The Experts below are selected from a list of 234 Experts worldwide ranked by ideXlab platform
Sandrine Etienne-manneville - One of the best experts on this subject based on the ideXlab platform.
-
Engagement of vimentin Intermediate Filaments in hypotonic stress
Journal of Cellular Biochemistry, 2019Co-Authors: Wei Gao, Sandrine Etienne-manneville, Fang Cheng, Yue Zhang, John Eriksson, Yaming JiuAbstract:Intermediate Filaments (IFs) play a key role in the control of cell structure and morphology, cell mechano-responses, migration, proliferation, and apoptosis. However, the mechanisms regulating IFs organization in motile adhesive cells under certain physical/pathological conditions remain to be fully understood. In this study, we found hypo-osmotic-induced stress results in a dramatic but reversible rearrangement of the IF network. Vimentin and nestin IFs are partially depolymerized as they are redistributed throughout the cell cytoplasm after hypo-osmotic shock. This spreading of the IFs requires an intact microtubule network and the motor protein associated transportation. Both nocodazole treatment and depletion of kinesin-1 (KIF5B) block the hypo-osmotic shock-induced rearrangement of IFs showing that the dynamic behavior of IFs largely depends on microtubules and kinesin-dependent transport. Moreover, we show that cell survival rates are dramatically decreased in response to hypo-osmotic shock, which was more severe by vimentin IFs depletion, indicating its contribution to osmotic endurance. Collectively, these results reveal a critical role of vimentin IFs under hypotonic stress and provide evidence that IFs are important for the defense mechanisms during the osmotic challenge. K E Y W O R D S cytoplasmic redistribution, hypo-osmosis, Intermediate Filaments, osmotic stress, vimentin
-
Cytoplasmic Intermediate Filaments in Cell Biology
Annual Review of Cell and Developmental Biology, 2018Co-Authors: Sandrine Etienne-mannevilleAbstract:Intermediate Filaments (IFs) are one of the three major elements of the cy-toskeleton. Their stability, intrinsic mechanical properties, and cell type-specific expression patterns distinguish them from actin and microtubules. By providing mechanical support, IFs protect cells from external forces and participate in cell adhesion and tissue integrity. IFs form an extensive and elaborate network that connects the cell cortex to intracellular organelles. They act as a molecular scaffold that controls intracellular organization. However, IFs have been revealed as much more than just rigid structures. Their dynamics is regulated by multiple signaling cascades and appears to contribute to signaling events in response to cell stress and to dynamic cellular functions such as mitosis, apoptosis, and migration.
-
Connecting the plasma membrane to the nucleus by Intermediate Filaments
Molecular Biology of the Cell, 2017Co-Authors: Sandrine Etienne-manneville, Jan LammerdingAbstract:Talks at the Minisymposium on “Intermediate Filaments from Cytoplasm to Nucleus” demonstrated the structural and functional diversity of Intermediate Filaments (IFs) and their multiple binding partners and highlighted their importance in both cellular mechanics and gene regulation.
-
Editorial overview: Cell architecture: Intermediate Filaments — from molecules to patients
Current Opinion in Cell Biology, 2015Co-Authors: Elly Hol, Sandrine Etienne-mannevilleAbstract:From microbes to man for cells to have shape, form and function they need a dynamic, internal skeleton. This skeleton is known as the cytoskeleton which comprises three major filament systems: microFilaments, microtu-bules, and Intermediate Filaments. Whereas microFilaments and microtu-bules serve as tracks for motor proteins and are engaged in cell motility, Intermediate Filaments are fundamentally engaged in determining cellular plasticity. Intermediate Filaments are crucial for the mechanical integrity and biological function of many different tissues in the body. In this issue of Current Opinion in Cell Biology, leaders from the field of Intermediate Filaments unravel the novel developments in biological, physical , and chemical technology which contribute to our recent increase in knowledge of the nanomechanics and biological function of the Intermediate filament cytoskeleton. In sharp contrast with the components of the microtubule and the actin cytoskeleton which are more or less ubiquitously expressed in all cell types, the Intermediate filament gene family comprises over 70 members which are introduced here by Peter and Stick. With the exception of the nuclear cytoskeleton formed by the ubiquitously expressed lamins, presented in the review of Gruenbaum and Medalia, Intermediate filament proteins are differentially expressed during development and in distinct cell types. In addition, it has recently been shown that splice variants of Intermediate filament proteins are expressed, adding a level of complexity to this system. The large variety of Intermediate filament proteins form highly specialized polymeric filamentous networks, such as keratins in skin, vimentin in mesenchymal cells, neuroFilaments, GFAP, a-internexin and synemin in the central nervous system, desmin and syncoilin in muscle, peripherin in the peripheral nervous system and nestin in neural stem cells. Reviews from Loschke et al., Hol and Pekny and Laser-Azogui et al. describe Intermediate filament networks specifically found in epithelial, glial, and neuronal cells and highlight their structural and functional properties. Despite the broad variety of Intermediate filament proteins expressed in different tissues, there is a high level of similarity in the structural design of the Intermediate filament cytoskeleton. The review by Chernyatina et al. offers an overview of the structure of Intermediate filament proteins. The monomers making up the Filaments do differ in their amino acid sequence, but share similar protein domain motifs, as they all consist of a central a-helical rod flanked by flexible and highly variable N-termini and C-termini. All Intermediate filament proteins form networks following a similar, hierarchical assembly scheme. Intermediate Filaments have very attractive
-
Cytoplasmic Intermediate Filaments mediate actin-driven positioning of the nucleus.
Journal of Cell Science, 2011Co-Authors: Isabelle Dupin, Yasuhisa Sakamoto, Sandrine Etienne-mannevilleAbstract:The localization of the nucleus is precisely regulated, and defects in nuclear positioning are observed in diseases such as lissencephaly, cerebellar ataxia and dysplasia. We show here that cytoplasmic Intermediate Filaments are essential players in actin-dependent positioning of the nucleus. The actin retrograde flow is relayed by a flow of Intermediate Filaments that accumulate asymmetrically around the nuclear envelope. Perturbations of the Intermediate filament network alter positioning of the nucleus in both migrating and immobile astrocytes. This function of Intermediate Filaments might be crucial for regulating cell motility, in particular in tumor cells expressing high levels of cytoplasmic Intermediate Filaments.
Harald Herrmann - One of the best experts on this subject based on the ideXlab platform.
-
History and phylogeny of Intermediate Filaments: Now in insects
BMC Biology, 2011Co-Authors: Harald Herrmann, Sergei V StrelkovAbstract:Intermediate Filaments include the nuclear lamins, which are universal in metazoans, and the cytoplasmic Intermediate Filaments, which are much more varied and form cell type-specific networks in animal cells. Until now, it has been thought that insects harbor lamins only. This view is fundamentally challenged by the discovery, reported in BMC Biology , of an Intermediate filament-like cytoplasmic protein, isomin, in the hexapod Isotomurus maculatus . Here we briefly review the history of research on Intermediate Filaments, and discuss the implications of this latest finding in the context of what is known of their structure and functions. See research article: http://www.biomedcentral.com/1741-7007/9/17
-
History and phylogeny of Intermediate Filaments: Now in insects
BMC biology, 2011Co-Authors: Harald Herrmann, Sergei V StrelkovAbstract:Intermediate Filaments include the nuclear lamins, which are universal in metazoans, and the cytoplasmic Intermediate Filaments, which are much more varied and form cell type-specific networks in animal cells. Until now, it has been thought that insects harbor lamins only. This view is fundamentally challenged by the discovery, reported in BMC Biology, of an Intermediate filament-like cytoplasmic protein, isomin, in the hexapod Isotomurus maculatus. Here we briefly review the history of research on Intermediate Filaments, and discuss the implications of this latest finding in the context of what is known of their structure and functions.
-
Intermediate Filaments: from cell architecture to nanomechanics
Nature Reviews Molecular Cell Biology, 2007Co-Authors: Harald Herrmann, Harald Bär, Sergei V Strelkov, Laurent Kreplak, Ueli AebiAbstract:Intermediate Filaments (IFs) are assembled from fibrous proteins that exhibit a central α-helical rod domain with a conserved substructure. This rod domain facilitates the formation of dimeric coiled-coil complexes. In metazoan cells, IF proteins constitute two distinct filament systems: one in the nucleus and one in the cytoplasm. In both cases, the major function of these Filaments is thought to be the buffering of mechanical stress. In conjunction with associated proteins, IFs generate networks that serve to generate and support the shape of cells. Recent nanomechanical experiments have demonstrated that IFs are characterized by a high propensity to withstand both tensile and bending stress. In line with this, disease mutations in human IF proteins indicate that the nanomechanical properties of cell-type-specific IFs are central to the pathogenesis of these diseases. Apart from structural functions, the analysis of complex diseases, such as cardiomyopathies, has revealed that IFs also have a significant role in cell-type-specific physiological functions and even contribute to the regulation of gene-expression programmes. Intermediate Filaments (IFs) constitute a major structural element of animal cells. They build two distinct systems, one in the nucleus and one in the cytoplasm. In both cases, their major function is assumed to be that of a mechanical stress absorber and an integrating device for the entire cytoskeleton. In line with this, recent disease mutations in human IF proteins indicate that the nanomechanical properties of cell-type-specific IFs are central to the pathogenesis of diseases as diverse as muscular dystrophy and premature ageing. However, the analysis of these various diseases suggests that IFs also have an important role in cell-type-specific physiological functions. Intermediate Filaments (IFs) are thought to function as absorbers of mechanical stress and form cytoskeletal networks that serve to support cell shape. The analysis of disease-causing mutations in IF proteins has revealed that IFs also have important roles in cell-type-specific physiological functions.
-
Intermediate Filaments: From cell architecture to nanomechanics
Nature Reviews Molecular Cell Biology, 2007Co-Authors: Harald Herrmann, Harald Bär, Sergei V Strelkov, Laurent Kreplak, Ueli AebiAbstract:Intermediate Filaments (IFs) constitute a major structural element of animal cells. They build two distinct systems, one in the nucleus and one in the cytoplasm. In both cases, their major function is assumed to be that of a mechanical stress absorber and an integrating device for the entire cytoskeleton. In line with this, recent disease mutations in human IF proteins indicate that the nanomechanical properties of cell-type-specific IFs are central to the pathogenesis of diseases as diverse as muscular dystrophy and premature ageing. However, the analysis of these various diseases suggests that IFs also have an important role in cell-type-specific physiological functions.
-
molecular architecture of Intermediate Filaments
BioEssays, 2003Co-Authors: Sergei V Strelkov, Harald Herrmann, U AebiAbstract:Together with microtubules and actin microFilaments, approximately 11 nm wide Intermediate Filaments (IFs) constitute the integrated, dynamic filament network present in the cytoplasm of metazoan cells. This network is critically involved in division, motility and other cellular processes. While the structures of microtubules and microFilaments are known in atomic detail, IF architecture is presently much less understood. The elementary 'building block' of IFs is a highly elongated, rod-like dimer based on an alpha-helical coiled-coil structure. Assembly of cytoplasmic IF proteins, such as vimentin, begins with a lateral association of dimers into tetramers and gradually into the so-called unit-length Filaments (ULFs). Subsequently ULFs start to anneal longitudinally, ultimately yielding mature IFs after a compaction step. For nuclear lamins, however, assembly starts with a head-to-tail association of dimers. Recently, X-ray crystallographic data were obtained for several fragments of the vimentin dimer. Based on the dimer structure, molecular models of the tetramer and the entire filament are now a possibility.
Takao Hijikata - One of the best experts on this subject based on the ideXlab platform.
-
Plectin tethers desmin Intermediate Filaments onto subsarcolemmal dense plaques containing dystrophin and vinculin
Histochemistry and Cell Biology, 2003Co-Authors: Takao Hijikata, Tohru Murakami, Harunori Ishikawa, Hiroshi YorifujiAbstract:Plectin is a versatile cytoskeletal linker protein that preferentially localizes at interfaces between Intermediate Filaments and the plasma membrane in muscle, epithelial cells, and other tissues. Its deficiency causes muscular dystrophy with epidermolysis bullosa simplex. To better understand the functional roles of plectin beneath the sarcolemma of skeletal muscles and to gain some insights into the underlying mechanism of plectin-deficient muscular dystrophy, we studied in vivo structural and molecular relationships of plectin to subsarcolemmal cytoskeletal components, such as desmin, dystrophin, and vinculin, in rat skeletal muscles. Immunogold electron microscopy revealed that plectin fine threads tethered desmin Intermediate Filaments onto subsarcolemmal dense plaques overlying Z-lines and I-bands. These dense plaques were found to contain dystrophin and vinculin, and thus may be the structural basis of costameres. The in vivo association of plectin with desmin, (meta-)vinculin, dystrophin, and actin was demonstrated by immunoprecipitation experiments. Treatment of plectin immunoprecipitates with gelsolin reduced actin, dystrophin, and (meta-)vinculin but not desmin, implicating that subsarcolemmal actin could partly mediate the interaction between plectin and dystrophin or (meta-)vinculin. Altogether, our data suggest that plectin, along with desmin Intermediate Filaments, might serve a vital structural role in the stabilization of the subsarcolemmal cytoskeleton.
-
Plectin is a linker of Intermediate Filaments to Z-discs in skeletal muscle fibers.
Journal of cell science, 1999Co-Authors: Takao Hijikata, Noboru Fujimaki, Tohru Murakami, M Imamura, Harunori IshikawaAbstract:Plectin is a versatile linker protein which is associated with various types of cytoskeletal components and/or Filaments including Intermediate Filaments, and its deficiency causes the disruption of myofibrils, or muscular dystrophy. To better understand the functional role of plectin in skeletal muscle fibers, we have examined the topological and structural relationships of plectin to Intermediate Filaments and Z-discs in rat diaphragm muscles by confocal and immunoelectron microscopy. Immunofluorescence analysis revealed that plectin was colocalized with desmin at the periphery of Z-discs. This plectin localization around Z-discs was constantly maintained irrespective of the contracted or extended state of the muscle fibers, suggesting either direct or indirect association of plectin with Z-discs. Immunogold labeling in skinned muscle fibers clearly demonstrated that plectin-labeled fine threads linked desmin Intermediate Filaments to Z-discs and connected Intermediate Filaments to each other. These results indicate that through plectin threads desmin Intermediate Filaments form lateral linkages among adjacent Z-discs, preventing individual myofibrils from disruptive contraction and ensuring effective force generation.
Sergei V Strelkov - One of the best experts on this subject based on the ideXlab platform.
-
History and phylogeny of Intermediate Filaments: Now in insects
BMC Biology, 2011Co-Authors: Harald Herrmann, Sergei V StrelkovAbstract:Intermediate Filaments include the nuclear lamins, which are universal in metazoans, and the cytoplasmic Intermediate Filaments, which are much more varied and form cell type-specific networks in animal cells. Until now, it has been thought that insects harbor lamins only. This view is fundamentally challenged by the discovery, reported in BMC Biology , of an Intermediate filament-like cytoplasmic protein, isomin, in the hexapod Isotomurus maculatus . Here we briefly review the history of research on Intermediate Filaments, and discuss the implications of this latest finding in the context of what is known of their structure and functions. See research article: http://www.biomedcentral.com/1741-7007/9/17
-
History and phylogeny of Intermediate Filaments: Now in insects
BMC biology, 2011Co-Authors: Harald Herrmann, Sergei V StrelkovAbstract:Intermediate Filaments include the nuclear lamins, which are universal in metazoans, and the cytoplasmic Intermediate Filaments, which are much more varied and form cell type-specific networks in animal cells. Until now, it has been thought that insects harbor lamins only. This view is fundamentally challenged by the discovery, reported in BMC Biology, of an Intermediate filament-like cytoplasmic protein, isomin, in the hexapod Isotomurus maculatus. Here we briefly review the history of research on Intermediate Filaments, and discuss the implications of this latest finding in the context of what is known of their structure and functions.
-
Intermediate Filaments: from cell architecture to nanomechanics
Nature Reviews Molecular Cell Biology, 2007Co-Authors: Harald Herrmann, Harald Bär, Sergei V Strelkov, Laurent Kreplak, Ueli AebiAbstract:Intermediate Filaments (IFs) are assembled from fibrous proteins that exhibit a central α-helical rod domain with a conserved substructure. This rod domain facilitates the formation of dimeric coiled-coil complexes. In metazoan cells, IF proteins constitute two distinct filament systems: one in the nucleus and one in the cytoplasm. In both cases, the major function of these Filaments is thought to be the buffering of mechanical stress. In conjunction with associated proteins, IFs generate networks that serve to generate and support the shape of cells. Recent nanomechanical experiments have demonstrated that IFs are characterized by a high propensity to withstand both tensile and bending stress. In line with this, disease mutations in human IF proteins indicate that the nanomechanical properties of cell-type-specific IFs are central to the pathogenesis of these diseases. Apart from structural functions, the analysis of complex diseases, such as cardiomyopathies, has revealed that IFs also have a significant role in cell-type-specific physiological functions and even contribute to the regulation of gene-expression programmes. Intermediate Filaments (IFs) constitute a major structural element of animal cells. They build two distinct systems, one in the nucleus and one in the cytoplasm. In both cases, their major function is assumed to be that of a mechanical stress absorber and an integrating device for the entire cytoskeleton. In line with this, recent disease mutations in human IF proteins indicate that the nanomechanical properties of cell-type-specific IFs are central to the pathogenesis of diseases as diverse as muscular dystrophy and premature ageing. However, the analysis of these various diseases suggests that IFs also have an important role in cell-type-specific physiological functions. Intermediate Filaments (IFs) are thought to function as absorbers of mechanical stress and form cytoskeletal networks that serve to support cell shape. The analysis of disease-causing mutations in IF proteins has revealed that IFs also have important roles in cell-type-specific physiological functions.
-
Intermediate Filaments: From cell architecture to nanomechanics
Nature Reviews Molecular Cell Biology, 2007Co-Authors: Harald Herrmann, Harald Bär, Sergei V Strelkov, Laurent Kreplak, Ueli AebiAbstract:Intermediate Filaments (IFs) constitute a major structural element of animal cells. They build two distinct systems, one in the nucleus and one in the cytoplasm. In both cases, their major function is assumed to be that of a mechanical stress absorber and an integrating device for the entire cytoskeleton. In line with this, recent disease mutations in human IF proteins indicate that the nanomechanical properties of cell-type-specific IFs are central to the pathogenesis of diseases as diverse as muscular dystrophy and premature ageing. However, the analysis of these various diseases suggests that IFs also have an important role in cell-type-specific physiological functions.
-
molecular architecture of Intermediate Filaments
BioEssays, 2003Co-Authors: Sergei V Strelkov, Harald Herrmann, U AebiAbstract:Together with microtubules and actin microFilaments, approximately 11 nm wide Intermediate Filaments (IFs) constitute the integrated, dynamic filament network present in the cytoplasm of metazoan cells. This network is critically involved in division, motility and other cellular processes. While the structures of microtubules and microFilaments are known in atomic detail, IF architecture is presently much less understood. The elementary 'building block' of IFs is a highly elongated, rod-like dimer based on an alpha-helical coiled-coil structure. Assembly of cytoplasmic IF proteins, such as vimentin, begins with a lateral association of dimers into tetramers and gradually into the so-called unit-length Filaments (ULFs). Subsequently ULFs start to anneal longitudinally, ultimately yielding mature IFs after a compaction step. For nuclear lamins, however, assembly starts with a head-to-tail association of dimers. Recently, X-ray crystallographic data were obtained for several fragments of the vimentin dimer. Based on the dimer structure, molecular models of the tetramer and the entire filament are now a possibility.
Harunori Ishikawa - One of the best experts on this subject based on the ideXlab platform.
-
Plectin tethers desmin Intermediate Filaments onto subsarcolemmal dense plaques containing dystrophin and vinculin
Histochemistry and Cell Biology, 2003Co-Authors: Takao Hijikata, Tohru Murakami, Harunori Ishikawa, Hiroshi YorifujiAbstract:Plectin is a versatile cytoskeletal linker protein that preferentially localizes at interfaces between Intermediate Filaments and the plasma membrane in muscle, epithelial cells, and other tissues. Its deficiency causes muscular dystrophy with epidermolysis bullosa simplex. To better understand the functional roles of plectin beneath the sarcolemma of skeletal muscles and to gain some insights into the underlying mechanism of plectin-deficient muscular dystrophy, we studied in vivo structural and molecular relationships of plectin to subsarcolemmal cytoskeletal components, such as desmin, dystrophin, and vinculin, in rat skeletal muscles. Immunogold electron microscopy revealed that plectin fine threads tethered desmin Intermediate Filaments onto subsarcolemmal dense plaques overlying Z-lines and I-bands. These dense plaques were found to contain dystrophin and vinculin, and thus may be the structural basis of costameres. The in vivo association of plectin with desmin, (meta-)vinculin, dystrophin, and actin was demonstrated by immunoprecipitation experiments. Treatment of plectin immunoprecipitates with gelsolin reduced actin, dystrophin, and (meta-)vinculin but not desmin, implicating that subsarcolemmal actin could partly mediate the interaction between plectin and dystrophin or (meta-)vinculin. Altogether, our data suggest that plectin, along with desmin Intermediate Filaments, might serve a vital structural role in the stabilization of the subsarcolemmal cytoskeleton.
-
Plectin is a linker of Intermediate Filaments to Z-discs in skeletal muscle fibers.
Journal of cell science, 1999Co-Authors: Takao Hijikata, Noboru Fujimaki, Tohru Murakami, M Imamura, Harunori IshikawaAbstract:Plectin is a versatile linker protein which is associated with various types of cytoskeletal components and/or Filaments including Intermediate Filaments, and its deficiency causes the disruption of myofibrils, or muscular dystrophy. To better understand the functional role of plectin in skeletal muscle fibers, we have examined the topological and structural relationships of plectin to Intermediate Filaments and Z-discs in rat diaphragm muscles by confocal and immunoelectron microscopy. Immunofluorescence analysis revealed that plectin was colocalized with desmin at the periphery of Z-discs. This plectin localization around Z-discs was constantly maintained irrespective of the contracted or extended state of the muscle fibers, suggesting either direct or indirect association of plectin with Z-discs. Immunogold labeling in skinned muscle fibers clearly demonstrated that plectin-labeled fine threads linked desmin Intermediate Filaments to Z-discs and connected Intermediate Filaments to each other. These results indicate that through plectin threads desmin Intermediate Filaments form lateral linkages among adjacent Z-discs, preventing individual myofibrils from disruptive contraction and ensuring effective force generation.