Faculty Opinions recommendation of Integrins stimulate E-cadherin-mediated intercellular adhesion by regulating Src-kinase activation and actomyosin contractility.

As part of the E-cadherin–β-catenin–αE-catenin complex (CCC), mammalian αE-catenin binds F-actin weakly in the absence of force, whereas cytosolic αE-catenin forms a homodimer that interacts more strongly with F-actin. It has been concluded that cytosolic αE-catenin homodimer is not important for intercellular adhesion because E-cadherin/αE-catenin chimeras thought to mimic the CCC are sufficient to induce cell–cell adhesion. We show that, unlike αE-catenin in the CCC, these chimeras homodimerize, bind F-actin strongly, and inhibit the Arp2/3 complex, all of which are properties of the αE-catenin homodimer. To more accurately mimic the junctional CCC, we designed a constitutively monomeric chimera, and show that E-cadherin–dependent cell adhesion is weaker in cells expressing this chimera compared with cells in which αE-catenin homodimers are present. Our results demonstrate that E-cadherin/αE-catenin chimeras used previously do not mimic αE-catenin in the native CCC, and imply that both CCC-bound monomer and cytosolic homodimer αE-catenin are required for strong cell–cell adhesion.

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Early effects of PP60v-src kinase activation on caveolae

Journal of Cellular Biochemistry ◽

10.1002/(sici)1097-4644(19981215)71:4<524::aid-jcb7>3.0.co;2-b ◽

1998 ◽

Vol 71 (4) ◽

pp. 524-535 ◽

Cited By ~ 22

Author(s):

Young-Gyu Ko ◽

Pingsheng Liu ◽

Ravindra K. Pathak ◽

Leonard C. Craig ◽

Richard G. W. Anderson

Keyword(s):

Src Kinase ◽

Kinase Activation ◽

Early Effects

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Expression of a dominant negative cadherin mutant inhibits proliferation and stimulates terminal differentiation of human epidermal keratinocytes

Journal of Cell Science ◽

10.1242/jcs.109.13.3013 ◽

1996 ◽

Vol 109 (13) ◽

pp. 3013-3023 ◽

Cited By ~ 17

Author(s):

A.J. Zhu ◽

F.M. Watt

Keyword(s):

Cell Adhesion ◽

Terminal Differentiation ◽

Intercellular Adhesion ◽

Dominant Negative ◽

Epidermal Keratinocytes ◽

Dominant Negative Mutant ◽

Beta Catenin ◽

Human Epidermal Keratinocytes ◽

Negative Mutant ◽

E Cadherin

Cell adhesion molecules are not only required for maintenance of tissue integrity, but also regulate many aspects of cell behaviour, including growth and differentiation. While the regulatory functions of integrin extracellular matrix receptors in keratinocytes are well established, such functions have not been investigated for the primary receptors that mediate keratinocyte intercellular adhesion, the cadherins. To examine cadherin function in normal human epidermal keratinocytes we used a retroviral vector to introduce a dominant negative E-cadherin mutant, consisting of the extracellular domain of H-2Kd and the transmembrane and cytoplasmic domains of E-cadherin. As a control a vector containing the same construct, but with the catenin binding site destroyed, was prepared. High levels of expression of the constructs were achieved; the dominant negative mutant, but not the control, formed complexes with alpha-, beta- and gamma-catenin. In cells expressing the dominant negative mutant there was a 5-fold decrease in the level of endogenous cadherins and a 3-fold increase in the level of beta-catenin. Cell-cell adhesion and stratification were inhibited by the dominant negative mutant and desmosome formation was reduced. Expression of the mutant resulted in reduced levels of the alpha 2 beta 1 and alpha 3 beta 1 integrins and increased cell motility, providing further evidence for cross-talk between cadherins and the beta 1 integrins. In view of the widely documented loss of E-cadherin in keratinocyte tumours it was surprising that the dominant negative mutant had an inhibitory effect on keratinocyte proliferation and stimulated terminal differentiation even under conditions in which intercellular adhesion was prevented. These results establish a role for cadherins in regulating keratinocyte growth and differentiation and raise interesting questions as to the relative importance of cell adhesion-dependent and -independent mechanisms.

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The effects of c-Src kinase on EMT signaling pathway in human lens epithelial cells associated with lens diseases

BMC Ophthalmology ◽

10.1186/s12886-019-1229-4 ◽

2019 ◽

Vol 19 (1) ◽

Cited By ~ 4

Author(s):

Xingyu Li ◽

Fang Wang ◽

Meixia Ren ◽

Minjuan Du ◽

Jian Zhou

Keyword(s):

Cell Proliferation ◽

Epithelial Cells ◽

Western Blot ◽

Src Kinase ◽

Human Lens ◽

Lens Epithelial Cells ◽

Protein Levels ◽

Human Lens Epithelial Cells ◽

And Migration ◽

E Cadherin

Abstract Background The signaling pathway of epithelial to mesenchymal transition (EMT) is regulated by c-Src kinase in many cells. The purpose of this study was to investigate the effects of c-Src kinase on EMT of human lens epithelial cells in vivo stimulated by different factors. Methods Human lens epithelial cells, HLE-B3, were exposed to either an inflammatory factor, specifically IL-1α, IL-6, TNF-α or IL-1β, at 10 ng/mL or high glucose (35.5 mM) for 30 mins. Activity of c-Src kinase was evaluated by the expression of p-Src418 with western blot assay. To investigate the effects of activation of c-Src on EMT, HLE-B3 cells were transfected with pCDNA3.1-SrcY530F to upregulate activity of c-Src kinase, and pSlience4.1-ShSrc to knock it down. The expressions of c-Src kinase and molecular markers of EMT such as E-cadherin, ZO-1, α-SMA, and Vimentin were examined at 48 h by RT-PCR and western blot. At 48 h and 72 h of transfection, cell proliferation was detected by MTT, and cell mobility and migration were determined by scratch and transwell assays. Results Activity of c-Src kinase, which causes the expression of p-Src418, was upregulated by different inflammatory factors and high glucose in HLE-B3 cells. When HLE-B3 cells were transfected with pCDNA3.1-SrcY530F, the expression of c-Src kinase was upregulated on both mRNA and protein levels, and activity of c-Src kinase, expression of p-Src418 increased. The expressions of both E-cadherin and ZO-1 were suppressed, while the expressions of vimentin and α-SMA were elevated on both mRNA and protein levels at the same time. Cell proliferation, mobility and migration increased along with activation of c-Src kinase. Conversely, when HLE-B3 cells were transfected with pSlience4.1-ShSrc, both c-Src kinase and p-Src418 expressions were knocked down. The expressions of E-cadherin and ZO-1 increased, but the expressions of Vimentin and α-SMA decreased; meanwhile, cell proliferation, mobility and migration reduced. Conclusions The c-Src kinase in lens epithelial cells is easily activated by external stimuli, resulting in the induction of cell proliferation, mobility, migration and EMT.

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