Cell-substrate contacts in cultured chick embryonic cells: an interference reflection study

1982 ◽  
Vol 58 (1) ◽  
pp. 165-183
Author(s):  
G.W. Ireland ◽  
C.D. Stern
Keyword(s):  
Focal Adhesions ◽  
Peripheral Zone ◽  
Embryonic Cells ◽  
Extracellular Material ◽  
Cell Contacts ◽  
Specialized Cell ◽  
Conspicuous Feature ◽  
Focal Contacts ◽  
Cell Substrate ◽  
Epithelial Sheets

Cell-substrate contacts in explants of different regions of early chick tissues were investigated using the technique of interference reflection microscopy. All the explants spread as epithelial sheets. During initial spreading a peripheral zone of 2–3 cells formed broad contacts with the substrate. In spread explants some cells in the centre made broad substrate contacts. A mat of extracellular material containing fibronectin was found under the explants. Focal contacts and focal adhesions increased in number during culture, and stress fibres were associated with them. These changes in cell contacts appeared more quickly in some tissues than in others. After 24 h, explants of hypoblast and definitive endoblast could easily be distinguished but by 7 days they were very similar. In the absence of serum, specialized cell contacts developed more quickly; in higher concentrations of serum, more slowly. Confrontations between explants were also examined. The most conspicuous feature was that cells in invading explants normally underlapped invaded cells. Invasion from above by an unspread explant could occur even if the invaded explant had formed many focal adhesions.

The subcellular distribution of the high molecular mass protein, HD1, is determined by the cytoplasmic domain of the integrin beta 4 subunit

1997 ◽  
Vol 110 (2) ◽  
pp. 169-178 ◽  
Author(s):  
P. Sanchez-Aparicio ◽  
A.M. Martinez de Velasco ◽  
C.M. Niessen ◽  
L. Borradori ◽  
I. Kuikman ◽  
...  
Keyword(s):  
Molecular Mass ◽  
Subcellular Distribution ◽  
Cytoplasmic Domain ◽  
High Molecular Mass ◽  
Integrin Subunit ◽  
Type Ii ◽  
Structural Protein ◽  
Focal Contacts ◽  
Cell Substrate ◽  
Beta 1 Integrin

The high molecular mass protein, HD1, is a structural protein present in hemidesmosomes as well as in distinct adhesion structures termed type II hemidesmosomes. We have studied the distribution and expression of HD1 in the GD25 cells, derived from murine embryonal stem cells deficient for the beta 1 integrin subunit. We report here that these cells possess HD1 but not BP230 or BP180; two other hemidesmosomal constituents, and express only traces of the alpha 6 beta 4 integrin. By immunofluorescence and interference reflection microscopy HD1 was found together with vinculin at the end of actin filaments in focal contacts. In OVCAR-4 cells, derived from a human ovarian carcinoma which, like GD25 cells, only weakly express alpha 6 beta 4, HD1 was also localized in focal contacts. Upon transfection of both GD25 and OVCAR-4 cells with cDNA for the human beta 4 subunit the subcellular distribution of HD1 changed significantly. HD1 is then no longer present in focal contacts but in other structures at cell-substrate contacts, colocalized with alpha 6 beta 4. These junctional complexes are probably the equivalent of the type II hemidesmosomes. Transfection of GD25 cells with beta 1 cDNA did not affect the distribution of HD1, which indicates that the localization of HD1 in focal contacts was not due to the absence of beta 1. Moreover, in GD25 cells transfected with cDNA encoding a beta 4/beta 1 chimera, in which the cytoplasmic domain of beta 4 was replaced by that of beta 1, the distribution of HD1 was unaffected. Our findings indicate that the cytoplasmic domain of beta 4 determines the subcellular distribution of HD1 and emphasize the important role of alpha 6 beta 4 in the assembly of hemidesmosomes and other junctional adhesive complexes containing HD1.

Integrin-Mediated Fibroblast Adhesion Strength: Role of the β1 Subunit

1993 ◽  
Vol 331 ◽  
Author(s):  
Kelly A. Ward ◽  
Jun-Lin Guan ◽  
Daniel A. Hammer
Keyword(s):  
Extracellular Matrix ◽  
Adhesion Strength ◽  
Cytoplasmic Domain ◽  
Integrin Receptors ◽  
Substrate Adhesion ◽  
Focal Contacts ◽  
Cell Substrate ◽  
Extracellular Matrix Molecules ◽  
Integrin Ligand ◽  
Cell Substrate Adhesion

AbstractCell-substratum adhesion is important in wound healing [4], embryogenic development [11], tissue architecture [6], and metastasis [7]. Integrins constitute a major class of heterodimeric cell-surface glycoproteins involved in receptor-mediated adhesion to the extracellular matrix (ECM). Focal contacts are regions of the cell-substratum adhesion in which clusters of integrin receptors connect the cytoskeleton to extracellular matrix molecules such as fibronectin. Focal contacts strengthen cell-substrate adhesion, and are sites of biochemical activity. Since cell adhesion strength in part depends on the cell's ability to cluster receptors and cytoskeleton into focal contacts, the integrity of the focal contact, and hence a cell's adhesive strength, will depend both on integrin-cytoskeletal binding as well as integrin-ligand binding.Using a centrifugation assay, we have quantified cell-substratum adhesion strength of mouse 3T3 cells transfected with the avian β1 integrin receptor (wild type), including various deletion mutants of its cytoplasmic domain, to surfaces containing varying concentrations of CSAT, a monoclonal antibody against the extracellular domain of the avian β1 subunit. For all the transfectants, adhesion strength decreases with decreasing CSAT concentration and increasing centrifugal strength. Different truncations of the cytoplasmic domain lead to different levels of adhesion. There is no simple correlation between the length of the cytoplasmic domain and the strength of adhesion.

scholarly journals The crosstalk between microtubules, actin and membranes shapes cell division

Open Biology ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 190314 ◽  
Author(s):  
Francesca Rizzelli ◽  
Maria Grazia Malabarba ◽  
Sara Sigismund ◽  
Marina Mapelli
Keyword(s):  
Membrane Trafficking ◽  
Mitotic Progression ◽  
Isolated Cells ◽  
Spindle Positioning ◽  
Substrate Adhesion ◽  
Cell Substrate ◽  
Epithelial Sheets ◽  
Cell Substrate Adhesion ◽  
Extracellular Signalling

Mitotic progression is orchestrated by morphological and mechanical changes promoted by the coordinated activities of the microtubule (MT) cytoskeleton, the actin cytoskeleton and the plasma membrane (PM). MTs assemble the mitotic spindle, which assists sister chromatid separation, and contact the rigid and tensile actomyosin cortex rounded-up underneath the PM. Here, we highlight the dynamic crosstalk between MTs, actin and cell membranes during mitosis, and discuss the molecular connections between them. We also summarize recent views on how MT traction forces, the actomyosin cortex and membrane trafficking contribute to spindle positioning in isolated cells in culture and in epithelial sheets. Finally, we describe the emerging role of membrane trafficking in synchronizing actomyosin tension and cell shape changes with cell–substrate adhesion, cell–cell contacts and extracellular signalling events regulating proliferation.

scholarly journals Supervillin modulation of focal adhesions involving TRIP6/ZRP-1

2006 ◽  
Vol 174 (3) ◽  
pp. 447-458 ◽  
Author(s):  
Norio Takizawa ◽  
Tara C. Smith ◽  
Thomas Nebl ◽  
Jessica L. Crowley ◽  
Stephen J. Palmieri ◽  
...  
Keyword(s):  
Focal Adhesions ◽  
Stress Fibers ◽  
Regulatory Sequence ◽  
Interacting Protein ◽  
Substrate Adhesion ◽  
Lim Domains ◽  
Cell Substrate ◽  
Thyroid Receptor ◽  
And Function ◽  
Cell Substrate Adhesion

Cell–substrate contacts, called focal adhesions (FAs), are dynamic in rapidly moving cells. We show that supervillin (SV)—a peripheral membrane protein that binds myosin II and F-actin in such cells—negatively regulates stress fibers, FAs, and cell–substrate adhesion. The major FA regulatory sequence within SV (SV342-571) binds to the LIM domains of two proteins in the zyxin family, thyroid receptor–interacting protein 6 (TRIP6) and lipoma-preferred partner (LPP), but not to zyxin itself. SV and TRIP6 colocalize within large FAs, where TRIP6 may help recruit SV. RNAi-mediated decreases in either protein increase cell adhesion to fibronectin. TRIP6 partially rescues SV effects on stress fibers and FAs, apparently by mislocating SV away from FAs. Thus, SV interactions with TRIP6 at FAs promote loss of FA structure and function. SV and TRIP6 binding partners suggest several specific mechanisms through which the SV–TRIP6 interaction may regulate FA maturation and/or disassembly.

scholarly journals Molecular heterogeneity of adherens junctions.

1985 ◽  
Vol 101 (4) ◽  
pp. 1523-1531 ◽  
Author(s):  
B Geiger ◽  
T Volk ◽  
T Volberg
Keyword(s):  
Adherens Junctions ◽  
Intercellular Junctions ◽  
The Other ◽  
Molecular Heterogeneity ◽  
Immunofluorescent Localization ◽  
Lens Fibers ◽  
Tissue Extracts ◽  
Focal Contacts ◽  
Cell Substrate ◽  
Membrane Bound

We describe here the subcellular distributions of three junctional proteins in different adherens-type contacts. The proteins examined include vinculin, talin, and a recently described 135-kD protein (Volk, T., and B. Geiger, 1984, EMBO (Eur. Mol. Biol. Organ.) J., 10:2249-2260). Immunofluorescent localization of the three proteins indicated that while vinculin was ubiquitously present in all adherens junctions, the other two showed selective and mutually exclusive association with either cell-substrate or cell-cell adhesions. Talin was abundant in focal contacts and in dense plaques of smooth muscle, but was essentially absent from intercellular junctions such as intercalated disks or adherens junctions of lens fibers. The 135-kD protein, on the other hand, was present in the latter two loci and was apparently absent from membrane-bound plaques of gizzard or from focal contacts. Radioimmunoassay of tissue extracts and immunolabeling of cultured chick lens cells indicated that the selective presence of talin and of the 135-kD protein in different cell contacts is spatially regulated within individual cells. On the basis of these findings it was concluded that adherens junctions are molecularly heterogeneous and consist of at least two major subgroups. Contacts with noncellular substrates contain talin and vinculin but not the 135-kD protein, whereas their intercellular counterparts contain the latter two proteins and are devoid of talin. The significance of these results and their possible relationships to contact-induced regulation of cell behavior are discussed.

scholarly journals The interplay of cell–cell and cell–substrate adhesion in collective cell migration

2014 ◽  
Vol 11 (100) ◽  
pp. 20140684 ◽  
Author(s):  
Chenlu Wang ◽  
Sagar Chowdhury ◽  
Meghan Driscoll ◽  
Carole A. Parent ◽  
S. K. Gupta ◽  
...  
Keyword(s):  
Cell Migration ◽  
Cell Surface ◽  
Actin Polymerization ◽  
Collective Cell Migration ◽  
Cell Contacts ◽  
Substrate Adhesion ◽  
Cell Substrate ◽  
Cell Shapes ◽  
Cell Substrate Adhesion ◽  
Cell Cell

Collective cell migration often involves notable cell–cell and cell–substrate adhesions and highly coordinated motion of touching cells. We focus on the interplay between cell–substrate adhesion and cell–cell adhesion. We show that the loss of cell-surface contact does not significantly alter the dynamic pattern of protrusions and retractions of fast migrating amoeboid cells ( Dictyostelium discoideum ), but significantly changes their ability to adhere to other cells. Analysis of the dynamics of cell shapes reveals that cells that are adherent to a surface may coordinate their motion with neighbouring cells through protrusion waves that travel across cell–cell contacts. However, while shape waves exist if cells are detached from surfaces, they do not couple cell to cell. In addition, our investigation of actin polymerization indicates that loss of cell-surface adhesion changes actin polymerization at cell–cell contacts. To further investigate cell–cell/cell–substrate interactions, we used optical micromanipulation to form cell–substrate contact at controlled locations. We find that both cell-shape dynamics and cytoskeletal activity respond rapidly to the formation of cell–substrate contact.

scholarly journals A Novel Integrin-Linked Kinase–Binding Protein, Affixin, Is Involved in the Early Stage of Cell–Substrate Interaction

2001 ◽  
Vol 153 (6) ◽  
pp. 1251-1264 ◽  
Author(s):  
Satoshi Yamaji ◽  
Atsushi Suzuki ◽  
Yuki Sugiyama ◽  
Yu-ichi Koide ◽  
Michihiko Yoshida ◽  
...  
Keyword(s):  
Early Stage ◽  
Binding Protein ◽  
Focal Adhesions ◽  
Leading Edge ◽  
Cell Spreading ◽  
Substrate Interaction ◽  
Substrate Adhesion ◽  
Cell Substrate ◽  
Integrin Linked Kinase

Focal adhesions (FAs) are essential structures for cell adhesion, migration, and morphogenesis. Integrin-linked kinase (ILK), which is capable of interacting with the cytoplasmic domain of β1 integrin, seems to be a key component of FAs, but its exact role in cell–substrate interaction remains to be clarified. Here, we identified a novel ILK-binding protein, affixin, that consists of two tandem calponin homology domains. In CHOcells, affixin and ILK colocalize at FAs and at the tip of the leading edge, whereas in skeletal muscle cells they colocalize at the sarcolemma where cells attach to the basal lamina, showing a striped pattern corresponding to cytoplasmic Z-band striation. When CHO cells are replated on fibronectin, affixin and ILK but not FA kinase and vinculin concentrate at the cell surface in blebs during the early stages of cell spreading, which will grow into membrane ruffles on lamellipodia. Overexpression of the COOH-terminal region of affixin, which is phosphorylated by ILK in vitro, blocks cell spreading at the initial stage, presumably by interfering with the formation of FAs and stress fibers. The coexpression of ILK enhances this effect. These results provide evidence suggesting that affixin is involved in integrin–ILK signaling required for the establishment of cell–substrate adhesion.

Podocytes are sensitive to fluid shear stress in vitro

2006 ◽  
Vol 291 (4) ◽  
pp. F856-F865 ◽  
Author(s):  
Colin Friedrich ◽  
Nicole Endlich ◽  
Wilhelm Kriz ◽  
Karlhans Endlich
Keyword(s):  
Shear Stress ◽  
Tyrosine Kinases ◽  
Fluid Shear Stress ◽  
Focal Adhesions ◽  
Fluid Shear ◽  
Cell Contacts ◽  
Tk Inhibitors ◽  
Static Conditions ◽  
Cell Cell

Podocytes are exposed to mechanical forces arising from glomerular capillary pressure and filtration. It has been shown that stretch affects podocyte biology in vitro and plays a significant role in the development of glomerulosclerosis in vivo. However, whether podocytes are sensitive to fluid shear stress is completely unknown. In the present study, we therefore exposed cells of a recently generated conditionally immortalized mouse podocyte cell line to defined fluid shear stress in a flow chamber, mimicking flow of the glomerular ultrafiltrate over the surface of podocytes in Bowman's space. Shear stress above 0.25 dyne/cm2 resulted in dramatic loss of podocytes but not of proximal tubular epithelial cells (LLC-PK1 cells) after 20 h. At 0.015–0.25 dyne/cm2, lamellipodia formation in podocytes was enhanced and the actin nucleation protein cortactin was redistributed to the cell margins. Shear stress further diminished stress fibers and the presence of vinculin in focal adhesions. Linear zonula occludens-1 distribution at cell-cell contacts remained unaffected at low shear stress. At 0.25 dyne/cm2, the monolayer was broken up and remaining cell-cell contacts were reinforced by F-actin and α-actinin. Because the cytoskeletal changes induced by shear stress suggested the involvement of tyrosine kinases (TKs), we tested several TK inhibitors that were all without effect on podocyte number under static conditions. At 0.25 dyne/cm2, however, the TK inhibitors genistein and AG 82 were associated with marked podocyte loss. Our data demonstrate that podocytes are highly sensitive to fluid shear stress. Shear stress induces a reorganization of the actin cytoskeleton and activates specific tyrosine kinases that are required to withstand fluid shear stress.

scholarly journals Cell motion as a stochastic process controlled by focal contacts dynamics

2019 ◽  
Author(s):  
Simon Lo Vecchio ◽  
Raghavan Thiagarajan ◽  
David Caballero ◽  
Vincent Vigon ◽  
Laurent Navoret ◽  
...  
Keyword(s):  
Control Cell ◽  
Focal Adhesions ◽  
Contact Dynamics ◽  
Driving Mechanism ◽  
Focal Contact ◽  
Focal Contacts ◽  
Consistent Model ◽  
Cell Motion

SUMMARYDirected cell motion is essential in physiological and pathological processes such as morphogenesis, wound healing and cancer spreading. Chemotaxis has often been proposed as the driving mechanism, even though evidence of long-range gradients is often lacking in vivo. By patterning adhesive regions in space, we control cell shape and the associated potential to move along one direction in another mode of migration coined ratchetaxis. We report that focal contacts distributions collectively dictate cell directionality, and bias is non-linearly increased by gap distance between adhesive regions. Focal contact dynamics on micro-patterns allow to integrate these phenomena in a consistent model where each focal contact can be translated into a force with known amplitude and direction, leading to quantitative predictions for cell motion in every condition. Altogether, our study shows how local and minutes timescale dynamics of focal adhesions and their distribution lead to long term cellular motion with simple geometric rules.

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