorage independent growth or growth of H-Ras-driven tumors in a mouse model. Finally, we show that pERK and Importin 7 protein interactions are significantly decreased in the SV40 large T antigen immortalized KO MEFs but not in the H-Ras transformed KO cells, relative to control MEFs. The data demonstrate that H-Ras transformation overrides a requirement for Tpm3.1 in growth factor-independent proliferation of immortalized MEFs. We propose that in the SV40 large T antigen immortalized MEFs, Tpm3.1 is partly responsible for the efficient interaction between pERK and Imp7 resulting in cell proliferation, but this is overidden by Ras transformation.
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47
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Janco M, Bonello TT, Byun A, Coster ACF, Lebhar H, Dedova I, Gunning PW, Böcking T. The impact of tropomyosins on actin filament assembly is isoform specific. Bioarchitecture 2016; 6:61-75. [PMID: 27420374 DOI: 10.1080/19490992.2016.1201619] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Tropomyosin (Tpm) is an α helical coiled-coil dimer that forms a co-polymer along the actin filament. Tpm is involved in the regulation of actin's interaction with binding proteins as well as stabilization of the actin filament and its assembly kinetics. Recent studies show that multiple Tpm isoforms also define the functional properties of distinct actin filament populations within a cell. Subtle structural variations within well conserved Tpm isoforms are the key to their functional specificity. Therefore, we purified and characterized a comprehensive set of 8 Tpm isoforms (Tpm1.1, Tpm1.12, Tpm1.6, Tpm1.7, Tpm1.8, Tpm2.1, Tpm3.1, and Tpm4.2), using well-established actin co-sedimentation and pyrene fluorescence polymerization assays. We observed that the apparent affinity (Kd(app)) to filamentous actin varied in all Tpm isoforms between ∼0.1-5 μM with similar values for both, skeletal and cytoskeletal actin filaments. The data did not indicate any correlation between affinity and size of Tpm molecules, however high molecular weight (HMW) isoforms Tpm1.1, Tpm1.6, Tpm1.7 and Tpm2.1, showed ∼3-fold higher cooperativity compared to low molecular weight (LMW) isoforms Tpm1.12, Tpm1.8, Tpm3.1, and Tpm4.2. The rate of actin filament elongation in the presence of Tpm2.1 increased, while all other isoforms decreased the elongation rate by 27-85 %. Our study shows that the biochemical properties of Tpm isoforms are finely tuned and depend on sequence variations in alternatively spliced regions of Tpm molecules.
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Affiliation(s)
- Miro Janco
- a Single Molecule Science , School of Medical Sciences and ARC Centre of Excellence in Advanced Molecular Imaging, University of New South Wales , Sydney , NSW , Australia
| | - Teresa T Bonello
- b School of Medical Sciences , University of New South Wales , Sydney , NSW , Australia
| | - Alex Byun
- b School of Medical Sciences , University of New South Wales , Sydney , NSW , Australia
| | - Adelle C F Coster
- c School of Mathematics and Statistics , University of New South Wales , Sydney , NSW , Australia
| | - Helene Lebhar
- d School of Biotechnology and Biomolecular Sciences , University of New South Wales , Sydney , NSW , Australia
| | - Irina Dedova
- b School of Medical Sciences , University of New South Wales , Sydney , NSW , Australia
| | - Peter W Gunning
- b School of Medical Sciences , University of New South Wales , Sydney , NSW , Australia
| | - Till Böcking
- a Single Molecule Science , School of Medical Sciences and ARC Centre of Excellence in Advanced Molecular Imaging, University of New South Wales , Sydney , NSW , Australia
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48
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Vrhovski B, McKay K, Schevzov G, Gunning PW, Weinberger RP. Smooth Muscle-specific α Tropomyosin Is a Marker of Fully Differentiated Smooth Muscle in Lung. J Histochem Cytochem 2016; 53:875-83. [PMID: 15995146 DOI: 10.1369/jhc.4a6504.2005] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Tropomyosin (Tm) is one of the major components of smooth muscle. Currently it is impossible to easily distinguish the two major smooth muscle (sm) forms of Tm at a protein level by immunohistochemistry due to lack of specific antibodies. α-sm Tm contains a unique 2a exon not found in any other Tm. We have produced a polyclonal antibody to this exon that specifically detects α-sm Tm. We demonstrate here the utility of this antibody for the study of smooth muscle. The tissue distribution of α-sm Tm was shown to be highly specific to smooth muscle. α-sm Tm showed an identical profile and tissue colocalization with α-sm actin both by Western blotting and immunohistochemistry. Using lung as a model organ system, we examined the developmental appearance of α-sm Tm in comparison to α-sm actin in both the mouse and human. α-sm Tm is a late-onset protein, appearing much later than actin in both species. There were some differences in onset of appearance in vascular and airway smooth muscle with airway appearing earlier. α-sm Tm can therefore be used as a good marker of mature differentiated smooth muscle cells. Along with α-sm actin and sm-myosin antibodies, α-sm Tm is a valuable tool for the study of smooth muscle.
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Affiliation(s)
- Bernadette Vrhovski
- The Children's Hospital at Westmead, Locked Bag 4001, Westmead, NSW 2145, Australia
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49
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Schevzov G, Vrhovski B, Bryce NS, Elmir S, Qiu MR, O'neill GM, Yang N, Verrills NM, Kavallaris M, Gunning PW. Tissue-specific Tropomyosin Isoform Composition. J Histochem Cytochem 2016; 53:557-70. [PMID: 15872049 DOI: 10.1369/jhc.4a6505.2005] [Citation(s) in RCA: 99] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Four distinct genes encode tropomyosin (Tm) proteins, integral components of the actin microfilament system. In non-muscle cells, over 40 Tm isoforms are derived using alternative splicing. Distinct populations of actin filaments characterized by the composition of these Tm isoforms are found differentially sorted within cells ( Gunning et al. 1998b ). We hypothesized that these distinct intracellular compartments defined by the association of Tm isoforms may allow for independent regulation of microfilament function. Consequently, to understand the molecular mechanisms that give rise to these different microfilaments and their regulation, a cohort of fully characterized isoform-specific Tm antibodies was required. The characterization protocol initially involved testing the specificity of the antibodies on bacterially produced Tm proteins. We then confirmed that these Tm antibodies can be used to probe the expression and subcellular localization of different Tm isoforms by Western blot analysis, immunofluorescence staining of cells in culture, and immunohistochemistry of paraffin wax-embedded mouse tissues. These Tm antibodies, therefore, have the capacity to monitor specific actin filament populations in a range of experimental systems.
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Affiliation(s)
- Galina Schevzov
- Oncology Research Unit, The Children's Hospital at Westmead, Locked Bag 4001, Westmead, NSW, Sydney, Australia
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50
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Chen Y, Gu M, Gunning PW, Russell SM. Dense small molecule labeling enables activator-dependent STORM by proximity mapping. Histochem Cell Biol 2016; 146:255-66. [PMID: 27246003 DOI: 10.1007/s00418-016-1451-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/20/2016] [Indexed: 12/18/2022]
Abstract
Stochastic optical reconstruction microscopy (STORM) enables high-resolution imaging, but multi-channel 3D imaging is problematic because of chromatic aberrations and alignment errors. The use of activator-dependent STORM in which spectrally distinct activators can be coupled with a single reporter can circumvent such issues. However, the standard approach of linking activators and reporters to a single antibody molecule is hampered by low labeling density and the large size of the antibody. We proposed that small molecule labels might enable activator-dependent STORM if the reporter or activator were linked to separate small molecules that bound within 3.5 nm of each other. This would greatly increase the labeling density and therefore improve resolution. We tested various mixtures of phalloidin- or mCling-conjugated fluorophore to demonstrate this feasibility. The specific activation was dependent on the choice of activator, its density, a matching activating laser and its power. In addition to providing an effective means of multi-channel 3D STORM imaging, this method also provides information about the local proximity between labels, potentially enabling super-resolved mapping of the conformation of the labeled structures.
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Affiliation(s)
- Ye Chen
- Immune Signalling Laboratory, Peter MacCallum Cancer Centre, East Melbourne, VIC, Australia.,Centre for Micro-Photonics, Faculty of Science, Engineering and Technology, Swinburne University of Technology, Hawthorn, VIC, Australia
| | - Min Gu
- Centre for Micro-Photonics, Faculty of Science, Engineering and Technology, Swinburne University of Technology, Hawthorn, VIC, Australia.,Artificial-Intelligence Nanophotonics Laboratory, School of Science, RMIT University, Melbourne, VIC, 3001, Australia
| | - Peter W Gunning
- School of Medical Sciences, UNSW Australia, Sydney, NSW, 2052, Australia
| | - Sarah M Russell
- Immune Signalling Laboratory, Peter MacCallum Cancer Centre, East Melbourne, VIC, Australia. .,Centre for Micro-Photonics, Faculty of Science, Engineering and Technology, Swinburne University of Technology, Hawthorn, VIC, Australia. .,Department of Pathology, The University of Melbourne, Parkville, VIC, Australia. .,Sir Peter MacCallum Department of Oncology, The University of Melbourne, Parkville, VIC, Australia.
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