scholarly journals Enhanced RhoA signaling stabilizes E-cadherin in migrating epithelial monolayers

2021 ◽  
Author(s):  
Shafali Gupta ◽  
Kinga Duszyc ◽  
Suzie Verma ◽  
Srikanth Budnar ◽  
Xuan Liang ◽  
...  
Keyword(s):  
Cell Adhesion ◽  
Mechanical Stress ◽  
Adherens Junctions ◽  
Mechanical Tension ◽  
Epithelial Migration ◽  
Epithelial Monolayers ◽  
Rhoa Signaling ◽  
Mcf 7 ◽  
E Cadherin ◽  
Cell Cell

Epithelia migrate as physically coherent populations of cells. Earlier studies revealed that mechanical stress accumulates in these cellular layers as they move. These stresses are characteristically tensile in nature and have often been inferred to arise when moving cells pull upon the cell-cell adhesions that hold them together. We now report that epithelial tension at adherens junctions between migrating cells also increases due to an increase in RhoA-mediated junctional contractility. We find that active RhoA levels were stimulated by p114 RhoGEF at the junctions between migrating MCF-7 monolayers, and this was accompanied by increased levels of actomyosin and mechanical tension. Applying a strategy to restore active RhoA specifically at adherens junctions by manipulating its scaffold, anillin, we found that this junctional RhoA signal was necessary to stabilize junctional E-cadherin during epithelial migration and promoted orderly collective movement. We suggest that stabilization of E-cadherin by RhoA serves to increase cell-cell adhesion against the mechanical stresses of migration.

scholarly journals Enhanced RhoA signaling stabilizes E-cadherin in migrating epithelial monolayers.

2021 ◽  
Author(s):  
Shafali Gupta ◽  
Kinga Duszyc ◽  
Suzie Verma ◽  
Srikanth Budnar ◽  
Xuan Liang ◽  
...  
Keyword(s):  
Cell Adhesion ◽  
Mechanical Stress ◽  
Adherens Junctions ◽  
Mechanical Tension ◽  
Epithelial Migration ◽  
Epithelial Monolayers ◽  
Rhoa Signaling ◽  
Mcf 7 ◽  
E Cadherin ◽  
Cell Cell

Epithelia migrate as physically coherent populations of cells. Earlier studies revealed that mechanical stress accumulates in these cellular layers as they move. These stresses are characteristically tensile in nature and have often been inferred to arise when moving cells pull upon the cell-cell adhesions that hold them together. We now report that epithelial tension at adherens junctions between migrating cells also reflects an increase in RhoAmediated junctional contractility. We find that active RhoA levels were stimulated by p114 RhoGEF at the junctions between migrating MCF-7 monolayers, and this is accompanied by increased levels of actomyosin and mechanical tension. By applying a strategy to restore active RhoA specifically at adherens junctions by manipulating its scaffold, anillin, we found that this junctional RhoA signal was necessary to stabilize junctional E-cadherin during epithelial migration. We suggest that stabilization of E-cadherin by RhoA serves to increase cell-cell adhesion against the mechanical stresses of migration.

scholarly journals Role of Nectin in Formation of E-Cadherin–based Adherens Junctions in Keratinocytes: Analysis with the N-Cadherin Dominant Negative Mutant

2003 ◽  
Vol 14 (4) ◽  
pp. 1597-1609 ◽  
Author(s):  
Yoshinari Tanaka ◽  
Hiroyuki Nakanishi ◽  
Shigeki Kakunaga ◽  
Noriko Okabe ◽  
Tomomi Kawakatsu ◽  
...  
Keyword(s):  
Cell Adhesion ◽  
Adhesion Molecule ◽  
Cell Adhesion Molecule ◽  
Adherens Junctions ◽  
Dominant Negative ◽  
Dominant Negative Mutant ◽  
Adhesion Activity ◽  
Negative Mutant ◽  
E Cadherin ◽  
Cell Cell

E-Cadherin is a Ca2+-dependent cell-cell adhesion molecule at adherens junctions (AJs) of epithelial cells. A fragment of N-cadherin lacking its extracellular region serves as a dominant negative mutant (DN) and inhibits cell-cell adhesion activity of E-cadherin, but its mode of action remains to be elucidated. Nectin is a Ca2+-independent immunoglobulin-like cell-cell adhesion molecule at AJs and is associated with E-cadherin through their respective peripheral membrane proteins, afadin and catenins, which connect nectin and cadherin to the actin cytoskeleton, respectively. We showed here that overexpression of nectin capable of binding afadin, but not a mutant incapable of binding afadin, reduced the inhibitory effect of N-cadherin DN on the cell-cell adhesion activity of E-cadherin in keratinocytes. Overexpressed nectin recruited N-cadherin DN to the nectin-based cell-cell adhesion sites in an afadin-dependent manner. Moreover, overexpression of nectin enhanced the E-cadherin–based cell-cell adhesion activity. These results suggest that N-cadherin DN competitively inhibits the association of the endogenous nectin-afadin system with the endogenous E-cadherin-catenin system and thereby reduces the cell-cell adhesion activity of E-cadherin. Thus, nectin plays a role in the formation of E-cadherin–based AJs in keratinocytes.

scholarly journals RAC1 Regulates Adherens Junctions through Endocytosis of E-Cadherin

2001 ◽  
Vol 12 (4) ◽  
pp. 847-862 ◽  
Author(s):  
Nasreen Akhtar ◽  
Neil A. Hotchin
Keyword(s):  
Cell Adhesion ◽  
Fluorescent Protein ◽  
Adherens Junctions ◽  
Expression Vectors ◽  
Epidermal Keratinocytes ◽  
Human Epidermal Keratinocytes ◽  
Cell Contacts ◽  
Green Fluorescent ◽  
E Cadherin ◽  
Cell Cell

The establishment of cadherin-dependent cell–cell contacts in human epidermal keratinocytes are known to be regulated by the Rac1 small GTP-binding protein, although the mechanisms by which Rac1 participates in the assembly or disruption of cell–cell adhesion are not well understood. In this study we utilized green fluorescent protein (GFP)-tagged Rac1 expression vectors to examine the subcellular distribution of Rac1 and its effects on E-cadherin–mediated cell–cell adhesion. Microinjection of keratinocytes with constitutively active Rac1 resulted in cell spreading and disruption of cell–cell contacts. The ability of Rac1 to disrupt cell–cell adhesion was dependent on colony size, with large established colonies being resistant to the effects of active Rac1. Disruption of cell–cell contacts in small preconfluent colonies was achieved through the selective recruitment of E-cadherin–catenin complexes to the perimeter of multiple large intracellular vesicles, which were bounded by GFP-tagged L61Rac1. Similar vesicles were observed in noninjected keratinocytes when cell–cell adhesion was disrupted by removal of extracellular calcium or with the use of an E-cadherin blocking antibody. Moreover, formation of these structures in noninjected keratinocytes was dependent on endogenous Rac1 activity. Expression of GFP-tagged effector mutants of Rac1 in keratinocytes demonstrated that reorganization of the actin cytoskeleton was important for vesicle formation. Characterization of these Rac1-induced vesicles revealed that they were endosomal in nature and tightly colocalized with the transferrin receptor, a marker for recycling endosomes. Expression of GFP-L61Rac1 inhibited uptake of transferrin-biotin, suggesting that the endocytosis of E-cadherin was a clathrin-independent mechanism. This was supported by the observation that caveolin, but not clathrin, localized around these structures. Furthermore, an inhibitory form of dynamin, known to inhibit internalization of caveolae, inhibited formation of cadherin vesicles. Our data suggest that Rac1 regulates adherens junctions via clathrin independent endocytosis of E-cadherin.

scholarly journals INDUCTION OF EPITHELIAL-TO-MESENCHYMAL TRANSITION IN MCF-7-SNAI1 CELLS LEADS TO REORGANIZATION OF ADHERENS JUNCTIONS AND ACQUISITION OF MIGRATORY ACTIVITY

2018 ◽  
Vol 17 (4) ◽  
pp. 24-29
Author(s):  
I. Y. Zhitnyak ◽  
N. I. Litovka ◽  
S. N. Rubtsova ◽  
N. A. Gloushankova
Keyword(s):  
Cell Adhesion ◽  
Culture Medium ◽  
Epithelial To Mesenchymal Transition ◽  
Epithelial Mesenchymal Transition ◽  
Mesenchymal Phenotype ◽  
Mesenchymal Transition ◽  
Migratory Activity ◽  
Mcf 7 ◽  
E Cadherin ◽  
Cell Cell

Using DIC and confocal microscopy, changes in morphology, migratory characteristics and adherence junctions (AJs) were analyzed in the mammary carcinoma cell line MCF-7-SNAI1  after activation of the EMT transcription factor SNAI1. Western Blot analysis showed that  after removal of tetracycline from the cell culture medium expression of SNAI1 reached its  peak in 24 hours and then plateaued for 7 days. During the 7 days the cells continued to  express E-cadherin; however, tangential AJs typical for cells with stable cell-cell adhesion,  changed into radial AJs. The radial AJs continued to accumulate E-cadherin during 24‑72  hours after tetracycline removal. As a result of SNAI1 activation, the cells underwent  epithelial-mesenchymal transition (EMT) and became migratory. On a two-dimensional  substrate, cells exhibited both individual and collective migration. As the tetracycline  washout period progressed, the fraction of the cells capable of migrating through migration chamber membranes increased; on the contrary, cells’ ability to invade an epithelial  monolayer decreased. These results demonstrate that retaining a hybrid epithelial/mesenchymal  phenotype and accumulation of E-cadherin in AJs during early stages of EMT do not impede  disruption of stable cell-cell adhesion and cells’ acquisition of migratory activity.

scholarly journals Hands and feet: Closer than you think in epithelial migration

2020 ◽  
Vol 219 (10) ◽  
Author(s):  
Shafali Gupta ◽  
Alpha S. Yap
Keyword(s):  
Cell Adhesion ◽  
Adherens Junctions ◽  
Actin Assembly ◽  
Epithelial Migration ◽  
Hands And Feet ◽  
Cell Cell

Epithelial migration requires that substrate-based motility be coordinated with cell–cell adhesion. In this issue, Ozawa et al. (2020. J. Cell Biol.https://doi.org/10.1083/jcb.202006196) identify a central role for actin assembly at adherens junctions that contributes to both of these processes.

scholarly journals Different effects of dominant negative mutants of desmocollin and desmoglein on the cell-cell adhesion of keratinocytes

2000 ◽  
Vol 113 (10) ◽  
pp. 1803-1811
Author(s):  
Y. Hanakawa ◽  
M. Amagai ◽  
Y. Shirakata ◽  
K. Sayama ◽  
K. Hashimoto
Keyword(s):  
Cell Adhesion ◽  
Adherens Junctions ◽  
Dominant Negative ◽  
Cell Contact ◽  
Beta Catenin ◽  
Hacat Cells ◽  
Subsequent Formation ◽  
Contact Sites ◽  
E Cadherin ◽  
Cell Cell

Desmosomes contain two types of cadherin: desmocollin (Dsc) and desmoglein (Dsg). In this study, we examined the different roles that Dsc and Dsg play in the formation of desmosomes, by using dominant-negative mutants. We constructed recombinant adenoviruses (Ad) containing truncated mutants of E-cadherin, desmocollin 3a, and desmoglein 3 lacking a large part of their extracellular domains (EcaddeltaEC, Dsc3adeltaEC, Dsg3deltaEC), using the Cre-loxP Ad system to circumvent the problem of the toxicity of the mutants to virus-producing cells. When Dsc3adeltaEC Ad-infected HaCaT cells were cultured with high levels of calcium, E-cadherin and beta-catenin, which are marker molecules for the adherens junction, disappeared from the cell-cell contact sites, and cell-cell adhesion was disrupted. This also occurred in the cells infected with EcaddeltaEC Ad. With Dsg3deltaEC Ad infection, keratin insertion at the cell-cell contact sites was inhibited and desmoplakin, a marker of desmosomes, was stained in perinuclear dots while the adherens junctions remained intact. Dsc3adeltaEC Ad inhibited the induction of adherens junctions and the subsequent formation of desmosomes with the calcium shift, while Dsg3deltaEC Ad only inhibited the formation of desmosomes. To further determine whether Dsc3adeltaEC directly affected adherens junctions, mouse fibroblast L cells transfected with E-cadherin (LEC5) were infected with these mutant Ads. Both Dsc3adeltaEC and EcaddeltaEC inhibited the cell-cell adhesion of LEC5 cells, as determined by the cell aggregation assay, while Dsg3deltaEC did not. These results indicate that the dominant negative effects of Dsg3deltaEC were restricted to desmosomes, while those of Dsc3adeltaEC were observed in both desmosomes and adherens junctions. Furthermore, the cytoplasmic domain of Dsc3adeltaEC coprecipitated both plakoglobin and beta-catenin in HaCaT cells. In addition, beta-catenin was found to bind the endogenous Dsc in HaCaT cells. These findings lead us to speculate that Dsc interacts with components of the adherens junctions through beta-catenin, and plays a role in nucleating desmosomes after the adherens junctions have been established.

scholarly journals A Novel Role of Nectins in Inhibition of the E-Cadherin–induced Activation of Rac and Formation of Cell-Cell Adherens Junctions

2004 ◽  
Vol 15 (3) ◽  
pp. 1077-1088 ◽  
Author(s):  
Takashi Hoshino ◽  
Kazuya Shimizu ◽  
Tomoyuki Honda ◽  
Tomomi Kawakatsu ◽  
Taihei Fukuyama ◽  
...  
Keyword(s):  
Cell Adhesion ◽  
G Protein ◽  
Adherens Junctions ◽  
Resonance Energy Transfer ◽  
Resonance Energy ◽  
Inhibitory Effect ◽  
Small G Protein ◽  
E Cadherin ◽  
Cell Cell

Nectins are Ca2+-independent immunoglobulin (Ig)-like cell-cell adhesion molecules. The trans-interactions of nectins recruit cadherins to the nectin-based cell-cell adhesion, resulting in formation of cell-cell adherens junctions (AJs) in epithelial cells and fibroblasts. The trans-interaction of E-cadherin induces activation of Rac small G protein, whereas the trans-interactions of nectins induce activation of not only Rac but also Cdc42 small G protein. We showed by the fluorescent resonance energy transfer (FRET) imaging that the trans-interaction of E-cadherin induced dynamic activation and inactivation of Rac, which led to dynamic formation and retraction of lamellipodia. Moreover, we found here that the nectins, which did not trans-interact with other nectins (non–trans-interacting nectins), inhibited the E-cadherin–induced activation of Rac and reduced the velocity of the formation of the E-cadherin-based cell-cell AJs. The inhibitory effect of non–trans-interacting nectins was suppressed by the activation of Cdc42 induced by the trans-interactions of nectins. These results indicate a novel role of nectins in regulation of the E-cadherin–induced activation of Rac and formation of cell-cell AJs.

scholarly journals Cathepsin G, a Neutrophil Protease, Induces Compact Cell-Cell Adhesion in MCF-7 Human Breast Cancer Cells

2009 ◽  
Vol 2009 ◽  
pp. 1-11 ◽  
Author(s):  
Tomoya Kudo ◽  
Hideaki Kigoshi ◽  
Takashi Hagiwara ◽  
Takahisa Takino ◽  
Masatoshi Yamazaki ◽  
...  
Keyword(s):  
Cell Adhesion ◽  
Human Breast Cancer ◽  
Breast Cancer Cells ◽  
Cathepsin G ◽  
Human Breast Cancer Cells ◽  
Human Breast ◽  
Cell Condensation ◽  
Mcf 7 ◽  
E Cadherin ◽  
Cell Cell

Cathepsin G is a serine protease secreted by activated neutrophils that play a role in the inflammatory response. Because neutrophils are known to be invading leukocytes in various tumors, their products may influence the characteristics of tumor cells such as the growth state, motility, and the adhesiveness between cells or the extracellular matrix. Here, we demonstrate that cathepsin G induces cell-cell adhesion of MCF-7 human breast cancer cells resulting from the contact inhibition of cell movement on fibronectin but not on type IV collagen. Cathepsin G subsequently induced cell condensation, a very compact cell colony, resulting due to the increased strength of E-cadherin-mediated cell-cell adhesion. Cathepsin G action is protease activity-dependent and was inhibited by the presence of serine protease inhibitors. Cathepsin G promotes E-cadherin/catenin complex formation and Rap1 activation in MCF-7 cells, which reportedly regulates E-cadherin-based cell-cell junctions. Cathepsin G also promotes E-cadherin/protein kinase D1 (PKD1) complex formation, and Go6976, the selective PKD1 inhibitor, suppressed the cathepsin G-induced cell condensation. Our findings provide the first evidence that cathepsin G regulates E-cadherin function, suggesting that cathepsin G has a novel modulatory role against tumor cell-cell adhesion.

scholarly journals Formation of E-Cadherin/β-Catenin–based Adherens Junctions in Hepatocytes Requires Serine-10 in p27(Kip1)

2008 ◽  
Vol 19 (4) ◽  
pp. 1605-1613 ◽  
Author(s):  
Delphine Théard ◽  
Marcel A. Raspe ◽  
Dharamdajal Kalicharan ◽  
Dick Hoekstra ◽  
Sven C.D. van IJzendoorn
Keyword(s):  
Cell Adhesion ◽  
Hepg2 Cells ◽  
Molecular Mechanisms ◽  
Functional Organization ◽  
Adherens Junctions ◽  
Oncostatin M ◽  
Wild Type ◽  
P27 Kip1 ◽  
E Cadherin ◽  
Cell Cell

The adhesion between epithelial cells at adherens junctions is regulated by signaling pathways that mediate the intracellular trafficking and assembly of its core components. Insight into the molecular mechanisms of this is necessary to understand how adherens junctions contribute to the functional organization of epithelial tissues. Here, we demonstrate that in human hepatic HepG2 cells, oncostatin M-p42/44 mitogen-activated protein kinase signaling stimulates the phosphorylation of p27(Kip1) on Ser-10 and promotes cell–cell adhesion. The overexpression of wild-type p27 or a phospho-mimetic p27S10D mutant in HepG2 cells induces a hyper-adhesive phenotype. In contrast, the overexpression of a nonphosphorylatable p27S10A mutant prevents the mobilization of E-cadherin and β-catenin at the cell surface, reduces basal cell–cell adhesion strength, and prevents the stimulatory effect of oncostatin M on cell–cell adhesion. As part of the underlying molecular mechanism, it is shown that in p27S10A-expressing cells β-catenin interacts with p27 and is prevented from interacting with E-cadherin. The intracellular retention of E-cadherin and β-catenin is also observed in hepatocytes from p27S10A knockin mice that express the p27S10A mutant instead of wild-type p27. Together, these data suggest that the formation of adherens junctions in hepatocytes requires Ser-10 in p27.

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