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 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 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.

Investigation of the role of beta 1 integrins in cell-cell adhesion

1995 ◽  
Vol 108 (11) ◽  
pp. 3635-3644 ◽  
Author(s):  
J.B. Weitzman ◽  
A. Chen ◽  
M.E. Hemler
Keyword(s):  
Cell Adhesion ◽  
Cell Lines ◽  
Cho Cells ◽  
Chinese Hamster ◽  
Inhibitory Effect ◽  
Laminin 5 ◽  
Widespread Phenomenon ◽  
Mediate Cell ◽  
Cell Cell

Various beta 1 integrins (VLA-2, VLA-3, VLA-4) have been suggested to bind directly to themselves or to each other, thus mediating cell-cell adhesion. Here we expressed the human alpha 2 and alpha 3 subunits in three different cell lines (human erythroleukemia K562, human rhabdomyosarcoma RD and Chinese hamster ovary CHO cells). Although cell surface alpha 2 beta 1 and alpha 3 beta 1 in the transfectants mediated adhesion to matrix ligands (collagen or laminin 5, respectively), in no case did we observe enhanced cell-cell adhesion. In the presence of a range of different divalent cation concentrations, stimulatory anti-beta 1 antibodies or anti-alpha 3 antibodies, VLA-2 and VLA-3 still did not appear to interact directly, through either heterophilic (i.e. VLA-3/VLA-2) or homophilic (i.e. VLA-3/VLA-3) mechanisms, to mediate cell-cell adhesion. Furthermore, in some but not all alpha 3 transfectants we observed an unexpected decrease in cell-cell adhesion, suggesting a novel anti-adhesive function. This inhibitory effect was not observed for alpha 2 transfection nor when the alpha 3 cytoplasmic tail was exchanged with that of another integrin alpha subunit. Finally, no evidence for VLA-4/VLA-4 mediated cell-cell adhesion was observed using alpha 4-transfected K562 and CHO cells. In conclusion, using many different combinations of cell lines, we found that cell-cell adhesion mediated by direct integrin/integrin interaction is not a widespread phenomenon, and is not observable in standard cell-cell adhesion assays. Furthermore, in some cell combinations, alpha 3 expression may actually cause diminished cell-cell adhesion.

scholarly journals CD151 regulates epithelial cell–cell adhesion through PKC- and Cdc42-dependent actin cytoskeletal reorganization

2003 ◽  
Vol 163 (1) ◽  
pp. 165-176 ◽  
Author(s):  
Masaki Shigeta ◽  
Noriko Sanzen ◽  
Masayuki Ozawa ◽  
Jianguo Gu ◽  
Hitoshi Hasegawa ◽  
...  
Keyword(s):  
Cell Adhesion ◽  
Epithelial Cell ◽  
Cytoskeletal Reorganization ◽  
Cortical Actin ◽  
A431 Cells ◽  
Kinase C ◽  
Integrin Α3β1 ◽  
E Cadherin ◽  
Cell Cell

CD151, a member of the tetraspanin family proteins, tightly associates with integrin α3β1 and localizes at basolateral surfaces of epithelial cells. We found that overexpression of CD151 in A431 cells accelerated intercellular adhesion, whereas treatment of cells with anti-CD151 mAb perturbed the integrity of cortical actin filaments and cell polarity. E-Cadherin puncta formation, indicative of filopodia-based adhesion zipper formation, as well as E-cadherin anchorage to detergent-insoluble cytoskeletal matrix, was enhanced in CD151-overexpressing cells. Levels of GTP-bound Cdc42 and Rac were also elevated in CD151-overexpressing cells, suggesting the role of CD151 in E-cadherin–mediated cell–cell adhesion as a modulator of actin cytoskeletal reorganization. Consistent with this possibility, engagement of CD151 by the substrate-adsorbed anti-CD151 mAb induced prominent Cdc42-dependent filopodial extension, which along with E-cadherin puncta formation, was strongly inhibited by calphostin C, a protein kinase C (PKC) inhibitor. Together, these results indicate that CD151 is involved in epithelial cell–cell adhesion as a modulator of PKC- and Cdc42-dependent actin cytoskeletal reorganization.

Mouse proximal tubular cell-cell adhesion inhibits apoptosis by a cadherin-dependent mechanism

2000 ◽  
Vol 278 (5) ◽  
pp. F758-F768 ◽  
Author(s):  
Eoin Bergin ◽  
Jerrold S. Levine ◽  
Jason S. Koh ◽  
Wilfred Lieberthal
Keyword(s):  
Cell Adhesion ◽  
Primary Cultures ◽  
Cell Aggregation ◽  
Cell Matrix ◽  
Proximal Tubular ◽  
Cell Matrix Interactions ◽  
Suspended Cells ◽  
E Cadherin ◽  
Cell Cell

Adhesion of epithelial cells to matrix is known to inhibit apoptosis. However, the role of cell-cell adhesion in mediating cell survival remains uncertain. Primary cultures of mouse proximal tubular (MPT) cells were used to examine the role of cell-cell adhesion in promoting survival. When MPT cells were deprived of both cell-matrix and cell-cell adhesion, they died by apoptosis. However, when incubated in agarose-coated culture dishes (to prevent cell-matrix adhesion) and at high cell density (to allow cell-cell interactions), MPT cells adhered to one another and remained viable. Expression of E-cadherin among suspended, aggregating cells increased with time. A His-Ala-Val (HAV)-containing peptide that inhibits homophilic E-cadherin binding prevented cell-cell aggregation and promoted apoptosis of MPT cells in suspension. By contrast, inhibition of potential β1-integrin-mediated interactions between cells in suspension did not prevent either aggregation or survival of suspended cells. Aggregation of cells in suspension activated phosphatidylinositol 3-kinase (PI3K), an event that was markedly reduced by the presence of the HAV peptide. LY-294002, an inhibitor of PI3K, also inhibited survival of suspended cells. In summary, we provide novel evidence that MPT cells, when deprived of normal cell-matrix interactions, can adhere to one another in a cadherin-dependent fashion and remain viable. Survival of aggregated cells depends on activation of PI3K.

scholarly journals Role of Cadherins in Cancer—A Review

2020 ◽  
Vol 21 (20) ◽  
pp. 7624
Author(s):  
Ilona Kaszak ◽  
Olga Witkowska-Piłaszewicz ◽  
Zuzanna Niewiadomska ◽  
Bożena Dworecka-Kaszak ◽  
Felix Ngosa Toka ◽  
...  
Keyword(s):  
Cell Adhesion ◽  
Tumor Progression ◽  
Signaling Pathways ◽  
Rho Gtpases ◽  
Epithelial Mesenchymal Transition ◽  
Clinical Importance ◽  
Mesenchymal Transition ◽  
E Cadherin ◽  
Cell Cell

Cadherins play an important role in tissue homeostasis, as they are responsible for cell-cell adhesion during embryogenesis, tissue morphogenesis, differentiation and carcinogenesis. Cadherins are inseparably connected with catenins, forming cadherin-catenin complexes, which are crucial for cell-to-cell adherence. Any dysfunction or destabilization of cadherin-catenin complex may result in tumor progression. Epithelial mesenchymal transition (EMT) is a mechanism in which epithelial cadherin (E-cadherin) expression is lost during tumor progression. However, during tumorigenesis, many processes take place, and downregulation of E-cadherin, nuclear β-catenin and p120 catenin (p120) signaling are among the most critical. Additional signaling pathways, such as Receptor tyrosine kinase (RTK), Rho GTPases, phosphoinositide 3-kinase (PI3K) and Hippo affect cadherin cell-cell adhesion and also contribute to tumor progression and metastasis. Many signaling pathways may be activated during tumorigenesis; thus, cadherin-targeting drugs seem to limit the progression of malignant tumor. This review discusses the role of cadherins in selected signaling mechanisms involved in tumor growth. The clinical importance of cadherin will be discussed in cases of human and animal cancers.

scholarly journals A-CAM: a 135-kD receptor of intercellular adherens junctions. II. Antibody-mediated modulation of junction formation.

1986 ◽  
Vol 103 (4) ◽  
pp. 1451-1464 ◽  
Author(s):  
T Volk ◽  
B Geiger
Keyword(s):  
Cell Adhesion ◽  
Adherens Junctions ◽  
Adherens Junction ◽  
Recovery Phase ◽  
Inhibitory Effect ◽  
Cell Junctions ◽  
Specific Cell ◽  
Normal Medium ◽  
Junction Formation ◽  
Cell Cell

Intercellular adherens junctions between cultured lens epithelial cells are highly Ca2+-dependent and are readily dissociated upon chelation of extracellular Ca2+ ions. Addition of Ca2+ to EGTA-treated cells results in the recovery of cell-cell junctions including the reorganization of adherens junction-specific cell adhesion molecule (A-CAM), vinculin, and actin (Volk, T., and B. Geiger, 1986, J. Cell Biol., 103:000-000). Incubation of cells during the recovery phase with Fab' fragments of anti-A-CAM specifically inhibited the re-formation of cell-cell adherens junctions. This inhibition was accompanied by remarkable changes in microfilament organization manifested by an apparent deterioration of stress fibers and the appearance of fragmented actin bundles throughout the cytoplasm. Incubation of EGTA-dissociated cells with intact divalent anti-A-CAM antibodies in normal medium had no apparent inhibitory effect on junction formation and did not affect the assembly of actin microfilament bundles. Moreover, adherens junctions formed in the presence of the divalent antibodies became essentially Ca2+-independent, suggesting that cell-cell adhesion between them was primarily mediated by the antibodies. These studies suggest that A-CAM participates in intercellular adhesion in adherens-type junctions and point to its involvement in microfilament bundle assembly.

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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