scholarly journals Hemidesmosomes modulate force generation via focal adhesions

2020 ◽  
Vol 219 (2) ◽  
Author(s):  
Wei Wang ◽  
Alba Zuidema ◽  
Lisa te Molder ◽  
Leila Nahidiazar ◽  
Liesbeth Hoekman ◽  
...  

Hemidesmosomes are specialized cell-matrix adhesion structures that are associated with the keratin cytoskeleton. Although the adhesion function of hemidesmosomes has been extensively studied, their role in mechanosignaling and transduction remains largely unexplored. Here, we show that keratinocytes lacking hemidesmosomal integrin α6β4 exhibit increased focal adhesion formation, cell spreading, and traction-force generation. Moreover, disruption of the interaction between α6β4 and intermediate filaments or laminin-332 results in similar phenotypical changes. We further demonstrate that integrin α6β4 regulates the activity of the mechanosensitive transcriptional regulator YAP through inhibition of Rho–ROCK–MLC– and FAK–PI3K–dependent signaling pathways. Additionally, increased tension caused by impaired hemidesmosome assembly leads to a redistribution of integrin αVβ5 from clathrin lattices to focal adhesions. Our results reveal a novel role for hemidesmosomes as regulators of cellular mechanical forces and establish the existence of a mechanical coupling between adhesion complexes.

2004 ◽  
Vol 15 (6) ◽  
pp. 2943-2953 ◽  
Author(s):  
Celeste M. Nelson ◽  
Dana M. Pirone ◽  
John L. Tan ◽  
Christopher S. Chen

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.


1999 ◽  
Vol 112 (18) ◽  
pp. 3081-3090 ◽  
Author(s):  
S. Hiscox ◽  
W.G. Jiang

Ezrin, radixin, moesin and merlin form a subfamily of conserved proteins in the band 4.1 superfamily. The function of these proteins is to link the plasma membrane to the actin cytoskeleton. Merlin is defective or absent in schwannomas and meningiomas and has been suggested to function as a tumour suppressor. In this study, we have examined the role of ezrin as a potential regulator of the adhesive and invasive behaviour of tumour cells. We have shown that following inhibition of ezrin expression in colo-rectal cancer cells using antisense oligonucleotides, these cells displayed a reduced cell-cell adhesiveness together with a gain in their motile and invasive behaviour. These cells also displayed increased spreading over matrix-coated surfaces. Immunofluorescence studies revealed that antisense-treated cells also displayed an increased staining of paxillin in areas representing focal adhesions. Furthermore, coprecipitation studies revealed an association of ezrin with E-cadherin and beta-catenin. Induction of the phosphorylation of ezrin by orthovanadate and hepatocyte growth factor/scatter factor resulted in changes similar to those seen with antisense treatment, together with a marked decrease in the association of ezrin with both beta-catenin and E-cadherin. It is concluded that ezrin regulates cell-cell and cell-matrix adhesion, by interacting with cell adhesion molecules E-cadherin and beta-catenin, and may thus play an important role in the control of adhesion and invasiveness of cancer cells.


2009 ◽  
Vol 186 (3) ◽  
pp. 423-436 ◽  
Author(s):  
Sabina E. Winograd-Katz ◽  
Shalev Itzkovitz ◽  
Zvi Kam ◽  
Benjamin Geiger

Cell adhesion to the extracellular matrix is mediated by elaborate networks of multiprotein complexes consisting of adhesion receptors, cytoskeletal components, signaling molecules, and diverse adaptor proteins. To explore how specific molecular pathways function in the assembly of focal adhesions (FAs), we performed a high-throughput, high-resolution, microscopy-based screen. We used small interfering RNAs (siRNAs) to target human kinases, phosphatases, and migration- and adhesion-related genes. Multiparametric image analysis of control and of siRNA-treated cells revealed major correlations between distinct morphological FA features. Clustering analysis identified different gene families whose perturbation induced similar effects, some of which uncoupled the interfeature correlations. Based on these findings, we propose a model for the molecular hierarchy of FA formation, and tested its validity by dynamic analysis of FA formation and turnover. This study provides a comprehensive information resource on the molecular regulation of multiple cell adhesion features, and sheds light on signaling mechanisms regulating the formation of integrin adhesions.


2004 ◽  
Vol 32 (3) ◽  
pp. 416-420 ◽  
Author(s):  
R. Zaidel-Bar ◽  
M. Cohen ◽  
L. Addadi ◽  
B. Geiger

The adhesion of cells to the extracellular matrix is a dynamic process, mediated by a series of cell-surface and matrix-associated molecules that interact with each other in a spatially and temporally regulated manner. These interactions play a major role in tissue formation, cellular migration and the induction of adhesion-mediated transmembrane signals. In this paper, we show that the formation of matrix adhesions is a hierarchical process, consisting of several sequential molecular events. One of the earliest steps in surface recognition is mediated, in some cells, by a 1 μm-thick cell-surface hyaluronan coat, which precedes the establishment of stable, cytoskeleton-associated adhesions. The earliest forms of these integrin-mediated contacts are dot-shaped FXs (focal complexes), which are formed under the protrusive lamellipodium of migrating cells. These adhesions recruit, sequentially, different anchor proteins that are involved in binding the actin cytoskeleton to the membrane. Conspicuous in its absence from FXs is zyxin, which is recruited to these sites only on retraction of the leading edge and the transformation of the FXs into a focal adhesion. Continuing application of force to focal adhesions results in the formation of fibrillar adhesions and reorganization of the extracellular matrix. The formation of these adhesions depends on actomyosin contractility and matrix pliability.


2007 ◽  
Vol 179 (7) ◽  
pp. 1583-1597 ◽  
Author(s):  
Klodiana Jani ◽  
Frieder Schöck

The integrin family of heterodimeric transmembrane receptors mediates cell–matrix adhesion. Integrins often localize in highly organized structures, such as focal adhesions in tissue culture and myotendinous junctions in muscles. Our RNA interference screen for genes that prevent integrin-dependent cell spreading identifies Z band alternatively spliced PDZ-motif protein (zasp), encoding the only known Drosophila melanogaster Alp/Enigma PDZ-LIM domain protein. Zasp localizes to integrin adhesion sites and its depletion disrupts integrin adhesion sites. In tissues, Zasp colocalizes with βPS integrin in myotendinous junctions and with α-actinin in muscle Z lines. Zasp also physically interacts with α-actinin. Fly larvae lacking Zasp do not form Z lines and fail to recruit α-actinin to the Z line. At the myotendinous junction, muscles detach in zasp mutants with the onset of contractility. Finally, Zasp interacts genetically with integrins, showing that it regulates integrin function. Our observations point to an important function for Zasp in the assembly of integrin adhesion sites both in cell culture and in tissues.


2008 ◽  
Vol 181 (6) ◽  
pp. 1013-1026 ◽  
Author(s):  
Mark D. Bass ◽  
Mark R. Morgan ◽  
Kirsty A. Roach ◽  
Jeffrey Settleman ◽  
Andrew B. Goryachev ◽  
...  

The fibronectin receptors α5β1 integrin and syndecan-4 cocluster in focal adhesions and coordinate cell migration by making individual contributions to the suppression of RhoA activity during matrix engagement. p190Rho–guanosine triphosphatase–activating protein (GAP) is known to inhibit RhoA during the early stages of cell spreading in an Src-dependent manner. This paper dissects the mechanisms of p190RhoGAP regulation and distinguishes the contributions of α5β1 integrin and syndecan-4. Matrix-induced tyrosine phosphorylation of p190RhoGAP is stimulated solely by engagement of α5β1 integrin and is independent of syndecan-4. Parallel engagement of syndecan-4 causes redistribution of the tyrosine-phosphorylated pool of p190RhoGAP between membrane and cytosolic fractions by a mechanism that requires direct activation of protein kinase C α by syndecan-4. Activation of both pathways is necessary for the efficient regulation of RhoA and, as a consequence, focal adhesion formation. Accordingly, we identify p190RhoGAP as the convergence point for adhesive signals mediated by α5β1 integrin and syndecan-4. This molecular mechanism explains the cooperation between extracellular matrix receptors during cell adhesion.


2015 ◽  
Vol 465 (3) ◽  
pp. 383-393 ◽  
Author(s):  
Karry M. Jannie ◽  
Shawn M. Ellerbroek ◽  
Dennis W. Zhou ◽  
Sophia Chen ◽  
David J. Crompton ◽  
...  

Vinculin transduces force and orchestrates mechanical signalling at cell–cell and cell–matrix adhesions. Cells expressing a mutant vinculin deficient in actin binding and bundling display migration and traction force defects. Vinculin binding to actin is critical for cell migration and force generation.


2018 ◽  
Author(s):  
Rishita Changede ◽  
Haogang Cai ◽  
Shalom Wind ◽  
Michael P. Sheetz

AbstractIntegrin-mediated cell matrix adhesions are key to sensing the geometry and rigidity of the extracellular environment to regulate vital cellular processes. In vivo, the extracellular matrix (ECM) is composed of a fibrous mesh. To understand the geometry that supports adhesion formation on fibrous substrates, we patterned 10 nm gold-palladium single lines or pairs of lines (total width within 100 nm), mimicking thin single ECM fibers or a minimal mesh geometry, respectively and functionalized it with integrin binding ligand Arg-Gly-Asp (RGD). Single lines showed reduced focal adhesion kinase (FAK) recruitment and did not support cell spreading or formation of focal adhesions, despite the presence of a high density of integrin-binding ligands. Using super resolution microscopy, we observed transient integrin clusters on single lines, whereas stable 110 nm integrin clusters formed on pairs of lines similar to those on continuous substrates. This indicated that two-dimensional ligand geometry is required for adhesion formation on rigid substrates. A mechanism to form modular 100nm integrin clusters bridging the minimal fiber mesh would require unliganded integrins. We observed that integrin mutants unable to bind ligand co-clustered with ligand-bound integrins when present in an active extended conformation. Thus, these results indicate that functional integrin clusters are required to form focal adhesions and unliganded integrins can co-cluster to bridge between thin matrix fibers and can form stable integrin adhesions on dense fibrous networks.


2018 ◽  
Author(s):  
Hedde van Hoorn ◽  
Dominique M. Donato ◽  
H. Emrah Balcioglu ◽  
Erik H. Danen ◽  
Thomas Schmidt

AbstractCell survival, differentiation, and migration are all dependent on the cell’s interaction with its external environment. In addition to chemical cues, cells react to their physical environment, particularly the stiffness of the substrate. In order for cells to react to these elements, they must make use of cellular machinery to signal changes in their microenvironment. One such proposed machinery is the protein p130Cas, which has been shown to regulate focal adhesion turnover, actin dynamics, and cell migration. Here we show that p130Cas localizes to focal adhesions depending on substrate stiffness and subsequently modulates cellular force exertion. We compared on substrates of tunable stiffness knock-out CAS-/-cells to cells re-expressing either the full-length p130Cas or a mutant lacking the focal adhesion targeting domains. On polyacrylamide gels, we observed that p130Cas prevented focal adhesion formation at low stiffness. On structured micro-pillar arrays, p130Cas preferentially localized to sites of force exertion when the apparent Young’s modulus of the substrate was higher than E = 47 kPa. Stiffness-dependent localization of p130Cas coincided with slower, but increased force exertion for the full-length p130Cas. Cas localization to focal adhesions preceded force build-up by three minutes, suggesting a coordinating role for p130Cas in the cellular mechanoresponse. Thus, p130Cas appears to relay mechanosensory information in the cell through its ability to tune force exertion at the focal adhesion.


2017 ◽  
Author(s):  
Kazuo Katoh

Specific regulation and activation of focal adhesion kinase (FAK) are thought to be important for focal adhesion formation, and activation of Rho-kinase has been suggested to play a role in determining the effects of FAK on the formation of stress fibers and focal adhesions. To clarify the role of FAK in stress fiber formation and focal adhesion organization, we examined the formation of new stress fibers and focal adhesions by activation of Rho-kinase in FAK knockout (FAK–/–) fibroblasts. FAK–/– cells were elliptical in shape, and showed reduced numbers of stress fibers and focal adhesions in the central part of the cells along with large focal adhesions in the peripheral regions. Activation of Rho-kinase in FAK–/– cells transiently increased the actin filaments in the cell center, but these did not form typical thick stress fibers. Moreover, only plaque-like structures as the origins of newly formed focal adhesions were observed in the center of the cell. Furthermore, introduction of an exogenous GFP-labeled FAK gene into FAK–/– cells resulted in increased numbers of stress fibers and focal adhesions in the center of the cells, which showed typical fibroblast morphology. These results indicated that FAK plays an important role in the formation of stress fibers and focal adhesions as well as in regulation of cell shape and morphology with the activation of Rho-kinase.


Sign in / Sign up

Export Citation Format

Share Document