Tyrosine Phosphorylation of VE-cadherin Prevents Binding of p120- and β-Catenin and Maintains the Cellular Mesenchymal State

In several pathological conditions, epithelial cells demonstrate a breakdown of barrier function and acquire an invasive phenotype. Endothelial cells in particular are maintained in a mesenchymal state during the cell invasion phase of angiogenesis. We show here that tyrosine phosphorylation of the adherens junction protein VE-cadherin at two critical tyrosines, Tyr-658 and Tyr-731, via tyrosine kinase activation or phosphatase inactivation was sufficient to prevent the binding of p120- and β-catenin, respectively, to the cytoplasmic tail of VE-cadherin. In fact, phosphorylation at either site led to the inhibition of cell barrier function. Cells expressing wild-type VE-cadherin showed decreased cell migration compared with cells lacking VE-cadherin, whereas expression of VE-cadherin with a simple phosphomimetic tyrosine-to-glutamic acid mutation of Y658E or Y731E was sufficient to restore the migratory response. These findings demonstrate that a single phosphorylation event within the VE-cadherin cytoplasmic tail is sufficient to maintain cells in a mesenchymal state. In several pathological conditions, epithelial cells demonstrate a breakdown of barrier function and acquire an invasive phenotype. Endothelial cells in particular are maintained in a mesenchymal state during the cell invasion phase of angiogenesis. We show here that tyrosine phosphorylation of the adherens junction protein VE-cadherin at two critical tyrosines, Tyr-658 and Tyr-731, via tyrosine kinase activation or phosphatase inactivation was sufficient to prevent the binding of p120- and β-catenin, respectively, to the cytoplasmic tail of VE-cadherin. In fact, phosphorylation at either site led to the inhibition of cell barrier function. Cells expressing wild-type VE-cadherin showed decreased cell migration compared with cells lacking VE-cadherin, whereas expression of VE-cadherin with a simple phosphomimetic tyrosine-to-glutamic acid mutation of Y658E or Y731E was sufficient to restore the migratory response. These findings demonstrate that a single phosphorylation event within the VE-cadherin cytoplasmic tail is sufficient to maintain cells in a mesenchymal state. Cadherins are important regulators of a number of epithelial cell barriers (1Perez-Moreno M. Jamora C. Fuchs E. Cell. 2003; 112: 535-548Abstract Full Text Full Text PDF PubMed Scopus (616) Google Scholar). While allowing cells to maintain impermeable cell monolayers, cadherins also act to prevent epithelial cell motility. During the epithelial to mesenchymal transition (EMT), 1The abbreviations used are: EMT, epithelial to mesenchymal transition; CA, constitutively active; CHO, Chinese hamster ovary; FAK, focal adhesion kinase; GFP, green fluorescent protein; HRP, horseradish peroxidase; PBS, phosphate-buffered saline; PTP, protein tyrosine phosphatase; PV, pervanadate; VEGF, vascular endothelial growth factor. epithelial cells acquire an invasive phenotype characterized by breakdown of cadherin-mediated cell-cell junctions and increased cell invasive activity (2Hazan R.B. Qiao R. Keren R. Badano I. Suyama K. Ann. N. Y. Acad. Sci. 2004; 1014: 155-163Crossref PubMed Scopus (481) Google Scholar). EMT has been associated with changes in cadherin cell surface expression, adhesive activity, and/or cytoskeletal linkage (3Berx G. Cleton-Jansen A.M. Nollet F. de Leeuw W.J. van de Vijver M. Cornelisse C. van Roy F. EMBO J. 1995; 14: 6107-6115Crossref PubMed Scopus (658) Google Scholar, 4Handschuh G. Candidus S. Luber B. Reich U. Schott C. Oswald S. Becke H. Hutzler P. Birchmeier W. Hofler H. Becker K.F. Oncogene. 1999; 18: 4301-4312Crossref PubMed Scopus (177) Google Scholar). The molecular mechanisms by which these processes occur are not entirely understood. VE-cadherin is an endothelium-specific cell-cell junctional protein that plays a critical role in vascular barrier function and angiogenesis (5Dejana E. Bazzoni G. Lampugnani M.G. Exp. Cell Res. 1999; 252: 13-19Crossref PubMed Scopus (209) Google Scholar, 6Vincent P.A. Xiao K. Buckley K.M. Kowalczyk A.P. Am. J. Physiol. 2004; 286: C987-C997Crossref PubMed Scopus (145) Google Scholar). The breakdown of the endothelial cell barrier leads to vascular permeability and remodeling, which are associated with a number of disease processes including cancer, inflammation, and ischemic injury. Additionally, endothelial cells must be maintained in a mesenchymal state during the invasive stage of angiogenesis. Vascular endothelial cell growth factor (VEGF) is produced in response to ischemic injury and cancer and has a profound influence on VE-cadherin and its capacity to mediate cell-cell adhesion (7Carmeliet P. Collen D. Ann. N. Y. Acad. Sci. 2000; 902: 249-262Crossref PubMed Scopus (227) Google Scholar, 8Weis S. Cui J. Barnes L. Cheresh D. J. Cell Biol. 2004; 167: 223-229Crossref PubMed Scopus (389) Google Scholar, 9Hicklin D.J. Ellis L.M. J. Clin. Oncol. 2005; 23: 1011-1027Crossref PubMed Scopus (2476) Google Scholar). Like all cadherin-mediated interactions, the integrity of the endothelial cell-cell junction depends on the adhesive function and cell surface expression of VE-cadherin as well as the ability of VE-cadherin to assemble with the underlying cytoskeleton. Cadherin-cytoskeletal interactions occur through a number of adaptor proteins that interact with the C-terminal portion of the cadherin cytoplasmic tail, including the α-, β-, and γ-catenin (6Vincent P.A. Xiao K. Buckley K.M. Kowalczyk A.P. Am. J. Physiol. 2004; 286: C987-C997Crossref PubMed Scopus (145) Google Scholar, 10Gumbiner B.M. Cell. 1996; 84: 345-357Abstract Full Text Full Text PDF PubMed Scopus (2930) Google Scholar). Additionally, VE-cadherin stability at the plasma membrane may be regulated by the binding of p120-catenin to the juxtamembrane region of the cytoplasmic tail (11Iyer S. Ferreri D.M. DeCocco N.C. Minnear F.L. Vincent P.A. Am. J. Physiol. 2004; 286: L1143-L1153Crossref PubMed Scopus (108) Google Scholar, 12Reynolds A.B. Roczniak-Ferguson A. Oncogene. 2004; 23: 7947-7956Crossref PubMed Scopus (231) Google Scholar, 13Xiao K. Allison D.F. Buckley K.M. Kottke M.D. Vincent P.A. Faundez V. Kowalczyk A.P. J. Cell Biol. 2003; 163: 535-545Crossref PubMed Scopus (346) Google Scholar). Growth factor- and cytokine-mediated signaling has been linked to the regulation of cadherins and their adhesion mechanisms (14Wheelock M.J. Johnson K.R. Curr. Opin. Cell Biol. 2003; 15: 509-514Crossref PubMed Scopus (234) Google Scholar, 15Cavallaro U. Christofori G. Nat. Rev. Cancer. 2004; 4: 118-132Crossref PubMed Scopus (1053) Google Scholar). In fact, tyrosine phosphorylation of the cadherin cytoplasmic tail or its catenin binding partners is thought to regulate cadherin adhesion and cell surface expression (16Lampugnani M.G. Corada M. Andriopoulou P. Esser S. Risau W. Dejana E. J. Cell Sci. 1997; 110: 2065-2077Crossref PubMed Google Scholar, 17Esser S. Lampugnani M.G. Corada M. Dejana E. Risau W. J. Cell Sci. 1998; 111: 1853-1865Crossref PubMed Google Scholar, 18Andriopoulou P. Navarro P. Zanetti A. Lampugnani M.G. Dejana E. Arterioscler. Thromb. Vasc. Biol. 1999; 19: 2286-2297Crossref PubMed Scopus (202) Google Scholar, 19Roura S. Miravet S. Piedra J. Garcia de Herreros A. Dunach M. J. Biol. Chem. 1999; 274: 36734-36740Abstract Full Text Full Text PDF PubMed Scopus (510) Google Scholar, 20Lambeng N. Wallez Y. Rampon C. Cand F. Christe G. Gulino-Debrac D. Vilgrain I. Huber P. Circ. Res. 2005; 96: 384-391Crossref PubMed Scopus (96) Google Scholar, 21Verin A.D. Am. J. Pathol. 2005; 166: 955-957Abstract Full Text Full Text PDF PubMed Scopus (10) Google Scholar). However, it remains unclear how this process is regulated and which tyrosine sites on cadherins are essential for the regulation of cell-cell junctional activity. To begin to understand the molecular events involved in the regulation of cadherin function, we stably expressed either wild-type or various mutants of VE-cadherin in CHO cells lacking endogenous cadherins. We identified two critical regulatory phosphorylation sites within the tail of VE-cadherin that lead to the disruption of cell-cell junctions. Phosphorylation of Tyr-658 and Tyr-731 leads to uncoupling of p120- or β-catenin, respectively, from the cytoplasmic tail of VE-cadherin. In fact, phosphomimetic mutations of Tyr-658 to Glu-658 or Tyr-731 to Glu-731 are not only sufficient to uncouple cell-cell junctions, but they also promote focal contact assembly and lead to cell migration. This change in biological behavior could not be explained by a simple loss of functional cadherin from the cell surface. These findings demonstrate that phosphorylation of a single tyrosine in a cadherin cytoplasmic domain is sufficient to maintain cells in a mesenchymal, invasive phenotype. Construction of Cell Lines Expressing VE-cadherin—cDNA of human VE-cadherin fused in-frame with GFP at the C terminus was a gift of Dr. Sunil Shaw (Harvard University). VE-cadherin-GFP was subcloned into pcDNA3.1 (Invitrogen). Y-E, Y-F, and Y-A mutants of VE-cadherin were constructed using the QuikChange site-directed mutagenesis kit (Stratagene). Plasmids were transfected into CHO cells using Lipofectamine PLUS (Invitrogen). CHO cells were cultured in complete Ham's F12 medium containing 10% fetal bovine serum, 2 mm GlutaMax (Invitrogen), 100 units/ml penicillin, 100 μg/ml streptomycin, 250 ng/ml amphotericin B, and 50 μg/ml gentamicin. Stable cell lines were selected using 500 μg/ml G418. Resistant cells were pooled and sorted by flow cytometry based on both GFP fluorescence and VE-cadherin cell surface expression. Because uniform flow cytometry gates were used to select the cells, all lines displayed approximately equivalent amounts of cell surface VE-cadherin. Biochemical Characterization of VE-cadherin Complexes—CHO cells were washed twice with cold PBS and lysed in 1% Triton X-100, 10% glycerol, 20 mm Tris (pH 7.5), 137 mm NaCl, 2 mm CaCl2, 10 mm NaF, 1× complete protease inhibitor mixture (Roche Applied Science), and 100 μm pervanadate (PV; prepared according to Ref. 16Lampugnani M.G. Corada M. Andriopoulou P. Esser S. Risau W. Dejana E. J. Cell Sci. 1997; 110: 2065-2077Crossref PubMed Google Scholar). Protein concentrations of cell extracts were determined using the BCA protein assay (Pierce), and VE-cadherin was immunoprecipitated from 500 μg of extract using 2 μg of anti-VE-cadherin antibody (C-19, Santa Cruz Biotechnology) followed by 10 μl of UltraLink protein A/G beads (Pierce). Beads were washed four times using cold PBS containing 300 μm PV, boiled in SDS-PAGE loading buffer, and resolved by SDS-PAGE. Gels were transferred onto nitrocellulose, and immunoblotting was carried out using antibodies against a number of proteins including VE-cadherin (C-19, Santa Cruz), p120-catenin (S-19, Santa Cruz), β-catenin (E-5, Santa Cruz), phosphotyrosine (PY99, Santa Cruz), Santa Cruz), Cell Cell and The and of were using cells were to with 100 μm for 20 at to tyrosine and kinase activity. cells were transfected with a constitutively to cell Cell CHO cells was into Cells were for was to the to a of 10 μl of medium was from the for to The of in the was by the 10 μl of medium with μl of single for followed by the of 100 μl of to the The of the at was determined and is of the of in the were with 10 μg/ml on the of the membrane and μg/ml on the of the cells, in complete Ham's F12 were into the at for the were for in and were in and cells were from the of the using a were and the in the migratory cells on the of the membrane was using and by at expressing VE-cadherin were on and in in PBS for 20 at were in mm in PBS for at Cells were in Triton in PBS for at and in bovine in PBS for at were in antibody to 2 μg/ml in for at were washed times in PBS and with antibody to μg/ml in and to in for at were washed times in PBS and using were using a with a and were for and using of the portion of human VE-cadherin was in of the portion of human into the expression (Invitrogen), was transfected into cells using Lipofectamine Stable were selected using 300 μg/ml B. cells were in medium with 2 mm GlutaMax and 100 μg/ml for during which the protein was into the protein was using a protein were using 10 μg/ml protein or human at were using 1% bovine for at and washed with cells, in μl of Ham's F12 were to were at for and at for 2 100 μl of was to the for were for in and and washed twice with in the cells was using and by at of in the of of cadherins or their associated proteins has been linked to changes in cadherin-mediated adhesive function. are in the cytoplasmic tail of VE-cadherin but their function remains To phosphorylation of or of these sites a role in cadherin function, wild-type VE-cadherin and VE-cadherin containing phosphomimetic tyrosine-to-glutamic acid mutations were stably expressed in CHO cells lacking endogenous cadherins. CHO cells are mesenchymal, of focal contact and migration not We that of wild-type VE-cadherin into CHO cells the cells to acquire an epithelial phenotype. we expression of of VE-cadherin in these cells the epithelial phenotype. To the functional of the phosphomimetic cells expressing wild-type or cadherins were to in and the barrier function of the cell was as by permeability to Cells expressing wild-type VE-cadherin showed increased barrier function compared with cells However, cells expressing either the Y658E or Y731E mutations displayed or barrier function, and mutations were These findings that both Tyr-658 and Tyr-731 regulate cell barrier function. Cadherins interact with the via that to the cadherin cytoplasmic were to the mutations that in disruption of cell barrier function could influence the binding of or to VE-cadherin within the of VE-cadherin containing the Y658E or Y731E mutations p120- or β-catenin, respectively, binding to the whereas all mutations were In expression of the mutations of VE-cadherin, and also in a complete loss of binding to p120- and β-catenin, not findings that of these sites VE-cadherin junctional activity. of Phosphorylation and that a role in cadherin regulation S. Cui J. Barnes L. Cheresh D. J. Cell Biol. 2004; 167: 223-229Crossref PubMed Scopus (389) Google Scholar, R. J. Cheresh Cell. 1999; 4: Full Text Full Text PDF PubMed Scopus Google Scholar, S. S. A. R. M. A. H. A. N. D. J. R. D. Cheresh D. J. Clin. 2004; PubMed Scopus Google Scholar, N. M. S. A. S. M. J. Cell Biol. PubMed Scopus Google Scholar, H. A. S. S. J. Birchmeier W. J. Cell Biol. 1995; PubMed Scopus Google Scholar). To phosphorylation of the VE-cadherin sites Tyr-658 and Tyr-731 be by CHO cells expressing wild-type or cadherin were transfected with of in cell in increased expression and phosphorylation of as wild-type VE-cadherin was in response to expression, the of VE-cadherin was at These findings that lead to the phosphorylation of Tyr-658 and Tyr-731 and may for the well role that in cell-cell junctional activity. However, these findings not a and role for in this phosphorylation is regulated by a and In fact, of cadherin regulation is to occur via tyrosine (16Lampugnani M.G. Corada M. Andriopoulou P. Esser S. Risau W. Dejana E. J. Cell Sci. 1997; 110: 2065-2077Crossref PubMed Google Scholar, R. G. A. S. U. G. M. U. D. EMBO J. PubMed Scopus Google Scholar, P. S. D.J. A. Am. J. Physiol. 2003; PubMed Scopus Google Scholar, J. H. S. J. J. Cell Biol. 1996; PubMed Scopus Google Scholar, J. Cell Biol. 1999; PubMed Scopus Google Scholar, M.J. J. Biol. Chem. 2000; Full Text Full Text PDF PubMed Scopus Google Scholar). we phosphatase activity in CHO cells expressing wild-type or cadherin by with a tyrosine phosphatase of cells led to phosphorylation of wild-type VE-cadherin and this was in cells expressing the mutants and or the kinase activity was increased in cells with pervanadate as by phosphorylation on tyrosine To the of the β-catenin regulatory site on VE-cadherin, we a antibody to a from this region of the containing phosphotyrosine at The of this antibody on phosphorylation at Tyr-731 not and was in from CHO cells expressing wild-type VE-cadherin but not in cells expressing the or GFP the antibody the of VE-cadherin in from but not endothelial cells These findings that Tyr-731 on endogenous VE-cadherin in endothelial cells in response to phosphatase of VE-cadherin by determined the and mutations VE-cadherin to functional regulation by CHO cells expressing GFP, wild-type VE-cadherin, or the of VE-cadherin were to on and the integrity of cell-cell junctions was in response to phosphatase of cells with pervanadate decreased cell-cell junctional integrity cells wild-type VE-cadherin In cells expressing the mutations maintained their cell-cell junctions in the of that the VE-cadherin in these cells is not to regulation by These findings that either activation of as and/or of to phosphorylation of VE-cadherin on Tyr-658 and/or Tyr-731 cell-cell junctions. of Cell by Phosphorylation of VE-cadherin on Tyr-658 and a critical of the cell that during associated with and cancer Curr. Opin. Cell Biol. 2003; 15: PubMed Scopus Google Scholar). EMT has been linked to loss of cadherin adhesive function, of expression from the cell and/or disruption in its with the cytoskeleton. In EMT in the of a migratory phenotype. CHO cells cadherin expression and a or mesenchymal not In CHO cells expressing wild-type VE-cadherin an with cadherin expression at cell junctions and focal Cells expressing the VE-cadherin mutants Y658E or Y731E to of cadherin at cell junctions, but these cells displayed increased of focal with a invasive phenotype and These focal could be identified with the antibody to tyrosine of FAK, a site in migratory cells D. Cheresh J. Cell Biol. PubMed Scopus Google Scholar). EMT has been linked to a loss of cadherin cell surface expression or a in cadherin-mediated To either of these for the change in cells expressing with mutations at sites Tyr-658 or Tyr-731, we the adhesive of CHO Cells expressing either wild-type or were to to VE-cadherin. of wild-type VE-cadherin led to adhesion of cells to an whereas cells lacking cadherin to To of the or mutations the expression of cadherin or the of these cells to the changes associated with VE-cadherin mutations be to decreased VE-cadherin adhesive function. However, assay was not to the of the and the mutations may VE-cadherin adhesive function. of Cell by VE-cadherin cells are characterized by their capacity to on the of increased of focal in the cells expressing the Y658E and Y731E we that these cells increased migration to cells expressing wild-type VE-cadherin. To this cells were in migration and to on a Cells expressing wild-type VE-cadherin showed decreased of migration compared with cells expressing GFP Cells expressing either Y658E or Y731E showed a in migration to cells expressing wild-type VE-cadherin and displayed migration to cells These findings that a single phosphomimetic mutation in the tail of VE-cadherin, the simple uncoupling of either p120- or β-catenin with change in cadherin adhesive or cell surface expression, is sufficient to a migratory response with the of a mesenchymal phenotype. cell-cell junctions a critical role in the epithelial cell phenotype and regulation of cell barrier function. disruption of cell-cell junctions has been associated with the breakdown of barriers and the of EMT H. F. A. J. Biol. 2004; PubMed Scopus Google Scholar, J. S. C. P. I. A. Cell. 2004; Full Text Full Text PDF PubMed Scopus Google Scholar). Growth or are regulators of cadherin function they that cell-cell junctions, promote and a migratory phenotype 2004; PubMed Scopus Google Scholar). that disruption of cell-cell junctions depends on and/or that regulate the phosphorylation state of cadherins and their binding partners including α-, β-, and p120-catenin (6Vincent P.A. Xiao K. Buckley K.M. Kowalczyk A.P. Am. J. Physiol. 2004; 286: C987-C997Crossref PubMed Scopus (145) Google Scholar, 10Gumbiner B.M. Cell. 1996; 84: 345-357Abstract Full Text Full Text PDF PubMed Scopus (2930) Google Scholar, 18Andriopoulou P. Navarro P. Zanetti A. Lampugnani M.G. Dejana E. Arterioscler. Thromb. Vasc. Biol. 1999; 19: 2286-2297Crossref PubMed Scopus (202) Google Scholar, 19Roura S. Miravet S. Piedra J. Garcia de Herreros A. Dunach M. J. Biol. Chem. 1999; 274: 36734-36740Abstract Full Text Full Text PDF PubMed Scopus (510) Google Scholar, S. S. A. R. M. A. H. A. N. D. J. R. D. Cheresh D. J. Clin. 2004; PubMed Scopus Google Scholar). cells of a of cadherins. is expressed by a of epithelial cells, whereas VE-cadherin is to endothelial cells it vascular permeability and angiogenesis (7Carmeliet P. Collen D. Ann. N. Y. Acad. Sci. 2000; 902: 249-262Crossref PubMed Scopus (227) Google Scholar, S. S. A. R. M. A. H. A. N. D. J. R. D. Cheresh D. J. Clin. 2004; PubMed Scopus Google Scholar, E. Lampugnani M.G. Bazzoni G. J. Biol. 2000; Google Scholar). In fact, has been to endothelial barrier function via disruption of cell-cell junctions S. Cui J. Barnes L. Cheresh D. J. Cell Biol. 2004; 167: 223-229Crossref PubMed Scopus (389) Google Scholar, R. J. Cheresh Cell. 1999; 4: Full Text Full Text PDF PubMed Scopus Google Scholar). This disruption of barrier function must be maintained the process of endothelial cell that during angiogenesis. VE-cadherin in response to S. Lampugnani M.G. Corada M. Dejana E. Risau W. J. Cell Sci. 1998; 111: 1853-1865Crossref PubMed Google it remains unclear this phosphorylation to loss of endothelial barrier function, of EMT, or of a mesenchymal state angiogenesis is are in the cytoplasmic tail of VE-cadherin, and we to understand or several of these sites a critical role in regulation of VE-cadherin function. To the role of phosphorylation in VE-cadherin function we expressed wild-type or of VE-cadherin in CHO cells that endogenous cadherins. tyrosine was to either acid or CHO cells expressing wild-type or cadherins were for cell-cell junctional activity. of the mutants and not only in cell barrier function VE-cadherin cell surface expression but also to p120- and β-catenin, These at the of of this protein to p120- and β-catenin P. L. Dejana E. J. Cell Biol. 1998; PubMed Scopus Google Scholar, A. C. E. J. Exp. Cell Res. 274: PubMed Scopus Google Scholar, M.G. Zanetti A. F. G. F. Corada M. R. M. V. Dejana E. Biol. Cell. PubMed Scopus Google Scholar). To cells expressing either of these two mutants with a mesenchymal as characterized by of focal and a migratory response. on these we that either Tyr-658 or Tyr-731 in VE-cadherin a critical role in regulation of VE-cadherin function and that functional VE-cadherin junctions on interactions with both β-catenin and kinase activation has been to promote uncoupling of VE-cadherin and In fact, in or or wild-type with a inhibitor profound in vascular permeability associated with the of endothelial cell-cell junctions S. Cui J. Barnes L. Cheresh D. J. Cell Biol. 2004; 167: 223-229Crossref PubMed Scopus (389) Google Scholar, R. J. Cheresh Cell. 1999; 4: Full Text Full Text PDF PubMed Scopus Google Scholar, S. S. A. R. M. A. H. A. N. D. J. R. D. Cheresh D. J. Clin. 2004; PubMed Scopus Google Scholar). a role for in the regulation of VE-cadherin, we that VE-cadherin mutants containing and showed decreased of tyrosine phosphorylation in CHO cells expressing constitutively However, it remains to be determined the role of in this process is or In to as and been to influence cadherin function R. G. A. S. U. G. M. U. D. EMBO J. PubMed Scopus Google Scholar, P. S. D.J. A. Am. J. Physiol. 2003; PubMed Scopus Google Scholar, J. H. S. J. J. Cell Biol. 1996; PubMed Scopus Google Scholar, J. Cell Biol. 1999; PubMed Scopus Google Scholar, M.J. J. Biol. Chem. 2000; Full Text Full Text PDF PubMed Scopus Google Scholar). is to with VE-cadherin and its of phosphorylation R. G. A. S. U. G. M. U. D. EMBO J. PubMed Scopus Google Scholar). we showed that phosphatase inhibition was of VE-cadherin phosphorylation at Tyr-658 and Tyr-731, to a disruption of cell-cell barrier function. In of this expression of phosphomimetic mutations also in a loss of barrier function. We that the loss in barrier function was to the uncoupling of cadherin from the via the of β-catenin or p120-catenin and not of a simple loss of VE-cadherin adhesive function or expression on the cell surface. a of cadherin cytoplasmic into the mechanisms by which cadherin are regulated the of the Tyr-658 site is well that phosphorylation of this may be a to cell barrier function. the Tyr-731 site is to VE-cadherin, that regulation of this may an endothelium-specific as be for vascular permeability to In to the role of p120-catenin in cadherin adhesion and A.B. Roczniak-Ferguson A. Oncogene. 2004; 23: 7947-7956Crossref PubMed Scopus (231) Google p120-catenin has also been in the regulation of cadherin expression at the cell surface. endothelial cells, several that disruption of binding of p120-catenin to VE-cadherin in cadherin and (11Iyer S. Ferreri D.M. DeCocco N.C. Minnear F.L. Vincent P.A. Am. J. Physiol. 2004; 286: L1143-L1153Crossref PubMed Scopus (108) Google Scholar, 13Xiao K. Allison D.F. Buckley K.M. Kottke M.D. Vincent P.A. Faundez V. Kowalczyk A.P. J. Cell Biol. 2003; 163: 535-545Crossref PubMed Scopus (346) Google Scholar, K. Allison D.F. Kottke M.D. S. Faundez V. Kowalczyk A.P. J. Biol. Chem. 2003; Full Text Full Text PDF PubMed Scopus Google Scholar). However, in VE-cadherin expression at the cell surface of CHO cells of cytoplasmic tail mutations that binding to This could be explained by that the of CHO cells compared with endothelial as cell the of flow cytometry to select for cells that VE-cadherin, it is that cells with cadherin cell surface expression were from findings into the regulation of We an that regulate this process via phosphorylation of the cadherin cytoplasmic tail and into the role that cadherins and their associated in remodeling, and various disease findings that of sites within the cadherin C terminus cells to maintain a mesenchymal phenotype.