1
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Infante E, Etienne-Manneville S. Intermediate filaments: Integration of cell mechanical properties during migration. Front Cell Dev Biol 2022; 10:951816. [PMID: 35990612 PMCID: PMC9389290 DOI: 10.3389/fcell.2022.951816] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2022] [Accepted: 07/07/2022] [Indexed: 11/22/2022] Open
Abstract
Cell migration is a vital and dynamic process required for the development of multicellular organisms and for immune system responses, tissue renewal and wound healing in adults. It also contributes to a variety of human diseases such as cancers, autoimmune diseases, chronic inflammation and fibrosis. The cytoskeleton, which includes actin microfilaments, microtubules, and intermediate filaments (IFs), is responsible for the maintenance of animal cell shape and structural integrity. Each cytoskeletal network contributes its unique properties to dynamic cell behaviour, such as cell polarization, membrane protrusion, cell adhesion and contraction. Hence, cell migration requires the dynamic orchestration of all cytoskeleton components. Among these, IFs have emerged as a molecular scaffold with unique mechanical features and a key player in the cell resilience to mechanical stresses during migration through complex 3D environment. Moreover, accumulating evidence illustrates the participation of IFs in signalling cascades and cytoskeletal crosstalk. Teaming up with actin and microtubules, IFs contribute to the active generation of forces required for cell adhesion and mesenchymal migration and invasion. Here we summarize and discuss how IFs integrate mechanical properties and signalling functions to control cell migration in a wide spectrum of physiological and pathological situations.
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Usman S, Aldehlawi H, Nguyen TKN, Teh MT, Waseem A. Impact of N-Terminal Tags on De Novo Vimentin Intermediate Filament Assembly. Int J Mol Sci 2022; 23:ijms23116349. [PMID: 35683030 PMCID: PMC9181571 DOI: 10.3390/ijms23116349] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2022] [Revised: 06/02/2022] [Accepted: 06/04/2022] [Indexed: 02/01/2023] Open
Abstract
Vimentin, a type III intermediate filament protein, is found in most cells along with microfilaments and microtubules. It has been shown that the head domain folds back to associate with the rod domain and this association is essential for filament assembly. The N-terminally tagged vimentin has been widely used to label the cytoskeleton in live cell imaging. Although there is previous evidence that EGFP tagged vimentin fails to form filaments but is able to integrate into a pre-existing network, no study has systematically investigated or established a molecular basis for this observation. To determine whether a tag would affect de novo filament assembly, we used vimentin fused at the N-terminus with two different sized tags, AcGFP (239 residues, 27 kDa) and 3 × FLAG (22 residues; 2.4 kDa) to assemble into filaments in two vimentin-deficient epithelial cells, MCF-7 and A431. We showed that regardless of tag size, N-terminally tagged vimentin aggregated into globules with a significant proportion co-aligning with β-catenin at cell–cell junctions. However, the tagged vimentin aggregates could form filaments upon adding untagged vimentin at a ratio of 1:1 or when introduced into cells containing pre-existing filaments. The resultant filament network containing a mixture of tagged and untagged vimentin was less stable compared to that formed by only untagged vimentin. The data suggest that placing a tag at the N-terminus may create steric hinderance in case of a large tag (AcGFP) or electrostatic repulsion in case of highly charged tag (3 × FLAG) perhaps inducing a conformational change, which deleteriously affects the association between head and rod domains. Taken together our results shows that a free N-terminus is essential for filament assembly as N-terminally tagged vimentin is not only incapable of forming filaments, but it also destabilises when integrated into a pre-existing network.
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Affiliation(s)
- Saima Usman
- Centre for Oral Immunobiology and Regenerative Medicine, Institute of Dentistry, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, Newark Street, London E1 2AT, UK; (S.U.); (T.K.N.N.); (M.-T.T.)
| | - Hebah Aldehlawi
- Department of Oral Diagnostic Sciences, Division of Oral Pathology and Medicine, Faculty of Dentistry, King Abdul Aziz University, Jeddah 21589, Saudi Arabia;
| | - Thuan Khanh Ngoc Nguyen
- Centre for Oral Immunobiology and Regenerative Medicine, Institute of Dentistry, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, Newark Street, London E1 2AT, UK; (S.U.); (T.K.N.N.); (M.-T.T.)
| | - Muy-Teck Teh
- Centre for Oral Immunobiology and Regenerative Medicine, Institute of Dentistry, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, Newark Street, London E1 2AT, UK; (S.U.); (T.K.N.N.); (M.-T.T.)
| | - Ahmad Waseem
- Centre for Oral Immunobiology and Regenerative Medicine, Institute of Dentistry, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, Newark Street, London E1 2AT, UK; (S.U.); (T.K.N.N.); (M.-T.T.)
- Centre for Immunobiology and Regenerative Medicine, Blizard Institute, 4 Newark Street, London E1 2AT, UK
- Correspondence: ; Tel.: +44-207-882-2387; Fax: +44-207-882-7137
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Kim S, Lim Y, Lee SY, Yoon HN, Yi H, Jang KH, Ku NO. Keratin 8 mutations in transgenic mice predispose to lung injury. J Cell Sci 2021; 134:jcs250167. [PMID: 34342355 DOI: 10.1242/jcs.250167] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Accepted: 06/28/2021] [Indexed: 11/20/2022] Open
Abstract
Keratin 8 (K8) is the cytoskeletal intermediate filament protein of simple-type epithelia. Mutations in K8 predispose the affected individual and transgenic mouse to liver disease. However, the role of K8 in the lung has not been reported in mutant transgenic mouse models. Here, we investigated the susceptibility of two different transgenic mice expressing K8 Gly62-Cys (Gly62 replaced with Cys) or Ser74-Ala (Ser74 replaced with Ala) to lung injury. The mutant transgenic mice were highly susceptible to two independent acute and chronic lung injuries compared with control mice. Both K8 Gly62-Cys mice and K8 Ser74-Ala mice showed markedly increased mouse lethality (∼74% mutant mice versus ∼34% control mice) and more severe lung damage, with increased inflammation and apoptosis, under L-arginine-mediated acute lung injury. Moreover, the K8 Ser74-Ala mice had more severe lung damage, with extensive hemorrhage and prominent fibrosis, under bleomycin-induced chronic lung injury. Our study provides the first direct evidence that K8 mutations predispose to lung injury in transgenic mice.
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Affiliation(s)
- Sujin Kim
- Interdisciplinary Program of Integrated OMICS for Biomedical Science, Graduate School, Yonsei University, Seoul 03722, Korea
| | - Younglan Lim
- Interdisciplinary Program of Integrated OMICS for Biomedical Science, Graduate School, Yonsei University, Seoul 03722, Korea
| | - So-Young Lee
- Interdisciplinary Program of Integrated OMICS for Biomedical Science, Graduate School, Yonsei University, Seoul 03722, Korea
| | - Han-Na Yoon
- Interdisciplinary Program of Integrated OMICS for Biomedical Science, Graduate School, Yonsei University, Seoul 03722, Korea
| | - Hayan Yi
- Interdisciplinary Program of Integrated OMICS for Biomedical Science, Graduate School, Yonsei University, Seoul 03722, Korea
| | - Kwi-Hoon Jang
- Interdisciplinary Program of Integrated OMICS for Biomedical Science, Graduate School, Yonsei University, Seoul 03722, Korea
| | - Nam-On Ku
- Interdisciplinary Program of Integrated OMICS for Biomedical Science, Graduate School, Yonsei University, Seoul 03722, Korea
- Department of Bio-Convergence ISED, Underwood International College, Yonsei University, Seoul 03722, Korea
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4
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Zhang X, Reinsmoen NL. Impact and production of Non-HLA-specific antibodies in solid organ transplantation. Int J Immunogenet 2020; 47:235-242. [PMID: 32426916 DOI: 10.1111/iji.12494] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2020] [Revised: 04/07/2020] [Accepted: 04/21/2020] [Indexed: 12/16/2022]
Abstract
Organ transplantation is an effective way to treat end-stage organ disease. Extending the graft survival is one of the major goals in the modern era of organ transplantation. However, long-term graft survival has not significantly improved in recent years despite the improvement of patient management and advancement of immunosuppression regimen. Antibody-mediated rejection is a major obstacle for long-term graft survival. Donor human leucocyte antigen (HLA)-specific antibodies were initially identified as a major cause for antibody-mediated rejection. Recently, with the development of solid-phase-based assay reagents, the contribution of non-HLA antibodies in organ transplantation starts to be appreciated. Here, we review the role of most studied non-HLA antibodies, including angiotensin II type 1 receptor (AT1 R), K-α-tubulin and vimentin antibodies, in the solid organ transplant, and discuss the possible mechanism by which these antibodies are stimulated.
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Affiliation(s)
- Xiaohai Zhang
- HLA and Immunogenetics Laboratory, Comprehensive Transplant Center, Cedars- Sinai Medical Center, Los Angeles, CA, USA
| | - Nancy L Reinsmoen
- HLA and Immunogenetics Laboratory, Comprehensive Transplant Center, Cedars- Sinai Medical Center, Los Angeles, CA, USA
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5
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Danielsson F, Peterson MK, Caldeira Araújo H, Lautenschläger F, Gad AKB. Vimentin Diversity in Health and Disease. Cells 2018; 7:E147. [PMID: 30248895 PMCID: PMC6210396 DOI: 10.3390/cells7100147] [Citation(s) in RCA: 157] [Impact Index Per Article: 26.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2018] [Revised: 09/16/2018] [Accepted: 09/17/2018] [Indexed: 12/11/2022] Open
Abstract
Vimentin is a protein that has been linked to a large variety of pathophysiological conditions, including cataracts, Crohn's disease, rheumatoid arthritis, HIV and cancer. Vimentin has also been shown to regulate a wide spectrum of basic cellular functions. In cells, vimentin assembles into a network of filaments that spans the cytoplasm. It can also be found in smaller, non-filamentous forms that can localise both within cells and within the extracellular microenvironment. The vimentin structure can be altered by subunit exchange, cleavage into different sizes, re-annealing, post-translational modifications and interacting proteins. Together with the observation that different domains of vimentin might have evolved under different selection pressures that defined distinct biological functions for different parts of the protein, the many diverse variants of vimentin might be the cause of its functional diversity. A number of review articles have focussed on the biology and medical aspects of intermediate filament proteins without particular commitment to vimentin, and other reviews have focussed on intermediate filaments in an in vitro context. In contrast, the present review focusses almost exclusively on vimentin, and covers both ex vivo and in vivo data from tissue culture and from living organisms, including a summary of the many phenotypes of vimentin knockout animals. Our aim is to provide a comprehensive overview of the current understanding of the many diverse aspects of vimentin, from biochemical, mechanical, cellular, systems biology and medical perspectives.
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Affiliation(s)
- Frida Danielsson
- Science for Life Laboratory, Royal Institute of Technology, 17165 Stockholm, Sweden.
| | | | | | - Franziska Lautenschläger
- Campus D2 2, Leibniz-Institut für Neue Materialien gGmbH (INM) and Experimental Physics, NT Faculty, E 2 6, Saarland University, 66123 Saarbrücken, Germany.
| | - Annica Karin Britt Gad
- Centro de Química da Madeira, Universidade da Madeira, 9020105 Funchal, Portugal.
- Department of Medical Biochemistry and Microbiology, Uppsala University, 75237 Uppsala, Sweden.
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6
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Tarbet HJ, Dolat L, Smith TJ, Condon BM, O'Brien ET, Valdivia RH, Boyce M. Site-specific glycosylation regulates the form and function of the intermediate filament cytoskeleton. eLife 2018. [PMID: 29513221 PMCID: PMC5841932 DOI: 10.7554/elife.31807] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Intermediate filaments (IF) are a major component of the metazoan cytoskeleton and are essential for normal cell morphology, motility, and signal transduction. Dysregulation of IFs causes a wide range of human diseases, including skin disorders, cardiomyopathies, lipodystrophy, and neuropathy. Despite this pathophysiological significance, how cells regulate IF structure, dynamics, and function remains poorly understood. Here, we show that site-specific modification of the prototypical IF protein vimentin with O-linked β-N-acetylglucosamine (O-GlcNAc) mediates its homotypic protein-protein interactions and is required in human cells for IF morphology and cell migration. In addition, we show that the intracellular pathogen Chlamydia trachomatis, which remodels the host IF cytoskeleton during infection, requires specific vimentin glycosylation sites and O-GlcNAc transferase activity to maintain its replicative niche. Our results provide new insight into the biochemical and cell biological functions of vimentin O-GlcNAcylation, and may have broad implications for our understanding of the regulation of IF proteins in general. Like the body's skeleton, the cytoskeleton gives shape and structure to the inside of a cell. Yet, unlike a skeleton, the cytoskeleton is ever changing. The cytoskeleton consists of many fibers each made from chains of protein molecules. One of these proteins is called vimentin and it forms intermediate filaments in the cytoskeleton. Many different types of cells contain vimentin and a lot of it is found in cancer cells that have spread beyond their original location to other sites in the body. Cells use chemical modifications to regulate cytoskeleton proteins. For example, through a process called glycosylation, cells can reversibly attach a sugar modification called O-GlcNAc to vimentin. O-GlcNAc can be attached to several different parts of vimentin and each location may have a different effect. It is not currently clear how cells control their vimentin filaments or what role O-GlcNAc plays in this process. Using genetic engineering, Tarbet et al. produced human cells in the laboratory with modified vimentin proteins. These altered proteins lacked some of the sites for O-GlcNAc attachment. The goal was to see whether the loss of O-GlcNAc at a specific location would affect fiber formation and cell behavior. The results showed one site where vimentin needs O-GlcNAc to form fibers. Without O-GlcNAc at this site, cells could not migrate towards chemical signals. In addition, in normal human cells, Chlamydia bacteria hijack vimentin and rearrange the filaments to form a cage around themselves for protection. However, the cells lacking O-GlcNAc on vimentin were resistant to infection by Chlamydia bacteria. These findings highlight the importance of O-GlcNAc on vimentin in healthy cells and during infection. Vimentin’s contribution to cell migration may also help to explain its role in the spread of cancer. The importance of O-GlcNAc suggests it could be a new target for therapies. Yet, it also highlights the need for caution due to the delicate balance between the activity of vimentin in healthy and diseased cells. In addition, human cells produce about 70 other vimentin-like proteins and further work will examine if they are also affected by O-GlcNAc.
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Affiliation(s)
- Heather J Tarbet
- Department of Biochemistry, Duke University School of Medicine, Durham, United States
| | - Lee Dolat
- Department of Molecular Genetics and Microbiology, Duke University School of Medicine, Durham, United States.,Center for Host-Microbial Interactions, Duke University School of Medicine, Durham, United States
| | - Timothy J Smith
- Department of Biochemistry, Duke University School of Medicine, Durham, United States
| | - Brett M Condon
- Department of Biochemistry, Duke University School of Medicine, Durham, United States
| | - E Timothy O'Brien
- Department of Biochemistry, Duke University School of Medicine, Durham, United States.,Department of Physics and Astronomy, University of North Carolina, Chapel Hill, United States
| | - Raphael H Valdivia
- Department of Molecular Genetics and Microbiology, Duke University School of Medicine, Durham, United States.,Center for Host-Microbial Interactions, Duke University School of Medicine, Durham, United States
| | - Michael Boyce
- Department of Biochemistry, Duke University School of Medicine, Durham, United States.,Center for Host-Microbial Interactions, Duke University School of Medicine, Durham, United States
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7
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Duran CL, Howell DW, Dave JM, Smith RL, Torrie ME, Essner JJ, Bayless KJ. Molecular Regulation of Sprouting Angiogenesis. Compr Physiol 2017; 8:153-235. [PMID: 29357127 DOI: 10.1002/cphy.c160048] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The term angiogenesis arose in the 18th century. Several studies over the next 100 years laid the groundwork for initial studies performed by the Folkman laboratory, which were at first met with some opposition. Once overcome, the angiogenesis field has flourished due to studies on tumor angiogenesis and various developmental models that can be genetically manipulated, including mice and zebrafish. In addition, new discoveries have been aided by the ability to isolate primary endothelial cells, which has allowed dissection of various steps within angiogenesis. This review will summarize the molecular events that control angiogenesis downstream of biochemical factors such as growth factors, cytokines, chemokines, hypoxia-inducible factors (HIFs), and lipids. These and other stimuli have been linked to regulation of junctional molecules and cell surface receptors. In addition, the contribution of cytoskeletal elements and regulatory proteins has revealed an intricate role for mobilization of actin, microtubules, and intermediate filaments in response to cues that activate the endothelium. Activating stimuli also affect various focal adhesion proteins, scaffold proteins, intracellular kinases, and second messengers. Finally, metalloproteinases, which facilitate matrix degradation and the formation of new blood vessels, are discussed, along with our knowledge of crosstalk between the various subclasses of these molecules throughout the text. Compr Physiol 8:153-235, 2018.
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Affiliation(s)
- Camille L Duran
- Department of Molecular and Cellular Medicine, Texas A&M Health Science Center, College Station, Texas, USA
| | - David W Howell
- Department of Molecular and Cellular Medicine, Texas A&M Health Science Center, College Station, Texas, USA
| | - Jui M Dave
- Department of Molecular and Cellular Medicine, Texas A&M Health Science Center, College Station, Texas, USA
| | - Rebecca L Smith
- Department of Molecular and Cellular Medicine, Texas A&M Health Science Center, College Station, Texas, USA
| | - Melanie E Torrie
- Department of Genetics, Development and Cell Biology, Iowa State University, Ames, Iowa, USA
| | - Jeffrey J Essner
- Department of Genetics, Development and Cell Biology, Iowa State University, Ames, Iowa, USA
| | - Kayla J Bayless
- Department of Molecular and Cellular Medicine, Texas A&M Health Science Center, College Station, Texas, USA
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8
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A vimentin binding small molecule leads to mitotic disruption in mesenchymal cancers. Proc Natl Acad Sci U S A 2017; 114:E9903-E9912. [PMID: 29087350 DOI: 10.1073/pnas.1716009114] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Expression of the transcription factor FOXC2 is induced and necessary for successful epithelial-mesenchymal transition, a developmental program that when activated in cancer endows cells with metastatic potential and the properties of stem cells. As such, identifying agents that inhibit the growth of FOXC2-transformed cells represents an attractive approach to inhibit chemotherapy resistance and metastatic dissemination. From a high throughput synthetic lethal screen, we identified a small molecule, FiVe1, which selectively and irreversibly inhibits the growth of mesenchymally transformed breast cancer cells and soft tissue sarcomas of diverse histological subtypes. FiVe1 targets the intermediate filament and mesenchymal marker vimentin (VIM) in a mode which promotes VIM disorganization and phosphorylation during metaphase, ultimately leading to mitotic catastrophe, multinucleation, and the loss of stemness. These findings illustrate a previously undescribed mechanism for interrupting faithful mitotic progression and may ultimately inform the design of therapies for a broad range of mesenchymal cancers.
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9
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Robert A, Hookway C, Gelfand VI. Intermediate filament dynamics: What we can see now and why it matters. Bioessays 2016; 38:232-43. [PMID: 26763143 DOI: 10.1002/bies.201500142] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The mechanical properties of vertebrate cells are largely defined by the system of intermediate filaments (IF). As part of a dense network, IF polymers are constantly rearranged and relocalized in the cell to fulfill their duty as cells change shape, migrate, or divide. With the development of new imaging technologies, such as photoconvertible proteins and super-resolution microscopy, a new appreciation for the complexity of IF dynamics has emerged. This review highlights new findings about the transport of IF, the remodeling of filaments by a process of severing and re-annealing, and the subunit exchange that occurs between filament precursors and a soluble pool of IF. We will also discuss the unique dynamic features of the keratin IF network. Finally, we will speculate about how the dynamic properties of IF are related to their functions.
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Affiliation(s)
- Amélie Robert
- Department of Cell and Molecular Biology, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA
| | - Caroline Hookway
- Department of Cell and Molecular Biology, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA
| | - Vladimir I Gelfand
- Department of Cell and Molecular Biology, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA
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10
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Ridge KM, Shumaker D, Robert A, Hookway C, Gelfand VI, Janmey PA, Lowery J, Guo M, Weitz DA, Kuczmarski E, Goldman RD. Methods for Determining the Cellular Functions of Vimentin Intermediate Filaments. Methods Enzymol 2015; 568:389-426. [PMID: 26795478 DOI: 10.1016/bs.mie.2015.09.036] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The type III intermediate filament protein vimentin was once thought to function mainly as a static structural protein in the cytoskeleton of cells of mesenchymal origin. Now, however, vimentin is known to form a dynamic, flexible network that plays an important role in a number of signaling pathways. Here, we describe various methods that have been developed to investigate the cellular functions of the vimentin protein and intermediate filament network, including chemical disruption, photoactivation and photoconversion, biolayer interferometry, soluble bead binding assay, three-dimensional substrate experiments, collagen gel contraction, optical-tweezer active microrheology, and force spectrum microscopy. Using these techniques, the contributions of vimentin to essential cellular processes can be probed in ever further detail.
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Affiliation(s)
- Karen M Ridge
- Division of Pulmonary and Critical Care Medicine, Chicago, Illinois, USA; Department of Cell and Molecular Biology, Northwestern University, Feinberg School of Medicine, Chicago, Illinois, USA; Veterans Administration, Chicago, Illinois, USA.
| | - Dale Shumaker
- Division of Pulmonary and Critical Care Medicine, Chicago, Illinois, USA; Department of Cell and Molecular Biology, Northwestern University, Feinberg School of Medicine, Chicago, Illinois, USA
| | - Amélie Robert
- Department of Cell and Molecular Biology, Northwestern University, Feinberg School of Medicine, Chicago, Illinois, USA
| | - Caroline Hookway
- Department of Cell and Molecular Biology, Northwestern University, Feinberg School of Medicine, Chicago, Illinois, USA
| | - Vladimir I Gelfand
- Department of Cell and Molecular Biology, Northwestern University, Feinberg School of Medicine, Chicago, Illinois, USA
| | - Paul A Janmey
- Institute for Medicine and Engineering, University of Pennsylvania, Philadelphia, Pennsylvania, USA; Departments of Physiology and Physics & Astronomy, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Jason Lowery
- Division of Pulmonary and Critical Care Medicine, Chicago, Illinois, USA
| | - Ming Guo
- School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts, USA
| | - David A Weitz
- School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts, USA; Department of Physics, Harvard University, Cambridge, Massachusetts, USA
| | - Edward Kuczmarski
- Department of Cell and Molecular Biology, Northwestern University, Feinberg School of Medicine, Chicago, Illinois, USA
| | - Robert D Goldman
- Division of Pulmonary and Critical Care Medicine, Chicago, Illinois, USA; Department of Cell and Molecular Biology, Northwestern University, Feinberg School of Medicine, Chicago, Illinois, USA
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11
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Lowery J, Kuczmarski ER, Herrmann H, Goldman RD. Intermediate Filaments Play a Pivotal Role in Regulating Cell Architecture and Function. J Biol Chem 2015; 290:17145-53. [PMID: 25957409 DOI: 10.1074/jbc.r115.640359] [Citation(s) in RCA: 182] [Impact Index Per Article: 20.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Intermediate filaments (IFs) are composed of one or more members of a large family of cytoskeletal proteins, whose expression is cell- and tissue type-specific. Their importance in regulating the physiological properties of cells is becoming widely recognized in functions ranging from cell motility to signal transduction. IF proteins assemble into nanoscale biopolymers with unique strain-hardening properties that are related to their roles in regulating the mechanical integrity of cells. Furthermore, mutations in the genes encoding IF proteins cause a wide range of human diseases. Due to the number of different types of IF proteins, we have limited this short review to cover structure and function topics mainly related to the simpler homopolymeric IF networks composed of vimentin, and specifically for diseases, the related muscle-specific desmin IF networks.
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Affiliation(s)
- Jason Lowery
- From the Department of Cell and Molecular Biology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois 60611 and
| | - Edward R Kuczmarski
- From the Department of Cell and Molecular Biology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois 60611 and
| | - Harald Herrmann
- the Division of Molecular Genetics (B060), German Cancer Research Center (DKFZ), D-69120 Heidelberg, Germany
| | - Robert D Goldman
- From the Department of Cell and Molecular Biology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois 60611 and
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12
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Dave JM, Bayless KJ. Vimentin as an integral regulator of cell adhesion and endothelial sprouting. Microcirculation 2015; 21:333-44. [PMID: 24387004 DOI: 10.1111/micc.12111] [Citation(s) in RCA: 116] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2013] [Accepted: 12/30/2013] [Indexed: 12/11/2022]
Abstract
Angiogenesis is a multistep process that requires intricate changes in cell shape to generate new blood vessels. IF are a large family of proteins that play an important structural and functional role in forming and regulating the cytoskeleton. Vimentin, a major type III intermediate filament protein is expressed in endothelial and other mesenchymal cells. The structure of vimentin is conserved in mammals and shows dynamic expression profiles in various cell types and different developmental stages. Although initial studies with vimentin-deficient mice demonstrated a virtually normal phenotype, subsequent studies have revealed several defects in cell attachment, migration, signaling, neurite extension, and vascularization. Regulation of vimentin is highly complex and is driven by posttranslational modifications such as phosphorylation and cleavage by intracellular proteases. This review discusses various novel functions which are now known to be mediated by vimentin, summarizing structure, regulation and roles of vimentin in cell adhesion, migration, angiogenesis, neurite extension, and cancer. We specifically highlight a pathway involving growth factor-mediated calpain activation, vimentin cleavage, and MT1-MMP membrane translocation that is required for endothelial cell invasion in 3D environments. This pathway may also regulate the analogous processes of neurite extension and tumor cell invasion.
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Affiliation(s)
- Jui M Dave
- Department of Molecular and Cellular Medicine, Texas A&M Health Science Center, College Station, Texas, USA
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13
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The Predicted Proteomic Network Associated with the Antiarthritic Action of Qingfu Guanjieshu in Collagen-II-Induced Arthritis in Rats. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2013; 2013:582493. [PMID: 23781264 PMCID: PMC3678439 DOI: 10.1155/2013/582493] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/31/2013] [Accepted: 04/23/2013] [Indexed: 11/25/2022]
Abstract
Qingfu Guanjieshu (QFGJS) is an herbal preparation for treating rheumatoid arthritis (RA). Previous studies revealed that QFGJS significantly inhibited experimental arthritis and acute inflammation, accompanied by reduction of proinflammatory cytokines and elevation of anti-inflammatory cytokines. This study aims to identify the targeted proteins and predict the proteomic network associated with the drug action of QFGJS by using 2D gel and MALDI-TOF-MS/MS techniques. Thirty female Wistar rats were evenly grouped as normal and vehicle- and QFGJS-treated CIA rats. The antiarthritic effect of QFGJS was examined with a 19-day treatment course, and the knee synovial tissues of animals from each group were obtained for 2D gel and MALDI-TOF-MS/MS analysis. Results showed that QFGJS significantly ameliorated collagen II-induced arthritis when administrated at 2.8 g/kg body weight for 19 days. 2D gel image analysis revealed 89 differentially expressed proteins in the synovial tissues among the normal and vehicle- and QFGJS-treated CIA rats from over 1000 proteins of which 63 proteins were identified by MALDI-TOF-MS/MS analysis, and 32 proteins were included for classification of functions using Gene Ontology (GO) method. Finally, 14 proteins were analyzed using bioinformatics, and a predicted proteomic network related to the anti-arthritic effect of QFGJS was established, and Pgk1 plays a central role.
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14
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The dermatan sulfate proteoglycan decorin modulates α2β1 integrin and the vimentin intermediate filament system during collagen synthesis. PLoS One 2012; 7:e50809. [PMID: 23226541 PMCID: PMC3513320 DOI: 10.1371/journal.pone.0050809] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2012] [Accepted: 10/25/2012] [Indexed: 11/23/2022] Open
Abstract
Decorin, a small leucine-rich proteoglycan harboring a dermatan sulfate chain at its N-terminus, is involved in regulating matrix organization and cell signaling. Loss of the dermatan sulfate of decorin leads to an Ehlers-Danlos syndrome characterized by delayed wound healing. Decorin-null (Dcn−/−) mice display a phenotype similar to that of EDS patients. The fibrillar collagen phenotype of Dcn−/− mice could be rescued in vitro by decorin but not with decorin lacking the glycosaminoglycan chain. We utilized a 3D cell culture model to investigate the impact of the altered extracellular matrix on Dcn−/− fibroblasts. Using 2D gel electrophoresis followed by mass spectrometry, we identified vimentin as one of the proteins that was differentially upregulated by the presence of decorin. We discovered that a decorin-deficient matrix leads to abnormal nuclear morphology in the Dcn−/− fibroblasts. This phenotype could be rescued by the decorin proteoglycan but less efficiently by the decorin protein core. Decorin treatment led to a significant reduction of the α2β1 integrin at day 6 in Dcn−/− fibroblasts, whereas the protein core had no effect on β1. Interestingly, only the decorin core induced mRNA synthesis, phosphorylation and de novo synthesis of vimentin indicating that the proteoglycan decorin in the extracellular matrix stabilizes the vimentin intermediate filament system. We could support these results in vivo, because the dermis of wild-type mice have more vimentin and less β1 integrin compared to Dcn−/−. Furthermore, the α2β1 null fibroblasts also showed a reduced amount of vimentin compared to wild-type. These data show for the first time that decorin has an impact on the biology of α2β1 integrin and the vimentin intermediate filament system. Moreover, our findings provide a mechanistic explanation for the reported defects in wound healing associated with the Dcn−/− phenotype.
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15
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Herpesviruses and intermediate filaments: close encounters with the third type. Viruses 2011; 3:1015-40. [PMID: 21994768 PMCID: PMC3185793 DOI: 10.3390/v3071015] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2011] [Revised: 06/07/2011] [Accepted: 06/24/2011] [Indexed: 01/29/2023] Open
Abstract
Intermediate filaments (IF) are essential to maintain cellular and nuclear integrity and shape, to manage organelle distribution and motility, to control the trafficking and pH of intracellular vesicles, to prevent stress-induced cell death, and to support the correct distribution of specific proteins. Because of this, IF are likely to be targeted by a variety of pathogens, and may act in favor or against infection progress. As many IF functions remain to be identified, however, little is currently known about these interactions. Herpesviruses can infect a wide variety of cell types, and are thus bound to encounter the different types of IF expressed in each tissue. The analysis of these interrelationships can yield precious insights into how IF proteins work, and into how viruses have evolved to exploit these functions. These interactions, either known or potential, will be the focus of this review.
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Thaiparambil JT, Bender L, Ganesh T, Kline E, Patel P, Liu Y, Tighiouart M, Vertino PM, Harvey RD, Garcia A, Marcus AI. Withaferin A inhibits breast cancer invasion and metastasis at sub-cytotoxic doses by inducing vimentin disassembly and serine 56 phosphorylation. Int J Cancer 2011; 129:2744-55. [PMID: 21538350 DOI: 10.1002/ijc.25938] [Citation(s) in RCA: 184] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2010] [Accepted: 12/22/2010] [Indexed: 11/11/2022]
Abstract
Withaferin A (WFA) is purified from the plant Withania somnifera and inhibits the vimentin cytoskeleton. Vimentin overexpression in cancer correlates with metastatic disease, induction of epithelial to mesenchymal transition and reduced patient survival. As vimentin functions in cell motility, we wanted to test the hypothesis that WFA inhibits cancer metastasis by disrupting vimentin function. These data showed that WFA had weak cytotoxic and apoptotic activity at concentrations less than or equal to 500 nM, but retained potent anti-invasive activity at these low doses. Imaging of breast cancer cell lines revealed that WFA induces perinuclear vimentin accumulation followed by rapid vimentin depolymerization. A concomitant induction of vimentin ser56 phosphorylation was observed, which is consistent with vimentin disassembly. Structure activity relationships were established using a set of chemically modified WFA analogs and showed that the predicted vimentin-binding region of WFA is necessary to induce vimentin ser56 phosphorylation and for its anti-invasive activity. Pharmacokinetic studies in mice revealed that WFA reaches peak concentrations up to 2 μM in plasma with a half-life of 1.36 hr following a single 4 mg/kg dose. In a breast cancer metastasis mouse model, WFA showed dose-dependent inhibition of metastatic lung nodules and induced vimentin ser56 phosphorylation, with minimal toxicity to lung tissue. Based upon these studies, we conclude that WFA is a potent breast cancer anti-metastatic agent and the anti-metastatic activity of WFA is, at least in part, mediated through its effects on vimentin and vimentin ser56 phosphorylation.
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Lee S, Sunil N, Tejada JM, Shea TB. Differential roles of kinesin and dynein in translocation of neurofilaments into axonal neurites. J Cell Sci 2011; 124:1022-31. [PMID: 21363889 DOI: 10.1242/jcs.079046] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Neurofilament (NF) subunits translocate within axons as short NFs, non-filamentous punctate structures ('puncta') and diffuse material that might comprise individual subunits and/or oligomers. Transport of NFs into and along axons is mediated by the microtubule (MT) motor proteins kinesin and dynein. Despite being characterized as a retrograde motor, dynein nevertheless participates in anterograde NF transport through associating with long MTs or the actin cortex through its cargo domain; relatively shorter MTs associated with the motor domain are then propelled in an anterograde direction, along with any linked NFs. Here, we show that inhibition of dynein function, through dynamitin overexpression or intracellular delivery of anti-dynein antibody, selectively reduced delivery of GFP-tagged short NFs into the axonal hillock, with a corresponding increase in the delivery of puncta, suggesting that dynein selectively delivered short NFs into axonal neurites. Nocodazole-mediated depletion of short MTs had the same effect. By contrast, intracellular delivery of anti-kinesin antibody inhibited anterograde transport of short NFs and puncta to an equal extent. These findings suggest that anterograde axonal transport of linear NFs is more dependent upon association with translocating MTs (which are themselves translocated by dynein) than is transport of NF puncta or oligomers.
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Affiliation(s)
- Sangmook Lee
- Center for Cellular Neurobiology and Neurodegeneration Research, Department of Biological Sciences, University of Massachusetts, One University Avenue, Lowell, MA 01854, USA
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18
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Zhou K, Hanna-Rose W. Movers and shakers or anchored: Caenorhabditis elegans nuclei achieve it with KASH/SUN. Dev Dyn 2010; 239:1352-64. [PMID: 20108325 DOI: 10.1002/dvdy.22226] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
The invariant cell division patterns that characterize Caenorhabditis elegans development make it an ideal system to study the mechanisms that control nuclear movement and positioning. Forward genetic screens in this system allowed identification of the key molecular machinery for connecting the nucleus to the cytoskeleton; pairs of protein partners, consisting of a KASH domain protein and a SUN domain protein, bridge the nuclear envelope to connect the nucleus to cytoskeletal components. The C. elegans genome encodes several KASH/SUN pairs, and mutant phenotypes as well as tissue-specific expression patterns suggest a diversity of functions. These functions include moving the nucleus but have been extended to effects on the chromosomes inside the nucleus as well. We review the impact of the C. elegans system in pioneering this field as well as the functions of these KASH/SUN protein pairs across spatial and temporal C. elegans development.
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Affiliation(s)
- Kang Zhou
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania 16802, USA
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19
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Kölsch A, Windoffer R, Leube RE. Actin-dependent dynamics of keratin filament precursors. ACTA ACUST UNITED AC 2009; 66:976-85. [DOI: 10.1002/cm.20395] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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20
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Uchida A, Alami NH, Brown A. Tight functional coupling of kinesin-1A and dynein motors in the bidirectional transport of neurofilaments. Mol Biol Cell 2009; 20:4997-5006. [PMID: 19812246 DOI: 10.1091/mbc.e09-04-0304] [Citation(s) in RCA: 109] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
We have tested the hypothesis that kinesin-1A (formerly KIF5A) is an anterograde motor for axonal neurofilaments. In cultured sympathetic neurons from kinesin-1A knockout mice, we observed a 75% reduction in the frequency of both anterograde and retrograde neurofilament movement. This transport defect could be rescued by kinesin-1A, and with successively decreasing efficacy by kinesin-1B and kinesin-1C. In wild-type neurons, headless mutants of kinesin-1A and kinesin-1C inhibited both anterograde and retrograde movement in a dominant-negative manner. Because dynein is thought to be the retrograde motor for axonal neurofilaments, we investigated the effect of dynein inhibition on anterograde and retrograde neurofilament transport. Disruption of dynein function by using RNA interference, dominant-negative approaches, or a function-blocking antibody also inhibited both anterograde and retrograde neurofilament movement. These data suggest that kinesin-1A is the principal but not exclusive anterograde motor for neurofilaments in these neurons, that there may be some functional redundancy among the kinesin-1 isoforms with respect to neurofilament transport, and that the activities of the anterograde and retrograde neurofilament motors are tightly coordinated.
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Affiliation(s)
- Atsuko Uchida
- Center for Molecular Neurobiology and Department of Neuroscience, The Ohio State University, Columbus, OH 43210, USA
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21
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Phua DC, Humbert PO, Hunziker W. Vimentin regulates scribble activity by protecting it from proteasomal degradation. Mol Biol Cell 2009; 20:2841-55. [PMID: 19386766 PMCID: PMC2695792 DOI: 10.1091/mbc.e08-02-0199] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2008] [Revised: 03/17/2009] [Accepted: 04/13/2009] [Indexed: 02/07/2023] Open
Abstract
Scribble (Scrib), Discs large, and Lethal giant larvae form a protein complex that regulates different aspects of cell polarization, including apical-basal asymmetry in epithelial cells and anterior-posterior polarity in migrating cells. Here, we show that Scrib interacts with the intermediate filament cytoskeleton in epithelial Madin-Darby canine kidney (MDCK) cells and endothelial human umbilical vein endothelial cells. Scrib binds vimentin via its postsynaptic density 95/disc-large/zona occludens domains and in MDCK cells redistributes from filaments to the plasma membrane during the establishment of cell-cell contacts. RNA interference-mediated silencing of Scrib, vimentin, or both in MDCK cells results in defects in the polarization of the Golgi apparatus during cell migration. Concomitantly, wound healing is delayed due to the loss of directional movement. Furthermore, cell aggregation is dependent on both Scrib and vimentin. The similar phenotypes observed after silencing either Scrib or vimentin support a coordinated role for the two proteins in cell migration and aggregation. Interestingly, silencing of vimentin leads to an increased proteasomal degradation of Scrib. Thus, the upregulation of vimentin expression during epithelial to mesenchymal transitions may stabilize Scrib to promote directed cell migration.
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Affiliation(s)
- Dominic C.Y. Phua
- *Epithelial Cell Biology Laboratory, Cancer and Developmental Cell Biology Division, Institute of Molecular and Cell Biology, Agency for Science, Technology and Research, Singapore 138673, Republic of Singapore; and
| | - Patrick O. Humbert
- Cell Cycle and Cancer Genetics Laboratory, Peter MacCallum Cancer Centre, Melbourne 8006, Victoria, Australia
| | - Walter Hunziker
- *Epithelial Cell Biology Laboratory, Cancer and Developmental Cell Biology Division, Institute of Molecular and Cell Biology, Agency for Science, Technology and Research, Singapore 138673, Republic of Singapore; and
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22
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Khismatullin DB. Chapter 3 The Cytoskeleton and Deformability of White Blood Cells. CURRENT TOPICS IN MEMBRANES 2009. [DOI: 10.1016/s1063-5823(09)64003-5] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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Pittenger JT, Hess JF, Budamagunta MS, Voss JC, FitzGerald PG. Identification of phosphorylation-induced changes in vimentin intermediate filaments by site-directed spin labeling and electron paramagnetic resonance. Biochemistry 2008; 47:10863-70. [PMID: 18803396 PMCID: PMC2656440 DOI: 10.1021/bi801137m] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Phosphorylation drives the disassembly of the vimentin intermediate filament (IF) cytoskeleton at mitosis. Chromatographic analysis has suggested that phosphorylation produces a soluble vimentin tetramer, but little has been determined about the structural changes that are caused by phosphorylation or the structure of the resulting tetramer. In this study, site-directed spin labeling and electron paramagnetic resonance (SDSL-EPR) were used to examine the structural changes resulting from protein kinase A phosphorylation of vimentin IFs in vitro. EPR spectra suggest that the tetrameric species resulting from phosphorylation is the A11 configuration. EPR spectra also establish that the greatest degree of structural change was found in the linker 2 and the C-terminal half of the rod domain, despite the fact that most phosphorylation occurs in the N-terminal head domain. The phosphorylation-induced changes notably affected the proposed "trigger sequences" located in the linker 2 region, which have been hypothesized to mediate the induction of coiled-coil formation. These data are the first to document specific changes in IF structure resulting from a physiologic regulatory mechanism and provide further evidence, also generated by SDSL-EPR, that the linker regions play a key role in IF structure and regulation of assembly/disassembly.
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Affiliation(s)
- Josh T. Pittenger
- Department of Cell Biology and Human Anatomy, School of Medicine, University of California, Davis, CA 95616
| | - John F. Hess
- Department of Cell Biology and Human Anatomy, School of Medicine, University of California, Davis, CA 95616
| | - Madhu S. Budamagunta
- Department of Biochemistry and Molecular Medicine, School of Medicine, University of California, Davis, CA 95616
| | - John C. Voss
- Department of Biochemistry and Molecular Medicine, School of Medicine, University of California, Davis, CA 95616
| | - Paul G. FitzGerald
- Department of Cell Biology and Human Anatomy, School of Medicine, University of California, Davis, CA 95616
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Tilleman K, Van Steendam K, Cantaert T, De Keyser F, Elewaut D, Deforce D. Synovial detection and autoantibody reactivity of processed citrullinated isoforms of vimentin in inflammatory arthritides. Rheumatology (Oxford) 2008; 47:597-604. [DOI: 10.1093/rheumatology/ken077] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
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25
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Intermediate filament assembly: dynamics to disease. Trends Cell Biol 2008; 18:28-37. [PMID: 18083519 DOI: 10.1016/j.tcb.2007.11.004] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2007] [Revised: 10/31/2007] [Accepted: 11/01/2007] [Indexed: 11/21/2022]
Abstract
Intermediate filament (IF) proteins belong to a large and diverse gene family with broad representation in vertebrate tissues. Although considered the 'toughest' cytoskeletal fibers, studies in cultured cells have revealed that IF can be surprisingly dynamic and highly regulated. This review examines the diversity of IF assembly behaviors, and considers the ideas that IF proteins are co- or post-translationally assembled into oligomeric precursors, which can be delivered to different subcellular compartments by microtubules or actomyosin and associated motor proteins. Their interaction with other cellular elements via IF associated proteins (IFAPs) affects IF dynamics and also results in cellular networks with properties that transcend those of individual components. We end by discussing how mutations leading to defects in IF assembly, network formation or IF-IFAP association compromise in vivo functions of IF as protectors against environmental stress.
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26
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Mignot C, Delarasse C, Escaich S, Della Gaspera B, Noé E, Colucci-Guyon E, Babinet C, Pekny M, Vicart P, Boespflug-Tanguy O, Dautigny A, Rodriguez D, Pham-Dinh D. Dynamics of mutated GFAP aggregates revealed by real-time imaging of an astrocyte model of Alexander disease. Exp Cell Res 2007; 313:2766-79. [PMID: 17604020 DOI: 10.1016/j.yexcr.2007.04.035] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2006] [Revised: 04/27/2007] [Accepted: 04/27/2007] [Indexed: 01/23/2023]
Abstract
Alexander disease (AxD) is a rare neurodegenerative disorder characterized by large cytoplasmic aggregates in astrocytes and myelin abnormalities and caused by dominant mutations in the gene encoding glial fibrillary acidic protein (GFAP), the main intermediate filament protein in astrocytes. We tested the effects of three mutations (R236H, R76H and L232P) associated with AxD in cells transiently expressing mutated GFAP fused to green fluorescent protein (GFP). Mutated GFAP-GFP expressed in astrocytes formed networks or aggregates similar to those found in the brains of patients with the disease. Time-lapse recordings of living astrocytes showed that aggregates of mutated GFAP-GFP may either disappear, associated with cell survival, or coalesce in a huge juxtanuclear structure associated with cell death. Immunolabeling of fixed cells suggested that this gathering of aggregates forms an aggresome-like structure. Proteasome inhibition and immunoprecipitation assays revealed mutated GFAP-GFP ubiquitination, suggesting a role of the ubiquitin-proteasome system in the disaggregation process. In astrocytes from wild-type-, GFAP-, and vimentin-deficient mice, mutated GFAP-GFP aggregated or formed a network, depending on qualitative and quantitative interactions with normal intermediate filament partners. Particularly, vimentin displayed an anti-aggregation effect on mutated GFAP. Our data indicate a dynamic and reversible aggregation of mutated GFAP, suggesting that therapeutic approaches may be possible.
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27
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Norlén L. Stratum corneum keratin structure, function and formation - a comprehensive review. Int J Cosmet Sci 2006; 28:397-425. [DOI: 10.1111/j.1467-2494.2006.00345.x] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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28
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Chan WKH, Yabe JT, Pimenta AF, Ortiz D, Shea TB. Neurofilaments can undergo axonal transport and cytoskeletal incorporation in a discontinuous manner. ACTA ACUST UNITED AC 2006; 62:166-79. [PMID: 16211584 DOI: 10.1002/cm.20089] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Neurofilaments (NFs) are thought to provide structural support for axons. Some NFs exhibit an extended residence time along axons, the nature of which remains unclear. In prior studies in NB2a/d1 cells, hypophosphorylated NFs were demonstrated to be dispersed throughout the axon and to undergo relatively rapid axonal transport, while extensively phosphorylated NFs organized into a "bundle" localized along the center of the axon. It was not conclusively determined whether bundled NFs underwent transport or instead underwent turnover via exchange with transporting individual NFs. Herein, using transfection with multiple constructs and regional photobleaching, we demonstrate that bundled NFs undergo relatively slow transport as well as exchange with surrounding individual NFs. We also demonstrate that newly synthesized NFs disperse nonhomogenously throughout axonal neurites and perikarya. These findings provide a mechanism by which some NFs exhibit extended residence time within axons, which lessens the metabolic burden of cytoskeletal turnover.
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Affiliation(s)
- Walter K-H Chan
- Center for Cellular Neurobiology and Neurodegeneration Research, Department of Biological Sciences, University of Massachusetts-Lowell, One University Avenue Lowell, Massachusetts 01854, USA
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29
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Ivaska J, Vuoriluoto K, Huovinen T, Izawa I, Inagaki M, Parker PJ. PKCepsilon-mediated phosphorylation of vimentin controls integrin recycling and motility. EMBO J 2005; 24:3834-45. [PMID: 16270034 PMCID: PMC1283946 DOI: 10.1038/sj.emboj.7600847] [Citation(s) in RCA: 202] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2005] [Accepted: 09/28/2005] [Indexed: 11/09/2022] Open
Abstract
PKCepsilon controls the transport of endocytosed beta1-integrins to the plasma membrane regulating directional cell motility. Vimentin, an intermediate filament protein upregulated upon epithelial cell transformation, is shown here to be a proximal PKCepsilon target within the recycling integrin compartment. On inhibition of PKC and vimentin phosphorylation, integrins become trapped in vesicles and directional cell motility towards matrix is severely attenuated. In vitro reconstitution assays showed that PKCepsilon dissociates from integrin containing endocytic vesicles in a selectively phosphorylated vimentin containing complex. Mutagenesis of PKC (controlled) sites on vimentin and ectopic expression of the variant leads to the accumulation of intracellular PKCepsilon/integrin positive vesicles. Finally, introduction of ectopic wild-type vimentin is shown to promote cell motility in a PKCepsilon-dependent manner; alanine substitutions in PKC (controlled) sites on vimentin abolishes the ability of vimentin to induce cell migration, whereas the substitution of these sites with acidic residues enables vimentin to rescue motility of PKCepsilon null cells. Our results indicate that PKC-mediated phosphorylation of vimentin is a key process in integrin traffic through the cell.
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Affiliation(s)
- Johanna Ivaska
- VTT Technical Research Centre for Finland, Medical Biotechnology and University of Turku Centre for Biotechnology, Turku, Finland
| | - Karoliina Vuoriluoto
- VTT Technical Research Centre for Finland, Medical Biotechnology and University of Turku Centre for Biotechnology, Turku, Finland
| | - Tuomas Huovinen
- VTT Technical Research Centre for Finland, Medical Biotechnology and University of Turku Centre for Biotechnology, Turku, Finland
| | - Ichiro Izawa
- Division of Biochemistry, Aichi Cancer Center Research Institute, Chikusa-ku, Nagoya, Aichi, Japan
| | - Masaki Inagaki
- Division of Biochemistry, Aichi Cancer Center Research Institute, Chikusa-ku, Nagoya, Aichi, Japan
| | - Peter J Parker
- Protein Phosphorylation Laboratory, London Research Institute, London, UK
- Protein Phosphorylation Laboratory, London Research Institute, 44 Lincoln's Inn Fields, London WC2A 3PX, UK. Tel.:+44 20 7269 3513; Fax: +44 20 7269 3094; E-mail:
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Kanaya H, Takeya R, Takeuchi K, Watanabe N, Jing N, Sumimoto H. Fhos2, a novel formin-related actin-organizing protein, probably associates with the nestin intermediate filament. Genes Cells 2005; 10:665-78. [PMID: 15966898 DOI: 10.1111/j.1365-2443.2005.00867.x] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Fhos1 is a mammalian formin-family protein, and functions as an organizer of the actin microfilament. Here we have cloned human and mouse cDNAs for a novel Fhos homolog, designated Fhos2. The messages for Fhos2 are expressed in the heart, kidney, and brain, where the Fhos1 mRNAs are not abundant. Two splice variants of Fhos2 exist in a tissue-specific manner; the longer variant Fhos2L is the major form in the heart, whereas the kidney and brain predominantly express Fhos2S that encodes a shorter protein. Over-expression of an active form of the two Fhos2 variants, as well as that of Fhos1, induces the formation of actin stress fibers in HeLa cells, suggesting that Fhos2 acts as an actin-organizing protein. Biochemical analysis using rat cardiomyoblastic H9c2 (2-1) cells reveals that endogenous Fhos2 is enriched in the intermediate filament fraction. Consistent with this, Fhos2 localizes to the nestin intermediate filament but not to other cytoskeletons, as demonstrated by staining of H9c2 (2-1) cells with anti-Fhos2 antibodies. Furthermore, Fhos2 is present in nestin-expressing neuroepithelial cells of the fetal rat brain. Thus, Fhos2 not only has the actin-organizing activity but also associates with nestin, which may imply a Fhos2-mediated link between the nestin intermediate filament and actin microfilament.
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Affiliation(s)
- Hideki Kanaya
- Medical Institute of Bioregulation, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan
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31
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Wöll S, Windoffer R, Leube RE. Dissection of keratin dynamics: different contributions of the actin and microtubule systems. Eur J Cell Biol 2005; 84:311-28. [PMID: 15819410 DOI: 10.1016/j.ejcb.2004.12.004] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
It has only recently been recognized that intermediate filaments (IFs) and their assembly intermediates are highly motile cytoskeletal components with cell-type- and isotype-specific characteristics. To elucidate the cell-type-independent contribution of actin filaments and microtubules to these motile properties, fluorescent epithelial IF keratin polypeptides were introduced into non-epithelial, adrenal cortex-derived SW13 cells. Time-lapse fluorescence microscopy of stably transfected SW13 cell lines synthesizing fluorescent human keratin 8 and 18 chimeras HK8-CFP and HK18-YFP revealed extended filament networks that are entirely composed of transgene products and exhibit the same dynamic features as keratin systems in epithelial cells. Detailed analyses identified two distinct types of keratin motility: (I) Slow (approximately 0.23 microm/min), inward-directed, continuous transport of keratin filament precursor particles from the plasma membrane towards the cell interior, which is most pronounced in lamellipodia. (II) Fast (approximately 17 microm/min), bidirectional and intermittent transport of keratin particles in axonal-type cell processes. Disruption of actin filaments inhibited type I motility while type II motility remained. Conversely, microtubule disruption inhibited transport mode II while mode I continued. Combining the two treatments resulted in a complete block of keratin motility. We therefore conclude that keratin motility relies both on intact actin filaments and microtubules and is not dependent on epithelium-specific cellular factors.
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Affiliation(s)
- Stefan Wöll
- Department of Anatomy, Johannes Gutenberg University Mainz, Becherweg 13, D-55128 Mainz, Germany
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Theiss C, Napirei M, Meller K. Impairment of anterograde and retrograde neurofilament transport after anti-kinesin and anti-dynein antibody microinjection in chicken dorsal root ganglia. Eur J Cell Biol 2005; 84:29-43. [PMID: 15724814 DOI: 10.1016/j.ejcb.2004.09.001] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
The purpose of the present study was to investigate the participation of the motor proteins kinesin and dynein in axonal transport of neurofilaments (NF) in cultured dorsal root ganglia neurons. Therefore, we performed live-recording studies of the green fluorescent protein-tagged neurofilament M (GFP-NF-M) to assay transport processes in neurons. Co-localization studies revealed that GFP-NF-M was capable to build a functional NF network with other NF subunits, including phosphorylated heavy neurofilaments (NF-H-PH). Time-lapse recordings using confocal laser scanning microscopy exhibited fast transport of NF dots in anterograde and retrograde direction through a photobleached gap. Following microinjection of anti-kinesin antibodies or colchicine treatment an impairment of anterograde as well as retrograde NF transport was observed during live-recording experiments. In contrast, microinjection of anti-dynein antibodies only impaired retrograde transport of NF whereas the anterograde movement of GFP-NF-M was unaffected. Treatment of the cells with unspecific antibodies had no effect.
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Affiliation(s)
- Carsten Theiss
- Department of Cytology, Institute of Anatomy, Faculty of Medicine, Ruhr-University Bochum, Universitätsstr 150, D-44780 Bochum, Germany.
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Norlén L, Al-Amoudi A. Stratum corneum keratin structure, function, and formation: the cubic rod-packing and membrane templating model. J Invest Dermatol 2004; 123:715-32. [PMID: 15373777 DOI: 10.1111/j.0022-202x.2004.23213.x] [Citation(s) in RCA: 94] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A new model for stratum corneum keratin structure, function, and formation is presented. The structural and functional part of the model, which hereafter is referred to as "the cubic rod-packing model", postulates that stratum corneum keratin intermediate filaments are arranged according to a cubic-like rod-packing symmetry with or without the presence of an intracellular lipid membrane with cubic-like symmetry enveloping each individual filament. The new model could account for (i) the cryo-electron density pattern of the native corneocyte keratin matrix, (ii) the X-ray diffraction patterns, (iii) the swelling behavior, and (iv) the mechanical properties of mammalian stratum corneum. The morphogenetic part of the model, which hereafter is referred to as "the membrane templating model", postulates the presence in cellular space of a highly dynamic small lattice parameter (<30 nm) membrane structure with cubic-like symmetry, to which keratin is associated. It further proposes that membrane templating, rather than spontaneous self-assembly, is responsible for keratin intermediate filament formation and dynamics. The new model could account for (i) the cryo-electron density patterns of the native keratinocyte cytoplasmic space, (ii) the characteristic features of the keratin network formation process, (iii) the dynamic properties of keratin intermediate filaments, (iv) the close lipid association of keratin, (v) the insolubility in non-denaturating buffers and pronounced polymorphism of keratin assembled in vitro, and (vi) the measured reduction in cell volume and hydration level between the stratum granulosum and stratum corneum. Further, using cryo-transmission electron microscopy on native, fully hydrated, vitreous epidermis we show that the subfilametous keratin electron density pattern consists, both in corneocytes and in viable keratinocytes, of one axial subfilament surrounded by an undetermined number of peripheral subfilaments forming filaments with a diameter of approximately 8 nm.
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Affiliation(s)
- Lars Norlén
- Group of Applied Physics-Biomedical, Department of Physics, University of Geneva, Geneva, Switzerland.
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Helfand BT, Chang L, Goldman RD. Intermediate filaments are dynamic and motile elements of cellular architecture. J Cell Sci 2004; 117:133-41. [PMID: 14676269 DOI: 10.1242/jcs.00936] [Citation(s) in RCA: 196] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Recent evidence showing that intermediate filaments (IFs) are dynamic, motile elements of the cytoskeletal repertoire of vertebrate cells has overturned the long-standing view that they simply form static 'space filling' cytoplasmic networks. In fact, many types of IF are now known to engage in a remarkable array of movements that are closely associated with their assembly, disassembly and subcellular organization. Some of these motile properties are intrinsic to IFs and others are attributable to molecular crosstalk with either microtubules or actin-containing microfilaments. This crosstalk is, to a large extent, mediated by molecular motors, including conventional kinesin and cytoplasmic dynein. These motors are responsible for the high-speed delivery of nonfilamentous IF precursors and short filaments to specific regions of the cytoplasm, where they assemble into long IFs. Interestingly, the patterns and speeds of IF movements vary in different cell types and even within different regions of the same cell. These differences in motility may be related to their interactions with different types of molecular motor and/or other factors, such as IF-associated proteins.
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Affiliation(s)
- Brian T Helfand
- Feinberg School of Medicine, Northwestern University, Department of Cell and Molecular Biology, 303 E. Chicago Avenue, Chicago, IL 60611, USA
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Windoffer R, Wöll S, Strnad P, Leube RE. Identification of novel principles of keratin filament network turnover in living cells. Mol Biol Cell 2004; 15:2436-48. [PMID: 15004233 PMCID: PMC404035 DOI: 10.1091/mbc.e03-09-0707] [Citation(s) in RCA: 73] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
It is generally assumed that turnover of the keratin filament system occurs by exchange of subunits along its entire length throughout the cytoplasm. We now present evidence that a circumscribed submembranous compartment is actually the main site for network replenishment. This conclusion is based on the following observations in living cells synthesizing fluorescent keratin polypeptides: 1) Small keratin granules originate in close proximity to the plasma membrane and move toward the cell center in a continuous motion while elongating into flexible rod-like fragments that fuse with each other and integrate into the peripheral KF network. 2) Recurrence of fluorescence after photobleaching is first seen in the cell periphery where keratin filaments are born that translocate subsequently as part of the network toward the cell center. 3) Partial keratin network reformation after orthovanadate-induced disruption is restricted to a distinct peripheral zone in which either keratin granules or keratin filaments are transiently formed. These findings extend earlier investigations of mitotic cells in which de novo keratin network formation was shown to originate from the cell cortex. Taken together, our results demonstrate that the keratin filament system is not homogeneous but is organized into temporally and spatially distinct subdomains. Furthermore, the cortical localization of the regulatory cues for keratin filament turnover provides an ideal way to adjust the epithelial cytoskeleton to dynamic cellular processes.
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Affiliation(s)
- Reinhard Windoffer
- Department of Anatomy, Johannes Gutenberg University, 55128 Mainz, Germany
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Windoffer R, Leube RE. Imaging of keratin dynamics during the cell cycle and in response to phosphatase inhibition. Methods Cell Biol 2004; 78:321-52. [PMID: 15646624 DOI: 10.1016/s0091-679x(04)78012-7] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Affiliation(s)
- Reinhard Windoffer
- Department of Anatomy, Johannes Gutenberg-University, 55128 Mainz, Germany
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Affiliation(s)
- Eric W Flitney
- Department of Cell and Molecular Biology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois 60611, USA
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Werner NS, Windoffer R, Strnad P, Grund C, Leube RE, Magin TM. Epidermolysis bullosa simplex-type mutations alter the dynamics of the keratin cytoskeleton and reveal a contribution of actin to the transport of keratin subunits. Mol Biol Cell 2003; 15:990-1002. [PMID: 14668478 PMCID: PMC363056 DOI: 10.1091/mbc.e03-09-0687] [Citation(s) in RCA: 82] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Dominant keratin mutations cause epidermolysis bullosa simplex by transforming keratin (K) filaments into aggregates. As a first step toward understanding the properties of mutant keratins in vivo, we stably transfected epithelial cells with an enhanced yellow fluorescent protein-tagged K14R125C mutant. K14R125C became localized as aggregates in the cell periphery and incorporated into perinuclear keratin filaments. Unexpectedly, keratin aggregates were in dynamic equilibrium with soluble subunits at a half-life time of <15 min, whereas filaments were extremely static. Therefore, this dominant-negative mutation acts by altering cytoskeletal dynamics and solubility. Unlike previously postulated, the dominance of mutations is limited and strictly depends on the ratio of mutant to wild-type protein. In support, K14R125C-specific RNA interference experiments resulted in a rapid disintegration of aggregates and restored normal filaments. Most importantly, live cell inhibitor studies revealed that the granules are transported from the cell periphery inwards in an actin-, but not microtubule-based manner. The peripheral granule zone may define a region in which keratin precursors are incorporated into existing filaments. Collectively, our data have uncovered the transient nature of keratin aggregates in cells and offer a rationale for the treatment of epidermolysis bullosa simplex by using short interfering RNAs.
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Affiliation(s)
- Nicola Susann Werner
- Institut fuer Physiologische Chemie, Abteilung fuer Zellbiochemie, Universitaetsklinikum Bonn, 53115 Bonn, Germany
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Herrmann H, Hesse M, Reichenzeller M, Aebi U, Magin TM. Functional complexity of intermediate filament cytoskeletons: from structure to assembly to gene ablation. INTERNATIONAL REVIEW OF CYTOLOGY 2003; 223:83-175. [PMID: 12641211 DOI: 10.1016/s0074-7696(05)23003-6] [Citation(s) in RCA: 150] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The cell biology of intermediate filament (IF) proteins and their filaments is complicated by the fact that the members of the gene family, which in humans amount to at least 65, are differentially expressed in very complex patterns during embryonic development. Thus, different tissues and cells express entirely different sets and amounts of IF proteins, the only exception being the nuclear B-type lamins, which are found in every cell. Moreover, in the course of evolution the individual members of this family have, within one species, diverged so much from each other with regard to sequence and thus molecular properties that it is hard to envision a unifying kind of function for them. The known epidermolytic diseases, caused by single point mutations in keratins, have been used as an argument for a role of IFs in mechanical "stress resistance," something one would not have easily ascribed to the beaded chain filaments, a special type of IF in the eye lens, or to nuclear lamins. Therefore, the power of plastic dish cell biology may be limited in revealing functional clues for these structural elements, and it may therefore be of interest to go to the extreme ends of the life sciences, i.e., from the molecular properties of individual molecules including their structure at the atomic level to targeted inactivation of their genes in living animals, mouse, and worm to define their role more precisely in metazoan cell physiology.
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Affiliation(s)
- Harald Herrmann
- Division of Cell Biology, German Cancer Research Center, D-69120 Heidelberg, Germany
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40
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Clarke EJ, Allan VJ. Cytokeratin intermediate filament organisation and dynamics in the vegetal cortex of living Xenopus laevis oocytes and eggs. CELL MOTILITY AND THE CYTOSKELETON 2003; 56:13-26. [PMID: 12905528 DOI: 10.1002/cm.10131] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Cytokeratin intermediate filaments are prominent constituents of developing Xenopus oocytes and eggs, forming radial and cortical networks. In order to investigate the dynamics of the cortical cytokeratin network, we expressed EGFP-tagged Xenopus cytokeratin 1(8) in oocytes and eggs. The EGFP-cytokeratin co-assembled with endogenous partner cytokeratin proteins to form fluorescent filaments. Using time-lapse confocal microscopy, cytokeratin filament assembly was monitored in live Xenopus oocytes at different stages of oogenesis, and in the artificially-activated mature egg during the first cell cycle. In stage III to V oocytes, cytokeratin proteins formed a loose cortical geodesic network, which became more tightly bundled in stage VI oocytes. Maturation of oocytes into metaphase II-arrested eggs induced disassembly of the EGFP-cytokeratin network. Imaging live eggs after artificial activation allowed us to observe the reassembly of cytokeratin filaments in the vegetal cortex. The earliest observable structures were loose foci, which then extended into curly filament bundles. The position and orientation of these bundles altered with time, suggesting that forces were acting upon them. During cortical rotation, the cytokeratin network realigned into a parallel array that translocated in a directed manner at 5 microm/minute, relative to stationary cortex. The cytokeratin filaments are, therefore, moving in association with the bulk cytoplasm of the egg, suggesting that they may provide a structural role at the moving interface between cortex and cytoplasm.
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Affiliation(s)
- Emma J Clarke
- School of Biological Sciences, University of Manchester, Manchester, United Kingdom
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41
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Chan WKH, Yabe JT, Pimenta AF, Ortiz D, Shea TB. Growth cones contain a dynamic population of neurofilament subunits. CELL MOTILITY AND THE CYTOSKELETON 2003; 54:195-207. [PMID: 12589678 DOI: 10.1002/cm.10084] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Neurofilaments (NFs) are classically considered to transport in a primarily anterograde direction along axons, and to undergo bulk degradation within the synapse or growth cone (GC). We compared overall NF protein distribution with that of newly expressed NF subunits within NB2a/d1 cells by transfection with a construct encoding green fluorescent protein (GFP) conjugated NF-M subunits. GCs lacked phosphorylated NF epitopes, and steady-state levels of non-phosphosphorylated NF subunits within GC were markedly reduced compared to those of neurite shaft as indicated by conventional immunofluorescence. However, GCs contained significant levels of GFP-tagged subunits in the form of punctate or short filamentous structures that in some cases exceeded that visualized along the shaft itself, suggesting that GCs contained a relatively higher concentration of newly synthesized subunits. GFP-tagged NF subunits within GCs co-localized with non-phosphorylated NF immunoreactivity. GFP-tagged subunits were observed within GC filopodia in which steady-state levels of NF subunits were too low to be detected by conventional immunofluorescence. Selective localization of fluorescein versus rhodamine fluorescene was observed within GCs following expression of NF-M conjugated to DsRed1-E5, which shifts from fluorescein to rhodamine fluorescence within hours after expression; axonal shafts contained a more even distribution of fluorescein and rhodamine fluorescence, further indicating that GCs contained relatively higher levels of the most-recently expressed subunits. GFP-tagged structures were rapidly extracted from GCs under conditions that preserved axonal structures. These short filamentous and punctate structures underwent rapid bi-directional movement within GCs. Movement of GFP-tagged structures within GCs ceased following application of nocodazole, cytochalasin B, and the kinase inhibitor olomoucine, indicating that their motility was dependent upon microtubules and actin and, moreover, was due to active transport rather than simple diffusion. Treatment with the protease inhibitor calpeptin increased overall NF subunits, but increased those within the GC to a greater extent than those along the shaft, indicating that subunits in the GC undergo more rapid turnover than do those within the shaft. Some GCs contained coiled aggregates of GFP-tagged NFs that appeared to be contiguous with axonal NFs. NFs extended from these aggregates into the advancing GC as axonal neurites elongated. These data are consistent with the presence of a population of dynamic NF subunits within GCs that is apparently capable of participating in regional filament formation during axonal elongation, and support the notion that NF polymerization and transport need not necessarily occur in a uniform proximal-distal manner.
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Affiliation(s)
- Walter K-H Chan
- Center for Cellular Neurobiology and Neurodegeneration Research, Department of Biological Sciences, University of Massachusetts-Lowell, MA 01854, USA
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Abstract
Intermediate filament (IF) proteins form the largest family of cytoskeletal proteins in mammalian cells. The function of these proteins has long been thought to be only structural. However, this single function does not explain their diverse tissue- and differentiation-specific expression patterns. Evidence is now emerging that IF also act as an important framework for the modulation and control of essential cell processes, in particular, signal transduction events. Here, we review the most recent developments in this growing and exciting new field.
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Affiliation(s)
- Jesus M Paramio
- Project on Cell and Molecular Biology and Gene Therapy, CIEMAT, Ave. Complutense 22, E-28040 Madrid, Spain.
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Delhaas T, Van Engeland S, Broers J, Bouten C, Kuijpers N, Ramaekers F, Snoeckx LHEH. Quantification of cytoskeletal deformation in living cells based on hierarchical feature vector matching. Am J Physiol Cell Physiol 2002; 283:C639-45. [PMID: 12107074 DOI: 10.1152/ajpcell.00535.2001] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The cytoskeleton is a dynamic scaffold in living cells even in the absence of externally imposed forces. In this study on cytoskeletal deformation, the applicability of hierarchical feature vector matching (HFVM), a new matching method, currently applied in space research and three-dimensional surface reconstruction, was investigated. Stably transfected CHO-K1 cells expressing green fluorescent protein (GFP) coupled to vimentin were used to visualize spontaneous movement of the vimentin cytoskeleton of individual cells using a confocal laser scanning system. We showed that, with proper parameter and configuration settings, HFVM could recognize and trace 60-70% of all image points in artificially translated, rotated, or deformed images. If only points belonging to the cytoskeleton were selected for matching purposes, the percentage of matched points increased to 98%. This high percentage of recognition also could be reached in a time series of images, in which a certain degree of bleaching of the fluorescence over the recording time of 30 min was inevitable. In these images, HFVM allowed the detection as well as the quantification of spontaneous cytoskeletal movements of up to 10% of the cell width. Therefore, HFVM appears to be a reliable method of quantifying dynamic cytoskeletal behavior in living cells.
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Affiliation(s)
- Tammo Delhaas
- Department of Physiology, Cardiovascular Research Institute, Maastricht University, University Hospital Maastricht, The Netherlands.
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44
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Gao YS, Vrielink A, MacKenzie R, Sztul E. A novel type of regulation of the vimentin intermediate filament cytoskeleton by a Golgi protein. Eur J Cell Biol 2002; 81:391-401. [PMID: 12160147 DOI: 10.1078/0171-9335-00260] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Whether the highly dynamic structure of the vimentin intermediate filament (IF) cytoskeleton responds to cues from cellular organelles, and what proteins might participate in such events is largely unknown. We have shown previously that the Golgi protein formiminotransferase cyclodeaminase (FTCD) binds to vimentin filaments in vivo and in vitro, and that overexpression of FTCD causes dramatic rearrangements of the vimentin IF cytoskeleton (Gao and Sztul, J. Cell Biol. 152, 877-894, 2001). Using real-time imaging, we now show that FTCD causes bundling of individual thinner vimentin filaments into fibers and that the bundling always originates at the Golgi. FTCD appears to be the molecular "glue" since FTCD cross-links vimentin filaments in vitro. To initiate the analysis of structural determinants required for FTCD function in vimentin dynamics, we used structure-based design to generate individual formiminotransferase (FT) and cyclodeaminase (CD) domains, and to produce an enzymatically inactive FTCD. We show that the intact octameric structure is required for FTCD binding to vimentin filaments and for promoting filament assembly, but that eliminating enzymatic activity does not affect FTCD effects on the vimentin cytoskeleton. Our findings indicate that the Golgi protein FTCD is a potent modulator of the vimentin IF cytoskeleton, and suggest that the Golgi might act as a reservoir for proteins that regulate cytoskeletal dynamics.
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Affiliation(s)
- Ya-Sheng Gao
- Department of Cell Biology, University of Alabama at Birmingham, 35294, USA
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45
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Abstract
Intermediate-filament proteins (IFPs) occur in the intracellular cytoskeleton of eukaryotic cells, and their expression in diverse tissues is related both to embryology as well as to differentiation. Although the available information concerning their functional properties in vivo is still incomplete, antibodies against individual IFPs are commonly used in immunohistochemical procedures as markers for differentiation, and these antibodies are of outstanding value in the routine histopathological evaluation of tumor specimens. This review presents a compilation of the currently available data concerning IFP expression in normal and diseased ocular tissues. Representatives of every known class of IFP have been detected in normal ocular tissues. The external epithelia exhibit complex expression patterns of cytokeratin (CK) polypeptides, with CK3 and CK12 being specific markers of the corneal epithelium. Recent research has revealed that single mutant CK polypeptides may play a role in the pathogenesis of corneal dystrophies. The internal ocular epithelia reveal simple but specific patterns of IFP expression, these comprising simple-epithelial CKs and/or the mesenchymal IFP, vimentin. The IFP complement of the neuronal structures of the eye embraces several distinct IFP classes and reflects the diversity of the cell types present at these sites. With respect to ocular tumors, the IFP profile of melanomas might be correlated with metastatic potential. In conclusion, IFP analysis may be able to cast light on the pathogenesis of ocular diseases, as well as being a valuable adjunct in ophthalmopathological diagnosis.
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Affiliation(s)
- Susanne Pitz
- Department of Ophthalmology, Johannes Gutenberg-Universität, Langenbeckstr. 1, D-55101 Mainz, Germany.
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46
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Windoffer R, Leube RE. De novo formation of cytokeratin filament networks originates from the cell cortex in A-431 cells. CELL MOTILITY AND THE CYTOSKELETON 2001; 50:33-44. [PMID: 11746670 DOI: 10.1002/cm.1039] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Of the three major cytoskeletal filament systems, the intermediate filaments are the least understood. Since they differ fundamentally from the actin- and microtubule-based networks by their lack of polarity, it has remained a mystery how and where these principally endless filaments are formed. Using a recently established epithelial cell system in which fluorescently labeled intermediate filaments of the cytokeratin type can be monitored in living cells, we address these issues. By multidimensional time-lapse fluorescence microscopy, we examine de novo intermediate filament network formation from non-filamentous material at the end of mitosis and show that it mirrors disassembly. It is demonstrated that filament formation is initiated from the cell cortex without focal preference after cytokinesis. Furthermore, it is shown that this process is dependent on energy, on the integrity of the actin filament network and the microtubule system, and that it can be inhibited by the tyrosine phosphatase inhibitor pervanadate. Based on these observations, a two-step working model is proposed involving (1) interactions within the planar cortical layer acting as an organizing center forming a two-dimensional network and (2) subsequent radial dynamics facilitating the formation of a mature three-dimensional network.
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Affiliation(s)
- R Windoffer
- Department of Anatomy, Johannes Gutenberg-University, Mainz, Germany
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Yabe JT, Chan WK, Chylinski TM, Lee S, Pimenta AF, Shea TB. The predominant form in which neurofilament subunits undergo axonal transport varies during axonal initiation, elongation, and maturation. CELL MOTILITY AND THE CYTOSKELETON 2001; 48:61-83. [PMID: 11124711 DOI: 10.1002/1097-0169(200101)48:1<61::aid-cm6>3.0.co;2-s] [Citation(s) in RCA: 73] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The forms in which neurofilament (NF) subunits undergo axonal transport is controversial. Recent studies from have provided real-time visualization of the slow axonal transport of NF subunits by transfecting neuronal cultures with constructs encoding green fluorescent protein (GFP)-conjugated NF-M subunits. In our studies in differentiated NB2a/d1 cells, the majority NF subunits underwent transport in the form of punctate NF precursors, while studies in cultured neurons have demonstrated transport of NF subunits in predominantly filamentous form. Although different constructs were used in these studies, transfection of the same cultured neurons with our construct yielded the filamentous pattern observed by others, while transfection of our cultures with their construct generated punctate structures, confirming that the observed differences did not reflect variances in assembly-competence among the constructs. Manipulation of intracellular kinase, phosphatase, and protease activities shifted the predominant form of GFP-conjugated subunits between punctate and filamentous, confirming, as shown previously for vimentin, that punctate structures represent precursors for intermediate filament formation. Since these prior studies were conducted at markedly differing neuronal differentiation states, we tested the alternate hypothesis that these differing results reflected developmental alterations in NF dynamics that accompany various stages of neuritogenesis. We conducted time-course analyses of transfected NB2a/d1 cells, including monitoring of transfected cells over several days, as well as transfecting cells at varying intervals prior to and following induction of differentiation and axonal neurite outgrowth. GFP-conjugated subunits were predominantly filamentous during the period of most robust axonal outgrowth and NF accumulation, and presented a mixed profile of punctate and filamentous forms prior to neuritogenesis and following the developmental slowing of neurite outgrowth. These analyses demonstrate that NF subunits are capable of undergoing axonal transport in multiple forms, and that the predominant form in which NF subunits undergo axonal transport varies in accord with the rate of axonal elongation and accumulation of NFs within developing axons.
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Affiliation(s)
- J T Yabe
- Center for Cellular Neurobiology and Neurodegeneration Research, Department of Biological Sciences, University of Massachusetts-Lowell, Lowell, USA
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48
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Meade-Tollin LC, Van Noorden CJ. Time lapse phase contrast video microscopy of directed migration of human microvascular endothelial cells on matrigel. Acta Histochem 2000; 102:299-307. [PMID: 10990067 DOI: 10.1078/s0065-1281(04)70037-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Migration of microvascular endothelial cells is an early and critical step in angiogenesis. Formation of branching and polygonal cellular aggregates by endothelial cells on matrigel has often been considered to be an in vitro model for angiogenesis, although formation of lumens has not always been confirmed. The dynamics of migration of living cells of a human dermal microvascular endothelial cell line (HMEC-1) on a reconstituted basement membrane matrix have been captured in real time using time lapse video microscopy. The cells exhibit periods of quiescence and directed rapid migration by formation of extensions towards a specific target cell. Cells repeatedly extend flexible protrusions from the cell body both within the plane of the matrix and out of the plane of the matrix into the incubation medium. Connections between protrusions and target cells are made frequently, but not all cells which start to form protrusions achieve connections with other cells. Some of these migrating cells which do not connect arrest before reaching the target, or arrest and retract to their origin. After formation of multicellular polygonal structures, the structures contract to form amorphous clusters of fused cells without visible effects on the underlying matrix. The study demonstrates that time lapse video microscopy is a simple but very useful approach to monitor the dynamics of movements which vary in speed and frequency during migration of living cells.
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Affiliation(s)
- L C Meade-Tollin
- University of Arizona College of Medicine, Department of Surgery, Tucson 85724, USA.
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49
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Frixione E. Recurring views on the structure and function of the cytoskeleton: a 300-year epic. CELL MOTILITY AND THE CYTOSKELETON 2000; 46:73-94. [PMID: 10891854 DOI: 10.1002/1097-0169(200006)46:2<73::aid-cm1>3.0.co;2-0] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Some unnoticed or seldom remembered precedents of current views on biological motion and its structural bases are briefly outlined, followed by a concise recapitulation of how the present theory has been constructed in the last few decades. It is shown that the evolution of the concept of fibers as main constituents of living matter led to hypothesizing microscopic structures closely resembling microtubules in the 18th century. At the beginning of this period, fibers sliding over each other and driven by interposed moving elements were envisioned as the cause of muscle contraction. In the following century, an account of the mechanism of myofibril contraction visualized longitudinal displacements of myosin-containing submicroscopic rodlets. The existence of fibrils in the protoplasm of non-muscle cells, a subject of long debate in the second half of the 19th century, was virtually discarded as irrelevant or fallacious 100 years ago. The issue resurfaced in the early 1930s as a theoretical notion--the cytosquelette--nearly two decades before intracellular filamentous structures were first observed with electron microscopy. The role originally assumed for such fibrils as signal conductors is nowadays being reappraised, although under new interpretations with a much wider significance including modulation of gene expression, morphogenesis, and even consciousness. Since all of the above ancestral conceptions were eventually abandoned, the corresponding current views are, to a certain extent, recurrent.
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Affiliation(s)
- E Frixione
- Departamento de Biología Celular and Departamento de Fisiología, Biofísica y Neurociencias, Centro de Investigacíon y de Estudios Avanzados del IPN, México.
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50
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Helmke BP, Goldman RD, Davies PF. Rapid displacement of vimentin intermediate filaments in living endothelial cells exposed to flow. Circ Res 2000; 86:745-52. [PMID: 10764407 DOI: 10.1161/01.res.86.7.745] [Citation(s) in RCA: 150] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Hemodynamic shear stress at the endothelial cell surface induces acute and chronic intracellular responses that regulate vessel wall biology. The cytoskeleton is implicated by acting both as a direct connector to local surface deformation and as a distribution network for mechanical forces throughout the cell; however, direct observation and measurement of its position during flow have only recently become possible. In this study, we directly demonstrate rapid deformation of the intermediate filament (IF) network in living endothelial cells subjected to changes in hemodynamic shear stress. Time-lapse optical sectioning and deconvolution microscopy were performed within the first 3 minutes after the introduction of flow (shear stress, 12 dyn/cm(2)). Spatial and temporal dynamics of green fluorescent protein-vimentin IFs in confluent endothelial cells were analyzed. The imposition of shear stress significantly increased the variability of IF movement throughout the cell in the x-, y-, and z-directions compared with the constitutive dynamics noted in the absence of flow. Acute polymerization and depolymerization of the IF network were absent. The magnitude and direction of flow-induced IF displacement were heterogeneous at the subcellular level. These qualitative and quantitative data demonstrate that shear stress acting at the luminal surface of the endothelium results in rapid deformation of a stable IF network.
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Affiliation(s)
- B P Helmke
- Institute for Medicine and Engineering, University of Pennsylvania, Philadelphia, PA 19104-6383, USA
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