scholarly journals V-src kinase shifts the cadherin-based cell adhesion from the strong to the weak state and beta catenin is not required for the shift.

1995 ◽  
Vol 131 (6) ◽  
pp. 1839-1847 ◽  
Author(s):  
H Takeda ◽  
A Nagafuchi ◽  
S Yonemura ◽  
S Tsukita ◽  
J Behrens ◽  
...  
Keyword(s):  
Cell Adhesion ◽  
Tyrosine Phosphorylation ◽  
Mdck Cells ◽  
Src Kinase ◽  
Cell Aggregation ◽  
Temperature Sensitive ◽  
Beta Catenin ◽  
Weak State ◽  
Adhesion Ability ◽  
Phosphorylation Level

The elevation of tyrosine phosphorylation level is thought to induce the dysfunction of cadherin through the tyrosine phosphorylation of beta catenin. We evaluated this assumption using two cell lines. First, using temperature-sensitive v-src-transfected MDCK cells, we analyzed the modulation of cadherin-based cell adhesion by tyrosine phosphorylation. Cell aggregation and dissociation assays at nonpermissive and permissive temperatures indicated that elevation of the tyrosine phosphorylation does not totally affect the cell adhesion ability of cadherin but shifts it from a strong to a weak state. The tyrosine phosphorylation levels of beta catenin, ZO-1, ERM (ezrin/radixin/moesin), but not alpha catenin, vinculin, and alpha-actinin, were elevated in the weak state. To evaluate the involvement of the tyrosine phosphorylation of beta catenin in this shift of cadherin-based cell adhesion, we introduced v-src kinase into L fibroblasts expressing the cadherin-alpha catenin fusion protein, in which beta catenin is not involved in cell adhesion. The introduction of v-src kinase in these cells shifted their adhesion from a strong to a weak state. These findings indicated that the tyrosine phosphorylation of beta catenin is not required for the strong-to-weak state shift of cadherin-based cell adhesion, but that the tyrosine phosphorylation of other junctional proteins, ERM, ZO-1 or unidentified proteins is involved.

Activation of TrkA tyrosine kinase in embryonal carcinoma cells promotes cell compaction, independently of tyrosine phosphorylation of catenins

2000 ◽  
Vol 113 (9) ◽  
pp. 1601-1610
Author(s):  
M. Cozzolino ◽  
B. Giovannone ◽  
A. Serafino ◽  
K. Knudsen ◽  
A. Levi ◽  
...  
Keyword(s):  
Cell Adhesion ◽  
Tyrosine Kinase ◽  
Tyrosine Phosphorylation ◽  
Tyrosine Kinases ◽  
Embryonal Carcinoma ◽  
Receptor Tyrosine Kinases ◽  
Mdck Cells ◽  
Current Evidence ◽  
Tyrosine Kinase Receptor ◽  
Beta Catenin

Cadherins are transmembrane receptors whose extracellular domain mediates homophilic cell-cell interactions, while their cytoplasmic domain associates with a family of proteins known as catenins. Although the mechanisms that regulate the assembly and functional state of cadherin-catenin complexes are poorly understood, current evidence supports a role for protein tyrosine kinase activity in regulating cell adhesion and migration. Tyrosine phosphorylation of catenins is thought to mediate loss of intercellular adhesion promoted by activation of receptor tyrosine kinases in epithelial cells. Here, we show that activation of ectopically expressed TrkA, the tyrosine kinase receptor for nerve growth factor (NGF), stimulates embryonal carcinoma P19 cells to develop extensive intercellular contacts and to assemble into closely packed clusters. Thus, activation of receptor tyrosine kinases can differentially regulate adhesiveness by cell-type-specific mechanisms. Furthermore, activation of TrkA in P19 and epithelial MDCK cells induces tyrosine phosphorylation of p120(ctn) and of beta-catenin, irrespective of the elicited cellular response. The selective Src tyrosine kinase inhibitor PP2, however, suppresses NGF- or HGF-induced tyrosine phosphorylation of catenins in both P19 and MDCK cells without interfering with the acquisition of a compacted or scattered phenotype. These findings provide a cogent argument for considering that tyrosine phosphorylation of catenins is dispensable for their interaction with cadherins and, ultimately, for the modulation of cadherin-based cell adhesion by receptor tyrosine kinases.

scholarly journals Expression of Podocalyxin Inhibits Cell–Cell Adhesion and Modifies Junctional Properties in Madin-Darby Canine Kidney Cells

2000 ◽  
Vol 11 (9) ◽  
pp. 3219-3232 ◽  
Author(s):  
Tetsuro Takeda ◽  
William Y. Go ◽  
Robert A. Orlando ◽  
Marilyn Gist Farquhar
Keyword(s):  
Cell Adhesion ◽  
Cho Cells ◽  
Direct Evidence ◽  
Mdck Cells ◽  
Chinese Hamster ◽  
Cell Aggregation ◽  
Madin Darby Canine Kidney ◽  
Adhesion Properties ◽  
Darby Canine Kidney ◽  
Canine Kidney

Podocalyxin is a major membrane protein of the glomerular epithelium and is thought to be involved in maintenance of the architecture of the foot processes and filtration slits characteristic of this unique epithelium by virtue of its high negative charge. However, until now there has been no direct evidence for podocalyxin's function. Podocalyxin is a type 1 transmembrane sialoprotein with an N-terminal mucin-like domain. To assess its function, we cloned rat podocalyxin and examined the effects of its expression on the cell adhesion properties of stably transfected Chinese hamster ovary (CHO)-K1 and Madin-Darby canine kidney (MDCK) cells and inducible ecdysone receptor–expressing (EcR)-CHO cells. In a cell aggregation assay, CHO-K1 cells expressing high levels of podocalyxin showed complete inhibition of cell aggregation, and MDCK transfectants showed greatly reduced aggregation (∼60–80%) compared with parental cells. In EcR-CHO cells, the expression level of podocalyxin induced by increasing levels of ecdysone analogue correlated closely with the antiadhesion effect. The inhibitory effect of podocalyxin was reversed by treatment of the cells with Arthrobacter ureafacienssialidase, indicating that sialic acid is required for inhibition of cell adhesion. Overexpression of podocalyxin also affected transepithelial resistance and the distribution of junctional proteins in MDCK cells by an unknown mechanism that may involve interaction with the actin cytoskeleton. These results provide direct evidence that podocalyxin functions as an antiadhesin that maintains an open filtration pathway between neighboring foot processes in the glomerular epithelium by charge repulsion.

scholarly journals Loss of E-cadherin-dependent cell-cell adhesion due to mutation of the beta-catenin gene in a human cancer cell line, HSC-39.

1995 ◽  
Vol 15 (3) ◽  
pp. 1175-1181 ◽  
Author(s):  
J Kawanishi ◽  
J Kato ◽  
K Sasaki ◽  
S Fujii ◽  
N Watanabe ◽  
...  
Keyword(s):  
Cell Adhesion ◽  
Cell Line ◽  
Cancer Cell ◽  
Cancer Cell Line ◽  
Cell Aggregation ◽  
Expression Vectors ◽  
Beta Catenin ◽  
Dependent Cell ◽  
E Cadherin ◽  
Cell Cell

Detachment of cell-cell adhesion is indispensable for the first step of invasion and metastasis of cancer. This mechanism is frequently associated with the impairment of either E-cadherin expression or function. However, mechanisms of such abnormalities have not been fully elucidated. In this study, we demonstrated that the function of E-cadherin was completely abolished in the human gastric cancer cell line HSC-39, despite the high expression of E-cadherin, because of mutations in one of the E-cadherin-associated cytoplasmic proteins, beta-catenin. Although immunofluorescence staining of HSC-39 cells by using an anti-E-cadherin antibody (HECD-1) revealed the strong and uniform expression of E-cadherin on the cell surface, cell compaction and cell aggregation were not observed in this cell. Western blotting (immunoblotting) using HECD-1 exhibited a 120-kDa band which is equivalent to normal E-cadherin. Northern (RNA) blotting demonstrated a 4.7-kb band, the same as mature E-cadherin mRNA. Immunoprecipitation of metabolically labeled proteins with HECD-1 revealed three bands corresponding to E-cadherin, alpha-catenin, and gamma-catenin and a 79-kDa band which was apparently smaller than that of normal beta-catenin, indicating truncated beta-catenin. The 79-kDa band was immunologically identified as beta-catenin by using immunoblotting with anti-beta-catenin antibodies. Examination of beta-catenin mRNA by the reverse transcriptase-PCR method revealed a transcript which was shorter than that of normal beta-catenin. The sequencing of PCR product for beta-catenin confirmed deletion in 321 bases from nucleotides +82 to +402. Southern blotting of beta-catenin DNA disclosed mutation at the genomic level. Expression vectors of Beta-catenin were introduced into HSC-39 cells by transfection. In the obtained transfectants, E-cadherin-dependent cell-cell adhesiveness was recovered, as revealed by cell compaction, cell aggregation, and immunoflourescence staining. From these results, it was concluded that in HSC-39 cells, impaired cell-cell adhesion is due to mutations in beta-catenin which results in the dysfunction of E-cadherin.

scholarly journals p120, a p120-related protein (p100), and the cadherin/catenin complex.

1995 ◽  
Vol 130 (2) ◽  
pp. 369-381 ◽  
Author(s):  
J M Staddon ◽  
C Smales ◽  
C Schulze ◽  
F S Esch ◽  
L L Rubin
Keyword(s):  
Cell Adhesion ◽  
Epithelial Cells ◽  
Mdck Cells ◽  
Peptide Sequencing ◽  
Beta Catenin ◽  
Related Protein ◽  
P120 Catenin ◽  
Tissue Sections ◽  
Segment Polarity ◽  
Cell Cell

Cadherins and catenins play an important role in cell-cell adhesion. Two of the catenins, beta and gamma, are members of a group of proteins that contains a repeating amino acid motif originally described for the Drosophila segment polarity gene armadillo. Another member of this group is a 120-kD protein termed p120, originally identified as a substrate of the tyrosine kinase pp60src. In this paper, we show that endothelial and epithelial cells express p120 and p100, a 100-kD, p120-related protein. Peptide sequencing of p100 establishes it as highly related to p120. p120 and p100 both appear associated with the cadherin/catenin complex, but independent p120/catenin and p100/catenin complexes can be isolated. This association is shown by coimmunoprecipitation of cadherins and catenins with an anti-p120/p100 antibody, and of p120/p100 with cadherin or catenin antibodies. Immunocytochemical analysis with a p120-specific antibody reveals junctional colocalization of p120 and beta-catenin in epithelial cells. Catenins and p120/p100 also colocalize in endothelial and epithelial cells in culture and in tissue sections. The cellular content of p120/p100 and beta-catenin is similar in MDCK cells, but only approximately 20% of the p120/p100 pool associates with the cadherin/catenin complex. Our data provide further evidence for interactions among the different arm proteins and suggest that p120/p100 may participate in regulating the function of cadherins and, thereby, other processes influenced by cell-cell adhesion.

scholarly journals Induction of tyrosine phosphorylation during ICAM-3 and LFA-1-mediated intercellular adhesion, and its regulation by the CD45 tyrosine phosphatase.

1994 ◽  
Vol 126 (5) ◽  
pp. 1277-1286 ◽  
Author(s):  
A G Arroyo ◽  
M R Campanero ◽  
P Sánchez-Mateos ◽  
J M Zapata ◽  
M A Ursa ◽  
...  
Keyword(s):  
Cell Adhesion ◽  
Cell Line ◽  
Tyrosine Phosphorylation ◽  
Molecular Mechanisms ◽  
Tyrosine Phosphatase ◽  
Cell Aggregation ◽  
Intercellular Adhesion ◽  
Lymphocyte Function ◽  
Late Antigen ◽  
Cell Cell

Intercellular adhesion molecule (ICAM)-3, a recently described counter-receptor for the lymphocyte function-associated antigen (LFA)-1 integrin, appears to play an important role in the initial phase of immune response. We have previously described the involvement of ICAM-3 in the regulation of LFA-1/ICAM-1-dependent cell-cell interaction of T lymphoblasts. In this study, we further investigated the functional role of ICAM-3 in other leukocyte cell-cell interactions as well as the molecular mechanisms regulating these processes. We have found that ICAM-3 is also able to mediate LFA-1/ICAM-1-independent cell aggregation of the leukemic JM T cell line and the LFA-1/CD18-deficient HAFSA B cell line. The ICAM-3-induced cell aggregation of JM and HAFSA cells was not affected by the addition of blocking mAb specific for a number of cell adhesion molecules such as CD1 1a/CD18, ICAM-1 (CD54), CD2, LFA-3 (CD58), very late antigen alpha 4 (CD49d), and very late antigen beta 1 (CD29). Interestingly, some mAb against the leukocyte tyrosine phosphatase CD45 were able to inhibit this interaction. Moreover, they also prevented the aggregation induced on JM T cells by the proaggregatory anti-LFA-1 alpha NKI-L16 mAb. In addition, inhibitors of tyrosine kinase activity also abolished ICAM-3 and LFA-1-mediated cell aggregation. The induction of tyrosine phosphorylation through ICAM-3 and LFA-1 antigens was studied by immunofluorescence, and it was found that tyrosine-phosphorylated proteins were preferentially located at intercellular boundaries upon the induction of cell aggregation by either anti-ICAM-3 or anti-LFA-1 alpha mAb. Western blot analysis revealed that the engagement of ICAM-3 or LFA-1 with activating mAb enhanced tyrosine phosphorylation of polypeptides of 125, 70, and 38 kD on JM cells. This phenomenon was inhibited by preincubation of JM cells with those anti-CD45 mAb that prevented cell aggregation. Altogether these results indicate that CD45 tyrosine phosphatase plays a relevant role in the regulation of both intracellular signaling and cell adhesion induced through ICAM-3 and beta 2 integrins.

scholarly journals Tyrosine Residue in Exon 14 of the Cytoplasmic Domain of Platelet Endothelial Cell Adhesion Molecule-1 (PECAM-1/CD31) Regulates Ligand Binding Specificity

1997 ◽  
Vol 138 (6) ◽  
pp. 1425-1435 ◽  
Author(s):  
Julie Famiglietti ◽  
Jing Sun ◽  
Horace M. DeLisser ◽  
Steven M. Albelda
Keyword(s):  
Cell Adhesion ◽  
Endothelial Cell ◽  
Amino Acid ◽  
Tyrosine Phosphorylation ◽  
Adhesion Molecule ◽  
Cell Adhesion Molecule ◽  
Cell Aggregation ◽  
Ligand Specificity ◽  
Platelet Endothelial Cell Adhesion ◽  
Endothelial Cell Adhesion

Platelet/endothelial cell adhesion molecule (PECAM-1) is a cell adhesion molecule of the immunoglobulin superfamily that plays a role in a number of vascular processes including leukocyte transmigration through endothelium. The presence of a specific 19– amino acid exon within the cytoplasmic domain of PECAM-1 regulates the binding specificity of the molecule; specifically, isoforms containing exon 14 mediate heterophilic cell–cell aggregation while those variants missing exon 14 mediate homophilic cell–cell aggregation. To more precisely identify the region of exon 14 responsible for ligand specificity, a series of deletion mutants were created in which smaller regions of exon 14 were removed. After transfection into L cells, they were tested for their ability to mediate aggregation. For heterophilic aggregation to occur, a conserved 5–amino acid region (VYSEI in the murine sequence or VYSEV in the human sequence) in the mid-portion of the exon was required. A final construct, in which this tyrosine was mutated into a phenylalanine, aggregated in a homophilic manner when transfected into L cells. Inhibition of phosphatase activity by exposure of cells expressing wild type or mutant forms of PECAM-1 to sodium orthovanadate resulted in high levels of cytoplasmic tyrosine phosphorylation and led to a switch from heterophilic to homophilic aggregation. Our data thus indicate either loss of this tyrosine from exon 14 or its phosphorylation results in a change in ligand specificity from heterophilic to homophilic binding. Vascular cells could thus determine whether PECAM-1 functions as a heterophilic or homophilic adhesion molecule by processes such as alternative splicing or by regulation of the balance between tyrosine phosphorylation or dephosphorylation. Defining the conditions under which these changes occur will be important in understanding the biology of PECAM-1 in transmigration, angiogenesis, development, and other processes in which this molecule plays a role.

scholarly journals Association between a transmembrane protein tyrosine phosphatase and the cadherin-catenin complex.

1996 ◽  
Vol 134 (6) ◽  
pp. 1519-1529 ◽  
Author(s):  
R M Kypta ◽  
H Su ◽  
L F Reichardt
Keyword(s):  
Cell Adhesion ◽  
Tyrosine Phosphorylation ◽  
Transmembrane Protein ◽  
Tyrosine Phosphatase ◽  
Beta Catenin ◽  
Dependent Manner ◽  
Calcium Dependent ◽  
Amino Terminal ◽  
Dependent Cell

Cadherins are calcium-dependent cell adhesion molecules that play fundamental roles in embryonic development, tissue morphogenesis, and cancer. A prerequisite for their function is association with the actin cytoskeleton via the catenins. Tyrosine phosphorylation of beta-catenin, which correlates with a reduction in cadherin-dependent cell adhesion, may provide cells with a mechanism to regulate cadherin activity. Here we report that beta-catenin immune precipitates from PC12 cells contain tyrosine phosphatase activity which dephosphorylates beta-catenin in vitro. In addition, we show that a member of the leukocyte antigen-related protein (LAR)-related transmembrane tyrosine phosphatase family (LAR-PTP) associates with the cadherin-catenin complex. This association required the amino-terminal domain of beta-catenin but does not require the armadillo repeats, which mediate association with cadherins. The interaction also is detected in PC9 cells, which lack alpha-catenin. Thus, the association is not mediated by alpha-catenin or by cadherins. Interestingly, LAR-PTPs are phosphorylated on tyrosine in a TrkA-dependent manner, and their association with the cadherin-catenin complex is reduced in cells treated with NGF. We propose that changes in tyrosine phosphorylation of beta-catenin mediated by TrkA and LAR-PTPs control cadherin adhesive function during processes such as neurite outgrowth.

scholarly journals Loss of epithelial differentiation and gain of invasiveness correlates with tyrosine phosphorylation of the E-cadherin/beta-catenin complex in cells transformed with a temperature-sensitive v-SRC gene.

1993 ◽  
Vol 120 (3) ◽  
pp. 757-766 ◽  
Author(s):  
J Behrens ◽  
L Vakaet ◽  
R Friis ◽  
E Winterhager ◽  
F Van Roy ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Tyrosine Phosphorylation ◽  
Epithelial Differentiation ◽  
Temperature Sensitive ◽  
Beta Catenin ◽  
Permissive Temperature ◽  
Collagen Gels ◽  
Epithelial Phenotype ◽  
Chick Heart ◽  
E Cadherin

Loss of histotypic organization of epithelial cells is a common feature in normal development as well as in the invasion of carcinomas. Here we show that the v-src oncogene is a potent effector of epithelial differentiation and invasiveness. MDCK epithelial cells transformed with a temperature-sensitive mutant of v-src exhibit a strictly epithelial phenotype at the nonpermissive temperature for pp60v-src activity (40.5 degrees C) but rapidly loose cell-to-cell contacts and acquire a fibroblast-like morphology after culture at the permissive temperature (35 degrees C). Furthermore, the invasiveness of the cells into collagen gels or into chick heart fragments was increased at the permissive temperature. The profound effects of v-src on intercellular adhesion were not linked to changes in the levels of expression of the epithelial cell adhesion molecule E-cadherin. Rather, we observed an increase in tyrosine phosphorylation of E-cadherin and, in particular, of the associated protein beta-catenin. These results suggest a mechanism by which v-src counteracts junctional assembly and thereby promotes invasiveness and dedifferentiation of epithelial cells through phosphorylation of the E-cadherin/catenin complex.

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