scholarly journals Desmoglein-2 harnesses a PDZ-GEF2/Rap1 signaling axis to control cell spreading and focal adhesions independent of cell–cell adhesion

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
W. Tucker Shelton ◽  
S. Madison Thomas ◽  
Hunter R. Alexander ◽  
C. Evan Thomes ◽  
Daniel E. Conway ◽  
...  
Keyword(s):  
Cell Adhesion ◽  
Control Cell ◽  
Focal Adhesions ◽  
Cell Spreading ◽  
Cell Junctions ◽  
A431 Cells ◽  
Signaling Crosstalk ◽  
Cell Matrix ◽  
And Migration ◽  
Cell Cell

AbstractDesmosomes have a central role in mediating extracellular adhesion between cells, but they also coordinate other biological processes such as proliferation, differentiation, apoptosis and migration. In particular, several lines of evidence have implicated desmosomal proteins in regulating the actin cytoskeleton and attachment to the extracellular matrix, indicating signaling crosstalk between cell–cell junctions and cell–matrix adhesions. In our study, we found that cells lacking the desmosomal cadherin Desmoglein-2 (Dsg2) displayed a significant increase in spreading area on both fibronectin and collagen, compared to control A431 cells. Intriguingly, this effect was observed in single spreading cells, indicating that Dsg2 can exert its effects on cell spreading independent of cell–cell adhesion. We hypothesized that Dsg2 may mediate cell–matrix adhesion via control of Rap1 GTPase, which is well known as a central regulator of cell spreading dynamics. We show that Rap1 activity is elevated in Dsg2 knockout cells, and that Dsg2 harnesses Rap1 and downstream TGFβ signaling to influence both cell spreading and focal adhesion protein phosphorylation. Further analysis implicated the Rap GEF PDZ-GEF2 in mediating Dsg2-dependent cell spreading. These data have identified a novel role for Dsg2 in controlling cell spreading, providing insight into the mechanisms via which cadherins exert non-canonical junction-independent effects.

scholarly journals Topographic cell instructive patterns to control cell adhesion, polarization and migration

2014 ◽  
Vol 11 (100) ◽  
pp. 20140687 ◽  
Author(s):  
Maurizio Ventre ◽  
Carlo Fortunato Natale ◽  
Carmela Rianna ◽  
Paolo Antonio Netti
Keyword(s):  
Cell Adhesion ◽  
Control Cell ◽  
Chemical Properties ◽  
Focal Adhesions ◽  
Adhesive Properties ◽  
Cellular Processes ◽  
Topographic Features ◽  
And Migration ◽  
Specific Length ◽  
And Chemical Properties

Topographic patterns are known to affect cellular processes such as adhesion, migration and differentiation. However, the optimal way to deliver topographic signals to provide cells with precise instructions has not been defined yet. In this work, we hypothesize that topographic patterns may be able to control the sensing and adhesion machinery of cells when their interval features are tuned on the characteristic lengths of filopodial probing and focal adhesions (FAs). Features separated by distance beyond the length of filopodia cannot be readily perceived; therefore, the formation of new adhesions is discouraged. If, however, topographic features are separated by a distance within the reach of filopodia extension, cells can establish contact between adjacent topographic islands. In the latter case, cell adhesion and polarization rely upon the growth of FAs occurring on a specific length scale that depends on the chemical properties of the surface. Topographic patterns and chemical properties may interfere with the growth of FAs, thus making adhesions unstable. To test this hypothesis, we fabricated different micropatterned surfaces displaying feature dimensions and adhesive properties able to interfere with the filopodial sensing and the adhesion maturation, selectively. Our data demonstrate that it is possible to exert a potent control on cell adhesion, elongation and migration by tuning topographic features’ dimensions and surface chemistry.

scholarly journals RAP1-RAC1 Signaling Has an Important Role in Adhesion and Migration in HNSCC

2020 ◽  
Vol 99 (8) ◽  
pp. 959-968 ◽  
Author(s):  
M. Liu ◽  
R. Banerjee ◽  
C. Rossa ◽  
N.J. D’Silva
Keyword(s):  
Cell Migration ◽  
Cell Adhesion ◽  
Matrix Adhesion ◽  
Cell Matrix ◽  
And Migration ◽  
Rap1 Activation ◽  
Cell Matrix Adhesion ◽  
Α5β1 Integrin ◽  
Hnscc Cell ◽  
Cell Cell

Cell-cell adhesion is a key mechanism to control tissue integrity and migration. In head and neck squamous cell carcinoma (HNSCC), cell migration facilitates distant metastases and is correlated with poor prognosis. RAP1, a ras-like protein, has an important role in the progression of HNSCC. RAC1 is an integrin-linked, ras-like protein that promotes cell migration. Here we show that loss of cell-cell adhesion is correlated with inactivation of RAP1 confirmed by 2 different biochemical approaches. RAP1 activation is required for cell-matrix adhesion confirmed by adhesion to fibronectin-coated plates with cells that have biochemically activated RAP1. This effect is reversed when RAP1 is inactivated. In addition, RAP1GTP-mediated adhesion is only facilitated through α5β1 integrin complex and is not a function of either α5 or β1 integrin alone. Moreover, the inside-out signaling of RAP1 activation is coordinated with RAC1 activation. These findings show that RAP1 has a prominent role in cell-matrix adhesion via extracellular matrix molecule fibronectin-induced α5β1 integrin and supports a critical role for the RAP1/RAC1 signaling axis in HNSCC cell migration.

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 Vascular Endothelial-Cadherin Regulates Cytoskeletal Tension, Cell Spreading, and Focal Adhesions by Stimulating RhoA

2004 ◽  
Vol 15 (6) ◽  
pp. 2943-2953 ◽  
Author(s):  
Celeste M. Nelson ◽  
Dana M. Pirone ◽  
John L. Tan ◽  
Christopher S. Chen
Keyword(s):  
Adhesion Formation ◽  
Focal Adhesions ◽  
Cell Spreading ◽  
Cell Contact ◽  
Matrix Adhesion ◽  
Cell Matrix ◽  
Focal Adhesion Formation ◽  
Cytoskeletal Tension ◽  
Cell Matrix Adhesion ◽  
Cell Cell

Changes in vascular endothelial (VE)-cadherin–mediated cell-cell adhesion and integrin-mediated cell-matrix adhesion coordinate to affect the physical and mechanical rearrangements of the endothelium, although the mechanisms for such cross talk remain undefined. Herein, we describe the regulation of focal adhesion formation and cytoskeletal tension by intercellular VE-cadherin engagement, and the molecular mechanism by which this occurs. Increasing the density of endothelial cells to increase cell-cell contact decreased focal adhesions by decreasing cell spreading. This contact inhibition of cell spreading was blocked by disrupting VE-cadherin engagement with an adenovirus encoding dominant negative VE-cadherin. When changes in cell spreading were prevented by culturing cells on a micropatterned substrate, VE-cadherin–mediated cell-cell contact paradoxically increased focal adhesion formation. We show that VE-cadherin engagement mediates each of these effects by inducing both a transient and sustained activation of RhoA. Both the increase and decrease in cell-matrix adhesion were blocked by disrupting intracellular tension and signaling through the Rho-ROCK pathway. In all, these findings demonstrate that VE-cadherin signals through RhoA and the actin cytoskeleton to cross talk with cell-matrix adhesion and thereby define a novel pathway by which cell-cell contact alters the global mechanical and functional state of cells.

scholarly journals Integrin-linked kinase tunes cell-cell and cell-matrix adhesions to regulate the switch between apoptosis and EMT downstream of TGFβ1

2021 ◽  
pp. mbc.E20-02-0092
Author(s):  
Ayse Nihan Kilinc ◽  
Siyang Han ◽  
Lena Barrett ◽  
Niroshan Anandasivam ◽  
Celeste M. Nelson
Keyword(s):  
Cell Adhesion ◽  
Epithelial Cells ◽  
Focal Adhesions ◽  
Cell Phenotype ◽  
High Cell ◽  
Potent Inducer ◽  
Mesenchymal Transition ◽  
Cell Matrix ◽  
Integrin Linked Kinase ◽  
Cell Cell

Epithelial-mesenchymal transition (EMT) is a morphogenetic process that endows epithelial cells with migratory and invasive potential. Mechanical and chemical signals from the tumor microenvironment can activate the EMT program, thereby permitting cancer cells to invade the surrounding stroma and disseminate to distant organs. Transforming growth factor β1 (TGFβ1) is a potent inducer of EMT that can also induce apoptosis depending on the microenvironmental context. In particular, stiff microenvironments promote EMT while softer ones promote apoptosis. Here, we investigated the molecular signaling downstream of matrix stiffness that regulates the phenotypic switch in response to TGFβ1, and uncovered a critical role for integrin-linked kinase (ILK). Specifically, depleting ILK from mammary epithelial cells precludes their ability to sense the stiffness of their microenvironment. In response to treatment with TGFβ1, ILK-depleted cells undergo apoptosis on both soft and stiff substrata. We found that knockdown of ILK decreases focal adhesions and increases cell-cell adhesions, thus shifting the balance from cell-matrix to cell-cell adhesion. High cell-matrix adhesion promotes EMT whereas high cell-cell adhesion promotes apoptosis downstream of TGFβ1. These results highlight an important role for ILK in controlling cell phenotype by regulating adhesive connections to the local microenvironment.

scholarly journals Impairment of cell adhesion and migration by inhibition of protein disulphide isomerases in three breast cancer cell lines

2020 ◽  
Vol 40 (10) ◽  
Author(s):  
Henry S. Young ◽  
Lucy M. McGowan ◽  
Katy A. Jepson ◽  
Josephine C. Adams
Keyword(s):  
Breast Cancer ◽  
Cell Adhesion ◽  
Cancer Cell ◽  
Breast Cancer Cell ◽  
Focal Adhesions ◽  
Cell Spreading ◽  
Secreted Proteins ◽  
Breast Cancer Cell Lines ◽  
Scratch Wound ◽  
And Migration

Abstract Protein disulphide isomerase A3 (PDIA3) is an endoplasmic reticulum (ER)-resident disulphide isomerase and oxidoreductase with known substrates that include some extracellular matrix (ECM) proteins. PDIA3 is up-regulated in invasive breast cancers and correlates in a mouse orthotopic xenograft model with breast cancer metastasis to bone. However, the underlying cellular mechanisms remain unclear. Here we investigated the function of protein disulphide isomerases in attachment, spreading and migration of three human breast cancer lines representative of luminal (MCF-7) or basal (MDA-MB-231 and HCC1937) tumour phenotypes. Pharmacological inhibition by 16F16 decreased initial cell spreading more effectively than inhibition by PACMA-31. Cells displayed diminished cortical F-actin projections, stress fibres and focal adhesions. Cell migration was reduced in a quantified ‘scratch wound’ assay. To examine whether these effects might result from alterations to secreted proteins in the absence of functional PDIA3, adhesion and migration were quantified in the above cells exposed to media conditioned by wildtype (WT) or Pdia3−/− mouse embryonic fibroblasts (MEFs). The conditioned medium (CM) of Pdia3−/− MEFs was less effective in promoting cell spreading and F-actin organisation or supporting ‘scratch wound’ closure. Similarly, ECM prepared from HCC1937 cells after 16F16 inhibition was less effective than control ECM to support spreading of untreated HCC1937 cells. Overall, these results advance the concept that protein disulphide isomerases including PDIA3 drive the production of secreted proteins that promote a microenvironment favourable to breast cancer cell adhesion and motility, characteristics that are integral to tumour invasion and metastasis. Inhibition of PDIA3 or related isomerases may have potential for anti-metastatic therapies.

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.

Regulation of Adhesion Strength by Focal Adhesion Position and Cell Shape

2012 ◽  
Author(s):  
Nathan D. Gallant ◽  
Kranthi Kumar Elineni
Keyword(s):  
Cell Adhesion ◽  
Adhesion Strength ◽  
Cell Shape ◽  
Microcontact Printing ◽  
Control Cell ◽  
Focal Adhesions ◽  
Cell Spreading ◽  
Spreading Area ◽  
Hydrodynamic Shear ◽  
Cell Spreading Area

Cell adhesion to extracellular matrices is critical to numerous cellular functions and is primarily mediated by integrin receptors. Binding and aggregation of integrins leads to the formation of focal adhesions (FA) which connect the cytoskeleton to the extracellular matrix in order to reinforce adhesion and transmit signals [1]. Preliminary observations indicated preferential recruitment of FAs to the periphery of the cell spreading area on both uniformly coated and micropatterned fibronectin surfaces (Fig. 1). The current study investigates the biophysical regulation of cell adhesion strength based on the size and position of FA with the central hypothesis that peripheral FAs stabilize adhesion strength. The hypothesis was tested by delineating the cell spreading area from the total cell adhesive area by employing microcontact printing to pattern substrates with a series of circular and annular adhesive islands which control cell shape (Fig. 2). A well characterized hydrodynamic shear assay known as the spinning disk device was used to quantify the adhesion strength of cells adhered to the micropatterns [2].

scholarly journals FAK and paxillin

2004 ◽  
Vol 166 (2) ◽  
pp. 157-159 ◽  
Author(s):  
Michael D. Schaller
Keyword(s):  
Cell Migration ◽  
Cell Adhesion ◽  
Cell Systems ◽  
Cell Matrix ◽  
Cell Adhesion And Migration ◽  
Positive Regulators ◽  
Cell Adhesions ◽  
And Migration ◽  
New Evidence ◽  
Cell Cell

FAK and paxillin are important components in integrin-regulated signaling. New evidence suggests that these two proteins function in crosstalk between cell–matrix and cell–cell adhesions. Further, new insight suggests that under some conditions these proteins inhibit cell migration, in contrast to their established roles in several cell systems as positive regulators of cell adhesion and migration.

scholarly journals p130Cas-associated Protein (p140Cap) as a New Tyrosine-phosphorylated Protein Involved in Cell Spreading

2004 ◽  
Vol 15 (2) ◽  
pp. 787-800 ◽  
Author(s):  
Paola Di Stefano ◽  
Sara Cabodi ◽  
Elisabetta Boeri Erba ◽  
Valentina Margaria ◽  
Elena Bergatto ◽  
...  
Keyword(s):  
Cell Adhesion ◽  
Growth Factor ◽  
Tyrosine Phosphorylation ◽  
Egf Receptor ◽  
Control Cell ◽  
Focal Adhesions ◽  
Cell Spreading ◽  
Growth Factor Signaling ◽  
Cell Extracts ◽  
Mouse Tissues

Integrin-mediated cell adhesion stimulates a cascade of signaling pathways that control cell proliferation, migration, and survival, mostly through tyrosine phosphorylation of signaling molecules. p130Cas, originally identified as a major substrate of v-Src, is a scaffold molecule that interacts with several proteins and mediates multiple cellular events after cell adhesion and mitogen treatment. Here, we describe a novel p130Cas-associated protein named p140Cap (Cas-associated protein) as a new tyrosine phosphorylated molecule involved in integrin- and epidermal growth factor (EGF)-dependent signaling. By affinity chromatography of human ECV304 cell extracts on a MBP-p130Cas column followed by mass spectrometry matrix-assisted laser desorption ionization/time of flight analysis, we identified p140Cap as a protein migrating at 140 kDa. We detected its expression in human, mouse, and rat cells and in different mouse tissues. Endogenous and transfected p140Cap proteins coimmunoprecipitate with p130Cas in ECV304 and in human embryonic kidney 293 cells and associate with p130Cas through their carboxy-terminal region. By immunofluorescence analysis, we demonstrated that in ECV304 cells plated on fibronectin, the endogenous p140Cap colocalizes with p130Cas in the perinuclear region as well as in lamellipodia. In addition p140Cap codistributes with cortical actin and actin stress fibers but not with focal adhesions. We also show that p140Cap is tyrosine phosphorylated within 15 min of cell adhesion to integrin ligands. p140Cap tyrosine phosphorylation is also induced in response to EGF through an EGF receptor dependent-mechanism. Interestingly expression of p140Cap in NIH3T3 and in ECV304 cells delays the onset of cell spreading in the early phases of cell adhesion to fibronectin. Therefore, p140Cap is a novel protein associated with p130Cas and actin cytoskeletal structures. Its tyrosine phosphorylation by integrin-mediated adhesion and EGF stimulation and its involvement in cell spreading on matrix proteins suggest that p140Cap plays a role in controlling actin cytoskeleton organization in response to adhesive and growth factor signaling.

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