scholarly journals A Novel Role for Integrin-linked Kinase in Epithelial Sheet Morphogenesis

2005 ◽  
Vol 16 (9) ◽  
pp. 4084-4095 ◽  
Author(s):  
Alisa Vespa ◽  
Sudhir J.A. D'Souza ◽  
Lina Dagnino
Keyword(s):  
Cell Membrane ◽  
Adherens Junction ◽  
Focal Adhesions ◽  
Cell Junctions ◽  
Keratinocyte Differentiation ◽  
Epidermal Keratinocytes ◽  
Cell Periphery ◽  
Integrin Linked Kinase ◽  
E Cadherin ◽  
Cell Cell

Integrin-linked kinase (ILK) is a multidomain protein involved in cell motility and cell-extracellular matrix interactions. ILK is found in integrin-containing focal adhesions in undifferentiated primary epidermal keratinocytes. Induction of keratinocyte differentiation by treatment with Ca2+ triggers formation of cell–cell junctions, loss of focal adhesions, and ILK distribution to cell borders. We now show that Ca2+ treatment of keratinocytes induces rapid (≤1 h) translocation to the cell membrane of the adherens junction (AJ) proteins E-cadherin and β-catenin. This is followed by slower (>6 h) localization of tight junction (TJ) proteins. The kinetics of ILK movement toward the cell periphery mimics that of AJ components, suggesting that ILK plays a role in the early formation of cell–cell contacts. Whereas the N terminus in ILK mediates localization to cell borders, expression of an ILK deletion mutant incapable of localizing to the cell membrane (ILK 191-452) interferes with translocation of E-cadherin/β-catenin to cell borders, precluding Ca2+-induced AJ formation. Cells expressing ILK 191-452 also fail to form TJ and sealed cell–cell borders and do not form epithelial sheets. Thus, we have uncovered a novel role for ILK in epithelial cell–cell adhesion, independent of its well-established role in integrin-mediated adhesion and migration.

scholarly journals Diverse cell junctions with unique molecular composition in tissues of a sponge (Porifera)

EvoDevo ◽  
2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Jennyfer M. Mitchell ◽  
Scott A. Nichols
Keyword(s):  
Extracellular Matrix ◽  
Focal Adhesion ◽  
Adherens Junction ◽  
Focal Adhesions ◽  
Molecular Composition ◽  
Cell Junctions ◽  
Adhesion Proteins ◽  
Focal Adhesion Proteins ◽  
Junction Protein ◽  
Cell Cell

Abstract The integrity and organization of animal tissues depend upon specialized protein complexes that mediate adhesion between cells with each other (cadherin-based adherens junctions), and with the extracellular matrix (integrin-based focal adhesions). Reconstructing how and when these cell junctions evolved is central to understanding early tissue evolution in animals. We examined focal adhesion protein homologs in tissues of the freshwater sponge, Ephydatia muelleri (phylum Porifera; class Demospongiae). Our principal findings are that (1) sponge focal adhesion homologs (integrin, talin, focal adhesion kinase, etc.) co-precipitate as a complex, separate from adherens junction proteins; (2) that actin-based structures resembling focal adhesions form at the cell–substrate interface, and their abundance is dynamically regulated in response to fluid shear; (3) focal adhesion proteins localize to both cell–cell and cell–extracellular matrix adhesions, and; (4) the adherens junction protein β-catenin is co-distributed with focal adhesion proteins at cell–cell junctions everywhere except the choanoderm, and at novel junctions between cells with spicules, and between cells with environmental bacteria. These results clarify the diversity, distribution and molecular composition of cell junctions in tissues of E. muelleri, but raise new questions about their functional properties and ancestry.

scholarly journals Microtubule Disruption in Keratinocytes Induces Cell-Cell Adhesion through Activation of Endogenous E-Cadherin

2001 ◽  
Vol 12 (7) ◽  
pp. 1983-1993 ◽  
Author(s):  
Sun-Ho Kee ◽  
Peter M. Steinert
Keyword(s):  
Cell Adhesion ◽  
Cell Lines ◽  
Epidermal Keratinocytes ◽  
Cell Periphery ◽  
Microtubule Disruption ◽  
Low Calcium ◽  
High Calcium ◽  
Long Term Treatment ◽  
E Cadherin ◽  
Cell Cell

The association of the cytoskeleton with the cadherin–catenin complex is essential for strong cell-cell adhesion in epithelial cells. In this study, we have investigated the effect of microtubule organization on cell-cell adhesion in differentiating keratinocytes. When microtubules of normal human epidermal keratinocytes (NHEKs) grown in low calcium media (0.05 mM) were disrupted with nocodazole or colcemid, cell-cell adhesion was induced through relocalization of the E-cadherin–catenin–actin complex to the cell periphery. This was accompanied by actin polymerization. Also, it was found that microtubule disruption-induced cell-cell adhesion was significantly reduced in more advanced differentiated keratinocytes. For example, when NHEK cells cultured under high calcium (1.2 mM) for 8 d and then in low calcium for 1 d were treated with nocodazole, there was no induction of cell-cell adhesion. Also long-term treatment of a phorbol ester for 48 h inhibited nocodazole-induced cell-cell adhesion of NHEK. Furthermore, this nocodazole-induced cell-cell adhesion could be observed in squamous cancer cell lines (A431 and SCC-5, -9, and -25) under low calcium condition, but not in the keratinocyte cell lines derived from normal epidermis (HaCaT, RHEK). On the other hand, HaCaT cells continuously cultivated in low calcium media regained a less differentiated phenotype such as decreased expression of cytokeratin 10, and increased K5; these changes were accompanied with inducibility of cell-cell adhesion by nocodazole. Together, our results suggest that microtubule disruption can induce the cell-cell adhesion via activation of endogenous E-cadherin in non- or early differentiating keratinocytes. However, this is no longer possible in advanced terminally differentiating keratinocytes, possibly due to irreversible changes effected by cell envelope barrier formation.

scholarly journals Integrin regulation of cell-cell adhesion during epithelial tubule formation

2001 ◽  
Vol 114 (5) ◽  
pp. 941-952 ◽  
Author(s):  
G.K. Ojakian ◽  
D.R. Ratcliffe ◽  
R. Schwimmer
Keyword(s):  
Extracellular Matrix ◽  
Adherens Junction ◽  
Cell Junctions ◽  
Junctional Complex ◽  
Tubule Formation ◽  
Epithelial Remodeling ◽  
Adherens Junction Proteins ◽  
Junction Proteins ◽  
E Cadherin ◽  
Cell Cell

The extracellular matrix plays an important role in regulation of epithelial development and organization. To determine more precisely the function of extracellular matrix in this process, the initial steps in collagen-mediated formation of epithelial tubules were studied using a model cell culture system. Previous studies have demonstrated that incubation of Madin-Darby canine kidney (MDCK) epithelial cells with a collagen gel overlay induces (beta)1 integrin-regulated epithelial remodeling accompanied by extensive cell rearrangements and formation of epithelial tubules. During epithelial remodeling there was extensive disruption of the epithelial junctional complex. Progressive opening of tight junctions was observed over 8 hours using transepithelial resistance measurements and immunofluorescence microscopy demonstrated that tight and adherens junction proteins were dispersed throughout the apical and basolateral membranes. Junction complex disruption allowed the formation of apical cell extensions and subsequent migration of selected cell sheets from the epithelial monolayer. Confocal microscopy demonstrated the presence of adherens junction (E-cadherin, (alpha)-catenin, (beta)-catenin, plakoglobin) and desmosomal (desmoplakin-1/2, plakoglobin) proteins on, and within, cell extensions demonstrating that cell junctions had undergone considerable disassembly. However, groups of cell extensions appeared to be associated by E-cadherin/catenin-mediated interactions. Association of E-cadherin/catenin complexes with the epithelial cytoskeleton was analyzed by differential detergent extraction. SDS-PAGE and immunoblot analysis demonstrated that adherens junction proteins were primarily cytoskeleton-associated in control cells. During integrin-regulated remodeling, there was a progressive reduction in the interaction of adherens junction proteins with the cytoskeleton suggesting that they play an important role in the maintenance of epithelial integrity. Since loss of transepithelial electrical resistance and disruption of junctional complexes were inhibited by an antifunctional integrin antibody, we propose that activation of integrin signaling pathways regulate junctional complex stability, cell-cell interactions and cell migration. These observations provide evidence that integrin-regulated MDCK epithelial tubule formation can serve as a model system for studying rearrangements of epithelial sheets which occur during development.

Mislocalization of Adherens Junction- Associated Proteins in a Patient with Darier Disease

2018 ◽  
Vol 2 (3) ◽  
pp. 184-201
Author(s):  
George D Glinos ◽  
Irena Pastar ◽  
Marjana Tomic-Canic ◽  
Rivka C Stone
Keyword(s):  
Adherens Junction ◽  
Cellular Adhesion ◽  
Calcium Flux ◽  
Keratinocyte Differentiation ◽  
Calcium Dependent ◽  
Endoplasmic Reticulum Calcium ◽  
Darier Disease ◽  
Associated Proteins ◽  
Attachment Proteins ◽  
E Cadherin

Darier disease (DD) is an autosomal dominant keratinizing genodermatosis that manifests clinically with red-brown pruritic papules in a seborrheic distribution often in association with palmoplantar pits and dystrophic nail changes. It is caused by mutation in ATP2A2 which encodes a sarco/endoplasmic reticulum calcium ATPase isoform 2 (SERCA2) pump that regulates calcium flux. Consequent alteration of intracellular calcium homeostasis is thought to impair trafficking of cellular adhesion proteins and to lead to aberrant keratinocyte differentiation, contributing to the characteristic histopathologic features of acantholysis and dyskeratosis in DD, though the precise mechanisms are incompletely understood. Previous studies have identified defective localization of desmosomal attachment proteins in skin biopsies and cultured keratinocytes from DD patients, but reports of effects on adherens junction proteins (including calcium-dependent E-cadherin) are conflicting. Here we describe a case of DD presenting with characteristic clinical and histologic features in which we performed immunofluorescence staining of four adherens junction-associated proteins (E-cadherin, α-catenin, β-catenin, and vinculin). In lesional (acantholytic) DD skin, we identified loss of distinctive bright membranous staining that was present at the periphery of keratinocytes throughout the epidermis in the healthy skin of a matched donor. Perilesional (non-acantholytic) portions of DD skin partially recapitulated the normal phenotype. Our findings support a role for SERCA2 dysfunction in impaired assembly of adherens junctions, which together with defective desmosomes contribute to acantholysis in DD.

scholarly journals Changes in E-cadherin rigidity sensing regulate cell adhesion

2017 ◽  
Vol 114 (29) ◽  
pp. E5835-E5844 ◽  
Author(s):  
Caitlin Collins ◽  
Aleksandra K. Denisin ◽  
Beth L. Pruitt ◽  
W. James Nelson
Keyword(s):  
Cell Adhesion ◽  
Signaling Molecules ◽  
Membrane Dynamics ◽  
Cell Contact ◽  
Adhesion Assay ◽  
Cell Periphery ◽  
Actin Organization ◽  
Rigidity Sensing ◽  
E Cadherin ◽  
Cell Cell

Mechanical cues are sensed and transduced by cell adhesion complexes to regulate diverse cell behaviors. Extracellular matrix (ECM) rigidity sensing by integrin adhesions has been well studied, but rigidity sensing by cadherins during cell adhesion is largely unexplored. Using mechanically tunable polyacrylamide (PA) gels functionalized with the extracellular domain of E-cadherin (Ecad-Fc), we showed that E-cadherin–dependent epithelial cell adhesion was sensitive to changes in PA gel elastic modulus that produced striking differences in cell morphology, actin organization, and membrane dynamics. Traction force microscopy (TFM) revealed that cells produced the greatest tractions at the cell periphery, where distinct types of actin-based membrane protrusions formed. Cells responded to substrate rigidity by reorganizing the distribution and size of high-traction-stress regions at the cell periphery. Differences in adhesion and protrusion dynamics were mediated by balancing the activities of specific signaling molecules. Cell adhesion to a 30-kPa Ecad-Fc PA gel required Cdc42- and formin-dependent filopodia formation, whereas adhesion to a 60-kPa Ecad-Fc PA gel induced Arp2/3-dependent lamellipodial protrusions. A quantitative 3D cell–cell adhesion assay and live cell imaging of cell–cell contact formation revealed that inhibition of Cdc42, formin, and Arp2/3 activities blocked the initiation, but not the maintenance of established cell–cell adhesions. These results indicate that the same signaling molecules activated by E-cadherin rigidity sensing on PA gels contribute to actin organization and membrane dynamics during cell–cell adhesion. We hypothesize that a transition in the stiffness of E-cadherin homotypic interactions regulates actin and membrane dynamics during initial stages of cell–cell adhesion.

scholarly journals HGF Converts ErbB2/Neu Epithelial Morphogenesis to Cell Invasion

2005 ◽  
Vol 16 (2) ◽  
pp. 550-561 ◽  
Author(s):  
Hanane Khoury ◽  
Monica A. Naujokas ◽  
Dongmei Zuo ◽  
Veena Sangwan ◽  
Melanie M. Frigault ◽  
...  
Keyword(s):  
Growth Factor ◽  
Hepatocyte Growth Factor ◽  
Cell Invasion ◽  
Single Cells ◽  
Epithelial Morphogenesis ◽  
Cell Junctions ◽  
Junction Protein ◽  
Hepatocyte Growth ◽  
E Cadherin ◽  
Cell Cell

Activation of the hepatocyte growth factor receptor Met induces a morphogenic response and stimulates the formation of branching tubules by Madin-Darby canine kidney (MDCK) epithelial cells in three-dimensional cultures. A constitutively activated ErbB2/Neu receptor, NeuNT, promotes a similar invasive morphogenic program in MDCK cells. Because both receptors are expressed in breast epithelia, are associated with poor prognosis, and hepatocyte growth factor (HGF) is expressed in stroma, we examined the consequence of cooperation between these signals. We show that HGF disrupts NeuNT-induced epithelial morphogenesis, stimulating the breakdown of cell-cell junctions, dispersal, and invasion of single cells. This correlates with a decrease in junctional proteins claudin-1 and E-cadherin, in addition to the internalization of the tight junction protein ZO-1. HGF-induced invasion of NT-expressing cells is abrogated by pretreatment with a pharmacological inhibitor of the mitogen-activated protein kinase kinase (MEK) pathway, which restores E-cadherin and ZO-1 at cell-cell junctions, establishing the involvement of MEK-dependent pathways in this process. These results demonstrate that physiological signals downstream from the HGF/Met receptor synergize with ErbB2/Neu to enhance the malignant phenotype, promoting the breakdown of cell-cell junctions and enhanced cell invasion. This is particularly important for cancers where ErbB2/Neu is overexpressed and HGF is a physiological growth factor found in the stroma.

scholarly journals Cortical Tension Initiates the Positive Feedback Loop Between E-cadherin and F-actin

2021 ◽  
Author(s):  
Qilin Yu ◽  
William R. Holmes ◽  
Jean P. Thiery ◽  
Rodney B. Luwor ◽  
Vijay Rajagopal
Keyword(s):  
Positive Feedback ◽  
Feedback Loop ◽  
Adherens Junctions ◽  
Force Balance ◽  
Intercellular Junction ◽  
Cell Junctions ◽  
Positive Feedback Loop ◽  
Cortical Tension ◽  
E Cadherin ◽  
Cell Cell

AbstractAdherens junctions (AJs) physically link two cells at their contact interface via extracellular homophilic interactions between cadherin molecules and intracellular connections between cadherins and the actomyosin cortex. Both cadherin and actomyosin cytoskeletal dynamics are reciprocally regulated by mechanical and chemical signals, which subsequently determine the strength of cell-cell adhesions and the emergent organization and stiffness of the tissues they form. However, an understanding of the integrated system is lacking. We present a new mechanistic computational model of intercellular junction maturation in a cell doublet to investigate the mechano-chemical crosstalk that regulates AJ formation and homeostasis. The model couples a 2D lattice-based model of cadherin dynamics with a continuum, reaction-diffusion model of the reorganizing actomyosin network through its regulation by Rho signaling at the intercellular junction. We demonstrate that local immobilization of cadherin induces cluster formation in a cis less dependent manner. We further investigate how cadherin and actin regulate and cooperate. By considering the force balance during AJ maturation and the force-sensitive property of the cadherin/F-actin linking molecules, we show that cortical tension applied on the contact rim can explain the ring distribution of cadherin and F-actin on the cell-cell contact of the cell-doublet. Meanwhile, the positive feedback loop between cadherin and F-actin is necessary for maintenance of the ring. Different patterns of cadherin distribution can be observed as an emergent property of disturbances of this feedback loop. We discuss these findings in light of available experimental observations on underlying mechanisms related to cadherin/F-actin binding and the mechanical environment.Significance StatementThe formation, maintenance and disassembly of adherens junctions (AJs) is fundamental to organ development, tissue integrity as well as tissue function. E-cadherins and F-actin are two major players of the adherens junctions (AJs). Although it is well known that cadherins and F-actin affect each other, how these two players work together to maintain the intercellular contact is unclear. Using a novel mechano-chemical model of E-cadherin and F-actin remodeling, we demonstrate that a positive feedback loop between cadherins and F-actin allows them to stabilize each other locally. Mechanical and chemical stimuli applied to the cell adhesion change E-cadherin and F-actin distribution by consolidating or interrupting the feedback loop locally. Our study mechanistically links mechanical force to E-cadherin patterning at cell-cell junctions.

scholarly journals Minus end–directed motor KIFC3 suppresses E-cadherin degradation by recruiting USP47 to adherens junctions

2014 ◽  
Vol 25 (24) ◽  
pp. 3851-3860 ◽  
Author(s):  
Kyoko Sako-Kubota ◽  
Nobutoshi Tanaka ◽  
Shigenori Nagae ◽  
Wenxiang Meng ◽  
Masatoshi Takeichi
Keyword(s):  
Cell Adhesion ◽  
Proteasome Inhibitors ◽  
Adherens Junction ◽  
Ubiquitin Protein Ligase ◽  
Juxtamembrane Region ◽  
Specific Protease ◽  
Ubiquitin Specific Protease ◽  
Epithelial Sheets ◽  
E Cadherin ◽  
Cell Cell

The adherens junction (AJ) plays a crucial role in maintaining cell–cell adhesion in epithelial tissues. Previous studies show that KIFC3, a minus end–directed kinesin motor, moves into AJs via microtubules that grow from clusters of CAMSAP3 (also known as Nezha), a protein that binds microtubule minus ends. The function of junction-associated KIFC3, however, remains to be elucidated. Here we find that KIFC3 binds the ubiquitin-specific protease USP47, a protease that removes ubiquitin chains from substrates and hence inhibits proteasome-mediated proteolysis, and recruits it to AJs. Depletion of KIFC3 or USP47 promotes cleavage of E-cadherin at a juxtamembrane region of the cytoplasmic domain, resulting in the production of a 90-kDa fragment and the internalization of E-cadherin. This cleavage depends on the E3 ubiquitin protein ligase Hakai and is inhibited by proteasome inhibitors. E-cadherin ubiquitination consistently increases after depletion of KIFC3 or USP47. These findings suggest that KIFC3 suppresses the ubiquitination and resultant degradation of E-cadherin by recruiting USP47 to AJs, a process that may be involved in maintaining stable cell–cell adhesion in epithelial sheets.

Ezrin regulates cell-cell and cell-matrix adhesion, a possible role with E-cadherin/beta-catenin

1999 ◽  
Vol 112 (18) ◽  
pp. 3081-3090 ◽  
Author(s):  
S. Hiscox ◽  
W.G. Jiang
Keyword(s):  
Cancer Cells ◽  
Focal Adhesions ◽  
Beta Catenin ◽  
Matrix Adhesion ◽  
Cell Matrix ◽  
Ezrin Expression ◽  
Coated Surfaces ◽  
Cell Matrix Adhesion ◽  
E Cadherin ◽  
Cell Cell

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.

Integrin-linked kinase is localized to cell-matrix focal adhesions but not cell-cell adhesion sites and the focal adhesion localization of integrin-linked kinase is regulated by the PINCH-binding ANK repeats

1999 ◽  
Vol 112 (24) ◽  
pp. 4589-4599 ◽  
Author(s):  
F. Li ◽  
Y. Zhang ◽  
C. Wu
Keyword(s):  
Focal Adhesion ◽  
Critical Role ◽  
Focal Adhesions ◽  
Subcellular Compartment ◽  
Cell Matrix ◽  
Integrin Binding Site ◽  
Integrin Linked Kinase ◽  
Cell Cell

Integrin-linked kinase (ILK) is a ubiquitously expressed protein serine/threonine kinase that has been implicated in integrin-, growth factor- and Wnt-signaling pathways. In this study, we show that ILK is a constituent of cell-matrix focal adhesions. ILK was recruited to focal adhesions in all types of cells examined upon adhesion to a variety of extracellular matrix proteins. By contrast, ILK was absent in E-cadherin-mediated cell-cell adherens junctions. In previous studies, we have identified PINCH, a protein consisting of five LIM domains, as an ILK binding protein. We demonstrate in this study that the ILK-PINCH interaction requires the N-terminal-most ANK repeat (ANK1) of ILK and one (the C-terminal) of the two zinc-binding modules within the LIM1 domain of PINCH. The ILK ANK repeats domain, which is capable of interacting with PINCH in vitro, could also form a complex with PINCH in vivo. However, the efficiency of the complex formation or the stability of the complex was markedly reduced in the absence of the C-terminal domain of ILK. The PINCH binding defective ANK1 deletion ILK mutant, unlike the wild-type ILK, was unable to localize and cluster in focal adhesions, suggesting that the interaction with PINCH is necessary for focal adhesion localization and clustering of ILK. The N-terminal ANK repeats domain, however, is not sufficient for mediating focal adhesion localization of ILK, as an ILK mutant containing the ANK repeats domain but lacking the C-terminal integrin binding site failed to localize in focal adhesions. These results suggest that focal adhesions are a major subcellular compartment where ILK functions in intracellular signal transduction, and provide important evidence for a critical role of PINCH and integrins in regulating ILK cellular function.

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