Spatially Selective Imaging of Cell‐Matrix and Cell‐Cell Junctions by Electrochemiluminescence

2021 ◽  
Author(s):  
Hao Ding ◽  
Ping Zhou ◽  
Wenxuan Fu ◽  
Lurong Ding ◽  
Weiliang Guo ◽  
...  
Keyword(s):  
Cell Junctions ◽  
Cell Matrix ◽  
Cell Cell

Long-range and selective autoregulation of cell-cell or cell-matrix adhesions by cadherin or integrin ligands

1998 ◽  
Vol 111 (3) ◽  
pp. 347-357 ◽  
Author(s):  
S. Levenberg ◽  
B.Z. Katz ◽  
K.M. Yamada ◽  
B. Geiger
Keyword(s):  
Cell Surface ◽  
Tyrosine Phosphorylation ◽  
Long Range ◽  
Cell Junctions ◽  
Complete Suppression ◽  
Beta Catenin ◽  
Focal Contact ◽  
Cell Matrix ◽  
Immunofluorescence Labeling ◽  
Cell Cell

In this study we demonstrate that local stimulation of cell surface cadherins or integrins induces a selective enhancement of adherens junction or focal contact assembly, respectively, throughout the cell. N-cadherin transfected CHO cells (CHO-Ncad) were incubated with different ligands including N-cadherin extracellular domain (NEC), anti-N-cadherin antibodies, fibronectin and concanavalin A (ConA), conjugated to synthetic beads. Electron microscopic examination indicated that both cadherin- and integrin-reactive beads bound tightly to the cell surface and were apparently endocytosed after several hours of incubation. The ConA-beads remained largely at the cell surface. Immunofluorescence labeling of the cells with antibodies to different adhesion-associated molecules indicated that both NEC- and anti-N-cadherin-conjugated beads induced a major increase in the level of junction-associated cadherin and beta-catenin labeling and a modest increase in junctional vinculin labeling, compared to untreated cells or cells bound to ConA-beads. FN-conjugated beads, on the other hand, significantly enhanced vinculin labeling at focal contacts and suppressed cadherin and beta-catenin staining in cell-cell junctions. The cadherin-reactive beads specifically stimulated tyrosine phosphorylation at cell-cell junctions, while the FN-beads increased the levels of focal contact-associated phosphotyrosine, as shown by immunofluorescence labeling of the cells for phosphotyrosine. Inhibition of this phosphorylation by genistein resulted in a complete suppression of the effects of both types of beads. These findings indicate that specific cadherin- and integrin-mediated surface interactions can trigger positively cooperative long-range signaling events which lead to the selective assembly of cell-cell or cell-matrix adhesions, and that these signals involve tyrosine phosphorylation.

scholarly journals Evolution of mechanisms controlling epithelial morphogenesis across animals: new insights from dissociation-reaggregation experiments in the sponge Oscarella lobularis

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Amélie Vernale ◽  
Maria Mandela Prünster ◽  
Fabio Marchianò ◽  
Henry Debost ◽  
Nicolas Brouilly ◽  
...  
Keyword(s):  
Functional Characterization ◽  
Protein Composition ◽  
Sister Group ◽  
Epithelial Morphogenesis ◽  
Cell Junctions ◽  
Last Common Ancestor ◽  
Cell Matrix ◽  
Cell Matrix Adhesion ◽  
Cell Cell

Abstract Background The ancestral presence of epithelia in Metazoa is no longer debated. Porifera seem to be one of the best candidates to be the sister group to all other Metazoa. This makes them a key taxon to explore cell-adhesion evolution on animals. For this reason, several transcriptomic, genomic, histological, physiological and biochemical studies focused on sponge epithelia. Nevertheless, the complete and precise protein composition of cell–cell junctions and mechanisms that regulate epithelial morphogenetic processes still remain at the center of attention. Results To get insights into the early evolution of epithelial morphogenesis, we focused on morphogenic characteristics of the homoscleromorph sponge Oscarella lobularis. Homoscleromorpha are a sponge class with a typical basement membrane and adhaerens-like junctions unknown in other sponge classes. We took advantage of the dynamic context provided by cell dissociation-reaggregation experiments to explore morphogenetic processes in epithelial cells in a non-bilaterian lineage by combining fluorescent and electron microscopy observations and RNA sequencing approaches at key time-points of the dissociation and reaggregation processes. Conclusions Our results show that part of the molecular toolkit involved in the loss and restoration of epithelial features such as cell–cell and cell–matrix adhesion is conserved between Homoscleromorpha and Bilateria, suggesting their common role in the last common ancestor of animals. In addition, sponge-specific genes are differently expressed during the dissociation and reaggregation processes, calling for future functional characterization of these genes.

A chimeric N-cadherin/beta 1-integrin receptor which localizes to both cell-cell and cell-matrix adhesions

1992 ◽  
Vol 103 (4) ◽  
pp. 943-951 ◽  
Author(s):  
B. Geiger ◽  
D. Salomon ◽  
M. Takeichi ◽  
R.O. Hynes
Keyword(s):  
Molecular Mechanisms ◽  
Cytoplasmic Domain ◽  
Cell Junctions ◽  
Integrin Receptor ◽  
Cell Contacts ◽  
Cell Matrix ◽  
Focal Contacts ◽  
Extracellular Region ◽  
Beta 1 Integrin ◽  
Cell Cell

To study the molecular mechanisms involved in formation of cell contacts, we have transfected cultured cells with a chimeric cDNA encoding the cytoplasmic and transmembrane domains of beta 1 integrin and the extracellular region of N-cadherin and determined the subcellular distribution of the chimeric molecule. We show that the chimeric receptor associates preferentially with cell-matrix focal contacts, suggesting that its distribution is directed by its beta 1 integrin segment, presumably via interactions of the cytoplasmic domain with cytoskeletal elements characteristic of focal contacts. Transfected cells which expressed relatively high levels of the cadherin/integrin chimera underwent an apparent epithelialization and contained the molecule both in cell-matrix and cell-cell contacts. Location in cell-cell contacts indicates competence of the cadherin extracellular domain to participate in formation of cell-cell junctions using a foreign cytoplasmic domain. Labeling of these cultures for talin, which is normally associated only with matrix adhesions, revealed specific labeling along the newly formed intercellular junctions. This suggests that the local association of talin with these sites is induced by the cytoplasmic tail of beta 1 integrin receptor presented by the chimeric protein. These results suggest that the formation of adherens-type junctions is driven by the cooperative interactions of the relevant adhesion molecules (cadherins and integrins) both with the respective extracellular ligands and with the cytoskeleton.

Spatially Selective Imaging of Cell‐Matrix and Cell‐Cell Junctions by Electrochemiluminescence

2021 ◽  
Author(s):  
Hao Ding ◽  
Ping Zhou ◽  
Wenxuan Fu ◽  
Lurong Ding ◽  
Weiliang Guo ◽  
...  
Keyword(s):  
Cell Junctions ◽  
Cell Matrix ◽  
Cell Cell

scholarly journals The Cryogenic Electron Microscopy Structure of the Cell Adhesion Regulator Metavinculin Reveals an Isoform-Specific Kinked Helix in Its Cytoskeleton Binding Domain

2021 ◽  
Vol 22 (2) ◽  
pp. 645
Author(s):  
Erumbi S. Rangarajan ◽  
Tina Izard
Keyword(s):  
Electron Microscopy ◽  
Cell Adhesion ◽  
Binding Domain ◽  
Cytoskeletal Proteins ◽  
Cell Junctions ◽  
Actin Binding ◽  
Cell Matrix ◽  
Actin Binding Domain ◽  
Α Helix ◽  
Cell Cell

Vinculin and its heart-specific splice variant metavinculin are key regulators of cell adhesion processes. These membrane-bound cytoskeletal proteins regulate the cell shape by binding to several other proteins at cell–cell and cell–matrix junctions. Vinculin and metavinculin link integrin adhesion molecules to the filamentous actin network. Loss of both proteins prevents cell adhesion and cell spreading and reduces the formation of stress fibers, focal adhesions, or lamellipodia extensions. The binding of talin at cell–matrix junctions or of α-catenin at cell–cell junctions activates vinculin and metavinculin by releasing their autoinhibitory head–tail interaction. Once activated, vinculin and metavinculin bind F-actin via their five-helix bundle tail domains. Unlike vinculin, metavinculin has a 68-amino-acid insertion before the second α-helix of this five-helix F-actin–binding domain. Here, we present the full-length cryogenic electron microscopy structure of metavinculin that captures the dynamics of its individual domains and unveiled a hallmark structural feature, namely a kinked isoform-specific α-helix in its F-actin-binding domain. Our identified conformational landscape of metavinculin suggests a structural priming mechanism that is consistent with the cell adhesion functions of metavinculin in response to mechanical and cellular cues. Our findings expand our understanding of metavinculin function in the heart with implications for the etiologies of cardiomyopathies.

scholarly journals Transition of responsive mechanosensitive elements from focal adhesions to adherens junctions on epithelial differentiation

2018 ◽  
Vol 29 (19) ◽  
pp. 2317-2325 ◽  
Author(s):  
Barbara Noethel ◽  
Lena Ramms ◽  
Georg Dreissen ◽  
Marco Hoffmann ◽  
Ronald Springer ◽  
...  
Keyword(s):  
Mechanical Stress ◽  
Adherens Junctions ◽  
Adhesion Formation ◽  
Focal Adhesions ◽  
Intercellular Junctions ◽  
Cell Junctions ◽  
Epithelial Tissue ◽  
Cell Matrix ◽  
Junction Protein ◽  
Cell Cell

The skin’s epidermis is a multilayered epithelial tissue and the first line of defense against mechanical stress. Its barrier function depends on an integrated assembly and reorganization of cell–matrix and cell–cell junctions in the basal layer and on different intercellular junctions in suprabasal layers. However, how mechanical stress is recognized and which adhesive and cytoskeletal components are involved are poorly understood. Here, we subjected keratinocytes to cyclic stress in the presence or absence of intercellular junctions. Both states not only recognized but also responded to strain by reorienting actin filaments perpendicular to the applied force. Using different keratinocyte mutant strains that altered the mechanical link of the actin cytoskeleton to either cell–matrix or cell–cell junctions, we show that not only focal adhesions but also adherens junctions function as mechanosensitive elements in response to cyclic strain. Loss of paxillin or talin impaired focal adhesion formation and only affected mechanosensitivity in the absence but not presence of intercellular junctions. Further analysis revealed the adherens junction protein α-catenin as a main mechanosensor, with greatest sensitivity conferred on binding to vinculin. Our data reveal a mechanosensitive transition from cell–matrix to cell–cell adhesions on formation of keratinocyte monolayers with vinculin and α-catenin as vital players.

scholarly journals Evolution of mechanisms controlling epithelial morphogenesis across animals: new insights from dissociation - reaggregation experiments in the sponge Oscarella lobularis.

2021 ◽  
Author(s):  
Amelie Vernale ◽  
Maria Mandela Prunster ◽  
Fabio Marchiano ◽  
Henry Debost ◽  
Nicolas Brouilly ◽  
...  
Keyword(s):  
Common Ancestor ◽  
Functional Characterization ◽  
Sister Group ◽  
Epithelial Morphogenesis ◽  
Cell Junctions ◽  
Last Common Ancestor ◽  
Cell Matrix ◽  
Cell Matrix Adhesion ◽  
Cell Cell

Background: The ancestral presence of epithelia in Metazoa is no longer debated. Even though Porifera seem to be the best candidates to be the sister group to all other Metazoa, hardly anything is known about the proteins involved in the composition of cell-cell junctions or about the mechanisms that regulate epithelial morphogenetic processes in this phylum. Results: To get insights into the early evolution of epithelial morphogenesis, we focused on morphogenic characteristics of the homoscleromorph sponge Oscarella lobularis. Homoscleromorpha are a sponge class with a typical basement membrane and adherens-like junctions unknown in other sponge classes. We took advantage of the dynamic context provided by cell dissociation-reaggregation experiments to explore morphogenetic processes in epithelial cells in an early lineage by combining fluorescent and electronic microscopy observations and RNA sequencing approaches at key time-points of the dissociation and reaggregation processes. Conclusions: Our results show that part of the molecular toolkit involved in the loss and restoration of epithelial features such as cell-cell and cell-matrix adhesion is conserved between Homoscleromorpha and Bilateria, suggesting their common role in the last common ancestor of animals. In addition, Sponge-specific genes are differently expressed during the dissociation and reaggregation processes, calling for future functional characterization of these genes.

scholarly journals Evolution of mechanisms controlling epithelial morphogenesis across animals: new insights from dissociation - reaggregation experiments in the sponge Oscarella lobularis

2021 ◽  
Author(s):  
Amélie Vernale ◽  
Maria Mandela Prünster ◽  
Fabio Marchianò ◽  
Henry Debost ◽  
Nicolas Brouilly ◽  
...  
Keyword(s):  
Common Ancestor ◽  
Functional Characterization ◽  
Sister Group ◽  
Epithelial Morphogenesis ◽  
Cell Junctions ◽  
Last Common Ancestor ◽  
Cell Matrix ◽  
Cell Matrix Adhesion ◽  
Cell Cell

Abstract Background: The ancestral presence of epithelia in Metazoa is no longer debated. Even though Porifera seem to be the best candidates to be the sister group to all other Metazoa, hardly anything is known about the proteins involved in the composition of cell-cell junctions or about the mechanisms that regulate epithelial morphogenetic processes in this phylum. Results: To get insights into the early evolution of epithelial morphogenesis, we focused on morphogenic characteristics of the homoscleromorph sponge Oscarella lobularis. Homoscleromorpha are a sponge class with a typical basement membrane and adherens-like junctions unknown in other sponge classes. We took advantage of the dynamic context provided by cell dissociation-reaggregation experiments to explore morphogenetic processes in epithelial cells in an early lineage by combining fluorescent and electronic microscopy observations and RNA sequencing approaches at key time-points of the dissociation and reaggregation processes. Conclusions: Our results show that part of the molecular toolkit involved in the loss and restoration of epithelial features such as cell-cell and cell-matrix adhesion is conserved between Homoscleromorpha and Bilateria, suggesting their common role in the last common ancestor of animals. In addition, Sponge-specific genes are differently expressed during the dissociation and reaggregation processes, calling for future functional characterization of these genes.

scholarly journals Mapping the dynamics of force transduction at cell–cell junctions of epithelial clusters

eLife ◽  
2014 ◽  
Vol 3 ◽  
Author(s):  
Mei Rosa Ng ◽  
Achim Besser ◽  
Joan S Brugge ◽  
Gaudenz Danuser
Keyword(s):  
Cell Junctions ◽  
Force Transmission ◽  
Cell Clusters ◽  
Cell Matrix ◽  
A Cell ◽  
Experimental Approaches ◽  
Cell Adhesions ◽  
Cell Force ◽  
Cell Cell ◽  
Force Transduction

Force transduction at cell-cell adhesions regulates tissue development, maintenance and adaptation. We developed computational and experimental approaches to quantify, with both sub-cellular and multi-cellular resolution, the dynamics of force transmission in cell clusters. Applying this technology to spontaneously-forming adherent epithelial cell clusters, we found that basal force fluctuations were coupled to E-cadherin localization at the level of individual cell-cell junctions. At the multi-cellular scale, cell-cell force exchange depended on the cell position within a cluster, and was adaptive to reconfigurations due to cell divisions or positional rearrangements. Importantly, force transmission through a cell required coordinated modulation of cell-matrix adhesion and actomyosin contractility in the cell and its neighbors. These data provide insights into mechanisms that could control mechanical stress homeostasis in dynamic epithelial tissues, and highlight our methods as a resource for the study of mechanotransduction in cell-cell adhesions.

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