Tomography of Actin Cytoskeletal Networks

2010 ◽  
pp. 203-214 ◽  
Author(s):  
Dorit Hanein
Keyword(s):  
Cytoskeletal Networks

3-D examination of the cytoskeletal sheets of mammalian eggs

1992 ◽  
Vol 50 (1) ◽  
pp. 914-915
Author(s):  
Carolyn A. Larabell ◽  
David G. Capco ◽  
G. Ian Gallicano ◽  
Robert W. McGaughey ◽  
Karsten Dierksen ◽  
...  
Keyword(s):  
Actin Filaments ◽  
Somatic Cells ◽  
Freeze Fracture ◽  
Blastocyst Stage ◽  
Cell Cytoplasm ◽  
Planar Structures ◽  
Cytoskeletal Network ◽  
Entire Cell ◽  
Cytoskeletal Networks ◽  
Mammalian Eggs

Mammalian eggs and embryos contain an elaborate cytoskeletal network of “sheets” which are distributed throughout the entire cell cytoplasm. Cytoskeletal sheets are long, planar structures unlike the cytoskeletal networks typical of somatic cells (actin filaments, microtubules, and intermediate filaments), which are filamentous. These sheets are not found in mammalian somatic cells nor are they found in nonmammalian eggs or embryos. Evidence that they are, indeed, cytoskeletal in nature is derived from studies demonstrating that 1) the sheets are retained in the detergent-resistant cytoskeleton fraction; 2) there are no associated membranes (determined by freeze-fracture); and 3) the sheets dissociate into filaments at the blastocyst stage of embryogenesis. Embedment-free sections of hamster eggs viewed at 60 kV show sheets running across the egg cytoplasm (Fig. 1). Although this approach provides excellent global views of the sheets and their reorganization during development, the mechanism of image formation for embedment-free sections does not permit evaluation of the sheets at high resolution.

scholarly journals Optimal orientation in branched cytoskeletal networks

2010 ◽  
Vol 63 (4) ◽  
pp. 735-755 ◽  
Author(s):  
D. A. Quint ◽  
J. M. Schwarz
Keyword(s):  
Optimal Orientation ◽  
Cytoskeletal Networks

scholarly journals Lis1 is essential for cortical microtubule organization and desmosome stability in the epidermis

2011 ◽  
Vol 194 (4) ◽  
pp. 631-642 ◽  
Author(s):  
Kaelyn D. Sumigray ◽  
Hsin Chen ◽  
Terry Lechler
Keyword(s):  
Cortical Microtubule ◽  
Cell Types ◽  
Epidermal Differentiation ◽  
Cell Cortex ◽  
Microtubule Organization ◽  
Specific Subset ◽  
Keratin Filaments ◽  
Perinatal Lethality ◽  
Cytoskeletal Networks ◽  
Centrosomal Proteins

Desmosomes are cell–cell adhesion structures that integrate cytoskeletal networks. In addition to binding intermediate filaments, the desmosomal protein desmoplakin (DP) regulates microtubule reorganization in the epidermis. In this paper, we identify a specific subset of centrosomal proteins that are recruited to the cell cortex by DP upon epidermal differentiation. These include Lis1 and Ndel1, which are centrosomal proteins that regulate microtubule organization and anchoring in other cell types. This recruitment was mediated by a region of DP specific to a single isoform, DPI. Furthermore, we demonstrate that the epidermal-specific loss of Lis1 results in dramatic defects in microtubule reorganization. Lis1 ablation also causes desmosomal defects, characterized by decreased levels of desmosomal components, decreased attachment of keratin filaments, and increased turnover of desmosomal proteins at the cell cortex. This contributes to loss of epidermal barrier activity, resulting in completely penetrant perinatal lethality. This work reveals essential desmosome-associated components that control cortical microtubule organization and unexpected roles for centrosomal proteins in epidermal function.

scholarly journals Mechanisms of Contractility and Coarsening of Active Cytoskeletal Networks

2012 ◽  
Vol 102 (3) ◽  
pp. 693a
Author(s):  
Taeyoon Kim ◽  
Ed Munro ◽  
Margaret L. Gardel
Keyword(s):  
Cytoskeletal Networks

scholarly journals Collective Dynamics of Active Cytoskeletal Networks

PLoS ONE ◽  
2011 ◽  
Vol 6 (8) ◽  
pp. e23798 ◽  
Author(s):  
Simone Köhler ◽  
Volker Schaller ◽  
Andreas R. Bausch
Keyword(s):  
Collective Dynamics ◽  
Cytoskeletal Networks

scholarly journals A FIJI macro for quantifying pattern in extracellular matrix

2021 ◽  
Vol 4 (3) ◽  
pp. e202000880
Author(s):  
Esther Wershof ◽  
Danielle Park ◽  
David J Barry ◽  
Robert P Jenkins ◽  
Antonio Rullan ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Fractal Dimension ◽  
Quantitative Analysis ◽  
Comprehensive Description ◽  
End Points ◽  
Wide Range ◽  
Automated Pipeline ◽  
Cytoskeletal Networks ◽  
Alignment Length ◽  
Imagej Plugin

Diverse extracellular matrix patterns are observed in both normal and pathological tissue. However, most current tools for quantitative analysis focus on a single aspect of matrix patterning. Thus, an automated pipeline that simultaneously quantifies a broad range of metrics and enables a comprehensive description of varied matrix patterns is needed. To this end, we have developed an ImageJ plugin called TWOMBLI, which stands for The Workflow Of Matrix BioLogy Informatics. This pipeline includes metrics of matrix alignment, length, branching, end points, gaps, fractal dimension, curvature, and the distribution of fibre thickness. TWOMBLI is designed to be quick, versatile and easy-to-use particularly for non-computational scientists. TWOMBLI can be downloaded from https://github.com/wershofe/TWOMBLI together with detailed documentation and tutorial video. Although developed with the extracellular matrix in mind, TWOMBLI is versatile and can be applied to vascular and cytoskeletal networks. Here we present an overview of the pipeline together with examples from a wide range of contexts where matrix patterns are generated.

scholarly journals Tensins – emerging insights into their domain functions, biological roles and disease relevance

2021 ◽  
Vol 134 (4) ◽  
pp. jcs254029
Author(s):  
Yi-Chun Liao ◽  
Su Hao Lo
Keyword(s):  
Focal Adhesion ◽  
Muscle Regeneration ◽  
Normal Tissue ◽  
Physiological Processes ◽  
Focal Adhesion Proteins ◽  
A Cell ◽  
Disease Relevance ◽  
Cytoskeletal Networks ◽  
Multiple Domains ◽  
Mechanical Sensing

ABSTRACTTensins are a family of focal adhesion proteins consisting of four members in mammals (TNS1, TNS2, TNS3 and TNS4). Their multiple domains and activities contribute to the molecular linkage between the extracellular matrix and cytoskeletal networks, as well as mediating signal transduction pathways, leading to a variety of physiological processes, including cell proliferation, attachment, migration and mechanical sensing in a cell. Tensins are required for maintaining normal tissue structures and functions, especially in the kidney and heart, as well as in muscle regeneration, in animals. This Review discusses our current understanding of the domain functions and biological roles of tensins in cells and mice, as well as highlighting their relevance to human diseases.

scholarly journals Loss of calpains-1 and -2 prevents repair of plasma membrane scrape injuries, but not small pores, and induces a severe muscular dystrophy

2020 ◽  
Vol 318 (6) ◽  
pp. C1226-C1237
Author(s):  
Ann-Katrin Piper ◽  
Reece A. Sophocleous ◽  
Samuel E. Ross ◽  
Frances J. Evesson ◽  
Omar Saleh ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Plasma Membrane ◽  
Muscular Dystrophy ◽  
Disease Genes ◽  
Spastic Paraplegia ◽  
Membrane Repair ◽  
Membrane Injury ◽  
Streptolysin O ◽  
Calpain 2 ◽  
Cytoskeletal Networks

The ubiquitous calpains, calpain-1 and -2, play important roles in Ca2+-dependent membrane repair. Mechanically active tissues like skeletal muscle are particularly reliant on mechanisms to repair and remodel membrane injury, such as those caused by eccentric damage. We demonstrate that calpain-1 and -2 are master effectors of Ca2+-dependent repair of mechanical plasma membrane scrape injuries, although they are dispensable for repair/removal of small wounds caused by pore-forming agents. Using CRISPR gene-edited human embryonic kidney 293 (HEK293) cell lines, we established that loss of both calpains-1 and -2 ( CAPNS1−/−) virtually ablates Ca2+-dependent repair of mechanical scrape injuries but does not affect injury or recovery from perforation by streptolysin-O or saponin. In contrast, cells with targeted knockout of either calpain-1 ( CAPN1−/−) or -2 ( CAPN2−/−) show near-normal repair of mechanical injuries, inferring that both calpain-1 and calpain-2 are equally capable of conducting the cascade of proteolytic cleavage events to reseal a membrane injury, including that of the known membrane repair agent dysferlin. A severe muscular dystrophy in a murine model with skeletal muscle knockout of Capns1 highlights vital roles for calpain-1 and/or -2 for health and viability of skeletal muscles not compensated for by calpain-3 ( CAPN3). We propose that the dystrophic phenotype relates to loss of maintenance of plasma membrane/cytoskeletal networks by calpains-1 and -2 in response to directed and dysfunctional Ca2+-signaling, pathways hyperstimulated in the context of membrane injury. With CAPN1 variants associated with spastic paraplegia, a severe dystrophy observed with muscle-specific loss of calpain-1 and -2 activity identifies CAPN2 and CAPNS1 as plausible candidate neuromuscular disease genes.

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