Dynamics of Tight and Adherens Junctions Under EGTA Treatment

Rothen‐Rutishauser, Barbara; Riesen, F.K.; Braun, Annette; Günthert, Maja; Wunderli‐Allenspach, Heidi

doi:10.1007/s00232-001-0182-2

Cited by 117 publications

(116 citation statements)

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“…A similar Ca 2+ -independent stability has been described using cross-linking techniques for lateral dimers (32,33). Previous work examining cadherin dynamics (34) and the Ca 2+ dependence of cadherin interactions (35) demonstrated changes with a much longer latency (minutes or hours, rather than seconds) than we have observed here. Our data indicate that extracellular Ca 2+ fluctuations result in a rapid regulation of cadherin interactions, and that these dynamics can invoke changes in intracellular signaling.…”

Section: Resultssupporting

confidence: 86%

Calcium-dependent dynamics of cadherin interactions at cell–cell junctions

Kim

Tai

Mok

et al. 2011

Proc. Natl. Acad. Sci. U.S.A.

146

116

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Cadherins play a key role in the dynamics of cell-cell contact formation and remodeling of junctions and tissues. Cadherincadherin interactions are gated by extracellular Ca 2+ , which serves to rigidify the cadherin extracellular domains and promote trans junctional interactions. Here we describe the direct visualization and quantification of spatiotemporal dynamics of N-cadherin interactions across intercellular junctions in living cells using a genetically encodable FRET reporter system. Direct measurements of transjunctional cadherin interactions revealed a sudden, but partial, loss of homophilic interactions (τ = 1.17 ± 0.06 s ), suggesting two types of native cadherin interactions-one that is rapidly modulated by changes in extracellular Ca 2+ and another with relatively stable adhesive activity that is Ca 2+ independent. The Ca 2+-sensitive dynamics of cadherin interactions were transmitted to the cell interior where β-catenin translocated to N-cadherin at the junction in both cells. These data indicate that cadherins can rapidly convey dynamic information about the extracellular environment to both cells that comprise a junction.cell adhesion | fluorescence resonance energy transfer | trans binding T he junctions between cells are populated with a variety of cell adhesion molecules that drive the recognition, assembly, and dynamics of cell-cell interactions. Parsing the distinct functions of different adhesion molecules has been challenging, in part due to a paucity of truly revealing in vivo assays. Among cell adhesion molecule families, the classic cadherins exhibit a unique dependence on extracellular Ca 2+ to rigidify the extracellular domains and enable trans junctional homophilic interactions. Three Ca 2+ ions bind with different affinities to each of the pockets between cadherin extracellular domains (1, 2). The affinity of the various Ca 2+ binding sites is in the micromolar to millimolar range (3-8), suggesting the possibility that cadherins can respond dynamically to changes in junctional Ca 2+ levels, and by virtue of physical interactions with cytoplasmic molecules, signal information about the junctional status to the cell interior.3D reconstructions of desmosomes by cryoelectron tomography reveal cadherins interact across intercellular interfaces (9, 10), and crystallographic data of several cadherin domains (4, 11, 12) implicate the first two extracellular repeats (ECs 1 and 2) as critical for homophilic interactions. Previous studies have indicated the importance of a highly conserved tryptophan residue (Trp2), present in the first EC domain, for cadherin-dependent adhesion (2, 12). This tryptophan inserts into the hydrophobic pocket of the partner N-cadherin (Ncad) molecule to form a strand-swapped dimeric structure (11, 12). Mutation of Trp2 to an alanine residue (W2A) prevents strand swapping (13) and results in a loss of adhesive function (2, 14, 15). Although extensive work has elucidated the structure (4, 9-14), biochemistry (2, 16) and single-molecule characterization (15, 17) of ...

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Section: Resultssupporting

confidence: 86%

Calcium-dependent dynamics of cadherin interactions at cell–cell junctions

Kim

Tai

Mok

et al. 2011

Proc. Natl. Acad. Sci. U.S.A.

146

116

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“…Interestingly, this gain in ERK activity was correlated to a complete decrease in AR accumulation thus assessing a functional link between the MAPK activity and the AR expression. Similar data were obtained by incubating differentiated cells for 5 h with EGTA 2 mM (not shown), which is known to alter the dynamics of tight junctions (Rothen-Rutishauser et al 2002).…”

Section: Ar Expression Is Dependent On the Establishment Of Tight Junsupporting

confidence: 82%

Crosstalk between androgen receptor and epidermal growth factor receptor-signalling pathways: a molecular switch for epithelial cell differentiation

Léotoing¹,

Manin²,

Monté³

et al. 2007

Journal of Molecular Endocrinology

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In the male, androgens promote growth and differentiation of sex reproductive organs through ligand activation of the androgen receptor (AR). Here, we show that androgens are not major actors of the cell cycle arrest associated with the differentiation process, and that the epidermal growth factor (EGF)-mediated signalling interferes with AR activities to regulate androgen response when epithelial cells are differentiated. Higher AR expression and enhanced androgen responsiveness correlate with reduction of phosphorylated ERK1/2 over differentiation. These modifications are associated with recruitment of cells in phase G 0 /G 1 , up-regulation of p27 kip1 , down-regulation of p21Cip1 and p53 proteins, and accumulation of hypo-phosphorylated Rb. Exposure to EGF reduces AR expression levels and blocks androgendependent transcription in differentiated cells. It also restores p53 and p21Cip1 levels, Rb hyper-phosphorylation, ERK1/2 activation and promotes cell cycle re-entry as p27 kip1 protein levels are decreased. Treatment with a MEK inhibitor reverses the EGF-mediated AR down-regulation in differentiated cells, thus suggesting the existence of an inverse correlation between EGF and androgen signalling in non-tumoural epithelia. Interestingly, when androgen signalling is set in differentiated cells, dihydrotestosterone exerts an inhibitory effect on ERK activity but paradoxically does not modify EGFR (ErbB1) phosphorylation, indicating that androgens are able to disrupt the EGFR-ERK cascade. Overall, our data demonstrate the existence of a balance between AR and mitogen-activated protein kinase activities that favours either the maintenance of differentiated conditions or the enhancement of cell proliferation capacities.

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“…The assembly of the tight junctions is always preceded by the formation of the adherens junctions and can be inhibited by an E-cadherin-blocking antibody (30 -32). Conversely, disruption or weakening of the adherens junctions by depletion of E-cadherin and catenins or by chelating Ca 2ϩ in the culture medium causes partial or complete disassembly of the tight junctions (33,34). Therefore, the integrity of the tight junctions depends on the intactness and stability of the adherens junctions.…”

Section: Discussionmentioning

confidence: 99%

Inverse Correlation between the Extent of N-Glycan Branching and Intercellular Adhesion in Epithelia

Vagin

Tokhtaeva

Yakubov

et al. 2008

Journal of Biological Chemistry

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The majority of cell adhesion molecules are N-glycosylated, but the role of N-glycans in intercellular adhesion in epithelia remains ill-defined. Reducing N-glycan branching of cellular glycoproteins by swainsonine, the inhibitor of N-glycan processing, tightens and stabilizes cell-cell junctions as detected by a 3-fold decrease in the paracellular permeability and a 2-3-fold increase in the resistance of the adherens junction proteins to extraction by non-ionic detergent. In addition, exposure of cells to swainsonine inhibits motility of MDCK cells. Mutagenic removal of N-glycosylation sites from the Na,K-ATPase ␤ 1 subunit impairs cell-cell adhesion and decreases the effect of swainsonine on the paracellular permeability of the cell monolayer and also on detergent resistance of adherens junction proteins, indicating that the extent of N-glycan branching of this subunit is important for intercellular adhesion. The N-glycans of the Na,K-ATPase ␤ 1 subunit and E-cadherin are less complex in tight renal epithelia than in the leakier intestinal epithelium. The complexity of the N-glycans linked to these proteins gradually decreases upon the formation of a tight monolayer from dispersed MDCK cells. This correlates with a cell-cell adhesion-induced increase in expression of GnT-III (stops N-glycan branching) and a decrease in expression of GnTs IVC and V (promote N-glycan branching) as detected by realtime quantitative PCR. Consistent with these results, partial silencing of the gene encoding GnT-III increases branching of N-glycans linked to the Na,K-ATPase ␤ 1 subunit and other glycoproteins and results in a 2-fold increase in the paracellular permeability of MDCK cell monolayers. These results suggest epithelial cells can regulate tightness of cell junctions via remodeling of N-glycans, including those linked to the Na,K-ATPase ␤ 1 -subunit.

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Dynamics of Tight and Adherens Junctions Under EGTA Treatment

Cited by 117 publications

References 0 publications

Calcium-dependent dynamics of cadherin interactions at cell–cell junctions

Calcium-dependent dynamics of cadherin interactions at cell–cell junctions

Crosstalk between androgen receptor and epidermal growth factor receptor-signalling pathways: a molecular switch for epithelial cell differentiation

Inverse Correlation between the Extent of N-Glycan Branching and Intercellular Adhesion in Epithelia

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